Quantification of a century-long stream and aquifer water exchange in the Mississippi embayment under a changing climate

Year: 2014 Authors: Ouyang Y., Wei J.

Groundwater depletion due to the increasing water demand for agricultural, domestic, and industrial usages under a changing climate is a critical concern worldwide. Many regions of the world are now experiencing a certain degree of groundwater resource depletion. Mississippi Embayment (ME), encompassing parts of Missouri, Illinois, Kentucky, Arkansas, Tennessee, Mississippi, Alabama, and Louisiana, is an intensive crop production region in midsouth US and is one of the fastest groundwater resource depletion regions in the world. An understanding of the long-term stream and aquifer water exchange is crucial to groundwater resource planning, allocation, and management in the ME. Using the US Geological Survey's MERAS (Mississippi Embayment Regional Aquifer Study) groundwater model, we estimated the stream and aquifer water exchange in the ME over a 115-year simulation period from 1900 to 2014 under the following six different scenarios: (1) a base case scenario represents the current agricultural practices, groundwater pumping, and natural conditions existing in the ME; (2) an extreme wet scenario that is the same as the base case scenario except that the precipitation rate is increased by 20%; (3) an extreme dry scenario that is the same as the base case scenario except that the precipitation rate is decreased by 20%; (4) a no-pumping scenario that is the same as the base case scenario except without groundwater pumping; (5) a scenario without pumping with 20% increase in precipitation, which is the same as the extreme wet scenario except for without groundwater pumping; and (6) a scenario without pumping with 20% decrease in precipitation, which is the same as the extreme dry scenario except for without groundwater pumping. Simulations showed that more waters leaked from the aquifers to the streams than from the streams flowed into the aquifers over the past 115 years. There was about 3 times more aquifer water leaked to the streams without pumping than with pumping. Our study suggested that the groundwater pumping rather than the extreme precipitation played a vital role in stream and aquifer water exchange of the ME.

KTS Wireless/High Yield Ag Solutions

Year: 2014 Authors: Koos W.

Since 2014 KTS Wireless (KTS) and subsidiary High Yield Ag Solutions (HYAG) have been collecting and managing data from sensors connected to our wireless products. The data has been delivered to our cloud-based servers where web applications have been created to provide decision making tools for growers and researchers. We have worked closely with Delta F.A.R.M. and Mississippi State University scientists to provide insight into water related agricultural field inputs and outputs. In addition to decision support insights for growers, the raw data is compiled for ease of direct download for research purposes. The sensors and tools include water levels, soil moisture and salinity, well flow rates, outflow pipe flow rates and volumes with water sampler triggering from changes in flow rate, irrigation pump control and weather data from our own agricultural weather station as well as third party sources. Our intent has been to develop a central data platform for capturing agricultural water data in a practical and affordable manner that provides value to growers and researchers alike.

Numerical Simulation of Fate and Transport of Chemical Contaminants in Dan River Due to Coal Ash Spill Accident

Year: 2014 Authors: Chao X., Zhang Y., Al-Hamdan M.

Large quantities of stored coal ash nationwide pose a serious threat to the environment and wildlife when accidently released into surface water systems. On February 2, 2014, the failure of a storm water pipe under the primary coal ash pond of the Dan River Steam Station owned by the Duke Energy released about 39,000 tons of coal ash and 27 million gallons of pond water into the Dan River near Eden, N.C., about 130 miles upstream of the Kerr Reservoir. Together with the coal ash, a number of contaminants attached to the particles and dissolved in the pond water were also released into Dan River.

Numerical model is an effective tool to simulate the transport processes of coal ash and associated chemical contaminants in river flow. In this case, the entire study reach of the river-reservoir system extends from the USGS Wentworth gauge on Dan River, about 22 km upstream of the spill location to the Kerr Dam, about 182 km downstream of the spill location. For such a long river-reservoir system, the CCHE1D model developed by National Center for Computational Hydroscience and Engineering at the University of Mississippi was applied to simulate the fate and transport of contaminants due to the Dan River coal ash spill accident. The processes of advection, diffusion, sedimentation, and adsorption/desorption of contaminants were considered in the model. Several chemical contaminants, including arsenic (As), mercury (Hg), and selenium (Se) were simulated, and their concentration distributions in water column and bed sediment were obtained. The simulated results were validated using the measured data obtained from EPA. Those results provide useful information for water environment evaluation and water resource management.

Microplastics in the Mississippi River and Mississippi Sound

Year: 2014 Authors: Cizdziel J.

Led by consumer products, the worldwide demand for plastic continues to grow with global production at nearly 350 megatons in 2017 (Plastics Europe 2018). Unfortunately, careless discarding of plastic and mishandling of the plastic waste stream has resulted in widespread plastic pollution, including the infamous oceanic garbage patches (Lebreton 2018). Further, plastics in the environment weather and degrade as a result of ultraviolet radiation, microorganisms, temperature changes, and mechanical forces (e.g. wave action), yielding smaller and smaller particles called micro- and nano-plastics. Here, we focus on MPs, which have been described as "any synthetic solid particle of polymeric matrix, with regular or irregular shape and with size ranging from 1 ?m to 5 mm, of either primary or secondary manufacturing origin, which are insoluble in water" (Frias 2019).

The occurrence of MPs in the aquatic environment is well documented, with higher concentrations generally found near population centers (Li 2018). MPs have also been detected in remote areas, including the Arctic Ocean (Lusher 2015), deep-sea sediments (Free 2014), and mountain lakes (Cauwenberghe 2013). Given their small size and ubiquitous nature in lakes, rivers, and oceans, their ingestion and impact on aquatic life poses a serious threat, particularly for small suspension-feeding organisms (Auta 2017). Moreover, MPs have been shown to be substrates (vectors) for other contaminants, including persistent organic pollutants such as dichloro-diphenyl-trichloroethane (DDT), both in laboratory studies and in field studies (Teuten 2009; Costa 2017; Tourinho 2019).

Unfortunately, there are often wildly different estimates reported for MP abundances in natural water, even from the same waterbodies, making meaningful comparisons difficult and hindering the utility of real-world MP surveys (Lusher 2017; Lenz 2018; Jiang 2018). Some of these disparate results may be due to inherent variability at the sites, but part of the problem may be the different sampling, sample preparation, and analytical methods used. On one hand, the wide range of approaches to MP analyses is not surprising given that MPs (1) are a diverse class of contaminant encompassing a wide variety of sizes, morphologies, and chemical and physical properties (Rochman 2019), (2) partition into different environmental compartments depending on size, density, biofouling, and other factors (Hartmann 2019), and (3) have only recently (in the last decade) caught the attention of the larger scientific community. On the other hand, MP analytical methods need to become more harmonized to increase the quality and comparability of experimental data.

Two common ways to sample plastic debris suspended in water is through use of a surface or subsurface tow net or by collecting a known volume of water at a specific location (bulk water sampling). Nets are typically used in investigating large areas with results being reported in particles/m3, whereas bulk water sampling is more accurate as a snapshot and is often reported in particles/L. A major drawback to sampling with a net is that it fails to capture particles smaller than the mesh opening (typically 333-?m), and these smaller particles tend to be the most abundant. In contrast, bulk water sampling captures all size fractions of particles in the water. Another advantage of bulk water sampling is the elimination of contamination from sampling equipment such as nylon nets and ropes. However, trawling with a net or bulk water sampling should be considered complementary techniques, covering different parts of the overall MP pollution (Tamminga 2019).

When using a net, the plastics caught in the cod end are typically rinsed out into a container for later processing in the laboratory. Determining the volume of water passing through the net or being pumped through collection sieves is important to accurately calculate MP concentrations. At some point the net and bulk sampling methods converge with the samples being filtered through a sieve or series of sieves to isolate particulates by size fraction(s). Larger particles can be removed by tweezers and analyzed by FTIR or other means. If the remaining solids collected on the sieves or filters are organic-rich they are typically subjected to either enzymatic digestion (Cole 2014) or wet peroxide oxidation, the latter sometimes in the presence of a Fe(II) catalyst (Tagg 2017), to digest labile organic matter and "clean" the plastic surfaces. A final filtering step is used to concentrate the MPs which can then be examined directly on a filter by conventional light microscopy (Masura 2015), stained with Nile Red dye and examined by fluorescence microscopy (Erni-Cassola 2017), or transferred to a spectroscopic window/slide or a suitable filter for chemical imaging by Focal Plane Array (FPA)-?FTIR or Raman spectroscopy (Loder 2015; Tagg 2015; Olesen 2017; Wolff 2019)

Evaluate the effect of BMPs on hydrology and water quality at field scale

Year: 2014 Authors: Risal A., Parajuli P.

In order to implement and regulate water resource management plans in a watershed, it is required to apply some Best Management Practices (BMPs) and evaluate their effects on hydrologic behavior and water quality. Field scale watershed model such as Agricultural Policy/Environmental Extender (APEX) can be applied to access the effect of such BMPs. APEX was applied to a sub-basin of the Big Sunflower River Watershed (BSRW). Calibration and validation of APEX for streamflow was conducted using the flow output from the calibrated Soil and Water Assessment Tool (SWAT) model for BSRW and that for sediment yield, Total Nitrogen (TN), and Total Phosphorous (TP) were conducted using observed data obtained every fifteen days from 2014 to 2016 for two locations within the sub-basin. Modeling scenarios such as crop rotation, tailwater pond, and vegetative filter strips (VFS) were applied and their effects in reducing runoff, sediment yield, TN, and TP concentration were evaluated. A significant difference in the amount of surface runoff, sediment yield, and nutrients concentration were observed for different BMP scenarios. The simulation results obtained from this study will provide a better idea to other modelers and decision makers in formulating decision regarding BMP implementation and proposing a suitable field scale BMPs in the reduction of surface runoff, sediment, and nutrient yield.

Effects of cover crops on edge-of-field water runoff in the mid-south

Year: 2014 Authors: Lucore A., Baker B., Aldridge C.

Efforts to reduce nutrient transport from agricultural landscapes has led to research and implementation of numerous conservation practices. Cover crops have been widely documented in certain regions of the country, primarily the Midwest, to provide water quality, soil health, and wildlife benefits to the environment, as well as to the agricultural system in the form of weed and pest suppression. A lesser body of research exists in the mid-south, particularly in respect to water quality where the bulk of the research refers to the benefits to soil and soil structure while the effects on water quality are ancillary. This study investigated the effects of cover crops on runoff in row-crop production systems. This study was conducted on a working farm located in Tippah County, Mississippi, where six plots (0.7–6.5 ha [1.8–16.1 ac]) served as treatments and controls. Four plots were randomly selected and planted with cover crops and the remaining two plots served as controls, all plots had been under no-till for 20+ years. Water quality was monitored via automated storm-based sampling at all locations for two years prior to cover crop implementation at the treatment sites (2014-2015) and for four years post cover crop implementation (2016-2019). Water samples were analyzed for nitrate-nitrite, total nitrogen, orthophosphorous, total phosphorous, and total suspended solids within 48 hours of sample collection. Data analysis indicated reductions among all analytes besides orthophosphorous with nitrate-nitrite concentrations being the most pronounced reduction. Additionally, there was considerable variability amongst season, cover crop type, and cash crop species.

Estimating the Optimal Water Requirement for Soybean Production in the State of Mississippi

Year: 2014 Authors: Li X., Feng G.

Determining the optimal water amount required for soybean production is a critical step to optimize irrigation management. Previous studies mainly used field experimental data or simulation data from process-based crop growth models. But results based on those data are not always applicable to the real world production fields. This study uses the actual historical data of dryland soybean production from the state of Mississippi to estimate the soybean water response. Given that the precipitation is the only source of water supply, rainfalls are generally random across years, this dataset can be viewed as a natural experiment of soybean water response. Soybean yield data are collected from the USDA RMA (Risk Management Agency) for 76 out of the 82 Mississippi counties spanning the period 1991 to 2014. Precipitation data are obtained from the PRISM (Parameter-elevation Relationships on Independent Slopes Model) Climate Data at 4 km grids and then aggregated to county level. A piecewise nonparametric quantile regression is utilized to estimate how the potential soybean yield changes with precipitation level. Our interest is the conditional quantiles (upper 99%, 95%, and 90%) of yields rather than the mean yields. That is because at a given precipitation level, the yields can still be limited by other growing factors such as temperature, disease, pest, weed, management, technology, and so forth. The more useful information for producers is what maximum yields can be possibly achieved under a certain amount of water supply, given that all other factors are properly managed. The results show the potential soybean yields first increase with precipitation, and reach maximum at the range of 800-1000 mm. After that, the potential yields decrease when precipitation further increases. At low precipitation level, such as under 400 mm, the potential yields are around 35 bu/ac. With adequate precipitation, such as 800 mm, the potential yield can reach up to 55 bu/ac. But excessive precipitation causes potential yields to drop again. The optimal precipitation also varies with temperature. In cooler years (average daily temperature below 23°C) the optimal precipitations are around 700 mm, while in warmer (average daily temperature above 23°C) the optimal precipitations are slight above 800 mm. Those findings provide useful guidelines for optimal irrigation water requirements for Mississippi soybean production.

Does the Sudden Influx of Broiler Production Impact Nearby Surface Water Quality?

Year: 2014 Authors: Moore M.T., Locke M.A.

The United States has the largest broiler chicken industry in the world. Arkansas (1 billion head) and Mississippi (740 million head) are two of the five top broiler producing states. Although poultry is the largest agricultural commodity for both Arkansas and Mississippi, until recently, large-scale broiler production has generally been limited to a small number of clustered counties within each state. In 2014, an industry partner invested $165 million in two northeast Arkansas counties for a significant poultry complex, and by 2017, hundreds of new chicken houses were built within the Current, Upper Black, and Lower Black River watersheds. These were areas new to the broiler chicken industry, as most broiler production had occurred in the middle and extreme northwestern parts of the states. Water quality issues of high levels of phosphorus and nitrate in the Illinois River Basin in northwestern Arkansas had raised the concern of possible surface and ground water contamination by an overwhelming number of chicken houses. In northeast Arkansas, the primary rivers within these watersheds (Current and Black) provide surface water for recreation and agricultural needs. Aquatic diversity is high, and several endangered freshwater mussel species are present in these watersheds. Because of the potential concern for water quality impairment by the sudden influx of chicken houses, a small-scale evaluation began in December 2016 on a six- acre recreation pond immediately downstream of newly constructed chicken houses. Seasonal water quality and sediment sampling are underway for basic physicochemical parameters, nutrient, and pesticide concentrations. Water quality trends will be examined and discussed, along with opportunities and suggestions on research collaborations to ensure continued agricultural commodity production is harmonized with the surrounding natural resources.

Two-Method Prediction Divergence of Water Level for the Mississippi River Valley Allluvial Aquifer to Inform Observational Network Review

Year: 2014 Authors: Asquith W.H.

Information gaps can be detected by quantifying statistical efficacy in estimation of phenomena such as groundwater levels at unmonitored locations for the Mississippi River Valley alluvial (MRVA) aquifer located within the Mississippi Alluvial Plain (MAP), south-central United States. Multi-agency water-level networks containing wells screened in the MRVA aquifer collect data in space (horizontal and vertical dimension) and time. Groundwater levels are also influenced by a given hydrogeologic framework (aquifer geometry and properties), well construction, local and regional pumping histories, and contexts of seasonal recharge and discharge. One common stakeholder inquiry concerns identification of information gaps. To quantify information gaps, a two-method approach for water-level prediction is proposed. Two statistics of interest were spring 2018 maxima (March-May) and fall 2018 minima (September-November) based on use of water-level data collected during these same months from 2014-2018 with prediction made for 2018. Spring maxima represent maximum seasonal aquifer recovery, whereas fall minima represent maximum aquifer drawdown attributable in part to irrigation demands. Data included for this study were computed from 1,411 unique wells for which 6,304 measurements (discrete or daily mean) were available. Our focus is not on the estimation of water levels per se but on the divergence between estimates using two methods (generalized additive models [GAMs] and support vector machines [SVMs]). Spatial coordinates, land-surface altitude, MRVA aquifer bottom altitude, and year were used as predictor variables. GAMs and SVMs are powerful estimation methods in their own right, but by their radically different mathematics, perform differently as extrapolation increases when predictions are increasingly made away from hyperspace of predictor variables and not necessarily away from spatial coordinates. GAMs can have curvatures away from the global mean, but SVMs must curve back to the global mean. Throughout the MAP and aligned to the 1-kilometer National Hydrogeologic Grid (NHG), absolute differences between GAM and SVM predictions were computed. Spatial depiction of the results on the NHG are shown for the entire MAP as well as for subdivision-specific GAM and SVM computations for the Boeuf, Cache, Delta, Grande Prairie, and St. Francis subdivisions. Various local areas in the MAP can be seen with large GAM-SVM divergence, and hence these areas have potential information gaps, indicating the need for additional water-level monitoring. Stakeholders are thus provided information on which to judge allocation of future resources in monitoring of the MRVA aquifer.

Improving the Corn Crop Coefficient Method in the Mississippi Irrigation Scheduling Tool (MIST)

Year: 2014 Authors: Buka H., Linhoss A., Tagert M.L., Pote J., Wax C.

This study examines the value of improving the crop coefficient method being used in the Mississippi Irrigation Scheduling Tool (MIST). Due to an overall increase in irrigated acreage, irregular distribution of rainfall during the summer growing season and continual decline of the Mississippi Alluvial River Valley Aquifer (MARVA), it is important to implement irrigation management practices that minimize water use without compromising crop production, yield, and quality through use of scientific models and soil monitoring devices. The objectives of this study were to 1) adjust and examine the Food and Agriculture Organization (FAO) crop coefficient method and the adjusted "SCS polynomial crop coefficient" method adapted and digitized from the former Soil Conservation Service (SCS, 1970) using a growing season of 120 and 150 days, 2) determine corn emergence and physiological maturity using 50 Growing Degree Days (GDD50) for use in adjusting the length of the growing season, 3) examine the importance of initiating the model at planting and emergence date, and 4) compare MIST modeled results to measured soil moisture data from Watermark soil moisture sensors for the 2014, 2016 and 2017 growing seasons. Currently, MIST uses a FAO crop coefficient with a growing season of 150 days, while the adjusted SCS method allows the growing season to be adjusted based on crop, variety, and maturity stages. Results showed that even though the adjusted SCS method called for irrigation earlier in the season, irrigation water was applied during the critical growth stages and did not trigger irrigation events after the crop reached physiological maturity. Results also showed that by using the adjusted SCS method and GDD50 to determine the growing season, fewer irrigation events and less total crop water use were indicated when irrigation was terminated at 2,700 and 2,900 GDD physiological maturity, depending on the variety used, as compared to the FAO crop coefficient. In addition, changing the timing of model initiation (planting vs emergence) was not important on the total crop water use, but it may have other benefits. Lastly, even though Watermark soil moisture sensors installed in the study field generally did not report similar results, especially around the mid-season, shallower sensor depth somewhat matched and showed similar trends with the MIST modeled results.

Salinity Effects from Treated Effluent as Irrigation

Year: 2014 Authors: Brock M., Tagert M.L.

Around the world, increasing and sometimes competing demands on water for irrigation, industrial processes, aquifer recharge, drinking and other systems require investigation into additional viable water sources. Effluent from industrial and municipal wastewater treatment systems is gaining more attention as a potential source to meet these demands. By receiving further treatment beyond these systems, reclaimed or recycled water has been developed as a means to use this effluent as a viable source. Southwest Florida has proven its successful use on a large scale for more than 40 years with 62 treatment facilities and widespread applications without harmful impacts on local water and soil quality (Reclaimed Water, 2014). Risk factors that must be addressed include pathogens, nutrients, and salinity. While standard treatment facilities meet established limits for these components, reclaimed water requires extra treatment in potential applications that have more direct contact with humans. Salinity is considered one of the greatest risk factors associated with irrigation applications as it affects hydraulic conductivity of soils and water uptake of plants. This study assesses salinity in wastewater effluent and examines its potential for irrigation. A potential solution combines effluent with other water sources to reduce salinity risks to soil. Using samples from Starkville Wastewater Plant, electrical conductivity and total dissolved solids of the effluent are tested and compared to values established by the Food and Agriculture Organization as water quality restrictions to irrigation (US EPA, 2012). Using these restrictions, effluent is diluted using a predetermined ratio with controls set as undiluted effluent and freshwater. Results will provide a basis for potential application of treated water for irrigation in Mississippi or demonstrate a need for additional treatment of wastewater to meet standards adopted by current reclaimed water facilities.

Long-Term Effect of Cover Crop on Water Use Efficiency in Manured and Rainfed Soybean-Corn Rotations

Year: 2014 Authors: Yang W., Feng G., Adeli A., Jenkins J.

Planting winter wheat cover crops in corn and soybean rotations is an effective to improve the effective utilization of soil moisture and enhance water use efficiency. However, the longer-term impact of this practice needs to be further investigated. The hybrid RZWQM-DSSAT model calibrated with 5 yr (2013-2017) field data was used to simulate the effects of this practice on crop evapotranspiration, yield, and water use efficiency under a rainfed condition in no-till corn-soybean cropping system at Mississippi Agricultural and Forestry Experiment Station in Pontotoc Mississippi. The poultry litter (13.4 Mg ha^-1) was applied to corn field with cover crop (CC) and no cover crop (NCC) in May 2014 and 2016. The model was calibrated well in terms of crop yield and biomass, plant N uptake, and soil moisture with percent error (PE) was within ±15%, Nash-Sutcliffe model efficiency (EF) > 0.7, and relative root mean square error (RRSME) < 15%. Longer-term simulations showed that planting a winter wheat cover crop increased corn yield by on average 1,560 kg ha^-1 (12%) and did not change soybean yield. The simulation also indicated that the practice increased annual evapotranspiration by 3.5 cm (9%) in corn years but did not affect evapotranspiration in soybean years. Simulated grain water use efficiency was increased by 17% for corn, and it was not changed in soybean. This study demonstrated that introducing winter wheat cover crops in a corn-soybean cropping system is a promising approach to increase corn water use efficiency in the subtropical agro-ecosystem.

Despite their differences, managed and non-managed wetlands in the Mississippi Delta achieve similar functional outcomes

Year: 2014 Authors: Ervin G.N., Shoemaker C.M.

This project aimed to evaluate abiotic and biotic characteristics of restored and non-managed wetlands in the Mississippi Delta, in an effort to determine whether restored wetlands are achieving desirable ecological functions in this predominantly agricultural landscape. With the assistance of USDA-NRCS, we identified 24 Wetland Reserve Program (WRP) wetlands and 6 non-restored, non-managed wetlands (NMW) for this work. These wetlands were assessed during 2014 and 2015 for water quality, hydrology, plant species composition, and landscape setting, as metrics of ecological condition and function.

Hydroperiods differed between NMWs and WRP sites, with longer, more intense flooding observed in NMWs; these differences were correlated with lower levels of plant species diversity, richness, and evenness in the NMWs, compared to WRP sites. We also found significant differences in soil organic matter content between wetland types, with NMWs having higher soil organic matter content, also likely correlated with the differences in hydroperiod between groups. In contrast to our observations of plant species and soils in these wetlands, few differences were found in water quality parameters between the two groups of wetlands.

At a broader scale, we found that WRP sites tended to be surrounded by higher levels of agriculture and conservation land, at distances from 100 to 500 m from the wetland edge, while NMWs tended to be surrounded by greater amounts of forested wetland cover. Additionally, we found that the conservation status of plant species in NMWs tended to be higher than that for WRP wetlands, which typically are situated in former marginal agricultural lands. Nevertheless, the lack of any substantial differences in water quality between NMWs and WRPs suggests that removal of excess nutrients associated with agricultural practices can be accomplished by wetlands across the agricultural landscape, even in moderately to heavily disturbed systems, such as the moist-soil managed wetlands typically created under the WRP efforts.

Drinking Water Supplies- How is Your Tap Water Regulated?

Year: 2014 Authors: Janasie C.

In the past, many Americans took the safety of their drinking water for granted. However, recent national news stories about the quality of drinking water have brought water quality to the forefront of many people's minds. Most noteworthy have been the stories of lead contamination in the drinking water supplies in cities like Flint, MI and Jackson, MS. In addition to lead contamination, additional issues with drinking water supplies have also appeared. For instance, in 2014 a harmful algal bloom forced Toledo, OH to issue a two-day ban on the use of the city's tap water, which had tested positive for the toxin microcystin. Further, lawsuits have emerged concerning the drinking water supplies in cities such as New York, NY and Des Moines, Iowa. Litigants in those cases claim there are Clean Water Act violations in the delivery of water to households in the respective cities.

This talk will focus first on how drinking water supplies are regulated in the United States. Next, the talk will review the requirements of the Safe Drinking Water Act, as well as what happens when a drinking water supply exceeds a contaminant level under the Act, such as when the lead level was exceeded in Jackson, MS. In addition, the talk will discuss the role that other environmental statutes, like the Clean Water Act, play in the regulation of our drinking water supplies. Finally, the talk will consider what changes may be coming to the regulation of drinking water in the United States.

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Round Island Marsh Restoration

Year: 2014 Authors: Tracy S.

The Utilization of Dredge Material for Marsh Restoration in Coastal Mississippi Project was funded by the National Fish and Wildlife Foundation (NFWF) in November 2014. Over many decades, priority bays on the Mississippi Gulf Coast have experienced significant impacts due to shoreline erosion, storm damage, and alterations to sediment transport, contributing to the loss of thousands of acres of tidal marsh habitat. In the past, most dredge material has been disposed of offshore or in upland dredge disposal areas. This project advances Mississippi's beneficial use program to facilitate a cost-effective, sustainable approach to restoring and protecting significant coastal marsh and bay shorelines. An example of one of these restoration efforts is located in Pascagoula, MS at the Round Island Coastal Preserve. Over 200 acres of marsh were created using dredge material provided by the U.S. Army Corps of Engineers from the Pascagoula Channel. This marsh will create habitat for living coastal and marine resources, reduce erosion along bay shorelines, and improve water quality.

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Numerical Simulations of Spilled Coal-Ash in The Dan River and The Environment Impact of the Incident

Year: 2014 Authors: Jia Y., Altinakar M., Chao X., Zhang Y.

39,000 ton of coal ash and 27 million gallons of waste water were released accidentally into the Dan River from the Dan River Steam Station on 2/2/2014. The chemicals brought with the coal-ash and the waste water into the Dan River caused serious concerns of the residents along the river and government agencies because the river is an important source of water supply. Studies supported by the Duke Energy using a 2D numerical model, CCHE2D, were carried out. This is a general free surface flow model with sediment transport, pollutant transport and bed change simulation capabilities. The Dan River from the spill site to the downstream School Field Reservoir, a 40km curved channel stretch was simulated. The channel morphologic change due to sediment transport and coal ash transport were simulated for allocating the coal ash deposition in the alluvial system. Both bed load sediment and suspended sediment transport were both simulated. The coal ash is of very fine particles, most of them are treated as suspended sediments. Transport of Arsenic and Selenium brought by the incident are simulated to evaluate the environment impact. The simulation results are comparable to the data measured in emergency.

Water consumption and yield variability of nonirrigated and irrigated soybeans in Mississippi dominant soils across years

Year: 2014 Authors: Feng G., Ouyang Y., Reginelli D., Jenkins J.

Soybean is the most important crop in Mississippi in both acreage and value. In 2015, the Mississippi soybean harvested area was 2.27 million acres and a total value of $1.04 billion, surpasses other major crops combined. Approximately one-half of Mississippi soybeans are grown under rainfed conditions and another half are irrigated. In order to stabilize dryland soybean yield and improve yield by irrigation, it is essential to determine yield, water requirement and consumption of both non-irrigated and irrigated soybeans in Mississippi dominant soils under different climate conditions over years.

Field experiments were conducted in Noxubee county for those objectives on Vaiden clay, Okolona silty clay, and Demopolis clay loam at a private Good Farm in 2014 and on the Brooksville silty clay at Mississippi State University Black Belt Branch experiment station in 2015 and 2016.

During the entire soybean growing season from 1895 to 2014, the average long-term reference evapotranspiration and crop water requirement (ETc) were 720 and 542 mm, mean rainfall was 432 mm, rainfall of wet, normal and dry category years was 597, 421 and 280 mm.

During soybean season in 2014, 2015 and 2016, rainfall were 365, 388 and 284 mm, soybean water requirement were 428, 455, and 504 mm. In 2014, 2015 and 2016, rainfed soybeans consumed 402, 417, and 347 mm water and produced 5672, 2736, and 1806 kg ha^-1 grain, in contrast, irrigated soybean consumed 440, 526, and 478 mm water and yielded 6264, 3109, and 3031 kg ha^-1 grain.

The APEX (Agricultural Policy/Environmental eXtender) model was applied on nine soil types (Vaiden clay, Catalpa, Okolona, Griffith, Sumter, Kipling and Brooksville silty clay, Demopolis clay loam, and Leeper sandy loam) in Eastern Central Mississippi from 2002 to 2014.

APEX simulated grain yield of rainfed soybean ranged broadly from 2.24 to 6.14 Mg ha^-1 on nine soil types over the 13 years. The average yield in wet, normal and dry years was 4.88, 4.51 and 3.74 Mg ha^-1, respectively. Simulated yield potential without water stress due to irrigation varied from 4.47 to 6.51 Mg ha^-1. Compared with rainfed soybean, the average increase in yield by irrigation ranged from 0.34 to 1.60 Mg ha^-1 among the nine soils. Griffith, Sumter and Demopolis had the highest average yield gap (difference between yield potential and the rainfed yield), ranged from 1.37 to 1.60 Mg ha^-1. Average irrigation amount required to achieve potential yield ranged from 16 to 377 mm across the nine soil types. High variability of water consumption as well as grain yield was observed for both nonirrigated and irrigated soybeans on different soils and on a given soil over different years. Therefore, it is necessary to explore production/management options for different soils that will increase opportunities for consistent yields and profits across years without irrigation.

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Application of AnnAGNPS for Evaluating the Nutrient Loading Control of an On-Farm Water Storage (OFWS) system in East Mississippi

Year: 2014 Authors: Karki R., Tagert M.L., Paz J., Bingner R.L.

Irrigation tailwater and storm runoff events from agricultural watersheds are a major source of nutrient loading in rivers and streams. According to the 2012 Mississippi Quality Assessment Report, nitrogen, phosphorus, sediments, and biological oxygen demand are the major pollutants of the Middle Tombigbee-Lubbub Watershed, which includes the study area. An On-Farm Water Storage (OFWS) system is a constructed best management practice (BMP) consisting of a tailwater recovery ditch or terraces and a water storage pond. These OFWS systems have demonstrated the ability to both reduce downstream nutrient loading and provide water for irrigation by capturing and recycling irrigation tailwater and rainfall runoff. The Annualized Agricultural Non-Point Source (AnnAGNPS) surface runoff model is a continuous simulation, daily time step, pollution loading model. This poster will present the preliminary results from the application of AnnAGNPS to estimate nitrate and phosphorus losses from a small agricultural watershed in East Mississippi over a one-year period from fall 2014 to fall 2015. Storm runoff events were captured using an ISCO auto sampler and will be used to calibrate and validate the model results. AnnAGNPS will also be used to estimate the nitrogen and phosphorus loads captured by the OFWS system during the study period. In addition, alternative management practices that could potentially decrease nutrient losses from the agricultural fields will be evaluated using the model.

Water availability in the Mississippi River alluvial plain: optimized monitoring and modeling for water management

Year: 2014 Authors: Barlow J.R., Haugh C.J.

The Mississippi River alluvial plain in northwestern Mississippi (referred to as the Delta), once a floodplain to the Mississippi River covered with hardwoods and marshland, is now a highly productive agricultural region of large economic importance. Water for irrigation in the Delta is supplied primarily by the Mississippi River Valley alluvial aquifer, and although the aquifer has significant storage capacity, there is evidence that the current rate of water use is exceeding the available supply. Groundwater modeling has shown that increasing withdrawals from the aquifer are having a direct impact on the interaction between the groundwater and surface-water systems. Groundwater level declines in the aquifer have resulted in decreased discharge to streams within the Delta to the extent that many stream reaches are presently net-losing streams throughout the year. This decrease in available groundwater discharge is directly impacting many ecosystem services such as maintaining baseflow conditions in streams; regulating temperature regimes for aquatic biota; and buffering contaminant transport at the streambed interface. To better understand and optimize water management and monitoring activities in the Delta, the U.S. Geological Survey and the Mississippi Department of Environmental Quality are collaborating to update and enhance an existing regional groundwater flow model. The model will be used to develop and assess conjunctive water-management optimization scenarios as well as improve and optimize current and future monitoring activities within the Delta. Key revisions include updating the model through 2014 with more recent water use, precipitation and recharge data, and streamflow and water-level observations. In fiscal year 2016, the updated model will be used to develop selected alternative water-supply scenarios to assess relative impacts to the alluvial aquifer and identify data needs for future optimization modeling.

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The Gulf of Mexico Alliance Water Resources Team Update

Year: 2014 Authors: Caviness-Reardon K.

The Gulf of Mexico Alliance (GOMA) was established in 2004 by the Gulf State Governors in response to the President's Ocean Action Plan. It is a State-led network of partners working together on projects related to the priority issues identified by the Governors of the five Gulf States. GOMA is a partnership of the five U.S. Gulf States, federal agencies, academic organizations, businesses, and other non-profits in the region. GOMA's mission is to significantly increase regional collaboration to enhance the environmental and economic health of the Gulf of Mexico. In 2014, after careful consideration and evaluation, the GOMA Alliance Management Team elected to modify the priorities supported by the GOMA partnership. Important to note is that none of the existing focus areas were eliminated, but were redistributed within the new team structure. One of the new teams to emerge from GOMA's restructure is the Water Resources Team, a combination of the former Nutrients and Water Quality Teams. The GOMA Water Resources Team is led by the Mississippi Department of Environmental Quality and will focus its efforts within three areas: (1) protection of human health, (2) protection of aquatic health, and (3) protection of economic health. The team will be focusing on various water resources issues across the Gulf including but not limited to hypoxia, nutrient pollution, pathogens, harmful algal blooms, freshwater inflows, and ultimately, working to increase understanding regarding how impacts to human health and aquatic health tie in directly to the economic health of the region. GOMA is currently developing Governors' Action Plan III for Healthy and Resilient Coasts, the third in a series of action plans to address issues common to all five Gulf States in a voluntary and cooperative way.

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Interspecific ecological and meteorological controls on forest canopy-derived hydrology and biogeochemistry in the southeastern United States.

Year: 2014 Authors: Siegert C.M., Limpert K.E., Karunarathna A.A.

During storm events, as precipitation moves through the forest canopy it is transformed in both quantity and quality, thus delivering highly enriched water to the forest floor. Throughfall is spatially distributed beneath the forest canopy while stemflow is localized to the roots and soils in the immediate vicinity of individual tree trunks. Previous research has demonstrated that storm characteristics (e.g., intensity, duration, and magnitude), canopy structural parameters, and species composition have a significant control on canopy-derived nutrient fluxes. However, in the southeastern United States, contributions of the forest canopy to nutrient cycling have largely been overlooked, although the magnitude of tree biodiversity in the region separates these forests from their more-studied counterparts. Therefore, a field study was established in an oak-hickory forest in Mississippi to categorize the interspecific control on canopy-mediated nutrient cycling during precipitation events. Throughfall collectors and stemflow collars were located underneath the canopies of four oak (Shumard, Southern Red, Post, and White) and two hickory species (Shagbark and Pignut), with three replicates for each species. Hydrologic flux and nutrient samples were collected following individual precipitation events beginning in Fall 2014 and continue to present. Meteorological characteristics and precipitation chemistry were collected at a nearby open site. Preliminary results indicate that stemflow volumetric flux was significantly different between species (p<0.001) but throughfall volumetric flux was not (p=0.624). Among the oak species, Shumard oak partitioned an average of 73.6% of incident precipitation into throughfall and 1.6% into stemflow, the largest among all species, with the remaining 24.8% partitioned into canopy interception. Mean concentrations of total nitrogen (TN) in throughfall were greatest in Shumard oak (1.44 mg/L) and post oak (1.39 mg/L) while stemflow concentrations were greatest in shagbark hickory (1.81 mg/L) and white oak (1.20 mg/L) and intermediate in Shumard oak (0.96 mg/L). Dissolved organic carbon (DOC) concentrations in throughfall were significantly different than precipitation (p=0.038) but not between species (p=0.342), while DOC concentrations in stemflow were significantly different than precipitation (p<0.001) and between species (p<0.001). Results suggest that Shumard oak canopies facilitate the largest hydrologic fluxes in oak-hickory forests that correspond to intermediate biogeochemical fluxes of nitrogen, enabling this species to directly modify the substrata and its growing conditions. Improved understanding of species-specific roles in nutrient cycles in highly diverse southern forests is critical to developing effective management strategies to mitigate shifts in species composition and ecosystem functions as regional climates change.

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Effects of land use on wetland plant diversity in Mississippi

Year: 2014 Authors: Shoemaker C.M., Windham E.L., Ervin G.N.

Restoration of former agricultural lands to wetlands has increased in the past 25 years, with public and private programs subsidizing the conversion of marginal farmland into wetlands. These wetlands were constructed with structural and functional goals in mind, such as increasing biodiversity and water quality within local and regional watersheds. While successful in terms of area restored, restored wetlands frequently do not meet desired management goals; often, these wetlands resemble highly degraded wetlands in terms of structure and function. While on-site parameters and management recommendations have recently received much attention, desired structural and functional components continue to fall short of management expectations. This study examined relationships between wetland site characteristics, measures of plant diversity, and land use. Data were collected in a total of 30 restored and naturally occurring wetlands in the Delta region of Mississippi during the 2014 and 2015 growing seasons. Wetland sites were surveyed twice during each growing season (May and August) from 50 evenly spaced observation points per wetland. Lower levels of plant diversity were observed in natural, compared to restored wetlands, with hydroperiod and management activities clearly affecting assemblages. Additionally, land use impacted observed plant community metrics, with the prevalence of agricultural and developed lands showing a negative relationship with plant species diversity. Wetland plant diversity showed a strong positive correlation with fallow land cover surrounding wetlands, with fallow land most often corresponding to land placed in conservation easements. Results thus suggest that low-intensity land use buffers associated with conversation easements are having a positive impact on wetland plant species diversity in the Mississippi Delta.

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Assessment of tailwater recovery system and on-farm storage reservoir water and nutrient harvesting

Year: 2014 Authors: Omer A.R.

The Lower Mississippi Alluvial Valley is economically important due to its highly productive agricultural land. However, producers in this region face two predominant environmental issues that are inherently linked to the intensity of the agricultural industry in this region. First, intensive agriculture practices have resulted in increased surface transport of nutrient-laden sediments, contributing to eutrophication in receiving waters and to the Gulf of Mexico Hypoxic Zone. Second, current water withdrawals from the Mississippi Alluvial Aquifer for irrigation are not sustainable. These issues threatening environmental resources necessitate use of best management practices and groundwater conservation. This research investigates systems of best management practices as water resource conservation methods. Such practices include surface water capture and irrigation reuse systems. Referred to as tailwater recovery systems (TWR), this practice consists of a tailwater recovery ditch which may be paired with on-farm storage reservoirs (OFS). Seven case studies of different TWR were monitored for nutrients during the 2014 and 2015 growing season at: inflow, edge of field, TWR, OFS, and overflow locations. Investigations highlight functionality for nutrient recycling, and descriptions of nutrient loss mitigation. Preliminary results for seven TWR in 2014 and 2015 show a mean of 94.05 mega liters of water being recycled applying a mean of 0.86 kg/ha total nitrogen and 0.2 kg/ha total phosphorus back onto the tillable landscape. These systems are proving successful in holding water on the landscape, recycling that water, and therefore nutrients; thereby preventing those nutrients from being lost to downstream waters. This suggests that TWR, or systems with similar water holding capacity, have potential for water resource conservation in the Lower Mississippi Alluvial Valley.

Refining Designated Uses For Mississippi's Surface Waters

Year: 2014 Authors: Caviness-Reardon K.

Water quality standards are required by the Clean Water Act and include three essential components: (1) designated uses for the water bodies, (2) criteria (either narrative or numeric) to support those uses, and (3) an antidegradation policy. Water quality standards establish the water quality goals for a water body. Designated uses are a critical component of water quality standards because they specify what a specific water body is being used for in order to define the appropriate water quality goals provide a way to evaluate whether or not these goals are being attained. Mississippi currently has a very simple water body classification structure. Within recent years, the Mississippi Department of Environmental Quality (MDEQ) has identified the need to examine the current water body classification structure and investigate further refinement of the existing water body classification structure. In 2014, MDEQ completed a preliminary analysis to consider potential options for refinement of the current structure. Further refinement of water use classifications will allow MDEQ to provide a more accurate distinction between water bodies around the state and allow for more appropriate criteria (or goals) to be established for those various water bodies. . Water use classification (or designated use) is the basic foundation of the water quality standards program, and improving the accuracy of water body classifications within Mississippi is a program priority for MDEQ's Water Quality Standards Program.

Prediction of Future Agricultural Water Needs in Mississippi Delta and Blackland Prairie under Surface Water Supply and Groundwater Pumping Scenarios

Year: 2014 Authors: Feng G., Ouyang Y., Reginelli D., Jenkins J.

The total area of Mississippi is approximately 30 million acre, grain crops take 4.6 million acre lands. Mississippi western Delta (5 million acre in total) and eastern Blackland Prairie (total 3 million acre) are two major agricultural regions where 80% of the MS croplands are planted. The Delta region accounts for 67% of the state croplands, over 90% of irrigation water is pumped from groundwater. The ongoing irrigation depletion of groundwater which has already declined to the alarming level in the Delta threaten agricultural productivity and sustainability. Enhancement of surface water supply is the solution to reduction of groundwater usage in the state which is rich with rainfall and surface. Sustainable conjunctive use of surface and ground water resources for irrigation requires knowledge of crop water requirement and deficit as well as prediction of future agricultural water needs. Soybean, corn and cotton are planted on 65% of croplands in Mississippi. Therefore, irrigation water needs of the three dominant crops were predicted. Patterns and trends of rainfall, reference evapotranspiration (ETo), water deficit and irrigation requirement in Delta (1915-2015) and Blackland Prairie (1894-2014) were analyzed using time series statistical models for annual, seasonal, and monthly periods. An AutoRegressive, Integrated, and Moving Average (ARIMA) approach was used to develop monthly and annual models for rainfall and ETo prediction. The ARIMA models forecasted 1319 mm of mean annual rainfall and 1203 mm of mean annual ETo in the two regions from 2016 to 2024. Those models predicted that soybean, corn and cotton need irrigation of 7.1, 6.6 and 6.9 inch yr-1. In 2014, there are 283,535 and 31,654 ac of cotton, 382,935 and 71,428 ac of corn, 1,595,363 and 217,640 ac of soybean in the Delta and Blackland Prairie, respectively. Totally, the three major row crops need 1.3 million acre feet of water in Delta and 0.2 million acre feet in the Blackland Prairie for irrigation each year. Surface water as an alternative option must be taken to place irrigation agriculture on a sustainable path. Our STELLA pond hydrological process model predicted that the ratio of pond size to irrigated crop land is 1:18. There are approximately 251,983 and 77,186 acre of surface water in the Delta and Blackland Prairie. If 19% and 16% of those surface water is used for irrigation in the two regions, at least 37% (481,155 acre feet) and 100% (185,837 acre feet) of groundwater could be saved in the MS Delta and Blackland Prairie, respectively.

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Spatial and temporal trends for mercury concentrations in fish from three north Mississippi lakes and human health risk assessment

Year: 2014 Authors: Willett K.L., Cizdziel J.V., Meals K., Brewer S., Thornton C.

Total mercury (Hg) concentrations were determined in the skeletal muscle of 310 fish collected during 2013 and 2014 from three northern Mississippi lakes (Sardis, Enid and Grenada) that are extensively used for fishing and recreation. Largemouth Bass (LMB), Channel Catfish (CC), White Crappie (WC), and Gizzard Shad (GS), that represent a range of trophic levels, were studied. Creel data indicated anglers harvested 372,711 kg of WC, 26,735 kg of CC, and 14,871 kg of LMB, the three most targeted species of fish, from the lakes. Median Hg concentrations (ng/g) were highest in LMB (443, n=64), followed by CC (211, n=72), WC (192, n=101), and GS (49, n=73). Fish-Hg concentrations were lower than those reported in fish >10 years ago, but there were significant differences between lakes consistent across species. Grenada fish-Hg concentrations were higher than those from Enid and Sardis. Because existing consumption advisories for CC are length-based, the lack of a significant relationship between length and Hg concentration indicated that the recommendations may not be protective enough. Furthermore, five different risk assessment paradigms yielded hazard quotient values suggesting that existing fish consumption advisories may be insufficient to protect adults, and especially children, from exposure to Hg.

Ecological Significance of Phyllosphere Leaf Traits on Throughfall Hydrology, Biogeochemistry and Leaf Litter among Quercus Species in the Southeaster

Year: 2014 Authors: Limpert K., Siegert C.M., Karunarathna A.A.

Quercus (oak) is a dominant species in many forest ecosystems across the United States that contribute vital ecosystem services through water and nutrient cycling. The recent decline of Quercus, largely due to fire suppression and forest mesophication, has the potential to alter forest hydrological and biogeochemical cycling. Given the prevalence, persistence, and diversity of Quercus leaves in forest ecosystems, it is likely that this species strongly mediate nutrient cycling when present. The objective of this study was to (1) quantify canopy-derived nutrients contributed to forest ecosystems and (2) determine interspecific temporal distribution of Quercus leaf fall in an oak-hickory forest in Mississippi. Beginning in Fall 2014, throughfall quantity and chemistry were measured during individual storm events under each of the four focal Quercus species and two non-Quercus (Carya) species and canopy litterfall was collected weekly to quantify changes in canopy leaf area index (LAI) and timing of species-specific leaf fall rates, and determine Throughfall depths decreased as leaves were lost but were greatest in Quercus species compared to Carya and were highest in Q. shumardii, and Q. stellata. The average total kjeldahl nitrogen (TKN) content of throughfall was highest in Q. shumardii (1.44 mgL-1) and Q. stellata (1.65 mg L-1) compared to other Quercus and non-Quercus species. Q. stellata had the greatest total organic carbon (TOC) for the majority of rain events with the largest amount reaching 119.43 mg/L-1. Quercus species contributed larger amounts of essential anions (Cl-1, NO3-, SO4-2). During the winter of 2014-2015, Q. shumardii had the highest leaf retention although non-oak species had a higher leaf retention in general. Leaf fall varied during the winter of 2015-2016 with Q. alba species having longer leaf retention compared to other Quercus and Carya species. Quercus shumardii had the lowest average C:N amounts (43.99 mg L-1) in leaf litter content compared to the other Quercus species. Non-oak species had a considerably lower average C:N ratio (Carya spp. 32.58 mg L-1).

Surface and groundwater modeling in the Platte River watershed to support water resource management

Year: 2014 Authors: Woodward D.

COHYST is a cooperative hydrologic study of the Platte River drainage basin in the central part of Nebraska. One objective of COHYST is to develop a comprehensive suite of tools to aid in conjunctively managing surface and groundwater to: 1) maintain the region's extensive irrigation economy; and 2) protect the river habitats used by endangered species. These tools must provide decision-makers with reliable quantitative information about the hydrologic consequences of alternative water management strategies. There also is a need to quantify past hydrologic changes, such as accounting for historic depletions of streamflow.

COHYST 2010 is the second generation of modeling tools within COHYST that involves developing an integrated computer-based model of basin hydrology to be used to calculate the effects of different management scenarios on stream flows and the regional aquifer. Phase I of COHYST 2010 involved design of the modeling work, and development of an observation based water budget for the study area to be used in model calibration. Phase 2 of COHYST 2010 had the objective of building the quantitative tools. Phase 3 is application of the tools to management scenarios and time period updates to the tools.

The Phase 2 tools were completed in 2014 and included a Watershed model, Surface Operations Model, and a MODFLOW groundwater model. We are in Phase 3 of the COHYST 2010 work effort. Models are being updated thru 2010 and the 2014 Model documentation is being edited to include model changes and integration work. An updated Stream depletion analysis along with Basin Water Supply and Basin Water Demands analysis are nearing completion. Conjunctive water management projects are also being simulated for project development.

Improving Port-Based Economic Development Marketing Websites

Year: 2014 Authors: Miller C.R., Kern T.

River and seaports are important assets for regional economic development. Many industries need to be located in close proximity or with efficient transportation connections to ports. Therefore, ports are important site selection factors for industrial attraction. The industrial site selection process typically involves an initial web-based screening of potential locations by consultants or internal real estate teams. Those few communities or states that appear to meet the criteria based on their websites are sent a Request for Information (RFI) seeking specific information. There is a final screening based on the RFI information before economic development negotiations begin so to be successful in industrial attraction certain information needs to be on a port's website or readily available. This research, which was part of the 2014 Mississippi Department of Transportation Statewide Port Needs and Marketing Assessment study, reviews the port related information requested from RFIs to compile a content analysis tool for evaluating port websites. Each of the 16 port websites in Mississippi and their associated economic development organization are evaluated using this checklist. Recommendations for marketing are developed that will improve industrial attraction and retention efforts by ports.

NOAA's Gulf of Mexico Hypoxia Watch

Year: 2014 Authors: Beard R.H.

The Gulf of Mexico Hypoxia Watch is a cooperative project of NOAA's National Marine Fisheries Service (NMFS), Southeast Fisheries Science Center (Pascagoula and Stennis Mississippi Labs), and NOAA's National Coastal Data Development Center (NCDDC). The purpose of the project is to collect measurements of bottom-dissolved oxygen using a Conductivity, Temperature, Depth (CTD) profiler with an oxygen sensor. The NOAA ship Oregon II goes to sea in June and July for the Southeast Area Monitoring and Assessment Program (SEAMAP) groundfish survey and collects the CTD measurements along with SEAMAP biological data. The CTD casts are done in a random pattern along the continental shelf, from the Texas/Mexico border to southern Florida, in water depths between 10 m and 200 m. After data processing, the bottom (deepest) oxygen values are sent via email to NCDDC where they are contoured and mapped. The contours show estimations of where high and low oxygen levels are likely occurring. The dissolved oxygen values range from 0 to 8 mg/L and the water is considered hypoxic if the value is 2 mg/L or less. During the cruise, values are often mapped daily, providing a near-real-time picture of the health of the Gulf. Currently, the Hypoxia Watch project includes data from 2001 through 2014. To access the data, view maps, or consult metadata for the project, please see http://www.ncddc.noaa.gov/hypoxia/.
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Contribution of total dissolved phosphorus in irrigation runoff from the Mississippi River Valley alluvial aquifer to phosphorus concentrations in a D

Year: 2014 Authors: Welch H.L., Rose C.E.

Water-quality of the Mississippi River Valley alluvial (MRVA) aquifer has the potential to influence water quality of streams located in the lower Mississippi River Valley either through irrigation runoff from fields during the growing season (May through August) or at times of baseflow when streams are comprised of mostly groundwater. Previous studies of groundwater from the MRVA aquifer have shown concentrations of total dissolved phosphorus ranging from 0.12 to 1.2 milligrams per liter (mg/L). These concentrations exceed 0.1 mg/L, which is the desired goal established by the U.S. Environmental Protection Agency for the prevention of nuisance plant grown in streams. In addition, watersheds in the lower Mississippi River Valley have been identified as having some of the highest total phosphorus yields in the Mississippi River basin, although application of phosphorus fertilizers to land in the basin is minimal. The contribution of phosphorus from the alluvial aquifer to the total phosphorus loads in the basin has not been determined. From June through September 2014, the U.S. Geological Survey conducted a study near a rice field located in Issaquena County, Mississippi, to quantify the effect of irrigation runoff on water quality in a small ditch draining the field. Thirteen groundwater samples were collected from a well screened in the MRVA aquifer used to irrigate the rice field. In addition, runoff samples were collected downstream of the well at two locations: (1) from a water furrow that drains the rice field and (2) from a ditch immediately downstream of the water furrow. All samples were analyzed for water temperature, pH, dissolved oxygen, specific conductivity, alkalinity, iron, manganese, orthophosphate, and total phosphorus. State and Federal agencies can use the results of this study to help with the establishment of nutrient reduction strategies in the lower Mississippi River Valley.

Inter-relationships of Coastal Water Quality, Ecosystem Health, Human Health, and Socioeconomics

Year: 2014 Authors: Ingram R.B.

Humans are a terrestrial species, we're also a social species. Our activities impact all environmental media in which we live; surface and ground water quality and quantity, air quality, aquatic and wildlife habitat, ecosystem structure, and climate. In a recent national report on water quality in the United States, 45% of assessed stream miles, 47% of assessed lake acres, and 32% of assessed bays and estuarine square miles were classified as polluted. Mississippi's current 303(d) List identifies 21 impaired water bodies in the Coastal Streams Basin, Lower Pascagoula River Basin, and Lower Pearl River Basin. In this same area 45 TMDLs have been developed. During 2014, 44 beach closures and/or water contact advisories were issued. Water quality, ecosystem health, and human health are all inextricably linked. Backed by science, acknowledgement of this is reflected in the tiered surface water designated use categories inherent in Mississippi's water quality protection standards (public water supply, shellfish harvesting, recreation, and fish and wildlife) all designed to collectively protect water quality, ecosystem health, and human health. Likewise, a strong relationship exists between water quality and socioeconomics at all scales, from the individual to the local community to the larger society. A significant portion of the coastal economy depends upon water quality to support industrial development and the creation of jobs, for the maintenance of healthy ecosystems and harvesting of marine resources, and to sustain the Gulf Coast's traditions, cultures, and quality of life.
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Utilizing NASA Earth Observations to Assist the Audubon Mississippi Coastal Bird Stewardship Program with Habitat Monitoring and Restoration Planning Activities

Year: 2014 Authors: Barrett S., Beasley B., Wylie L., McDaniel B.

Coastal and migratory bird habitats in Mississippi are highly dynamic and constantly threatened by human activity. Today, these coastal and migratory species can be found on managed public lands. However, as of 2014, the Pascagoula River Audubon Center (PRAC) and the National Fish and Wildlife Foundation (NFWF) reported shorebird populations in coastal Mississippi have declined. In response, the Mississippi Audubon Coastal Bird Stewardship Program (CBSP) plans to focus habitat management on approximately twenty sites in coastal Mississippi. Activities includes planning and conducting standardized monitoring, implementing best-practice restoration projects, and a campaign to educate diverse audiences to increase understanding of the threats to and environmental and societal benefits of coastal and migratory birds. To support these efforts, this NASA DEVELOP project used current Landsat 8 OLI imagery to produce habitat classification maps that incorporated land use land cover, vegetation health, and water quality indices of areas in coastal Mississippi where these vital bird habitats are located. The project yielded maps for declining coastal bird species such as the least tern. End products and methodologies aided end-users in focusing habitat restoration efforts based on individual species' propensity to a particular area.

Utilizing NASA Earth Observations to Assist the Audubon Mississippi Coastal Bird Stewardship Program with Habitat Monitoring and Restoration Planning Activities

Year: 2014 Authors: Barrett S., Beasley B., Wylie L., McDaniel B., Bosarge A.

Coastal and migratory bird habitats in Mississippi are highly dynamic and constantly threatened by human activity. Today, these coastal and migratory species can be found on managed public lands. However, as of 2014, the Pascagoula River Audubon Center (PRAC) and the National Fish and Wildlife Foundation (NFWF) reported shorebird populations in coastal Mississippi have declined. In response, the Mississippi Audubon Coastal Bird Stewardship Program (CBSP) plans to focus habitat management on approximately twenty sites in coastal Mississippi. Activities includes planning and conducting standardized monitoring, implementing best-practice restoration projects, and a campaign to educate diverse audiences to increase understanding of the threats to and environmental and societal benefits of coastal and migratory birds. To support these efforts, this NASA DEVELOP project used current Landsat 8 OLI imagery to produce habitat classification maps that incorporated land use land cover, vegetation health, and water quality indices of areas in coastal Mississippi where these vital bird habitats are located. The project yielded maps for declining coastal bird species such as the least tern. End products and methodologies aided end-users in focusing habitat restoration efforts based on individual species' propensity to a particular area.

Design and implementation of a groundwater-streamgage network to assess groundwater and surface water interaction in the Mississippi Delta

Year: 2014 Authors: Roberts B.A., Barlow J.R.

In 2014, the U.S. Geological Survey (USGS), Mississippi Water Science Center, in cooperation with the U.S. Army Corp of Engineers, Vicksburg District, installed and instrumented a total of ten groundwater-streamgages throughout the Yazoo Basin. Each groundwater-streamgage collects and transmits, at minimum, stream stage, stream temperature, groundwater level, and groundwater temperature. Site instrumentation consisted of installing near-stream piezometers near existing or new streamgages. These piezometers house pressure transducers with temperature recorders and provide a means to measure and record periodic water-levels in order to check the continuous data from the logger. Each groundwater-streamgage is operated and maintained on a regular schedule (approx. 8 week interval), and all data are transmitted real-time to a project web page. Groundwater-streamgages provide a framework to document the spatiotemporal variability of groundwater and surface-water interaction. Data will be used to better understand the potential connectivity between the stream and the alluvial aquifer within the Yazoo River Basin and how connectivity affects water quantity and quality throughout both. This network will also help understand and quantify the extent that the interaction between streams and the alluvial aquifer has been affected by declining water levels in the alluvial aquifer.

Water Quality in Bangs Lake: effects of recurrent phosphate spills to a coastal estuary

Year: 2014 Authors: Dillon K., Caffrey J., Carmichael R., Holcomb S., Griffin C., Allen J., Jones T., Price K.

Bangs Lake, an estuarine water body in the Grand Bay NERR, has been the site of three industrial phosphate spills from a nearby fertilizer plant since 2005. Due to restricted tidal exchange in Bangs Lake, these events have had long lasting effects on water column phosphate concentrations which may stimulate biological activity and alter the biogeochemical cycling of essential elements within the water column and the sediments. To determine the fate of excess phosphate from the industrial spills, we measured soluble reactive phosphate concentrations in sediment pore water and total particulate phosphate concentrations from sediment cores (0-25 cm depth) from four locations: North Bangs Lake (closest to spill locations), Bangs Lake, and two low impact reference sites (Bayou Cumbest and Bayou Heron). We also conducted phosphate adsorption experiments and measured benthic chlorophyll concentrations with sediments from these sites to determine if the excess PO4 was fertilizing benthic microalgae to determine the fate of this excess PO4. Pore water phosphate concentrations were highest (21 uM) from 10 to 20 cm depths in North Bangs Lake cores however pore water from the surface sections of these cores had much lower phosphate concentrations (<0.5 uM). Pore water from the Bangs Lake cores consistently had elevated phosphate concentrations (2 to 5 uM) throughout the core length while pore water phosphate concentrations from one reference site were much lower (<0.7 uM), likely reflecting background levels. Phosphate adsorption experiments show that surface sediments from North Bangs Lake and Bayou Cumbest rapidly stripped phosphate from solution to final concentrations of <3 uM while surface sediments from Bangs Lake had greatly reduced phosphate adsorption capacity with much higher final concentrations (24 to 32 uM) indicating these sediments are near saturation. In 2013 and 2014, Sediment chlorophyll a concentrations were higher in Bangs Lake compared to the reference site. Sediment chlorophyll a was significantly correlated with extractable phosphate concentration in sediments (r = 0.88). In addition, grow out experiments with amendments of phosphorus to water and sediment samples stimulated the growth of cyanobacteria capable of fixing nitrogen.

Drivers of plant community composition in Delta wetlands

Year: 2014 Authors: Shoemaker C., Ervin G.N.

Intensive agricultural practices in watersheds have the potential to lead to high inputs of non-point source pollutants as a byproduct of nitrogen and phosphorus fertilizer applications. Excess amounts of these nutrients can lead to the eutrophication of receiving water bodies and cause water quality degradation at local, regional, and national scales. To combat this problem, wetland restoration is seen as a potential remediation strategy for reducing nutrient loads entering into larger water bodies. However, wetlands differ in their ability to remove nutrients, in part a result of the plant diversity within wetlands. This study examined natural and restored herbaceous wetlands across the northern Delta in Mississippi to determine drivers of plant community composition and their subsequent effect on water quality. Six naturally occurring wetlands along with 24 restored wetlands enrolled in the Wetland Reserve Program (WRP) were sampled across 12 watersheds stratified by expected nitrogen loads (based on USDA agricultural statistics data). Wetlands were visited in May and August of 2014, with species presence and abundance recorded at 50 sampling plots within each wetland. On the restored sites, redvine (Brunnichia ovata) and trumpet creeper (Campsis radicans) frequently were recorded at 50% or more of our sample points per wetland, while knotweed (Polygonum spp.) was common throughout. Additionally, woody species, such as buttonbush (Cephalanthus occidentalis), swamp chestnut oak (Quercus michauxii), slippery elm (Ulmus rubra) and other bottomland hardwood species were found in greater abundance on the six natural sites compared to restored sites. Ongoing analyses are aimed at investigating components of water quality that may be driving or driven by plant species composition in these wetlands.

Water quality-land use interactions in restored wetlands of the Mississippi Delta

Year: 2014 Authors: Ervin G.N.

Restoration of former agricultural land to wetlands, through programs such as the Wetlands Reserve Program (WRP) and Conservation Reserve Program (CRP), often focuses on restoring functions such as water quality improvement and wildlife habitat enhancement. However, results are inconclusive as to the long-term successes of these restorations. Our work is aimed at determining whether wetland restorations in the Mississippi Delta achieve sustained water quality improvements, and whether key water quality parameters are influenced by surrounding land use. During the summer of 2014, we assessed vegetation, land use, soils, and water quality in and around 24 restored and 6 naturally occurring wetlands across a gradient of human land use in the Delta. Initial analyses were based on classifying wetlands into watersheds with high, medium, or low levels of agricultural intensity, based on data from the USDA National Agricultural Statistics Service. We found differences in soils and surrounding land use of natural vs. restored wetlands but few differences attributable solely to our a priori classification of wetlands based on surrounding agricultural land use. When we examined correlations between water quality parameters and land use within 200m of the wetlands, we unexpectedly found no significant correlations. Nutrient concentrations were quite high in these wetlands; thus, it is possible that concentrations alone may be uninformative about impacts of surrounding land use. Additional work is planned to examine changes in water quality as surface waters move through these wetlands, as this may be a better metric of ecological function for Mississippi Delta wetlands.
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Groundwater and surface-water dynamics in the Mississippi Delta: a coupled monitoring-modeling approach for better understanding and management of gro

Year: 2014 Authors: Barlow J.R., Connor J.H.

The Mississippi River alluvial plain in northwestern Mississippi (referred to as the Delta), once a floodplain to the Mississippi River covered with hardwoods and marshland, is now a highly productive agricultural region of large economic importance to Mississippi. Water for irrigation is supplied primarily by the Mississippi River Valley alluvial aquifer, and although the alluvial aquifer has a large reserve, there is evidence that the current rate of water use from the alluvial aquifer is not sustainable. Prior to extensive use of groundwater for irrigation, the regional groundwater flow path generally followed the topography of the alluvial plain, discharging to the streams and rivers within the Delta. Presently, the regional groundwater flow path is intercepted by a large cone of depression in the central Delta with maximum drawdown occurring in Sunflower County, formed as a result of groundwater pumping for irrigation. Water-level declines have resulted in decreased groundwater discharge to streams to the extent that many stream reaches in the Delta are presently net losing streams throughout the year. These changes in flow to and from the aquifer have decreased the amount of water available within the alluvial aquifer and have diminished many ecosystem services provided by groundwater discharge to streams such as maintaining baseflow in streams, regulating stream temperature regimes for aquatic biota, and buffering the transport of contaminants through the streambed interface.

An effort is currently underway to update and enhance an existing regional groundwater flow model in order to develop and run conjunctive water management optimization scenarios. This effort is jointly conducted by personnel from the U.S. Geological Survey and the Mississippi Department of Environmental Quality through a memorandum of understanding between the two agencies. Key revisions to the model include updating the model through 2014 with the addition of more recent water use data, precipitation and recharge data, and streamflow and water-level observations.

Refinement and regionalization of phosphorus assessment tools in Mississippi

Year: 2014 Authors: Ramirez-Avila J.J., Oldham J.L., Ortega-Achury S.L., Osmond D., Martin J.L., Locke M., Read J.J.

Phosphorus is a major nonpoint source pollutant that causes eutrophication in surface waters. Phosphorus (P) Indices are applied assessment tools used to identify agricultural fields most vulnerable to P loss by accounting for major source and transport factors controlling P movement. There is a wide range in formulation and management recommendations of P Indices among the southern states leading to differences in P-management recommendations under relatively similar site conditions. This situation creates the need for rigorous evaluations of P Indices to determine directional and magnitudinal correctness. Mississippi State University-based investigators participate in a southern multistate research program with the objectives to coordinate and advance P management in the region by ensuring that P assessment tools developing using guidance in the 2011 NRCS 590 standard are compared to water quality data. The research goals include producing tools that provide more consistent results across physiographic regions that will encourage greater similarity between southern state P Index ratings and ensuing recommendations. Values of annual P loss measured in two Mississippi physiographic regions, i.e. agricultural fields in the Mississippi Delta and pastures in the poultry production counties in South Mississippi, are used to compare southern P Index assessments against water quality data, and to calibrate and validate the Agricultural Policy/Environmental eXtender (APEX) model. Results will show the assessment for P loss vulnerability estimated by different southern P Indices and the performance of the APEX model before and after calibration and validation procedures for the proposed scenarios.

Numerical Modeling of Flow and Mercury Distribution in Enid Lake, Mississippi

Year: 2014 Authors: Chao X., Hossain A.K., Cizdziel J., Jia Y.

The Yazoo River Basin is the largest basin in Mississippi. Four large flood control reservoirs: Arkabutla Lake, Sardis Lake, Enid Lake and Grenada Lake, are located in this region, providing significant natural and recreational resources. The soils in this region are highly erodible, resulting in a large amount of sediment discharged into the water bodies. Sediments are normally associated with many pollutants and greatly affect water quality and aquatic lives. Mercury concentrations in water, sediment and fish in Enid Lake are relatively high, and a fish consumption advisory was issued by Mississippi Department of Environmental Quality (MDEQ) in 1995. In this study, a numerical model was developed based on CCHE3D, a three-dimensional free surface hydrodynamic, sediment and water quality model to simulate the flow, sediment and mercury distributions in Enid Lake. Total mercury in water and sediment were simulated, and the major processes, including advection, diffusion, adsorption/desorption, bed release, atmosphere deposition, settling, etc., were considered in the model. This model was calibrated and validated using field measurements and remote sensing data. This model provides useful tools for understanding the fate and transport of mercury in natural lakes.

Developing Numeric Nutrient Criteria For Mississippi

Year: 2014 Authors: Young A., Caviness K.

Nutrient loads, including nitrogen and phosphorus, have been a major cause of impairments in water bodies nationwide. In 2001 the USEPA developed an Action Plan requiring that all states develop numeric nutrient criteria in order to protect uses from nutrient pollution. Since then, the Mississippi Department of Environmental Quality (MDEQ) has been active in pursing this goal, including creating a Nutrient Criteria Development Plan and collecting data to derive scientifically defensible nutrient criteria. A technical advisory group (TAG) consisting of members of state, federal, and research scientists has been formed to aid MDEQ in deriving these criteria with their technical knowledge and regional experience. The methods used to determine criteria are data compilation, classification of waters, and data analysis. In an effort to be more scientifically defensible, MDEQ is applying the multiple lives of evidence approach for nutrient criteria development. The multiple lines of evidence approach involves looking at several lines of analysis, such as distributional analysis, stressor-response, scientific literature, and water quality models to create a final endpoint. In addition to developing criteria, MDEQ recognizes that moving forward the implementation of these criteria is also a priority of the state. An implementation work group has been formed to address issues such as permits, assessment, total maximum daily loads (TMDLs), waste load allocations (WLAs), and watershed planning. The MDEQ, along with the support of the TAG and the involvement of stakeholders, are making great strides in developing criteria for the Mississippi's rivers, streams, lakes, coastal and Delta waters.

Leaching of copper from different copper treated woodwastes

Year: 2014 Authors: Singleton B., Borazjani H., Cox M.

There has been a significant increase in production of copper treated lumber since voluntary halt in production of chromated copper arsenate (CCA) for residential use by the wood treating industry. Disposal of copper treated wood wastes have become an environmental issue for companies using these products for residential applications. This study evaluated recovery of copper from sawdust of copper azole(CA),micronized copper azole(MCA), azole copper quat(ACQ), and micronized copper quat(MCQ) using two different extraction procedures(toxicity characteristic leaching procedure(TCLP), and sonication) in acidic water. No significant differences in copper recovery were observed between CA and MCA by both extraction procedures. The same results were observed for ACQ and MCQ also. However, copper recovery for MCQ and ACQ were significantly higher than CA, and MCA.

Diamondhead MS BMP Demonstration Site, Outreach Tools and Model Ordinance

Year: 2014 Authors: Gallo W.C.

Researchers at Mississippi State University along with the Mississippi Department of Environmental Quality (MDEQ) have developed new BMP demonstrations, educational outreach material and policy tools for coastal Mississippi. A proposal for a BMP demonstration site was developed that promotes resilient community design and development in Diamondhead, MS. The demonstration site is designed to accommodate future commercial development, protect watershed health, and demonstrate small and large scale structural BMPs from infiltration basins to regional detention. Two presentations and two brochures were also developed that focus on homeowners and policy makers. Both sets of documents are designed to provide a broad overview of the tools, policies and practices homeowners and policy makers can adapt to better protect their a home watershed and a community watershed. All documents will be available for use from the MDEQ to meet NPDES Phase II education and outreach requirements. Lastly, a new model ordinance was created based on a review of other model ordinances throughout the country and adapted for the specific needs of coastal Mississippi. The ordinance is designed to be flexible and adaptable to any community's requirements by providing options and insights into the choices available throughout the document. This document will also be available for municipalities use from the MDEQ.

The Migratory Bird Habitat Initiative: Managing Waterbird Habitats After The 2010 Gulf Oil Spill

Year: 2014 Authors: Kaminski R.M., Davis J.B., Webb L., Tapp J., Weegman M.M.

In response to the 2010 Deepwater Horizon Gulf Oil Spill, the USDA Natural Resources Conservation Service (NRCS) funded the Migratory Bird Habitat Initiative (MBHI), providing landowners in eight Gulf coastal states $40 M in cost-share assistance to manage wetland habitats for waterbirds inland from the spill through 1-3-year contracts. As part of the comprehensive MBHI, we quantified (1) waterbird use of MBHI managed (i.e., primarily artificial flooding), non-managed, and other wetlands and (2) potential food resources for these birds in wetlands in the Lower Mississippi Alluvial Valley (MAV). Managed Wetlands Reserve Program (WRP) lands received significantly greater use by waterbirds than passively or non-managed WRP easements. In Louisiana and Mississippi, nearly 3 times more dabbling ducks (Anatini) and all ducks combined (Anatinae) were observed on MBHI than on non-managed WRP wetlands. Additionally, waterbirds other than waterfowl and shorebirds were nearly twice more abundant on MBHI than non-managed WRP wetlands. In Arkansas and Missouri, MBHI wetlands attracted over 2 times more dabbling ducks than non-managed WRP wetlands. Concerning food abundance and habitat carrying capacity for waterbirds, MBHI wetlands in Louisiana and Mississippi contained =1.26 and =1.53 times more total seed biomass and biomass of seeds known to be eaten by waterfowl, respectively, than non-managed WRP wetlands. In Arkansas and Missouri, seed biomass during winter was 21% greater on MBHI wetlands than non-managed WRP wetlands. While no significant differences in aquatic invertebrate biomass or number of invertebrate families were detected between managed and non-managed WRP wetlands in Arkansas and Missouri, production of invertebrates during autumn was 3 times greater on MBHI wetlands than non-managed WRP wetlands. During winter, invertebrate biomass was approximately 40% greater on MBHI and non-managed WRP wetlands than public-owned managed wetlands in these states. Our evaluation implies that MBHI management increased waterbird use and potential foraging carrying capacity of WRP wetlands for waterbirds and possibly provided alternative habitats for these birds inland from oil impacted Gulf coastal wetlands. Continued financial incentives to landowners in the MAV and nationally to manage wetlands at conservation easements following restoration have the potential to increase contribution of private lands to waterbird habitat availability and carrying capacity.

Mississippi Water Resources Inventory & Projections for Economic Development

Year: 2014 Authors: Linhoss A., Balwebber J., Pote J.

Mississippi's water resources are an important part of the state's economy, environment, and quality of life. Water is an essential commodity and the importance of water to Mississippi's economy is clear given the number of economic sectors that rely on the resource (e.g. agriculture, industry, energy, and public supply). However, the economic value of water is in many ways immeasurable because (1) it provides life whose economic value is incalculable, (2) there many external factors that are often not accounted for in the market value of water (e.g. pollution and environmental impacts), (3) users often self-supply and do not pay a market value for the resource, and (4) water is a complex resource whose value depends on volume, timing, reliability, and quality. The objective of this research is to assess the value of Mississippi's water resources within an integrative environmental and economic development framework. Mississippi is blessed with rich water resources. The state has the second highest rate of annual rainfall in the continental U.S. and major ground water aquifers underlie 83% of the state. River flow through Mississippi is dominated by the Mississippi River which discharges an average of 723,000 cubic feet per second. When combined, the rest of the rivers in Mississippi discharge approximately 60,000 cubic feet per second, which is only 7% of the flow in the Mississippi River. Eight dams in the state (0.2%) have the primary purpose of water supply and Mississippi has the least number of reservoirs with the purpose of water supply, relative to neighboring states. Mississippi's water use is dominated by groundwater and agriculture. 32% of Mississippi's water withdrawal permits are from surface water and the remaining 68% are from ground water. Irrigation for agriculture is the primary groundwater beneficial use category and industry is the primary surface water beneficial use category. Mississippi's high dependence on groundwater runs opposite the trend for most of the comparison states and Mississippi withdraws the least amount of groundwater relative to neighboring states. As Mississippi moves forward through economic and community development it is important to recognize the environmental and economic values of water. This research provides a broad perspective for assessing water use in Mississippi as well as understanding the vulnerable aspects of our water resources.

The Mississippi Freshwater Assessment: A New Tool for Supporting Decision Making for Mississippi's Freshwater Resources

Year: 2014 Authors: Piazza B.

TNC is in the early phases a project to compile, analyze, and present scientific information to improve conservation and protection of Mississippi's freshwater resources. This comprehensive statewide freshwater assessment is a scientifically sound evaluation of watershed and landscape integrity (i.e., land use and cover, floodplain connectivity, channelization), water quality, surface flow, groundwater trends, and biological health (i.e., trends in species diversity indicators,) of all of the state's watersheds. The data resource and analysis tool will provide a powerful, online mapper with decision-support capability to facilitate the development of freshwater science and conservation objectives and prioritize freshwater conservation statewide. It will be freely available and useful for any stakeholder, including policy- and decision-makers, environmental resource managers, local watershed conservation groups, and the general public, and will allow both technical and lay audiences to evaluate the effects of current and future water use and watershed development proposals. This assessment will provide the capability to draw attention to the status of Mississippi's watersheds, develop agency, NGO, and industry partnerships, and provide quickly accessible facts and figures to support science-based and sound policy outcomes about water. This presentation will describe the framework, components, and capabilities of the assessment system, and will investigate an example of a similar system built for Louisiana. When complete, our Mississippi Freshwater Assessment will integrate with Louisiana's system as well as TNC's Gulf of Mexico Resilience decision support tool (maps.coastalresilience.org) to move toward the ultimate goal of providing a common approach and framework for supporting decision making and management of freshwater and coastal resources across the northern Gulf of Mexico.

Austin's Quadrant: a new framework for assessing water use models

Year: 2014 Authors: Czarnecki J.M., Kröger R., Omer A.R.

Although water resources are frequently discussed as an issue of Tragedy of the Commons, this paradigm has well-published shortcomings which make it irrelevant in some situations. A new framework for water use models is proposed where regions are evaluated on two continua, infrastructure and supply. A quadrant is formed wherein regions in quadrant I experience both ample water supply and adequate infrastructure with which to utilize available supply. Regions falling within quadrants II and IV experience a shortage of either supply (II) or infrastructure (IV) but adequate levels of the opposite factor. Regions falling within quadrant III bear the double burden of limited supply and infrastructure. This paper explores case studies within the four quadrants and attempts to answer the questions: (1) What does it take to move from quadrants III or IV to quadrants II or I, and more importantly (2) how do regions in quadrant I not move into quadrant II? Engineered infrastructure must increase concomitantly with governance infrastructure or regions will slide farther down the supply continuum. Education and outreach hold the most promise to shoring up the future of water resources for these regions. Users who make the connection between individual use and its effect on aquifer supply are more likely to engage in conserving behavior and to be more accepting of regulation of use. If adequate education alone is unable to stem overuse, then at least regulation will be supported.

An Assessment of Private Wells Used for Drinking Water in Mississippi and Alabama

Year: 2014 Authors: Barrett J., Grammer P.

Most residents of Mississippi and Alabama are served by one of the over 1,700 public water systems in these states. Having access to a public water system provides citizens with safety and quality of water through the regulatory enforcement of the Mississippi State Department of Health-Bureau of Public Water Supply (MSDH) and the Alabama Department of Environmental Management (ADEM). Mississippi and Alabama citizens on private wells do not have the luxury of knowing the quality and/or quantity of their water on a regular basis. Unfortunately, a reliable method for determining the population that depends on a private well for their water supply has not existed since the 1990 census. This presentation will compare currently available methods and present a new methodology for estimating private well usage in Mississippi and Alabama. This novel method uses connections reported to the Safe Drinking Water Information System adjusted to account for non-residential connections, along with census data to generate improved estimates that are quite different from other available sources. This method has been used to generate well usage estimates for all counties in Mississippi and Alabama that can be utilized to better strategize water infrastructure improvements and well monitoring programs.

Enhancing the USGS Streamgaging Network in the Mississippi River Basin: Continuous Water-Quality and Groundwater Data

Year: 2014 Authors: Roberts B.A.

The U.S. Geological Survey (USGS), Mississippi Water Science Center, in cooperation with the U.S. Army Corp of Engineers, Vicksburg District, is in the process of enhancing selected streamgages throughout the Mississippi River Basin to include continuous hourly water-quality and groundwater data. In Mississippi, the USGS is installing a ultraviolet nitrate sensor to collect continuous nitrate data, and a water-quality sonde to collect continuous temperature, specific conductance, turbidity, chlorophyll-a, and dissolved organic matter data on the Mississippi River near Vicksburg, Miss., and the Bogue Phalia near Leland, Miss. Both sites will be operated in conjunction with the USGS National Water Quality Assessment Program to understand nitrate dynamics during extreme hydrologic conditions such as baseflow and storms and to provide a more complete data set for future nitrate load calculations.

Quality of water in public supply wells located in the Southeastern Coastal Plain and Coastal Lowlands aquifer systems, Mississippi, 2013

Year: 2014 Authors: Welch H.L., Barlow J.R.

Groundwater provides over one-third of the water used for public supply in the United States and nearly half of the water used for public water supply in the southeastern United States. In 2013, the U.S. Geological Survey's National Water Quality Assessment Program began studies to provide nationally consistent water-quality data from principal aquifer systems that account for the majority of withdrawals for public supply throughout the United States. Two of these principal aquifers, the Southeastern Coastal Plain and Coastal Lowlands aquifer systems, were selected for sampling in 2013. These aquifer systems are located in the southeastern part of the United States, and each consists of unconsolidated to semiconsolidated sand, silt and clay deposits that thicken and dip coastward. The Southeastern Coastal Plain aquifer system spans approximately 90,000 sq miles and includes parts of 6 states, and the Coastal Lowlands aquifer system spans approximately 98,000 sq miles and includes parts of 5 states. Public-supply wells were selected for sampling using an equal-area grid approach to ensure a spatially unbiased sampling distribution.

Indirect Regulation of the MRVA Aquifer: Options for the Mississippi Delta

Year: 2014 Authors: Massey J.H.

An intensively used resource requires intensive management. The Mississippi River Valley Alluvial aquifer is an intensively used resource whose value will only grow as demand for irrigation continues to rise. Effective regulation is necessary in the management of commonly-held resources, and may be direct or indirect in form. Direct regulation includes actions such as permitting, metering, monitoring of water extractions, and assessment of extraction fees. Indirect regulation seeks to manage a resource without coming in direct contact with it. Educational and certification programs represent indirect forms of regulation. Water-resource management literature suggests that indirect regulation is more effective and practical in situations where large numbers of geographically-diffuse extractors use the resource. This is because the cost of effective direct regulation is often prohibitively expensive. Given that there are more than 18,000 active agricultural groundwater well permits distributed over a 17 county area in the Mississippi Delta, indirect regulation will, by necessity, play an important role in the successful management of the alluvial aquifer. The purpose of this presentation is to discuss options for the indirect regulation of the Mississippi River Valley Alluvial aquifer.

Nutrient Reduction In Mississippi: Partnering For Success

Year: 2014 Authors: Bhowal P.

Mississippi is blessed with abundant water resources, and protection of these water resources is essential to ensure sustainability of Mississippi's ecosystems and economies. One of the biggest challenges for Mississippi's surface waters, the Mississippi River and the Gulf of Mexico is the presence of excess nutrients in these waters. The Gulf of Mexico contains a hypoxic zone that is a result of nutrient-rich water from the Mississippi River flowing into the Gulf. Nutrients, in the form of nitrogen and phosphorus, come from a variety of sources including farmlands and lawns where fertilizers are used, wastewater treatment facilities, animal wastes from farms and pasturelands. Accordingly, the issues of nutrient pollution and Gulf Hypoxia have become priorities for Mississippi's Delta, Upland and Coastal regions that contribute significant nutrients loading to the Gulf. Mississippi's approach to reduce nutrient loadings within basins and to the Gulf of Mexico is a highly collaborative, stakeholder supported process centered on development and implementation of comprehensive nutrient reduction strategies for the Delta (December 2009), Coastal (March 2011), and Upland (March 2011) regions of the state. These strategies identified 11 strategic elements to help reduce nutrient loading to Mississippi's surface waters. Over 50 staff from multiple state and federal resource agencies and other organizations in Mississippi have been working together to help develop and implement these comprehensive nutrient reduction strategies. Implementation includes engaging stakeholders, characterizing watersheds, determining status and trends, documenting management programs, establishing quantitative targets, selecting analytical tools, identifying/implementing established and innovative best management practices (BMPs), designing monitoring work, providing incentive and funding, and communicating results. These nutrient reduction strategies are currently being implemented in 10 priority watersheds in the Delta (7), Upland (2), and Coastal (1) regions of the state.

Benefits of On-Farm Water Storage Systems in Porter Bayou Watershed

Year: 2014 Authors: Tagert M.L., Paz J.O., Pote J.W., Kirmeyer R.L.

Since the 1970's, groundwater levels in the Mississippi Alluvial Aquifer have decreased as the number of irrigated acres in the Mississippi Delta has increased. Today, there are roughly 18,000 permitted irrigation wells dependent on water from the Mississippi Alluvial Aquifer, with approximately 50,000 new irrigated acres added both in 2011 and 2012. As concern has grown over groundwater declines and increasing fuel costs to run irrigation pumps, farmers have been implementing more irrigation conservation measures, such as on farm water storage (OFWS) systems. These systems began appearing in the Mississippi Delta in 2010 in conjunction with the implementation of the Mississippi River Basin Healthy Watersheds Initiative (MRBI). OFWS systems typically are surrounded by fields that are padded and piped, directing rainfall and runoff to a tailwater recovery ditch, from where it is then pumped into a pond for storage. Water is pumped from the pond and used for irrigation at a later date. These systems offer farmers the dual benefit of providing water for irrigation and also capturing nutrient rich tailwater for on farm reuse. This presentation will give an update on the project, which has monitored water savings and nutrient levels at two OFWS systems, one each at Metcalf Farm and at Pitts Farm, in the Porter Bayou Watershed, Mississippi. Data collection began in February 2012 and is ongoing, with water samples collected for analysis every three weeks throughout the growing season from March-October and every six weeks through the off season. Cumulative readings were also taken on flow meters to measure water use from the storage pond. The ability of these systems to reduce downstream nutrient concentrations has been mixed, with systems performing better when the tailwater recovery ditch is not full and can contain runoff on site. Thus, better management will improve the nutrient reduction potential of these systems. The water savings potential of these systems has been substantial. Metcalf Farm used 42 and 17 million gallons of water from the storage pond in 2012 and 2013, respectively; Pitts Farm used 60 and 56 million gallons of water from the storage pond in 2012 and 2013, respectively. These amounts reflect savings in groundwater that was not pumped from the Mississippi Alluvial Aquifer.

Assessing new BMPS: efficiencies of a Tailwater Recover System and On-farm Storage Reservoir

Year: 2014 Authors: Omer A., Kröger R.

The Lower Mississippi Alluvial Valley in Mississippi is economically important due to its highly productive agricultural land. However, producers in this region face two predominant environmental issues that are inherently linked to the agricultural industry. Firstly, intensive agriculture practices which have resulted in increased surface transport of nutrient laden sediments, contributing to eutrophication in receiving waters and to the Gulf of Mexico Hypoxic Zone. Secondly, current water withdrawals from the Mississippi River Valley alluvial aquifer for irrigation during the growing season when precipitation is minimal are not sustainable. These issues threatening environmental resources necessitate best management practices (BMPs) and groundwater conservation. This research investigates BMP systems as water resource conservation methods. Such practices include surface water capture and irrigation re-use systems, referred to as tailwater recovery systems (TWR) and on-farm storage reservoirs (OFS). A single year investigation of two TWRs and one OFS highlighted water holding capacities for irrigation reuse and functionality for nutrient capture as well. Research also included the investigation of the delivery of nutrients and water from a TWR to rice fields during the 2013 growing season, which allowed for the calculation of potential economic savings by a producer pumping surface water rather than ground water. While this research is ongoing, initial investigations indicate that TWRs and OFSs have much promise for water conservation in the Lower Mississippi Alluvial Valley.

Using low-grade weirs as a BMP: Effects on nutrient remediation and microbial denitrification

Year: 2014 Authors: Poganski B., Kröger R.

Although the term "anthropogenic influence" often has a negative connotation surrounding it, it encompasses all human influences to the environment, including flood control, restoration, and conservation practices. Interestingly, in addition to land use purposes, water management practices, such as BMPs, can also influence factors affecting denitrification. A study was conducted evaluating the composition of microbial communities involved in key processes of denitrification following physiochemical changes introduced by low-grade weir implementation. Investigations of functional genes involved in denitrification via quantitative polymerase-chain reaction (qPCR) included those encoding for subunits of nitrate reductase (nirK, nirS) and nitrous oxide (nosZ). Understanding how low-grade weirs alter drainage environments in such a way that impacts microbial community structure and function, and subsequent nutrient transformations, which will advance engineering and remediation strategies. Understanding the impacts of low-grade weirs on nutrient reduction capacities will also provide a greater understanding of how to improve nutrient management strategies to reduce Gulf of Mexico hypoxia.

Effects of organic carbon amendments on nitrogen removal in agricultural drainage ditch sediments

Year: 2014 Authors: Faust D.R., Kröger R.

Agricultural fertilizer applications have resulted in loading of nitrogen nutrients to agricultural drainage ditches in the Lower Mississippi Alluvial Valley, contributing to the Gulf of Mexico hypoxic zone. Previous studies have observed that nitrogen loading decreases with implementation of best management practices within and in proximity to aquatic ecosystems in agricultural settings. The purpose of this study was to determine effects of organic carbon amendments on nitrogen removal in agricultural drainage ditch water at various lengths of time and carbon-to-nitrogen (C:N) ratios. In one experiment, control, dissolved organic carbon (DOC), and particulate organic carbon (POC) amendment groups were prepared in laboratory microcosms for time treatments of 3, 7, 14, and 28 days with six replicates per treatment. In a second experiment, control, DOC, and POC amendment groups were prepared in microcosms at C:N ratios of 5, 10, 15, and 20 with six replicates per treatment. A permutational multivariate analysis of variance was used to detect statistically significant differences in nitrogen nutrient among treatments (F11,60=19.0, P=0.001 and F8,45=23.2, P<0.001). Mean increases of 3.27 ± 0.52 and 19.2 ± 4.5 mg N L-1 of total nitrogen were observed in overlying water of all treatments of experiments one and two, respectively. However, 60-100% removal of nitrate-nitrogen in overlying water was observed in all treatments with removal occurring in DOC and POC treatments. These results indicate that amendments of organic carbon made to drainage ditch sediments increase nitrate-nitrogen removal, particularly over longer periods of time. Any amendments of DOC increase N removal, regardless of C:N ratio, while amendments of POC at a C:N ratio of five are optimal for N removal. This study provides support for using organic carbon amendments as a best management practice in agricultural drainage ditches.

Distribution and Cycling of Mercury Species in Wetlands and Reservoirs in Northern Mississippi

Year: 2014 Authors: Cizdziel J., Brown G.

Methylmercury (MeHg) is a neurotoxin that accumulates in tissues and biomagnifies up the aquatic food chain. Fish consumption advisories have been issued Enid Lake and the Yocona River, a large reservoir and its tributary in north-central Mississippi. This study examined the origin, distribution, and cycling of mercury species in the Yocona River, Enid Lake and associated wetlands. Environmental conditions can have a dramatic impact on the production, transport and fate of Hg species in a given area. Wetlands play a critical role in the cycling of Hg in watersheds and have been shown to be net sources of MeHg to ecosystems. Total-Hg and MeHg were determined seasonally over the course of two years in the inflow and outflow of Enid and Sardis Lakes, in associated wetlands. The Hg species were also measured during storm events (i.e., in runoff from urban, agricultural, and wetland/forest areas). A range of water quality parameters were measured to determine the primary factors controlling the distribution and transport of Hg species in the watershed. The project served as an important step toward building a mass balance for mercury in Enid Lake. Key findings include: - Wetland areas were determined to be hotspots for MeHg in the watershed with relatively high concentrations in water and fish - Levels of Hg in river water were highest at peak flows during storm events. - Forest soil and wetland sediment had higher levels of Hg and organic matter than agriculture soils. - Hg levels were highest in the urban runoff, followed by forest/wetland, and agriculture. - Runoff from highly erodible agricultural areas likely provides the largest input of Hg to Enid Lake by transport of particle-bound-Hg. - MeHg in wetland water was about double that found in lake water, and both spiked during the summer months, with wetlands reaching as high as 1.3 ng/L. - MeHg in the wetland water was negatively correlated with oxidizing reducing potential. - The net flux of T-Hg in Enid Lake was the most negative in the winter due to lowering of lake water levels to accommodate spring rains, and most positive during storm events, suggesting that rain storm events contribute a significant portion of Hg to the lakes. - The net flux of MeHg in Enid Lake was more negative in the summer than fall and spring due to higher methylation and evaporation rates.

Flood Inundation Mapping to Aid Emergency Management Planning in the Cities of Hattiesburg and Petal

Year: 2014 Authors: Storm J.

Many cities throughout Mississippi are located on or near major rivers or streams. As a result, residential, commercial, and industrial areas, as well as transportation structures can be at risk when flooding occurs. The cities of Hattiesburg and Petal are located along the Leaf River and have experienced flooding in the past including major events in 1961, 1974, and 1983. The largest recorded flood event occurred on April 15, 1974 and affected approximately 6,000 people and caused damages in excess of $8.3 million (1974 value unadjusted for inflation). The U.S. Geological Survey (USGS), in cooperation with the Cities of Hattiesburg and Petal, Forrest County, Mississippi Emergency Management Agency, Mississippi Department of Homeland Security, and the Emergency Management District, has developed a series of flood inundation maps at 1-foot increments ranging in stage from bank-full (22.0 ft) to approximately the peak of record flood (34.0 ft) for a 6.8 mile reach of the Leaf River through the cities. A one-dimensional steady-flow model was calibrated with the stage/discharge relationship at the USGS stream gaging station 02473000 Leaf River at Hattiesburg, MS (http://waterdata.usgs.gov/ms/nwis/uv/?site_no=02473000&PARAmeter_cd=00065,00060), and flood profile information obtained following the 1974 event. The model results were coupled with land surface elevation data from Light Detection and Ranging (LiDAR) surveys and GIS to produce inundation maps depicting the areal extent of flooding in Hattiesburg and Petal at pre-defined river stages. The inundation maps are available to the public through a web based interactive mapper that allows the user to select the river stage and then display the corresponding inundation map. Estimated water depths are shown by clicking anywhere within the inundated area on the map. Emergency management personnel will be able to use the inundation maps to manage and plan a course of action for future floods by pre-determining affected residences, businesses, municipalities, and roadways at forecasted National Weather Service (NWS) flood levels. Citizens will be able to visually determine what affect there may be to their property or business and take appropriate action ahead of time. The maps are available to the public through the USGS and from the NWS at the following links: http://wim.usgs.gov/FIMI/ http://water.weather.gov/ahps/inundation.php

Quantitative Estimation of Suspended Sediments and Associated Mercury Concentration in Enid Lake Using Remote Sensing Techniques

Year: 2014 Authors: Hossain A., Chao X., Cizdziel J., Jia Y.

The streams, lakes, and reservoirs in the Yazoo River Basin provide significant natural and recreational resources in Mississippi. However, since the soils in this region are highly erodible, large amount of sediments are discharged into the water bodies. Sediments are often associated with pollutants, which cause many water bodies in this region to be impaired due to the contaminated sediments. Mercury is one of the widely distributed and persistent pollutants in this environment. Mississippi currently has 11 water bodies under fish consumption advisories for mercury, including Enid Lake. To study the mercury contamination issue in the Enid Lake, the National Center for Computational Hydroscience and Engineering at the University of Mississippi has an on-going research project funded by the Mississippi Water Resources Research Institute and USGS to study the transport, fate, and risk of mercury in Enid Lake. As one of the tasks of this project the potential of the remote sensing techniques were explored to estimate the mercury concentration associated with suspended sediments in Enid Lake. Suspended sediment concentration has been estimated and mapped successfully using remote sensing for the last three decades. Different approaches and algorithms had been developed over time for SSC estimation using optical satellite data. Several studies had success in estimating total suspended sediments (TSS) using simple linear regression techniques involving the Moderate-resolution Imaging Spectroradiometer (MODIS) visible and near infra red (VNIR) data and in situ measurements. Similar approach was used in this study to estimate TSS and associated mercury concentration in Enid Lake, MS. The correlation coefficients of the regression equations were obtained using in situ measurements of TSS and mercury from two field campaigns, and near-real time reflectance values of the VNIR bands of MODIS imagery. Preliminary results indicate that these regression equations can be used for quantitative estimation of TSS and associated mercury in Enid Lake with reasonable accuracy

An Integrated Watershed Approach to Water Sanitation and Hygiene priorities for Lake Chivero, Zimbabwe

Year: 2014 Authors: Buka H., Linhoss A., Pote J.

This paper describes an integrated watershed approach to water sanitation and hygiene for a water supply reservoir near Harare, Zimbabwe`s capital city. From the construction of the lake to the present, considerable difficulties have been experienced in water quality and water treatment. Discharges from urban and rural agriculture, sewage treatment works and industries have caused severe stresses on the lake's water quality. To combat eutrophication in the mid-1970s, a Hydrobiology Research Unit was established to facilitate pollution research and a biological nutrient removal sewage treatment plant was also installed. This was successful for a decade but afterwards water quality started to deteriorate due to increases in population. The original sewage treatment plants were designed to handle 18 million liters of human waste a day for a population of about 500,000 people but now the estimated population has exceeded 1.4 million people therefore overloading the sewage works. Continued deposition of sewage effluents has contributed to the spread of aquatic weeds such as water hyacinth (Eichhornia crassipes), blue-green algae (Anabaenopsis sp) and spaghetti weed (Hydrocotyle ranunculoides). The weeds strive under a constant supply of nitrogen and phosphorus as they are the major nutrients in the Lake. The area around the lake has been designated as a wildlife sanctuary, which offers the potential for managing water quality better. In 1997 there were recorded fish kills especially the Green headed Tilapia due to low levels of oxygen. A total of 11,735 cholera cases were recorded as of December 2008 due to poor sanitation and water shortages. For these reasons the objective of this review is to assess the integrated impacts of water quality on the environment and sanitation throughout the lake, watershed, and water supply service area.

Regional Rainfall Frequency Analysis and drought reduction in the Tombigbee River Basin

Year: 2014 Authors: Ramirez-Avila J.J., McAnally W.H., Tagert M.L., Ortega-Achury S.L.

A regional frequency analysis was conducted for precipitation to bring more detailed information about the amount and distribution of rainfall over the Tombigbee River Basin to promote efficient water resources management in the study area. In addition, the results of the regional frequency analysis were combined with climatological drought reduction information to determine the probability that a cumulative precipitation depth needed to end a drought will be equaled or exceeded at least once in a specific season in the Tombigbee River Basin. A total of 28 precipitation gages in eastern and northeastern Mississippi and western Alabama were included in the study representing 1,352 station years of record. A regional analysis methodology was utilized, and the Tombigbee River Basin was considered a homogeneous region to increase the dataset and improve the reliability of precipitation-frequency estimates. The International Center for Integrated Water Resources (ICIWaRM) Regional Analysis of Frequency Tool (ICI-RAFT) was used to develop the regional frequency analysis. The software involves the application of the L-moments to characterize the variability, skewness and kurtosis of the data, determine heterogeneity in the region, and assist in the identification of appropriate regional probability distribution(s). Verification of results indicated that the selected frequency distributions provide reliable exceedance values for precipitation. Results also showed that spring would be the season with a more probable chance of recovery from a moderate or severe drought in the Tombigbee River Basin.

Interdisciplinary Assessment of Mercury Transport, Fate and Risk in Enid Lake, Mississippi

Year: 2014 Authors: Chao X., Cizdziel J.V., Willett K., Hossain A.K.

Enid Lake is one of the important large recreation lakes in Mississippi, and the mercury level is relatively high compared with other large lakes. This research brought together a team of scientists that with their expertise in analytical chemistry, remote sensing technology, hydraulic modeling and risk assessment to study the transport, fate and risks of mercury in Enid Lake. Two field measurements were conducted in spring and fall to measure the flow, sediment and mercury in Enid Lake. The remote sensing technology was applied to analyze the concentration distributions of sediment and mercury in the whole lake, and the results are generally in good agreement with measured data. A numerical model was developed to simulate the flow, sediment, and mercury in the lake, and the interaction between the mercury and sediment was taken into accounted. Risk assessment was conducted to analyze the potential risk of mercury both in the environment and human fish consumption. The research results help us understand the transport mechanisms of sediment and mercury in large lakes, and provide useful information for decision makers to evaluate established TMDLs and fish consumption advisories.

The Red Creek Consolidated Mitigation Bank and the Challenges of Stream Restoration in Gulf Coastal Plain Soils and Weather

Year: 2014 Authors: Maurer B.

Since the Mobile and Vicksburg districts of the Corps began regulating impacts to streams, the Mississippi Department of Transportation has been proactive in acquiring advance credits for future impacts in several watersheds. One such project is the Red Creek Consolidated Mitigation Bank, located in coastal Jackson County and established in partnership with The Nature Conservancy. Approved in 2011, this wetland and stream bank is providing credits on wet pine flats, bayhead and bottomland hardwood forest, and 3,345 linear feet of stream restoration primarily on two reaches of a tributary to Red Creek. The site is part of an ecologically-significant conservation area in the Pascagoula River watershed. The two restoration reaches have distinctive features; a Priority 2 Restoration was completed on steep and highly entrenched section of the upper stream to arrest severe headcutting. In the second reach, Priority 1 stream relocation was completed in a low-gradient bottomland forest to prevent active downcutting. Completed in the spring of 2012, the stream restoration work was subject to several substantial rain storms (including Hurricane Isaac, which dropped 15-20 inches on the site) before soils had settled and vegetation was fully established. In addition, unforeseen seepage areas developed on some of the steeper slopes causing slumping in the toe areas. Significant damage from storms in these seepage areas and later universally throughout much of the project forced a re-evaluation of the design before repairs were completed. This presentation will discuss and contrast the two restoration reaches, including the challenges of choosing Best Management Practices (BMPs)for stream restoration, and establishing vegetation in erodible, relatively low-nutrient soils and unfavorable weather conditions (hot and dry with periodic intense rainfall). Finally, we will evaluate the damage and repairs to restoration reaches, and how the untimely storms quickly taught us what worked best and what needed improvement.

Groundwater Depletion in the Mississippi Delta as Observed by the Gravity Recovery and Climate Experiment (GRACE) Satellite System

Year: 2014 Authors: Hossain A.

The Gravity Recovery and Climate Experiment (GRACE), launched in early 2002, is a satellite mission jointly managed by the US National Aeronautics and Space Administration (NASA) and the German Aerospace Center (DLR). Its goal is to map Earth's gravity field with high precision, approximately on a monthly basis. Global representations of Earth's gravity field are produced based on a K-band microwave system, which measures the distance (loosely controlled at about 220 km) between two identical satellites nearly continuously as they revolve in a tandem, near polar orbit, at an initial 485 km altitude. The gravitational effects of changes in atmospheric surface pressure and ocean bottom pressure are removed using numerical model analyses, such that the remaining variability can be attributed primarily to the redistribution of terrestrial water storage, thus provide measurements of column integrated terrestrial water storage (TWS) for the entire globe. Several recent studies clearly demonstrated that GRACE-derived estimates of variations of total water storage (all of the snow, ice, surface water, soil water and groundwater in a region), when combined with auxiliary hydrological datasets, can provide groundwater storage change estimates of sufficient accuracy to benefit water management. This paper summarizes the recent studies that conducted to investigate the groundwater depletion in the Mississippi Delta using GRACE data. This paper also presents the results obtained from the analysis of last ten years monthly GRACE Level 3 data for the Mississippi Delta areas.

Water Depth In An Oxbow Lake-Wetland And Its Influence On Soil Chemistry, Cypress Tree Growth, And Groundwater Recharge

Year: 2014 Authors: Lahiri C., Davidson G.R., Threlkeld S.T.

Sky Lake, MS, is an oxbow lake-wetland that was once part of the ancestral Ohio-Mississippi River system. It hosts some of the largest and oldest cypress trees in the state, with several trees exceeding 40 ft in circumference. An elevated boardwalk recently built into the heart of the wetland now allows unique access to the public and has provided a platform for mounting experimental equipment to monitor several environmental parameters pertinent to managing wetlands and water resources. An ongoing study along the boardwalk is currently monitoring changes in water level, water and soil chemistry (pH, Eh, DO, conductivity, temperature), and atmospheric parameters (precipitation, temperature, relative humidity), and relating the data to tree growth (sap flow rates, trunk expansion) and to changes in groundwater level in a monitoring well located inside the meander loop. Preliminary data indicate that both the flow and chemistry of water within the root zone is highly variable over short distances, likely caused by physical heterogeneity created by fallen and buried tree limbs in various stages of decomposition. Substantial changes in soil zone Eh, an indicator of the redox potential that can influence nutrient uptake by plant roots, were observed over time with no significant correlation between measurement locations. This means that single measurements of soil chemistry at point locations in this wetland environment are not necessarily representative of the conditions for the system as a whole. Measurements at multiple locations are required to adequately assess the chemical conditions that contribute to the health of wetland flora. Groundwater levels measured in the monitoring well rose and fell over a several month period corresponding to high and low water levels in the wetland, respectively, suggesting a possible surface-groundwater connection. Digital cameras set up with dendrometer bands are allowing collection of daily changes in the circumference of four different trees that will allow correlation with sap flow and the monitored environmental variables.

Delineation of Watersheds in Northwestern Mississippi to the Sub-Watershed Level

Year: 2014 Authors: Rose C.E.

In 2009, river systems in Mississippi were delineated to the watershed level, and most were delineated to the subwatershed level. One of the exceptions was the northwestern part of Mississippi in the lower part of the Yazoo River Basin (locally referred to as the "Delta") where only watershed-level delineations were completed. Watersheds and sub-watersheds previously delineated in Mississippi were based on elevation change and water body locations as observed from topographic maps, digital elevation models, and aerial photographs. Previous attempts to delineate watersheds in the Mississippi Delta region to the sub-watershed boundaries were problematic due to the following issues: topographically-uniform, low relief land elevations (less than 100 feet of rise in land-surface elevation from Vicksburg to Memphis); land management practices employed by land owners and growers who frequently change drainage patterns; and insufficient scale of available elevation to allow delineation of subtle topographic features. Therefore, the Mississippi Delta region was not delineated to the sub-watershed level until more precise digital elevation tools were available for use. Delineation of watershed boundaries and designation of watershed numbering and naming is an important first step for resource managers that are concerned with ecosystem and water body health and remediation of point and non-point source pollution. Previous scientific studies have implicated the Delta region as a contributor to the hypoxic zone in the Gulf of Mexico, and a large percentage of Delta waters are listed as impaired on the section 303(d) List of Impaired Waters. For Delta streams, ecosystem health and mitigation of nonpoint source pollution is a primary concern for resource managers, and delineation of watersheds in this region is a critical and necessary step for future planning and mitigation activities. Since the publication of the Mississippi Watershed Boundary Dataset in 2009, the entire Yazoo River Basin (including the Mississippi Delta region) has been mapped using Light Detection and Ranging (LiDAR) technology (funded by the U.S. Army Corps of Engineers, Vicksburg District), which has a root mean square error vertical land surface bare-earth accuracy of 9 centimeters. With the availability of LiDAR data, it is now more reasonable to delineate the Mississippi Delta region to the sub-watershed level. The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental Quality, has completed the delineation of river systems in the Mississippi Delta region to the subwatershed level.

Pathogen Indicator Monitoring in the Ross Barnett Reservoir

Year: 2014 Authors: Capps P., Hicks M., Surbeck C.Q.

Man-made reservoirs are often used for both water supply and recreation. The US Environmental Protection Agency's (EPA) recent National Lakes Assessment survey includes water quality concerns for beneficial uses of such man-made reservoirs. The EPA ranks the Ross Barnett Reservoir watershed as the most important in the state of Mississippi and has selected it as a Priority Watershed. The Ross Barnett Reservoir, a 33,000-acre lake, provides drinking water to the city of Jackson, MS, and forty-eight surrounding communities. Further, an estimated 2.5 million people visit the reservoir each year for recreational purposes, including boating, fishing, water-skiing, and swimming. Substantial residential and commercial developments in Madison and Rankin counties along the 105 miles of reservoir shoreline have the potential to affect water quality in the reservoir. Due to the reservoir's important role as a water-supply source, the protection of the water quality in the reservoir is crucial for human health. A collaborative investigation is underway by the University of Mississippi, the U.S. Geological Survey, and the Mississippi Department of Environmental Quality, to assess pathogen indicator concentrations in the Ross Barnett Reservoir. Sources of the pathogens may include stormwater runoff, failing septic systems, lake-bottom sediments, and humans in direct contact with the water. Data for pathogen indicators and other water-quality parameters such as water temperature, pH, dissolved oxygen, conductivity, nitrate, phosphate, and solar strength, were collected at two recreational sites at the reservoir twice a week for 23 weeks through the spring and summer of 2013. Average concentrations for all E. coli, enterococci, and fecal coliform were 264 cfu/100mL, 175 cfu/100mL, and 298 cfu/100mL, and standard deviations for each were 654 cfu/100mL, 249 cfu/100mL, and 952 cfu/100mL, respectively. The concentrations of pathogen indicators and nutrients, and values of physical parameters will be statistically analyzed to provide insight about contamination sources. A review of past monitoring efforts in other related fresh-water lakes will also be reported.

Water quality modeling in the Ross Barnett Reservoir

Year: 2014 Authors: Jackson G.

This study presentation investigates the utilization and economic feasibility of hydrodynamic models as tools for assessing factors impacting water quality in the Ross Barnett Reservoir and the Pearl River for nutrient TMDL development. The primary focus is the development steps necessary to create a hydrodynamic model that provides transport information to subsequent application of a water quality model (WASP). Environmental Fluid Dynamics Code (EFDC) is a complex, dynamic, multi-dimensional computer model used to simulate hydrology in water bodies. The hydrodynamic model output feeds directly into the WASP water quality simulation. The secondary focus is on data acquisition and EFDC model manipulation methods for completing the hydrodynamic modeling. Monitoring was completed to create modern bathymetry of Ross Barnett Reservoir to provide accurate model cell grid representation. Temperature and dissolved oxygen profile monitoring were gathered to provide data for model output comparison. The EFDC model successfully predicted lake stratification and subsequent mixing based on changes in observed meteorological conditions. Finally, the model development costs and level of difficulty must be justified to consider broad use of this model development combination for state water quality agencies. EFDC / WASP model development tools that will reduce the development costs are in production, and should improve the usefulness of the EFDC / WASP model combination in the future.

Climate Variability Impacts on Crop and Sediment Yields

Year: 2014 Authors: Parajuli P.B., Jayakody P., Sassenrath G.

This study evaluated future climate variability impact on stream flow, crop and sediment yields under three different tillage systems in the Big Sunflower River Watershed (BSRW) in Mississippi. The Soil and Water Assessment Tool (SWAT) was applied to the BSRW using observed stream flow and crop yields data. The model was successfully calibrated and validated and future climate scenarios were simulated. Results showed that there is no significant difference (p > 0.05) between average corn and soybean yields under simulated tillage systems in the BSRW. However, results determined a significant difference on sediment yields from three simulated tillage systems (p values of 0.002 for corn, and 0.003 for soybean). The model simulated results showed that future average maximum temperature may increase and experience a longer summer periods with frequent extreme rainfall events but similar monthly precipitation patterns.

A STELLA model for estimating phosphorus removal from wastewater in a vertical-flow constructed wetland system

Year: 2014 Authors: Ouyang Y.

Elevated phosphorus (P) in surface waters can cause eutrophication of aquatic ecosystems and can impair water for drinking, industry, agriculture, and recreation. Vertical flow constructed wetland (VFCW) can purify P contaminated wastewaters before they discharge into streams and rivers. The goal of this study is to develop a model for predicting the fate, transport, and removal of P from wastewaters in a VFCW using the commercial available STELLA (Structural Thinking, Experiential Learning Laboratory with Animation) software. The VFCW used in this study consists of soil and plant species with variably saturation conditions such as wetting (ponding) and drying (draining) cycles. The water movement through the soil, xylem, and surrounding atmosphere in the VFCW system is calculated using water potential theory, whereas the fate and transport mechanisms of P used in this model include: (1) application of wastewater (containing P) to the VFCW; (2) adsorption of P in the soil; (3) uptake of P by plant roots, (4) mineralization of organic P; and (5) leaching of soluble P. Additionally, the surficial processes such as rainfall and evapotranspiration are included in the model. The resulted model is calibrated and validated with experimental data prior to its applications. A simulation scenario is then performed to estimate P removal from a domestic wastewater in the VFCW system under varying hydraulic retention times. Simulation results will be presented and discussed.

Quantification of Harmful Algal Blooms (HABs) in the Grand Bay in Jackson County, MS

Year: 2014 Authors: Dampier J., Dash P., Begonia M.F.

Harmful Algal Blooms (HABs) are caused by species of tiny plants, phytoplankton. HABs may cause harm through the production of potent chemical toxins or by their accumulated biomass. Impacts include massive fish kills, loss of sales revenue primarily from fisheries and tourism, loss of commercially valuable and culturally vital shellfish resources, illness and death in populations of protected marine species, and threats to human health. Among the many HAB impacts in the northern Gulf of Mexico, those due to coastal blooms of the diatoms genus Pseudo-nitzschia with its associated toxin domoic acid, and the dinoflagellates of the genus Karenia with its associated toxin brevetoxin are of particular concern. This work (a field, laboratory and satellite remote sensing research) focused on quantifying HABs in the Grand Bay. It encompasses the collection of field data which is analyzed in the laboratory for pigments, suspended sediments, dissolved materials, and toxins as well as a satellite remote sensing component focused on developing techniques for mapping HABs from space. Recently, a procedure was developed to estimate cyanobacterial concentrations by quantifying chlorophyll a and the primary cyanobacterial pigment phycocyanin using OCM satellite data. This required the development of an atmospheric correction and vicarious calibration methodology for satellite data in inland and coastal waters. It has been tested to work for data from several satellite sensors such as OCM, SeaWiFS, MODIS, MERIS and QuickBird. This research is focused on use of satellite sensors, NPP VIIRS and MODIS AQUA, and the developed techniques to quantify HABs in the Grand Bay. In addition to algal toxins, the toxicity of environmental pollutants (i.e., heavy metals such as Pb, Cd, etc.) in the water was investigated and the mutual relationships between the heavy metals and HABs will be examined. This research will enhance the current state of knowledge on detection and mapping of the HABs in the Grand Bay and thus support state and coastal community efforts to manage fisheries in the region.

Groundwater Level Forecasting in Sunflower County, Mississippi using Artificial Neural Networks

Year: 2014 Authors: Guzm S., Paz J.O., Tagert M.L.

The Mississippi Delta Region is one of the most important in the United States given the high productivity levels of crops such as corn, cotton, rice, and soybean. Most of these crops require supplemental irrigation to sustain yield and to reduce the impacts of extended periods of dryness during the growing season. Due to the expansion of croplands , the annual volume of groundwater withdrawals have increased dramatically over the past two decades, exceeding aquifer recharge and generating an important reduction in the aquifer levels. In this study, we present the preliminary groundwater level simulation results for a well in Sunflower County that is within the Mississippi River Valley Shallow Alluvial (MRVA) aquifer. The performance of two different artificial neural networks (ANN) for groundwater level forecasting was evaluated in order to identify an optimal architecture that can simulate decreasing trends of the groundwater level in summer season. Two algorithms, Levenberg-Marquardt and Bayesian Regularization, were evaluated in order to obtain a model that shows better results in the simulation of changes in groundwater level and provide acceptable predictions up to 3 months ahead. The ANN predictive performance was assessed based on the comparison between Root Mean Square Error (RMSE) for each algorithm. Neural networks learn and recognize patterns in the nonlinear temporal data through mathematical analysis and computational architecture inspired by how the human brain works given a set of examples. This methodology is a tool to predict in a short period of time, groundwater levels at specific control points that would be used in an optimized regional plan to manage water withdrawals, and help farmers and water managers decide how to implement plan control procedures and conservation practices.

Evaluating the impacts of crop rotations on groundwater recharge and water table depth in the Mississippi Delta

Year: 2014 Authors: Dakhlalla A.O., Parajuli P.B.

The Mississippi River Valley Alluvial Aquifer (MRVA), which underlies the Big Sunflower River Watershed (BSRW), is the most heavily used aquifer in Mississippi. Because the MRVA is primarily used for irrigating crops such as corn, cotton, soybean, and rice, the water levels have been declining rapidly over the past few decades. Each crop rotation practice demands certain irrigation amounts and applications, which in turn can affect the hydrogeology of the aquifer. The objective of this study is to assess the impacts of crop rotation practices on groundwater recharge rates and water table depths in the BSRW using the Soil and Water Assessment Tool (SWAT) model. The SWAT model was hydrologically calibrated for monthly streamflow using observed streamflow data from 3 USGS gage stations (Merigold, Sunflower, and Leland). Because this study focuses on groundwater processes, the model was also calibrated for water table depths at several ground water wells throughout the BSRW. The observed water table depths used to calibrate the model were provided by the Yazoo Management District (YMD). The model was evaluated based on the coefficient of determination, Nash-Sutcliffe Efficiency, and root mean square error statistics. The crop rotation scenarios that will be employed in this study are corn after soybean, soybean after rice, and continuous soybean. This study will provide some insight into which crop rotation practices cause the most fluctuations on groundwater recharge and water table depths.

Identifying A Mechanism For An Infiltration Threshold From The Sunflower River, MS To The Underlying Alluvial Aquifer

Year: 2014 Authors: Patton A.C., Davidson G.R., Rigby J.R., Barlow J.

Long-term groundwater level and river stage measurements at a USGS coupled groundwater stream-gaging station located on the Sunflower River at Sunflower, MS show an apparent stage-threshold for infiltration to the underlying alluvial aquifer. This site is located near the center of a large regional cone of depression in the Mississippi River Valley alluvial aquifer and therefore provides insight into the effects of groundwater declines on streamflow in the Big Sunflower River. Groundwater levels respond to changes in river stage only when river stage exceeds 34 m msl (mean sea level). The purpose of this research was to identify the responsible mechanism. Two hypotheses were considered: (1) scour of infiltration-limiting fine-grained bottom sediments during high flow rate events at higher stage, and (2) lateral infiltration at high stage into more permeable coarser grained sedimentary layers intersecting the stream channel at higher elevation.

Empirical evidence of recharge in the Mississippi Alluvial Aquifer

Year: 2014 Authors: Johnson D.R., Barlow J.

Multiple groundwater models have been constructed to model the alluvial aquifer. These models differ significantly in the allocation of water for recharge. This paper will examine the potential sources of recharge and estimate their magnitudes. Other literature will be used to validate the assumptions presented in this paper.

National Weather Service Flood Surveys & Post-Event Analysis of Hurricane Isaac

Year: 2014 Authors: Lincoln W.S.

After the substantial impact to the United States East Coast from Hurricane Sandy, Hurricane Isaac may become the forgotten hurricane of 2012. With its above average size and slow forward motion, Isaac produced higher storm surge than typically seen by a storm of its wind category, and also dropped notably heavy rainfall across portions of southeast Louisiana and south Mississippi. Over a four day period from August 28th to August 31st, rainfall totals ranged from 10-15 inches across most of the area, with a few areas seeing more than 20 inches. This significant rainfall caused flooding of numerous rivers in the forecast area of the National Weather Service (NWS) Lower Mississippi River Forecast Center, especially areas within the county warning area of the New Orleans/Baton Rouge Weather Forecast Office. Because of the rare nature of the event, a team composed of NWS staff from multiple offices was assembled to record the impacts, survey flood crests when necessary, and discuss the event with local residents. Post-event flood surveys were conducted over a number of days in early September, 2012, particularly across the Wolf, Tchoutacabouffa, Biloxi, and Escatawpa River watersheds in Mississippi and the Tangipahoa River watershed in Louisiana. A vast amount of observations, anecdotal data, and recommendations were collected by the survey teams and summarized in a report for the River Forecast Center and the Weather Forecast Office. Flooding of numerous locations was of a magnitude seen only on very rare occasions and may have been the worst flooding yet-experienced by numerous long term residents. Luckily, due to the sparse population density in most of the river floodplain areas, impacts were not as severe as would typically be expected. Findings from the post-event flood surveys and analysis of data from numerous sources will be presented to further our understanding of Isaac's hydrologic impact.

The Role of Long-term Monitoring In Understanding Phosphate Spills Into A National Estuarine Research Reserve

Year: 2014 Authors: Cressman K., Woodrey M., Ruple D.

Grand Bay National Estuarine Research Reserve (GBNERR) is an 18,400-acre protected area in southeastern Jackson County, MS. The GBNERR, along with 27 other Reserves, collects long-term environmental data, including water quality, weather and nutrient parameters, following accepted national protocols as part of a System-Wide Monitoring Program (SWMP). In 2005, a phosphate facility on GBNERR's western border released wastewater into Bangs Lake. Data from SWMP were used to help determine the timing and duration of the event. The pH measured by a data logger deployed at the Bangs Lake water quality station dropped to 3.7. Orthophosphate, tested monthly in the water column and usually below the detection limit of 0.01 mg/L, spiked to over 4 mg/L: more than 400 times higher than normal. PO4 concentrations returned to baseline levels after Hurricane Katrina and remained below 0.01 mg/L until September 2012, when Hurricane Isaac led to another release into Bangs Lake. Routine nutrient sampling three weeks after Isaac found phosphate levels over 1 mg/L in Bangs Lake. Phosphate was also high at further distances from the plant. As of December 2013, other stations' water column phosphate concentrations had returned to normal, but phosphate in Bangs Lake remained higher than historical levels. Research by collaborators at nearby institutions has helped fill in details of the magnitude and spatial patterns of the 2012 spill. This work, combined with the long-term context of SWMP data, led to the formation of a Phosphate Working Group, which will continue to explore the ecological effects of this long-term addition of phosphorus to Bangs Lake.

Investigating the Water Quality of Four Large Mississippi Lakes and Grand Bay, MS-AL Gulfcoast

Year: 2014 Authors: Dash P., Ikenga J.O., Pinckney J.L.

Harmful Algal Blooms (HABs), harmful microorganisms, and toxic metals represent three main water quality deteriorating agents in the water-bodies. The objectives of this research were to take a systems level approach to investigate the water quality of four large Mississippi freshwater lakes including lakes Sardis, Enid, Grenada and Ross Barnett Reservoir and the Grand Bay in Mississippi Alabama gulf coast. Ten field campaigns were undertaken to the freshwater lakes and six sampling trips were organized to the Grand Bay to collect water samples, to measure the physical parameters including temperature, salinity, dissolved oxygen and pH, to measure remote sensing reflectance and backscattering at twelve discrete sites in each of the water bodies. The water samples were collected for high performance liquid chromatography (HPLC) photopigments, colored dissolved organic matter (CDOM), suspended particulate matter (SPM), phycotoxins, nutrients, absorption, bacterial counts, toxic metals, and microscopy analyses. In all these water-bodies, organic SPM surpassed its inorganic counterpart, which indicates that organics have a bigger share in the water quality deterioration in these systems. The photo-pigments derived relative abundances of major algal groups suggested the abundance of cyanobacteria, diatoms and dinoflagellates in all these systems. An investigation of the species composition will reveal the detail community structure. Phycotoxins and several types of bacteria and toxic metals were found in all the water bodies. The observation of these water quality issues warrants continuous operational monitoring of the water quality, investigation of fate and transport of pollutants, and implementation of best management practices for all these water-bodies.

Flow Characteristics of Selected River Basins in Mississippi

Year: 2014 Authors: Runner M.

The U.S. Geological Survey has been collecting stage and flow data at select locations in Mississippi for more than 100 years. The first data collection station was built on the Tombigbee River at Columbus in 1895. Currently, continuous flow data are collected at more than 70 locations and instantaneous peak flow data at an additional 95. Stage and flow data have many uses and serve a variety of purposes filling a valuable need for both governmental agencies, academic institutions, and the general public at large.

There are many benefits to a stable streamgaging program including resource management, flood operations of structures, and flood forecasting. Most of these benefits are derived from access to current flow data, but there are benefits from long-term data sets that are not as readily apparent. One of these is the ability to use these data to detect trends in flow characteristics over time.

This report presents statistical summaries for data sets of select gages near the mouth of major river basins in Mississippi. Data for the Tombigbee, Chickasawhay, Leaf, Pascagoula, Yazoo, Big Black, and other select rivers are presented.