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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #114129

Title: EVALUATION OF ANNAGNPS ON MISSISSIPPI DELTA MSEA WATERSHEDS

Author
item YUAN, YONGPING
item Bingner, Ronald - Ron

Submitted to: American Society of Civil Engineers Water Resources Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/22/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Pollution entering a water body can significantly affect the ecological balance needed in maintaining healthy recreational and municipal river or reservoir systems. A study was conducted to determine the capabilities of the AnnAGNPS watershed computer model to evaluate the effectiveness of alternative farming operations used to reduce pollutants entering oxbow lakes in the Mississippi Delta MSEA Project. Crop management operations included planting winter wheat after cotton or soybeans and comparing simulated with measured runoff and erosion from the study fields. The results of the study showed the AnnAGNPS watershed model is very capable of reproducing runoff and erosion from very flat and intensively farmed fields in Mississippi's Delta farmland. This is critical because of the magnitude of agricultural farmland in the Mississippi Delta and the potential impact this area has on pollutants entering the numerous oxbow lakes, Delta rivers, and eventually the Mississippi River. By successfully applying this watershed model to these areas, alternative farming practices can be evaluated before their actual implementation, thus reducing the time and costs needed to determine the best practices that benefit society.

Technical Abstract: Pollutants entering a water body can be very destructive to the health of that system. BMP's can be used to reduce these pollutants, but understanding the most effective practices can be difficult. Watershed models are an effective tool to aid in the decision making process of selecting the BMP that is most effective in reducing the pollutant loading, but is also the most cost effective. The Annualized Agricultural Non-Point Source Pollution model (AnnAGNPS) is one such tool and was used to estimate runoff and sediment yield for the Deep Hollow watershed of the Mississippi Delta MSEA project. The AnnAGNPS predicted results were compared with MSEA monitored data in order to test the prediction capability of the model. Test results show that AnnAGNPS provides a reasonable estimate (+15%) of long term monthly and annual runoff and sediment yield without calibration. AnnAGNPS is a tool suitable for long term evaluation of the effects of BMP's and can be used for ungauged watershed simulation of runoff and sediment yield.