Proceedings of the 2020 Mississippi Water Resources Conference

Year: 2020 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.