Abstract

Influences of Land Surface Characteristics on Precipitation over the Lower Mississippi River Alluvial Plain

Author(s): Dyer, J.

The lower Mississippi River alluvial valley, covering sections of Mississippi, Arkansas, and Louisiana, is well recognized as a major agricultural center of the US. The region is characterized by extremely fertile soils deposited through repeated flooding of the Mississippi River; therefore, a large portion of the area is cultivated. Since roughly 1940, land use, vegetation, and soil characteristics have remained relatively consistent over the area, with irrigation levels increasing in association with crop density. Research has shown that agriculture can have an influence on regional weather variability through land use, soil type, and vegetation patterns by influencing energy and moisture transport into the atmospheric boundary layer. Due to the relatively sharp contrasts in these surface characteristics between the alluvial valley and surrounding regions, it is suspected that anthropogenic weather modification may be occurring in the form of enhanced mesoscale convective circulations. These circulations are most evident during the warm season when radiational surface heating is greatest and synoptic-scale forcings are minimal, and can have a direct influence on agriculture by varying the intensity and distribution of convective precipitation. The purpose of this project is to define and quantify the location and intensity of convective boundaries and associated precipitation over the lower Mississippi River alluvial valley. This will aid water resource managers and meteorological forecasters in recognizing the relative climatological patterns of rainfall during the growing season, and will provide information on the influence of anthropogenic land use and soil moisture boundaries on precipitation distribution. Initial results from the study indicate an eastward shift in warm-season precipitation relative to predominantly agricultural areas, such that rainfall is minimized over the lower Mississippi River alluvial valley and maximized directly eastward along the Hwy. 45 corridor. Although there are a number of factors that combine to generate this pattern, it is expected that enhanced soil moisture and latent heat flux due to heavy irrigation over the alluvial plain may play an important role in generating more intense convective boundaries over the region, leading to increased downstream transport of atmospheric moisture and subsequent precipitation.







 

Technical Presentations

  • Delta Water Quality
  • Delta Water and Agriculture
  • Wetlands
  • Water Quality
  • Sediments
  • Non-Point
  • Management and Sustainability
  • Wood Treatment
  • Modeling
  • Soil and Water Treatment

Workshops

Responsible Site Design: Implementing Innovative Stormwater Management Strategies

The primary goal of the workshop is to create a dynamic learning experience that examines the role of stormwater management in the built environment. The workshop will focus on integrating ecologically sound water management approaches into site design. After the workshop, attendees will be familiar with the following concepts and technical issues:

  • Knowledge of the stormwater treatment chain
  • Knowledge of the impact of land use codes on stormwater management
  • Application of a design process that mitigates the effects of stormwater on-site
  • Knowledge of the relationship between land use codes and design for innovative stormwater management

Information

For information contact:
Jessie Schmidt
MWRRI
Box 9680
Mississippi State, MS 39762
662-325-3295
jschmidt@cfr.msstate.edu