Watershed, as it comprehensively represents any part of water resource on our land, is considered the most appropriate units not only for the assessment of water environment, analysis and usage of water resources, but also for the management of water quality. Therefore, many scholars use watershed management to deal with the arising water problems and maintain sustainable development at watershed scale. Considering the complication and uncertainty of watershed system, previous scholars began to use various newly-built models to fulfill the task of watershed management, that is, the multi-objec...
