A study on the impact of human activities on the ecosystem health of Three-River-source national park

This study focused on the Three-River-Source National Park (TNP), constructing a five-dimensional human activity intensity( HAI )evaluation index system encompassing land use, economy, population, policy management, and pollution emissions. Using the comprehensive index method and the Vigor-Service-Resilience (VSR) model, combined with Geodetector and Geographically Weighted Regression (WGR), it analyzed the spatiotemporal changes in HAI from 2000 to 2020 and its impact on ecosystem health. The results showd: (1) From 2000 to 2020, the overall HAI in the study area decreased by 12.36%, with a spatial pattern of “higher in the south than in the north”. The Lancang River Source zone had the highest intensity, and high-intensity areas were concentrated around county administrative centers but their proportion contracted. (2) Ecosystem health increased by 1.85%, exhibited an “east high, west low” pattern. The Yellow River Source zone had the highest and increasing health level, while the Yangtze River Source zone showed a decline. (3) Human activities had a dual effect on ecosystem health, with population density and construction land proportion being the main influencing factors. Ecological protection policies have a mitigating effect on ecological pressure. (4)The impact of human activities on ecological health was predominantly positive across the park zones, and the areas with positive effects expanded. • From 2000 to 2020, TNP's HAI dropped 12.36%, showing a “south-high, north-low” pattern with high-intensity areas contracting. • Ecosystem health of TNP rose 8.15%, presenting an “east-high, west-low” pattern; YeP performed best, YP declined. • Population density and construction land proportion are key factors affecting TNP's ecosystem health. • Human activities' positive impact on TNP's ecosystem health expanded, driven by effective ecological protection policies. • Factor interactions (mostly nonlinear/bi-factor enhancement) significantly influence TNP's ecosystem health.