Integrating analyzing water retention and vulnerability on the Qinghai-Tibet Plateau for regional water security and sustainable development

Study region: The Qinghai-Tibet Plateau (QTP) Study focus: With the acceleration of population and economic growth, coupled with increasing resource demands, the uncertainty of water retention capabilities has risen, along with heightened risks of water vulnerability. The QTP has attracted attention for its water retention function and vulnerability amid environmental changes. This study aims to investigate the interplay between water retention capacity and water vulnerability on the QTP, identifying critical areas for water resource conservation. The study employed InVEST and SERV models to assess water retention and water vulnerability on the QTP from 2005 to 2020. New hydrological insights for the region: This study assessed water retention capacity and water vulnerability across the QTP from 2005 to 2020. The results revealed that water retention capacity exhibited an overall increasing trend, with an average annual growth rate of 0.5 %. The southeastern region demonstrated significantly higher retention capacity, averaging 150 mm per year, compared to only 15 mm per year in the northwestern region. Meanwhile, overall water vulnerability showed a decreasing trend, though regions such as Kashgar and Hotan exhibited water vulnerability indices exceeding 0.75, categorizing them as high-risk areas. Cities characterized by the 'low water retention-high vulnerability' trade-off were predominantly located in the northwestern region of the plateau, whereas 'high water retention-low vulnerability' cities were concentrated in the southeastern region. Correlation analyses revealed that water retention capacity was significantly associated with population density and GDP, both with statistical significance (p < 0.01). The study highlights the spatial heterogeneity between water retention and water vulnerability, providing an in-depth analysis of key urban water resource characteristics and protection policies. These findings offer valuable scientific insights for policymakers, supporting targeted water resource management strategies to enhance sustainability and ecological stability across the QTP.