Assessment of the Impacts of Land Use and Future Climate Changes On Optimal Selection and Placement of Best Management Practices.

Nonpoint source pollutions from agricultural lands may cause the degradation of water quality due to sediment and nutrients. Best management practices (BMPs) have been extensively applied to control and reduce the movement of agricultural nonpoint sources into the water body. However, widespread application of BMPs can be cost prohibitive and redundant in pollution control. Thus, it is important to select the most cost effective BMPs scenarios. Furthermore, it has been widely recognized that land use and climate changes in the future will have significant impact on water quality of the watershed, which can result in the change in optimal measure and location of BMPs. Therefore, it is necessary to consider the land use and climate changes in selecting the suitable BMPs. The objective of this study was to assess the impacts of land use and climate changes on optimal selection and placement of BMPs.

  In this study, the Soil and Water Assessment Tool (SWAT) model was applied to evaluate the water quality effects of BMPs in the Yazoo River Basin in northwestern Mississippi. The SWAT model was calibrated and validated using stream flow and water quality data obtained from the U. S. Geological Survey gage stations. Model calibration and validation performances will be evaluated using coefficient of determination (R²), Nash-Sutcliffe efficiency (E), root and mean square error (RMSE). The calibrated SWAT model will be applied with various land use change scenarios as well as climate change scenarios generated by using the LARS-WG stochastic weather generator. A genetic algorithm (GA) will be utilized for cost effective allocation of BMPs under all scenarios. These results of this study will evaluate the effect of land use and climate changes on optimal selection and placement of BMPs.