Study on vegetation disturbance in the Yarlung Zangbo River Basin under the background of hydropower development

This study analyzed spatiotemporal vegetation dynamics and their driving forces in the Yarlung Zangbo River Basin by calculating the Normalized Difference Vegetation Index (NDVI) from time-series Landsat images. The analysis integrated linear trend modeling, LandTrendr-based change detection, and partial correlation analysis, with a particular focus on regions influenced by existing hydropower infrastructure. Results showed that: (1) The overall vegetation of the Yarlung Tsangpo River basin shows a stable growth trend, with only 5 078.70 km² of vegetation undergoing significant changes over the past 20 years, of which the areas of positive and negative changes were 3 205.80 km² and 1 872.90 km² respectively; (2) Vegetation degradation was most pronounced within 1 km upstream of hydropower stations during dam construction and reservoir impoundment phases. In contrast, accelerated vegetation growth was observed during operational periods, primarily beyond 2 km from the hydropower-associated river buffer zone; (3) Vegetation patterns were strongly dependent on elevation, with climatic variables exerting greater influence than anthropogenic factors. Temperature was identified as the most significant climatic driver of vegetation variability in the region.