138 / 2023-08-15 15:29:43

Multiscale and multisource data reveal the ecological restoration of mineral concentration areas under different disturbances

Ecological restoration; Remote sensing monitoring; Ecological assessment; Mining area

Identifying ecological disturbance and restoration at different scales is crucial for addressing ecological problems in mining areas. The ecological restoration of mining areas has centered on geological environment management, vegetation restoration, and land reclamation, focusing more on landscape restoration and less on ecological restoration process. Mining area is a collection area of mining and utilization of mineral resources, land resources occupation and destruction, but also the concentration of economic development and environmental protection conflict area, high frequency and long time of mining disturbance caused by the ecological restoration difficulties, poor reclamation effect. This paper proposes an ecological restoration assessment framework with 8 dimensions and 24 indicators on the macroscale, taking a mineral concentration area (MCA) in southeastern Hubei as a case study, the ecological status of the MCA in 2000, 2010 and 2019 was evaluated by the subjective and objective combination weighting method. On the time series NDVI data set from 1986 to 2022, LandTrendr and random forest algorithms were used at the mesoscale to extract and classify different disturbance and recovery types in a 3-km buffer around the mine sites. The ecological disturbance and restoration characteristics were analyzed in different mining areas at the microscale. The findings demonstrated that the ecological quality decreased before increased from 2000 to 2019. The total ecological restoration area increased by 10.092% from 2010 to 2019, showing an improving trend. The ecological deterioration areas were mainly in the urban areas in the northeast of the MCA and around the water area. the trend of poor ecological quality shifted from the southwest of the study area (Daye City) to the northeast (along the Yangtze River), spreading from a surface to a belt-like extension with a gradual decrease. Continued mining is a critical cause of ecological degradation. In different mining ecological composite areas, the areas with poor ecological quality are similar to the spatial distribution of mining disturbance, and the mining area is the center and expands outward. The main disturbance types around the mining area were farmland reclamation and building development. Natural restoration occurred in forest areas around mining sites. Disturbances due to construction development still occur in areas surrounding closed mining areas, especially in Huangshi National Mine Park and Tonglvshan Copper Mine. These sites require continuous attention to prevent damage caused by secondary disturbances. In conclusion, the ecological restoration of mines should consider objectives and regional geographical conditions at multiple scales to obtain maximum ecological benefits.