Assessment of Climate Change Impact on Water Yield Services in the Yangtze River Economic Belt Using the SSPs–InVEST Coupling Approach

The Yangtze River Economic Belt (YREB) is a critical region for ecological and environmental protection in China, exerting significant influence on regional and national development. However, the intensification of climate change poses severe challenges to its ecological service patterns. To address this, climate scenarios based on Shared Socioeconomic Pathways (SSPs) are integrated with the Annual Water Yield (AWY) module in the InVEST model to examine changes in water yield ecosystem services from 2000 to 2060. A quantitative impact assessment model was established to analyze these changes. The research findings reveal the following: (i) From 2000 to 2020, the total water yield of the YREB was 1.68 × 1012 m3. The average annual water yield under the four future SSP scenarios (2022–2060) is projected to range from 1.73 × 1012 m3 to 1.82 × 1012 m3. (ii) Among the four SSP scenarios, SSP1-2.6 exhibits the highest increase in water yield services, followed by SSP5-8.5, SSP3-7.0, and SSP2-4.5. (iii) The climate change impact index on water yield services (K) demonstrates a spatial distribution trend of high values in the east and low values in the west, with pronounced spatial variations. (iv) The comprehensive change index of water yield services (K*) across the 11 provinces and cities affected by climate change ranges from −0.0954 to 0.1005 under the four scenarios, indicating that climate change exerts both positive and negative impacts on water yield services in the YREB. (v) The quantitative impact assessment model constructed in this study offers scientific support for ecosystem restoration and water resource management optimization in the YREB.