Comparison And Selection Of Multiple Scenarios For Simulating Reclamation Of Damaged Land In Mining Areas

Exploitation and utilization of mineral resources have made great contributions to energy production and economic development in Changzhi City,Shanxi Province,but the cost of ecological damage and environmental pollution is huge.Mining will lead to different types of geological disasters,such as land excavation,landslides,etc.,forming a large number of damaged land,but also threatening people's lives.Idle damaged land in mining areas not only wastes precious land resources,but also seriously restricts the all-round development of economy and society.Therefore,it is of great practical significance to reclaim damaged land in mining areas.At present,there are many researches on land quality evaluation in mining areas,and many scholars have put forward different methods,and the most commonly used method is land suitability evaluation.That is to say,the land type and quality are comprehensively evaluated,and the main land types for reclamation are determined.However,this method has some shortcomings,and it is difficult to quantitatively analyze the ecological value of land with different uses.In this study,the above problems were analyzed,and Changzhi City,Shanxi Province was taken as an example.The problems in mineral resources development and land management were analyzed,and the types of land damage were divided,on the basis of which the reclamation direction was determined.The ecological benefits of reclamation schemes in various scenarios were compared and analyzed,and the optimal scheme model was obtained.The research results show that:(1)At the end of 2019,the damaged land in Changzhi mining area reached 7,597.12hectares,which was mainly divided into four types:underground mining subsidence land,occupied land,open-pit mining excavation land and solid waste stacking pressure land.According to the collapse depth and whether there is a large amount of accumulated water,the underground mining subsidence land is divided into underground mining subsidence land(accumulated water area)and underground mining subsidence land(non-accumulated water area);(2)The reclamation of underground mining subsidence land(non-waterlogged area)takes cultivated land as a single suitable direction,while the reclamation of underground mining subsidence land(waterlogged area)takes wetland as a single suitable direction.The reclamation of occupied land and solid waste piled up and occupied land has multiple adaptability,and can be reclaimed in multiple directions of woodland,cultivated land and grassland.(3)The ecosystem service values of scenarios A,B,C,D,E,F,G and H correspond to 4.78,4.81,5.03,5.05,5.04,5.07,529 and 531 million yuan.The largest one is H.Therefore,under the condition of manual intervention,the damaged land excavated by open-pit mining,the land occupied by solid waste piled up and reclaimed as woodland,the occupied land reclaimed as grassland,the underground mining subsidence land(non-stagnant water area)mainly cultivated land,and the underground mining subsidence land(stagnant water area)reclaimed as wetland utilization have the greatest ecological value,which is the best comprehensive reclamation mode in Changzhi City.(4)From 2020 to 2035,in Changzhi City,without reclamation measures,the cultivated land will be reduced by 6940.28 hm~2,the forest area will be reduced by 1989.32 hm~2,the grassland area will be reduced by 1391.27 hm~2,and the total ecological value will be reduced by80,164,800 yuan.Similarly,if all the industrial and mining damaged land in Changzhi City is converted into reclaimed land,the situation is exactly the opposite of the situation without reclamation measures.That is,the cultivated land in Changzhi City will increase by 6940.28 hm~2,the grassland area will increase by 1391.27 hm~2,and the forest land area will increase by1989.32 hm~2.The total ecological value will increase by 80,164,800 yuan.Under the condition of mining and restoration of damaged land in Changzhi City,cultivated land increased by4453.34 hm~2,woodland increased by 1276.48 hm~2,grassland increased by 892.73 hm~2,and the total ecological value of Changzhi City increased by 239 million yuan.This paper has a certain pertinence for guiding the formulation of reclamation and utilization strategy of damaged land in Changzhi mining area on the medium and macro scale.