REM:A remote sensing ecological index of mining areas considering plant diversity and rock-soil difference

Remote sensing ecological environment for mining areas can provide necessary monitoring information for mining land reclamation or ecological restoration. It can also provide required management tool for related management. Therefore,it is essential to develop a comprehensive remote sensing ecological index of mining areas. However, in terms of mining areas,most of the existing methods have not fully considered the difference between soil and sock over sparse vegetation area (abbreviated as rock-soil difference) and the role of plant diversity over dense vegetation area (abbreviated as plant diversity). In order to monitor and evaluate the ecological environment of mining areas more comprehensively and accurately,a framework called VegetationImpervious surface (or bare rock)-Soil for Mining area (VIS-M) was constructed. Then a Remote sensing Ecological index of Mining areas considering plant diversity and rock-soil difference (abbreviated as REM) was proposed based on the VIS-M. Taking the Fushun Western Open-pit coal mine in Liaoning province,China as the study area,the REM was implemented at 10 m spatial resolution and one-year temporal resolution from 2016 to 2021 with Sentinel-2 data. The field survey data with 95 sampling sites and land cover classification data in 2 years were also used to evaluate the REM. Results indicated:① there was well consistence between the REM value and the ecological environment quality indicated by the land cover type. Also,the REM can distinguish the difference between soil and rock. ② The REM values presented well consistence with the field survey data (correlation coefficient is 0. 899 4 at a significant level P < 0. 01). Moreover,the REM can demonstrate the role of plant diversity over dense vegetation area. ③ The REM illustrated the spatiotemporal pattern of ecological environment for the study area from 2016 to 2021. Furthermore,through the difference between 2021 REM and 2016 REM,the ecological restoration area was clearly mapped. Finally,the grading criteria of REM was discussed and some convenient ways of determining weights and plant diversity were suggested. In summary,the REM model can accurately describe the quality of the ecological environment in the mining area,and at the same time, it can effectively take into account the issues of rock-soil difference and plant diversity. Of course,the parameters in the REM model may need to be adjusted in time to adapt to the changing laws of rocksoil difference and plant diversity in different geographical areas,data conditions or mining scenarios.