Spatiotemporal diversity and attribution analysis of land surface temperature in China from 2001 to 2020

The variation of land surface temperature (LST) has a vital impact on the energy balance of the land surface process and the ecosystem stability. Based on MDO11C3, we used methods including regression analysis, GIS spatial analysis, correlation analysis, and center-of-gravity model, etc., to analyze the LST variation and its spatiotemporal diversity in China from 2001 to 2020. Finally, the Geodetector was used to identify the leading factors of LST variation in 38 eco-geographical zones of China, and explore the causes of its pattern. The results show that: (1) the average LST in China from 2001 to 2020 is 9.6 ℃, which is high in the plains, and low in the mountainous areas. Generally, LST has a striking negative correlation with altitude, with a correlation coefficient of -0.66. China's First Ladder has the most conspicuous negative correlation, with a correlation coefficient of -0.76 and the lapse rate of LST is 0.57 ℃/100 m. (2) The change rate of LST in China during the study period is 0.21 ℃/10 a, and the warming area accounts for 78%, showing the spatial characteristics of "multi-core warming and axial cooling" in general. (3) LST's variation has prominent seasonal characteristics in the whole country. The spatial distribution of average value in winter and summer is quite different and fluctuates obviously; the moving trajectory of the centroid in the warming/cooling area is close to a loop shape. The movement direction shows the corresponding seasonal reverse, and the movement range in the cooling zone is larger, indicating that the regional difference and seasonal variability of the cooling zone are more obvious. (4) China's LST variation is driven by natural conditions and human activities, of which natural factors contribute more, with sunshine hours and altitude being the key factors. The boundary trend between the two dominant type areas is highly consistent with the "Heihe-Tengchong Line". The easern region is mostly dominated by human activity intensity and interacts with terrain factors, while the western region is dominated by natural factors, which enhance/weaken the change range of LST through mutual coupling with the climate, terrain, vegetation, and other factors. This study can provide scientific references for dealing with climate change, analyzing surface environmental models, and protecting the ecological environment. © 2022, Science Press. All right reserved.