Abstracts

Quantification of groundwater contributions to the Bogue Phalia in northwestern Mississippi using an End-member mixing analysis

Author(s): Rose, C.; Detavernier, A.; Coupe, R.

End-member mixing analyses use chemical signatures of water sources to determine the contribution of each source to a stream. Low flow in the Bogue Phalia, a river in northwestern Mississippi, during the summer season is typically from two primary sources; (1) baseflow from shallow groundwater and bank storage, and (2) irrigation return flow. Irrigation return flow originates from the Mississippi River Valley alluvial aquifer’s deep irrigation wells. This water has sometimes been shown to have dissolved phosphorus concentrations (0.01 to 1.0 mg/L), and sometimes have exceeded the USEPA surface water criteria. There is concern that irrigation return flow might be adversely affecting the quality of the surface water. The chemical signature of the shallow groundwater was determined from water samples collected from the Bogue Phalia in the fall, during baseflow. Water samples from the alluvial aquifer were used to determine the chemical signature of the irrigation return flow. These two water sources have distinctly different specific conductance values; this enabled the determination of the contribution of water from both sources to the Bogue Phalia during the irrigation season, when the influence of rainfall or other water sources would be minimal. An end-member mixing analysis was used to estimate of the percentage of both water sources. From this method, which consisted of the use of a numerical formula, discharge and continuous specific conductance data from the Bogue Phalia from 2001 to 2008, the influence on the in-stream concentration of phosphorus from irrigation return flow can be determined.

Go back

Contact

Technical Sessions

Session I Sedimentation
Session II Weather/Climate
Session III Coastal Resources
Session IV Surface Water Management
Session V Wetlands
Session VI Education
Session VII Management/Planning
Session VIII Wetlands
Session IX Delta Groundwater
Session X Nutrients
Session XI Delta Water Resources
Session XII Ports

Click here to view the entire agenda