Temporal and spatial evolution of surface thermal environment in Huainan Mining Area in the last decade

Land surface temperature(LST) is an important parameter to describe land surface processes and reflect land surface characteristics. It is of great significance to study the spatio-temporal evolution characteristics of surface temperature in the mining area in the last decade for understanding the influence of coal mining activities on the ecological environment. Huainan Mining Area is a typical high-phreatic mining area in eastern China. In order to explore the relationship between spatio-temporal heterogeneity of surface temperature and mining disturbance in this area, surface temperature inversion and underlying surface information extraction are carried out by using five periods of Landsat images from 2008 to 2018. Combined with the calculation of thermal landscape pattern index and urban heat island proportion index, the spatial and temporal evolution characteristics of surface thermal environment in Huainan Mining Area are analyzed. The results show that the surface temperature distribution pattern and its change are closely related to the underlying surface structure and its change in Huainan Mining Area. From 2008 to 2018, this mining area is mainly the middle temperature area, followed by the sub-low temperature and sub-high temperature area, with the area and proportion of the high temperature and low temperatures area being relatively low. Due to the construction of towns and mines, as well as the accumulation of coal gangue and mining subsidence water from coal mining, the area of construction land and water area is constantly increasing, and the vegetation area is constantly decreasing. Correspondingly, the low, sub-high and high temperature zones are increasing, and the middle and sub-low temperature zones are decreasing. On the whole, the urban heat island proportion index and the heat island effect are increasing. In the low temperature region, the patch fragmentation and complexity are decreasing and the dominance is increasing. The changes of patch fragmentation and complexity, landscape agglomeration and connectivity, diversity and evenness at other temperatures are divided into three stages: 2008-2013, 2013-2015 and 2015-2018. In 2013-2015, the intensity of human disturbance was higher. And the patch fragmentation and complexity increased, so did the landscape agglomeration and connectivity. The diversity and uniformity were reduced. The research results provide a scientific basis for the restoration and management of ecological environment and urban industrial planning in Huainan Mining Area.