The Evolution Process Of Ecological Risk And Prevention Mechanism In Coal Mining Area

China is being in the important strategic period for the development of economy and society,which is eliminated by the resources and ecvironment.As an important energy mineral resource,coal resources widely distributed in ecologically fragile regions.The mining poses a great disturbance to the environment,leading to regional ecosystem degradation.Thus,it is necessary to clarify the occurrence and development rules of mining area ecological risk,and study the prevention mechanism in the new normal.With combination of field survey and the interview,this paper summarizes the potential risk characterization of the nature-social ecosystem in mining area.Moreover,it analyses the temporal and spatial variation of ecological risk in the process of land destruction and reclamation based on the quantitative classification and qualitative evaluation.The main conclusions are as follows:(1)The occurrence and development of the mining area ecological risk associated with the land disturbance caused by human activities,and it is embodied in the forms of environment risks and society risks.Affected by external and internal forces,such as global environmental change,economic development policy and other macro factors,the way of mining activities and management measures,etc.,mining area ecological risk types are divided into three kinds,the original risk,profit oriented risk and invalid management risk.The national coal accumulation area can be divided into nine ecological risk areas from two aspects of natural environment districts and mining disturbance to reflect the ecological risk differentiation characteristics under the macro space.(2)With application of remote sensing and GIS,this paper analyses the feature classification of NDVI change in Pingshuo mining area from 1987 to 2015.The results are concluded that,due to different mining and reclamation schedule the ratio of area with and without vegetation coverage presents periodic fluctuations.The average time for non-vegetated status by mining and vegetated status to original level by reclamation is 11 and 5.6 years.The time needed for restoration engineering is affected by the dump process and management level,but not closely related to the beginning time of reclamation.(3)Frequency and intensity of mining activities,scientificity of mining and land reclamation measures determines the change degree of mining area ecological risk.This paper divided study area into 30 m by 30 m grid unit,through to the evaluation of each unit,realize the mapping and classification of ecological risk in mining area.The land destruction cumulative effect model is used to calculate the cumulative effect value of risk sources,and remote-sensing images and the field measurements were used to calculate the ecological vulnerability value.By calculating indexes we get ecological risk values of mining area in 2001 and 2010.The result shows that: with the increase of coal production,the range of land destruction cumulative effect had been increased 7,095.17 hm2 from 2001 to 2010.With the continuing eastward of open-pit mining area,its effect to west study area is weakening.After 10 years of land reclamation and ecological reconstruction,the ecological risk values of reclaimed dumps are on the decline and eco-system trend to be stable.The medium and low risk area account for 0.02% of the mining disturbed area in 2001,and up to 16.77% in 2010,and it means that land reclamation is helpful to reduce the effects of ecological risk.Different scenarios were established based on the ordered weighted averaging(OWA)algorithm in the risk assessment.(4)Based on the field investigation and survey,this paperdiscusses the “mining,land use and population” dilemma caused by mining development and analysesthe characteristics,driving forces and management countermeasures of the change of farmers’ living and production style by constructing pressure-state-driving-response model.Mining activity is the most direct reason to result in the deterioration of living,production and ecological environment for the the surrounding residential areas.(5)Mining area is a compound ecosystem by the combination of natural ecosystem and social ecosystem.This paper establishes ecological risk prevention and control mechanism of coal mining area from three aspects of prevention,monitoring and coordination.In view of the different stakeholders,different scales and different prevention levels to establish the sustainable development of mining area.