Scenario Analysis on the Water Environment Carrying Capacity of Wuliangsuhai Lake Basin

Abstract

Rapid social-economic development and the ever-increasing water pollutant discharge of Wuliangsuhai lake basin made the water quality deteriorated; the lake eutrophication intensified and heavily restricted the sustainable development of the watershed’s social economy. Wuliangsuhai lake basin was selected as the study area. By the use of system dynamics simulation model the water environment and social economy were connected, and three kinds of improved scenarios (resource-environment constrained type, social economy constrained type, coordinated development type) were proposed based on the inertial and planning schemes. Ten indexes of water environment carrying capacity, i.e. the GDP per capita, ratio of industrial output to GDP, et al., were selected, and fuzzy comprehensive evaluation method was used. Results showed that, the water environmental capacity utilization ratios of COD and TN in the resource-environment constrained scenario were 69.5% and 57.9% in 2020, respectively. And the water environment carrying capacity index increased from 0.19 in 2008 to 0.31 in 2020. Under the coordinated development scenario, the surplus environmental capacity of COD and TN were 1755.46t/a, 260.21t/a respectively, and the water environment carrying capacity index was up to 0.29 in 2020. The sustainable development plan was proposed and some feasible suggestions and strategies were put forward.