Projecting Water Yield Amidst Rapid Urbanization: A Case Study of the Taihu Lake Basin

Changes in land cover and land use (LULC) can impact water availability by altering the structure and functioning of land ecosystems. Accurately projecting the impacts of LULC on water yield (WY) is of utmost importance for regional landscape management. Taking the rapidly urbanizing Taihu Lake Basin (TLB) as an example, coupled with the PLUS-InVEST model, three scenarios of a natural development (ND) scenario, urban development (UD) scenario, and ecological protection (EP) scenario were set to simulate the response mechanisms of land use changes for WY and the influence of policy-making on the water conservation capacity of river basins. (1) During 2000 and 2020, the Taihu Lake Basin (TLB) experienced rapid urbanization, which was evident in the conversion of forest and cropland for urban development. (2) From 2000 to 2020, the TLB’s WY first decreased and then increased, ranging from 201.52 × 10 8 m 3 to 242.70 × 10 8 m 3 . Spatially, an uneven distribution pattern of WY depth emerged, with mountainous and hilly regions exhibiting higher WY compared to plain areas. Temporally, changes in total WY were primarily influenced by precipitation, while areas with increased WY showed a certain correlation with regions experiencing an expansion of construction land. (3) By 2030, the TLB will continue to expand construction land under the UD scenario, while the area of ecological land will expand under the EP scenario. WY is expected to vary across scenarios, with the highest yield observed under the UD scenario, followed by the ND scenario, while the EP scenario exhibits the lowest yield. These findings can offer scientifically informed insights and guidance for future WY changes, carrying substantial effects for maintaining ecological preservation and promoting high-quality development in the TLB.