Increased Precipitation Yet Decreased Runoff: Unveiling Hydrological Shifts in the Yellow River Source Region Through Permafrost, Snow, and Vegetation Dynamics

This study presents a comprehensive analysis of the hydrological changes in the Yellow River source region, a key component of the Qinghai-Tibet Plateau's Three-River Source Region. During the period 1960-2020, we observed a significant increase in precipitation but paradoxically, a slight decrease in runoff. The region, characterized by its critical positioning at the boundary of permanent and seasonal permafrost, has undergone substantial environmental changes due to global warming. By integrating historical data and multi-source remote sensing, our research dissects the complex interactions between the altered permafrost, snow cover, and vegetation dynamics. We specifically examine how these changes influence the regional hydrological cycle, particularly focusing on the mechanisms leading to reduced runoff despite increased precipitation. Our findings provide novel insights into the impacts of climate change on high-altitude hydrological systems. They hold significant implications for water resource management and ecological conservation in the face of ongoing climatic shifts. This study contributes to the broader understanding of hydrological responses to environmental changes in sensitive mountainous regions.