Spatio-temporal Characteristics Of Land Degradation Of Open-pit Coal Mine Area In Shengli And Its Ecological Remediation Effect

Open-pit mining has seriously damaged the ecological environment.How to reconcile the contradiction between coal mining and environmental protection has attracted academic attention.Taking Shengli open-pit coal mine area(CMA)as an example,the degree and spatial distribution of land degradation were discussed based on 3S technology monitoring method,according to soil,vegetation and land damage data,combined with change vector analysis method.And the geographical detector model and multiple regression analysis were used to screen out the leading factors,and the effect of mine ecological restoration was analyzed from the perspective of time and space.Finally,suggestions were put forward for environmental protection and ecological restoration of the eastern grassland open-pit CMAs.The research results can provide scientific and technological support for green mine construction and ecological remediation in CMAs.And they are of great significance in realizing the coordinated development of the coal industry and ecological protection.The main conclusions were as follows:(1)The total area of land improvement in CMA in Shengli from 2000 to 2019 accounts for 53.65%,showing an overall improvement trend.During the study period,there were differences in the degradation degree at different scales.The degradation degree at the CMA-scale was higher than that at the mine-scale,and the overall land improvement in the grassland area was good.In space,the severe degradation is concentrated in the area of mine pits and dumps which are gradually increasing,and the agglomeration characteristics are obvious.Therefore,the open-pit mining seriously disturbs the ecological environment.(2)Land degradation is strengthened by many factors in CMA in Shengli from2000 to 2019.Human activities are the dominant factors,and the impact of excavation damage and occupation is the most obvious.The closer the distance to excavation damage and occupation,the more serious the degree of land degradation.In addition,the promulgation of relevant policies is an important influencing factor in China;The single factor of climate had a great influence on the temporal variation,but the explanatory power of the spatial distribution was small(1.26%-4.31%).However,the interaction is significantly increased,and the annual precipitation,annual temperature,annual wind speed and relative humidity are the main climatic factors;Natural local conditions have little effect.(3)The changes of NDVI were calculated before and after ecological restoration,and the NDVI values of the landfill and surrounding natural cover after remediation were compared.Through the verification of albedo,the ecological restoration effect of Shengli Mine was good on the whole and increased year by year.On the other hand,the vegetation coverage of the restored dumps was significantly higher than that before remediation,and the NDVI value of Shengli No.1 Mine dumps has no significant difference with that of the surrounding dumps in 2015 and 2019,indicating the most obvious restoration effect.Ecological remediation can reduce the damage to the ecological environment caused by open-pit mining and is beneficial to the improvement of the ecological environment.(4)In order to comprehensively improve the ecological environment of the CMA,relevant suggestions are put forward from the perspective of "overall perspective,source control,dynamic monitoring,comprehensive management and common progress ".Overall perspective: we should improve the policy of returning grazing land to grassland and achieve regional sustainable development;Source control:priority should be given to ecological protection and scientific exploitation of mineral resources;Dynamic monitoring: the multi-scale ecological monitoring system of open-pit mining area is constructed by highlighting the correlation of elements;Comprehensive management: we should optimize the target path and promote the ecological restoration of multiple mines;Common progress: to promote the positive development of mining area economy and land.The thesis has 43 figures,20 tables and 118 references.