Optimal Best Management Practice Placement Strategies for Nonpoint Source Pollution Management in the Fei-Tsui Reservoir Watershed

摘要

The purpose of this study was to develop a tool for the optimal placement strategy of structural best managementnpractices (BMPs) at the watershed scale. It consists of three interacting components: a simplified BMPs simulationnmodel, a zero-dimensional reservoir water quality model (unsteady, time-variable Vollenweider model), and annoptimization model (genetic algorithms). A posttreatment program that combines BMP simulation, channelnrouting, reservoir water quality models, and genetic algorithms was developed. Both total suspended solids andntotal phosphorus were taken into account, and three types of BMPs were considered. By changing the constraints,nthree scenarios were analyzed in this study. The total phosphorus concentration should satisfy oligotrophic,nmesotrophic, and eutrophic conditions, while the total suspended solids concentration should be kept belown25mg=L. This study analyzes three different time-scale scenarios: short term (March 28, 2003 to April 14, 2003),nlong term(2002–2003), and design storms (2-year=2-h and 5-year=4-h). Near optimal solutions found in this studynwere compared with former research on the Fei-Tsui Reservoir watershed. For future detailed planning andndesigning, decision makers or designers can adopt the BMPs placement strategies developed in this study. Severalnnonstructural BMPs are also suggested as sound alternatives for nonpoint source pollution control when there arentopographic and land ownership problems.