Water erosion in the middle reaches of the Brahmaputra in Tibet: Characteristics and driving factors in the recent 30 years

Abstract The fragile ecological environment is one of the core reasons for the sustainable development of society in the Lhasa Basin of Tibet. Ecological restoration is one of the main means for human beings to effectively curb ecological degradation. To curb environmental degradation, the Tibet Government carries out ecological restoration, however, its efficacy is unknown. To increase the understanding of the impacts of ecological restoration on soil erosion and ecological service functions, we used the universal soil loss equation to determine the temporal and spatial variability in soil erosion for years 1985–2015. We also monitored changes in land-cover, and climatic variables to understand the driving forces of soil stability and movement. The results showed that the dominant land cover types in the study area were forest and grassland. Soil erosion generally decreased annually, while precipitation and temperature increased, and vegetation cover increased slowly. Soil erosion decreased mainly in the middle and southwestern parts of the basin. Temporal variability in soil erosion in the Brahmaputra River was mainly affected by precipitation, temperature, vegetation, and slope gradient. Soil erosion was positively correlated with precipitation and temperature, and areas with increasing temperature were mainly distributed in the degraded grassland areas in the north, where risk of soil erosion increased.