关键词: 青藏高原, 植被覆盖度, 降水, 地温, 气温, 人类活动

Abstract: Systematically understanding the spatiotemporal variations of vegetation coverage and driving factors on the Qinghai-Tibet Plateau can provide scientific basis for ecological sustainable development. By integrating MODIS normalized difference vegetation index (NDVI), land surface temperature and meteorological data, we explored the spatiotemporal variations of vegetation coverage and the relationships with the factors of precipitation, temperature, and human activities on the Qinghai-Tibet Plateau from 2001 to 2020, using dimidiate pixel model, trend analysis, partial correlation analysis, and residual analysis. Vegetation coverage on the Tibetan Plateau showed a fluctuating upward trend from 2001 to 2020, and increased spatially from northwest to southeast. There were positive correlations between vegetation coverage and climate factors, with complementarity between the effects of precipitation and temperature. There was a negative correlation between vegetation cover and surface temperature. The rise and fall amplitudes of land surface temperature were higher than that of air temperature. Air temperature was more likely to be a factor limiting the growth of vegetation. The areas where human activities have improved vegetation cover were mainly located in north-central Qinghai and north of Ngari. The degraded areas included some grassland areas of central-eastern Yushu and parts of Nagqu and Lhasa.

Key words: Qinghai-Tibet Plateau, vegetation coverage, precipitation, land surface temperature, air temperature, human activity.