Ecological environment quality evaluation and evolution analysis of a rare earth mining area under different disturbance conditions.

The negative impacts of the overexploitation of resources on regional environments have become increasingly obvious. The contradiction between the environment and development and the management of the ecological environment in mining areas are urgent problems to be solved. This paper uses Landsat images from four temporal phases from 1991 to 2018 in the Lingbei mining area of Dingnan County, China, to construct a rare earth remote sensing-based ecological index (RE-RSEI) suitable for rare earth mining areas and to analyze the impacts of different rare earth mining methods, mining scales and environmental management measures on the mining area environment over the past 27 years. The results show that since 1991, due to the mining techniques of "pond leaching" and "heap leaching" and the soil condition, mining has caused severe damage to the land and vegetation, and the ecological environment quality of the entire mining area has been seriously reduced with its RE-RSEI value dropping from 0.744 to 0.675. After 2010, through the optimization of mining technology and the government's attention to ecological environmental governance, the quality of the ecological environment was slowly restored, and the recovery effect at some mine sites was remarkable. The RE-RSEI model has good applicability to rare earth mining areas, can intuitively reflect the destruction and restoration of the ecological environment of rare earth mining areas under different mining modes, and provides scientific guidance for promoting the coordination of the development and utilization of rare earth resources and mine ecological environmental protection and sustainable development.