Assessing ecosystem services under water stress in the largest inland river basin in China based on hydro-ecological modeling

Abstract. Ecological changes in arid lands are often determined by the available water resources. For ecological protection, it is important to consider both hydrological and ecological processes. This paper presents a modeling approach to assess environmental changes and ecosystem services (ESS) in the largest inland river basin in China. Current water cycle and ecosystem protection measures were simulated, and future land use change scenarios were proposed accordingly. China is on the frontline of ecosystem protection and afforestation, but according to the simulation results, the available water resources cannot support more vegetation in its largest inland river basin. Without an additional water supply, 25.9 % of the existing area of natural vegetation will be degraded by 2050. A reduction in the area of cotton plantation did not substantially reduce farming incomes in the simulation. Drip irrigation and ecological flooding was effective for improving ESS, especially agricultural provisioning and riparian forest provisioning services, as well as regulating and supporting services. The assessment of ESS can achieve socio-economic and ecological benefits in a sustainable way, and also enable the impact of the complex environmental factors to be understood. The results can be used to evaluate current situations and develop creative solutions.