System dynamics modelling of the water and salt balance of Bosten Lake in northwest China: implications for ecologically sustainable management

Salinisation of Bosten Lake threatens the eco-system in the Kaidu-Kongque Basin in northwest China. A water-salt balance model of Bosten Lake is helpful to understand inherent mechanism of salinisation and develop appropriate water management strategies. A system dynamics (SD) model was developed to simulate the water and salt balance of Bosten Lake using a commercial system dynamics modelling environment, Vensim. The model was used to investigate the optimal water table for salinisation control and investigate strategies for sustainable management under different scenarios. Through scenario analysis, we suggest that more water be pumped to Kongque River or diverted to Tarim River for irrigation or ecological restoration, to lower the water level and reduce evaporation losses during high inflow years. As for low inflow, increasing inflow through pumping groundwater and reducing irrigation diversion from Kaidu River should be an effective way for avoiding high salt concentrations. Other scenarios can be easily evaluated by using the framework presented in this paper.