Research On The Spatial And Temporal Differences Of Ecological Risks In Large-scale Open-pit Coal Mines And Zoning Control

While mining production activities have driven the country's economic development,they have also caused significant damage to the ecological environment.Ecological risk assessment in mining areas has a prominent position in the management of ecological restoration in mining areas,and can provide theoretical and technical support for promoting the coordinated development of economy and ecology in mining areas.This paper selects the Baorixile open-pit mining area located in the "two screens and three belts" ecological area as the research object,using remote sensing images,field surveys,statistical yearbooks and other data,using spatial analysis,statistical analysis and other quantitative and qualitative methods to construct The risk causality chain in the mining area is determined,the evaluation unit is determined,the hazardvulnerable comprehensive ecological risk evaluation index system is established,the temporal and spatial evolution of the ecological risk in the mining area is analyzed,and the recommendations for the divisional management and control of risks are proposed,and the following conclusions are drawn:(1)Based on the NDVI index,the ecological contribution rate of the boundary area and sensitive area of the treasure mine planning is calculated,and the ecological contribution rate within the 10 km sensitive area is significantly correlated.The vegetation coverage fluctuated in the mining area from 1997 to 2019.The vegetation coverage of the open pit was the lowest and affected the surrounding vegetation.The vegetation coverage of the mining area showed a layout of low vegetation coveragelower vegetation coverage-higher vegetation coverage.In the mining area,the patch density of low vegetation coverage is small,the degree of agglomeration is large,and the area perimeter fractal dimension is close to 1.Mining activities are an important factor in the reduction of regional vegetation.(2)The ecological risks in mining areas are complex and are affected by both natural and human disturbance.The causes of risks in the ecological risk chain of mining areas are natural environment and human activities,and finally get the risk source-risk receptor-exposure response-risk end point.Risk causal chain.Using the principle of amplitude effect,1500m is determined as the size of the evaluation unit in this paper.On the basis of the ecological risk causality chain,an evaluation index system was constructed.The natural hazard degree evaluated the degree of drought hazard from the perspective of "pregnancy and disaster bearing";the degree of hazard caused by mining was characterized by the cumulative impact coefficient of land damage;the degree of industrial pollution hazard It is characterized as the buffer setting of the atmospheric influence range of different industrial types;the harm degree of urban expansion is characterized by calculating the size of urban construction land in the evaluation unit.Vulnerability starts from the two aspects of ecological fragility and ecological importance,and builds a vulnerability evaluation system of bare soil index,soil erosion degree,landscape loss degree,wetness index,and ecosystem service value,forming a comprehensive ecological risk assessment of the mining area.system.(3)With the help of the spatial analysis tool of Arc GIS 10.2 platform,the ecological risk of the mining area after the weights of ecological risk hazard and ecological vulnerability are multiplied by calculation.In terms of space,the ecological risk of the mining area is high in the central and southern parts and low in the northwest.In the planned area of the Baorixile open-pit mine,the ecological risk value stripping area> unreclaimed area> mining area> coal dump area> industrial square >Reclaimed area;on the time scale,the ecological risk has been increasing from 1997 to 2019.The level 5 ecological risk increased from 0 in 1997 to 3.16% in 2013,and then decreased to 2.38% in 2019.The area of level 5 ecological risk Related to the area of open-pit mining operations,from the analysis of spatial correlation,the ecological risk Moran'I index from 1997 to 2019 has increased year by year.It is necessary to increase the control of ecological risks in mining areas and reduce the impact of high-risk areas on surrounding areas.Effects of radiation.(4)Based on the dominant factor method,the ecological risk management and control units of the mining area are divided into risk monitoring and early warning areas,ecological protection and restoration areas,early warning protection areas,and natural adaptation control areas,and use geographic detector tools to detect differentiation factors and interactions.Take detection results as the focus of risk management and control,and realize risk management and control that takes into account ecological,economic and social benefits.The paper has 51 pictures,31 tables,and 114 references.