Evaluating land surface temperature variation and its responses to
climate change and human activities ------A case study of the Yarlung
Zangbo River, southeastern Tibetan Plateau
Abstract
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.