Spatiotemporal evolution and interaction of water constraints and their socio-ecological drivers in the Taihu Lake Basin

Abstract

To effectively manage water constraints (WCs) within a basin, it is crucial to first scientifically delineate their spatial distribution and thoroughly understand the interactions between WCs. Investigating the complex driving mechanisms at multiple scales is also essential. In this study, a basin WC evaluation framework is constructed using a conflict risk assessment model. The spatiotemporal variations of four types of WCs across three spatial scales in the Taihu Lake Basin (TLB) are thoroughly investigated. Furthermore, the study quantifies the trade-offs, synergy effects, and bundle patterns of these water constraints. The study employs the Optimal Parameters-based Geographic Detector (OPGD) and multivariate linear regression to identify the key socio-ecological drivers of WCs. Our findings indicate that between 2010 and 2020, water resource constraint (WREC), water environment constraint (WENC), water safety constraint (WSAC), water ecology constraint (WECC), and the comprehensive WC (CWC) displayed varying degrees of heterogeneity. Particularly, the mean values of WSAC, WECC, and CWC witnessed an increase over the decade. Additionally, all WCs exhibited a strong positive spatial autocorrelation. Synergistic interactions among WCs were predominantly observed in pairs such as WREC-WSAC, WREC-WECC, and WSAC-WECC, while a weaker trade-off effect was noted in the WENC-WECC pair. At multiple scales, we identified eight types of WC bundles capable of undergoing mutual transformations, especially at the basin scale. The primary drivers of WCs varied across different stages and scales, with most factors collectively exerting a more significant impact than individually. Notably, factors like secondary and tertiary industry GDP (X2), population density (X3), precipitation (X6), and elevation (X7) were identified as core drivers influencing the evolution of WCs in the TLB. Integrating these spatiotemporal characteristics and driving mechanisms of WC interactions into basin planning and management can significantly support the alleviation of multidimensional water constraints in territorial spaces.