Dynamic stability and resilience of water conservation in the three-river headwaters region: Trajectory differentiation and causal mechanisms

Abstract

Water conservation is a key ecosystem service of the Three-River Source region, the core area of the “Asian Water Tower”. Current studies on water conservation in alpine regions predominantly focus on static spatial patterns and overall driving analyses, while lacking systematic exploration of multi-scale evolutionary characteristics, dynamic trajectory classification, and differential mechanisms of ecological resilience under dry-wet disturbances. To address these research gaps, this study innovatively constructs a coupled integrated framework of “spatiotemporal quantification–trajectory diagnosis–resilience assessment–typed causal identification”. By integrating wavelet periodic analysis, dynamic trajectory recognition, multi-dimensional resilience quantification, and the optimized GPC causal model, this framework overcomes the limitations of traditional static and homogeneous research, and systematically reveals the dynamic evolution, resilience differentiation, and differentiated driving mechanisms of water conservation in the Three-River Source region from 1990 to 2020. The results indicate that water conservation in the study area exhibits multi-scale fluctuation characteristics with a dominant 22-year low-frequency oscillation and a secondary 5-year periodic variation, presenting a long-term spatial agglomeration pattern of “high in the south and low in the north”. Trajectory statistics show that the neutral trajectory accounts for the largest proportion (60.0%), followed by the positive trajectory (29.8%) and the negative trajectory (10.2%). Specifically, the positive linear trajectory possesses the highest comprehensive resilience, whereas the positive and negative step trajectories show the weakest resilience. This indicates that gradual improvement contributes to the accumulation of ecological resilience, while abrupt succession tends to trigger system vulnerability. Significant trajectory differentiation exists in driving mechanisms: stable areas are constrained by the coupled effects of topography, soil, and climatic natural background factors; improved areas are synergistically driven by climatic humidification and underlying surface regulation; degraded and mutated areas are mainly characterized by eco-hydrological decoupling, combined with local human disturbances that induce degradation risks. The study demonstrates that the water conservation capacity of the Three-River Source region is generally stable, but local areas face potential threshold degradation risks. This research provides significant theoretical and practical implications for ecological conservation and refined water resource management in the Three-River Source National Park.