The main problems and prevention measures of mine ecological restoration

(1) Geomorphic remodeling refers to the reconstruction of a new landform in harmony with the surrounding landscape by taking measures such as orderly discharge and land reshaping, aiming at the landform characteristics of the mining area, combined with mining design, mining technology and land damage methods, so as to eliminate and alleviate factors affecting vegetation restoration and land productivity improvement to the maximum extent. In general, Geomorphic remodeling is the basis of land quality restoration in mining area.

(2) Soil reconstruction is aimed at soil restoration or reconstruction of damaged land in mining areas. Appropriate reconstruction technology and engineering measures as well as physical, chemical, biological and ecological measures are adopted to reconstruct a suitable soil profile, restore and improve the productivity of reconstructed soil in a relatively short period of time, and improve the environmental quality of reconstructed soil [6].

(3) On the basis of geomorphic remodeling and soil reconstruction, vegetation restoration is based on different types and degrees of land damage in mines, comprehensive climate, altitude, slope, slope direction, surface material composition and effective soil layer thickness, etc., for different types of damaged land, the selection of pioneer plants and suitable plants and other vegetation configuration, planting and management are carried out to ensure the sustained stability of the restored plant community.

It has become a common understanding to learn from nature to reshape landform, reconstruct soil and restore vegetation, but how to define and realize the imitation of natural restoration is still a difficult problem and bottleneck to be solved. At present, there are also many cases due to the imitation of only part of the original ecological environment structure or the imitation is not in place, resulting in unreasonable reconstruction of the landscape, low soil productivity, vegetation population allocation and so on. The author believes that ecological restoration is a gradual and dynamic process, and the restoration scheme should be planned systematically and scientifically according to the original landform characteristics of the mining area, from the aspects of basin connectivity, landscape connectivity, ecological structure stability and so on. Therefore, the basic theories of the three key technologies of geomorphic remodeling, soil remodeling and vegetation restoration should be deeply studied to achieve a major breakthrough in the theory and practice of imitating nature restoration as soon as possible.

2.3 Improve the supervision mechanism and implement it

As mentioned above, the Regulations on the Protection of Mining Geological Environment and the Measures for the Implementation of the Regulations on Land Reclamation all put forward requirements for the monitoring and supervision of mine ecological restoration. However, due to the involvement of mining enterprises, the public, restoration enterprises and other multi-party interests [8], the implementation has not been in place so far. In 2021, the Ministry of Natural Resources plans to complete the inspection of the damage pattern of the national abandoned mines, after which the ecological restoration plan will be formulated and the treatment results will be monitored annually. At the same time, combined with the reform of mining rights, it is planned to strengthen the supervision and management of ecological restoration in production mines, and normalize the annual report system.

Some provinces and cities are trying to establish a big data platform for the supervision of mine ecological restoration to gradually implement the supervision mechanism. If the mechanism operates normally, the old account of ecological restoration will be completed year by year, and the new account will not increase or increase less, and the monitoring and supervision of mine ecological restoration with the help of big data platform is a practical way. Therefore, in the new round of territorial space planning and territorial space ecological restoration planning, self-examination is required to establish a database in the county, and the ecological restoration work will fall to the map spot, including the ecological restoration work in mines. For example, the big data platform for territorial ecological restoration in Shaanxi Province can realize the unified information platform, unified portal and unified management of geological environment monitoring, management and restoration, land reclamation, development management, comprehensive management of territorial space, restoration of mountain, water, forest, farmland, lake and grassland system in Shaanxi Province. At the same time, the implementation of the annual report system of mine ecological restoration is also crucial, and the future focus is to improve its reporting, approval and acceptance system, clarify responsibilities and time requirements of each link, and formulate corresponding incentives and punishment measures.

2.4 Strengthen the supervision and management of production mines, and vigorously promote the technology of mining while repairing