| Yushenfu coalmine is one of key mine in Yu Lin city.In recent years,with increase of mining activities,the surface environment of coalmine is degaraded by different degrees.FVC and soil erosion are important aspects to consider whether land is degraded.Therefore,this thesis analyzes land degradation in coalmine from these aspects,and connecting with natural factors and human activity factors to analyze its impact on FVC and soil erosion,so as to provide scientific references for the restoration and reconstruction of ecological environment and sustainable land use in Yushenfu coalmine.The major conclusions of this thesis are as follows:(1)Basing on the MOD13Q1 of MODIS data,the spatio-temporal distribution characteristics and inter-annual change trend of FVC were studied using the pixel dichotomy model and linear regression trend.Results showed that the area of low FVC was distributed in the south of Wulanmulun River and the north of Wuding river;the area of high FVC was located in Shenfu mining and the south of Yuheng mining.The inter-annual trend of FVC showed a(first descend and then rise)improved trend from northeast to southwest.In addition,basing on the research of spatio-temporal evolution of desertification,area and its percentage of non-desertification and slight desertification showed a increasing trend year by year,moderate and severe desertification's area and its percentage gradually decreased.this suggested that desertification degree in Yushenfu coalmine was weakened year by year.(2)Studying the dynamic change trend of land use conversion and the spatio-temporal characteristic of soil erosion in Yushenfu coalmine by the GIS spatial analysis,transfer matrix and RUSLE.The soil erosion and land use change in Yushenfu coalmine were more drastic.The urban land,unused land and farmland have most change.The main land use types in the transfer direction: woodland,grassland into urban land,farmland and unused land,unused land into grassland,woodland and farmland,woodland and grassland mutual transformation.The extent and area of unused land was shrinking and concentrated on the south of Yushenfu coalmine.Soil erosion of Yushenfu coalmine was dominated by micro-degree,mild and moderate erosion.Its result shows that micro-eroded erosion was mainly located in the south of S301,the north of S204 and the west of Shenyu expressway,and other grades erosion were scattered throughout the study area.In addition,soil erosion in the key coal mining area was aggravated,which indicates that mining activity aggravates the degree of soil erosion.(3)Through the analysis of FVC driving factors.At elevation(899-1000m),slope(0-4 and over 28 degrees)and plain were the most obvious change part of mean-FVC.The effect of land use conversion types on vegetation in 2010-2015 is better than that in 2005-2010.The impact of mining intensity,land subsidence and plant/dump on vegetation were the most obvious.Analyzing driving factors of soil erosion,results showed that slope had an obvious influence on soil erosion,while altitude and the landform had less influence on it.Over time,the area percentage change of micro-degreeslight,intensity and acute erosion grades in subsidence area were not obvious,and the change range of slight and moderate erosion grades were severe.Area percentage of moderate and below erosion grade in coal mining intensity was increased;and the other erosion grade area was decreased year by year,but its distribution area was expanded.The impact of socio-economic factors on soil erosion was increased first and then decreased(2009-2016).By analyzing spatial heterogeneity of driving factors,it was found that climate and mining activities have a higher impact on FVC;topography,mining activities and socio-economic impact on soil erosion was relatively high. |
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