摘要：The continuous supply of ecosystem services is the foundation of the sustainable development of human society. The identification of the supply–demand relationships and risks of ecosystem services is of considerable importance to the management of regional ecosystems and the effective allocation of resources. This paper took the Yihe River Basin as the research area and selected water yield, carbon sequestration, food production, and soil conservation to assess changes in the supply and demand of ecosystem services and their matching status from 2000 to 2018. Risk identification and management zoning were also conducted. Results show the following: (1) The spatial distribution of the four ecosystems service supply and demand in the Yihe River Basin was mismatched. The food production supply levels in the middle and lower reaches and the upstream water yield, carbon sequestration, and soil conservation supply levels were high. However, most of the areas with high demand for ecosystem services were concentrated downstream. (2) From 2000 to 2018, the supply of water yield and carbon sequestration in the Yihe River Basin decreased, while that of food production and soil conservation increased. The demand for the four ecosystem services also increased. (3) Water yield faced considerable supply–demand risks. Fifty percent of the sub-basins were at a high-risk level, and the risk areas were concentrated in the middle and lower reaches. The three remaining services were mainly at low-risk levels. The Yihe River Basin was divided into eight types of supply–demand risk spatial management zones based on the ecosystem service supply and demand levels, which will help promote refined regional ecosystem management and sustainable development. The supply and demand assessment of ecosystem services from a risk perspective can integrate the information of natural ecosystems and socio-economic systems and provide scientific support for watershed spatial management.
