The Yarlung Zangbo River Basin (YZRB), located in the Qinghai-Tibetan Plateau, has been significantly impacted by global warming and greening. Serving as an indicator of coupled vegetation growth and climate variation, the spatiotemporal land surface temperature (LST) has undergone substantial changes in recent decades. In this study, we evaluated the components of the water and energy cycle from 1980 to 2015 using the VIC model, a widely recognized and applied distributed hydrological model, to obtain continuous 35-year daily LST data. The results demonstrated that the VIC model exhibited high adaptability in the YZRB. Then, the fluctuation of LST was examined, and the influence of environmental elements on LST was identified. Our modeling indicated that climate factors were increasing, while human activities remained stable in the YZRB. In YZRB, the greening was witnessed while LST showed an increasing trend. By distinguishing the impacts of climate and human activities on LST, LST was mainly affected by climate with contribution rate at 70.36% from 1980 to 1995. After 1995, LST was mainly affected by human activities, and its contribution rate was 55%. Grassland with medium cover showed the potential of a cooling influence. Among all environmental factors, albedo showed a negative and delayed effect on LST. Temperature, precipitation, and evapotranspiration were positively correlated with LST and displayed relatively synchronous changes. Soil moisture and NDVI were detected as leading positive changes in LST. Our study contributes to clarifying the mechanisms influencing LST in high-altitude and high-latitude regions under global greening, providing fundamental insights for socio-economic development in alpine mountainous regions.

The Yarlung Zangbo River Basin (YZRB), located in the Qinghai-Tibetan Plateau, has been dramatically affected by global warming. In recent decades, serving as the indicator of coupled vegetation growth and climate variation, the spatiotemporal land surface temperature has been changed substantially by changes in environmental factors while greening spreading. In this study, we evaluated the components of water and energy cycle during 1980-2015 based on the VIC model, one of the widely recognized and applicated distributed hydrological model. The fluctuation of LST was examined and the influence of environmental elements on LST was identified. The results showed that VIC model performed a high adaptability in applying and conducting in YZRB with R 2 over 0.7 and Er at 5.03%. Climate factors were increasing while human activities stayed stable in YZRB by our modeling. In addition, climate factors (precipitation, evapotranspiration, temperature) and underlying factors (soil moisture, NDVI, Albedo) were detected as influencing factors of LST. In YZRB, the greening was witnessed while LST showed an increasing trend. By distinguishing the climate and human activities on LST, ET and NDVI are two dominant factors effecting LST. From 1980 to 1995, LST was mainly affected by climate and its contribution rate was 70.36%. After 1995, LST was affected by human activities, and its contribution rate was 55%. Grassland with medium cover showed the potential of a cooling influence. Among all the environmental factors, Albedo showed a negative and a lagged behind effect on LST. Temp, P and ET were positively related to LST and displayed changes that are relatively in phase. SM, NDVI, were detected as leading the changes in LST, positively. Our study contributes to clarifying the mechanisms influencing LST in high-altitude and high-latitude regions under the global greening and is fundamental for socio-economic development in alpine mountainous regions.