Harmony in Extraction: A Variable Weight Theory Approach to Unraveling the Ecological Security Veins in China's Rare Earth Mining Under Variable Pressures

Abstract

The unique mining process of China's ion-adsorption rare earth (RE) mines has changed the structure of the mine ecosystem, and the interplay between the natural red soil characteristics and economic and social activities has exacerbated environmental problems such as the degradation of regional vegetation cover and soil erosion. These issues have had a profound and detrimental impact on the ecological security (ES) of the mining areas. The existing static evaluation study cannot comprehensively assess the ES status and dynamic evolution trend of the mining area, and cannot meet the needs of the complex ecosystem in the mining area. Therefore, this article constructs an ES evaluation index system based on the driver-pressure-state-impact-response-management causal framework model, and uses the variable weight (VW) theory to formulate a penalty-dominated state VW function to calculate the weight values of the indicators in different contexts of each year and evaluation unit. Finally, a dynamic evaluation of the spatial and temporal evolution trend of the ES of the Lingbei RE mining area is carried out during the period from 2000 to 2020. The geodetector model is then applied to reveal the driving factors impacting the ES of the mining area in different time periods. The results show that 1) Compared to the constant weight method, VW can provide a more detailed distribution of the ES level in the mining area, which has good application value in the small and dispersed ionic RE mining area. 2) The overall ES status of the Lingbei mining area shows a dynamic trend of deterioration followed by improvement and finally stabilization. 3) The vegetation health status is one of the most important driving factors of ES in the mine site, and the interaction between any two factors is greater than the explanatory power of the individual factors. This study provided insights into the ES and sustainable development of mining areas.

Keywords

• Driver-pressure-state-impact-response-management (DPSIRM) model
• driving factors
• dynamic evolution
• ecological security
• rare earth ore
• variable weight theory