EVALUATION OF SPATIAL AND TEMPORAL CHANGES OF MINE ECOLOGICAL ENVIRONMENT IN ILI VALLEY BASED ON REMOTE SENSING ECOLOGICAL INDEX

This paper analyses the characteristics of the temporal changes of ecological environment quality in the mining area of the Ili Valley from 2013-2021 to provide a scientific basis for improving the ecological environment in the region. Based on 5 issues of Landsat8 OLI data from 2013-2021, the remote sensing ecological index (RSEI) was constructed by using principal component analysis and selecting Normalised differential vegetation index (NDVI), the wetness component of the tasseled cap transformation (WET), the dryness index synthesised by the building index and the normalised difference soil index (NDSI), and the land surface temperature (LST). The RSEI is classified into 5 levels by reclassification, and the centre of gravity migration of RSEI levels I-V is analysed according to the centre of gravity migration method, and the spatial change pattern of RSEI is analysed to realise the dynamic monitoring and evaluation of ecological environment quality in the mining area of Ili Valley by using RSEI. The experimental results show that: (i) The ecological environment condition of the mining area in the Ili Valley is significantly improved in 2013-2021, in which the area with an increasing trend accounts for 38.36% of the total area of the mining area, and the NDVI and WET have a greater impact on the ecological environment quality of the mining area; (ii) The ecological environment quality of the mining area is mainly level I, II and III, and the migration of level IV and V is larger and the centre of gravity moves to the northeast and southeast of the mining area. The ecological and environmental quality of the mining area in the Ili Valley shows a general upward trend from 2013 to 2021, which is influenced by the growth of vegetation and human activity factors.