Abstract:Based on the layout information and monitoring data of 77 cross-border dynamic monitoring sites in Jiangsu, Zhejiang provinces and Shanghai city, this paper analysized the current complex multi-agency composited monitoring system and its problems, including the unnecessarily repeated setting of the monitoring sites on provincial boundary and inadequate monitoring frequency of important trans-boundary sections. Considering the water environmental effect factors such as the hydrological features of the trans-boundary area, migration situation of cross-border contaminants, as well as distribution of environmentally sensitive areas in upstream and downstream area, the layout of water environment monitoring sites has been optimized, which means that a new layout of the monitoring sites has been formed by combining multiple monitoring means such as automatic online monitoring and manual monitoring and etc, making up a system consisting of transboundary water environment dynamic monitoring sites. Under the optimization principle of representative monitoring sites, comprehensive monitoring and economic rationality, the new layout of monitoring sites will provide supporting data and decision basis for handling transboundary pollution accidents and transboundary water environment management in Taihu Lake Basin.