Analyzing the spatial intercorrelations of hydrological ecosystem services of different land use/land cover at the catchment scale

Understanding the spatial dynamics and interactions of hydrological ecosystem services (HES) is critical for sustainable watershed management under increasing land use pressure and climate variability. This study evaluates five key HES indicators—freshwater provision, green water scarcity, green water vulnerability, flood regulation, and erosion regulation—in the Zhuoshui River Basin, Taiwan, using the SWAT model for the period 2002–2020. Spatial autocorrelation (global and local Moran's I) was employed to identify clustering patterns of high and low HES performance. The results reveal pronounced spatial disparities: downstream areas experience higher green-water stress, especially during the wet season, whereas forested upstream regions provide stronger regulatory functions. Urban and agricultural zones exhibit reduced freshwater provision. Spearman's correlation analysis indicates trade-offs between freshwater provision and regulatory services in intensively managed landscapes, along with strong synergies among green-water-related indicators. ANOVA with Scheffé post hoc tests further confirms that land-use type significantly influences HES performance. Overall, the findings advance spatially explicit HES assessment and offer a decision-support framework to guide ecological restoration, land-use zoning, and climate-adaptation planning at the subbasin scale.