Time series analysis of multi source data of coordinated evolution of vegetation in open-pit mining area:taking Jungar Mining Area as an example

In order to reveal the cooperative evolution law between artificial vegetation in the reclamation area of the open-pit coal mine waste dump and undisturbed original vegetation around the mining area, based on Landsat TM/OLI and MODIS satellite remote sensing data, combined with the observation data of meteorological stations, this study adopted the unary linear regression method to analyze the time series changes of NDVI value and vegetation coverage in Jungar Mining Area from 1988 to 2020 and inverted Landsat satellite thermal infrared band data to obtain the surface temperature changes of Jungeer Mining Area since 2000. In addition, the spatial distribution and temporal change of drought index in mining area and its surrounding areas were calculated under ArcGIS platform. The results of the study show that the vegetation coverage in the undisturbed area around Jungar Mining Area shows an overall upward trend in 33 years, from 37% in the early stage of mine construction in 1988 to 63% in 2020. The artificial vegetation area of waste dump has increased from 15.49 hm2 in 1994 to 1 694.86 hm2 in 2020; 74.74% of the vegetation within the 5 km buffer zone of the mining area has been moderately improved; the surface temperature of the mining area showed a downward trend, and the drought level has dropped from drought to normal. Comprehensive results show that since the construction of Jungar Mining Area in 1988, the artificial ecological restoration of waste dump in the mining area and the undisturbed original ecological environment of the surrounding area have been improved. The main reason is that the land reclamation of waste dump in open-pit coal mine and coal mining are carried out at the same time. With the increase of reclamation scale and intensity, the vegetation selection and reclamation modes become more scientific and reasonable. With the progress of reclamation and succession, the vegetation in the waste dump site gradually merges with the undisturbed vegetation area outside the mining area. The vegetation canopy density in the mining area increases and the surface temperature decreases. It is inferred that a regional microclimate is formed, which accelerates the succession of undisturbed vegetation around the mining area. The artificial restoration of the ecology in the mining area and the improvement of the original undisturbed vegetation in the periphery are consistent.