Analyzing Spatiotemporal Changes and Drivers of the Water Yield Service in the Malian River Basin on the Loess Plateau, China

In the context of global climate change and increasing water scarcity, water yield (WY) service has gained widespread scientific attention. This study analyzed spatial distribution and variations of the WY service in the Malian River Basin (MRB) from 1990 to 2020, as well as its influencing drivers, using the integrated valuation of ecosystem services and trade-offs (InVEST) model. Results indicated that the WY spatial distribution of MRB remained stable over time, showing a step-like pattern from north to south. The WY values in the basin in 1990, 2000, 2010, and 2020 were 4.563 × 10⁸, 2.640 × 10⁸, 3.853 × 10⁸, and 3.264 × 10⁸ m³, respectively. The global Moran’s I (0.925–0.928) exhibited a significant positive spatial autocorrelation overall. Precipitation (PRE) had the greatest impact on the spatial differentiation of the WY service (Pearson’s r = 0.76–0.80), showed positive correlation, while elevation (ELE), actual evapotranspiration (AET), temperature (TEM), and normalized difference vegetation index (NDVI) showed negative correlations. The lower reaches of MRB were identified as a critical WY service and spatial correlation area requiring protection. This study provides theoretical and scientific bases for water resource management on the similar Loess Plateau regions, the InVEST model with local parametrization can also be applied to these regions.