Srp Model Based Spatial-temporal Differentiation Analysis Of Ecological Vulnerability For Resources-exhausted Region

With the rapid development of social economy and the human and society's increasing demand for natural resources,the pressure that natural ecological environment bears is gradually increasing,which cause the damage of ecological environment,especially in resource-exhausted cities.Fuxin in Liaoning Province is a typical case of resource-exhausted cities that thrive with rich coals and fall with poor coals.Several decades ago,rich mineral resources and wide mining land were found in this city.However,excessive development of mine left this place mass of industrial wasteland such as pits and coal mining subsidence area,which caused serious ecological environment destruction;Meanwhile,Fuxin locates in north temperate continental monsoon climate zone,an area that seasons are clearly defined,sunshine is abundant,the air is dry and the wind is plenty.What is more,the spatial-temporal distribution of rainfall is unevenly distributed,and the general trend of precipitation is decreasing from southeast to northwest.This is a typical pattern of ecological vulnerability area in ecotone between agriculture and animal husbandry in north China.Eco-environmental problems caused by the superposition of natural factors and human activity severely constrain the economic development of Fuxin.The ecological vulnerability research for Fuxin not only devotes to understanding the impact of climate change and human activities on the ecological environment,also help revealing the spatial-temporal distribution rules of resource-exhausted city's ecological vulnerability.Meanwhile,it has vital significance for developing regional ecological restoration and reconstruction and promoting the sustainable development of society,economy and natural environment in Fuxin.Based on the eco-environmental characteristics of Fuxin City,using the basic data such as land use,climate,precipitation,remote sensing image and soil,digital elevation Model(DEM)of Fuxin in 2000,2005,2010 and 2015 years,combining with statistical data such as demographic and socio-economic development of Fuxin and utilizing GIS and RS technology to combine ecological sensitivity-ecological recovery-ecological pressure model(SRP),this work is aimed at researching the spatial-temporal changes of ecological fragility in Fuxin from 2000 to 2015.The findings are as follows:Firstly,found on analyzing the causes of ecological fragility of resource-exhausted cities,the criterion layer including ecological recovery force,ecological sensitivity and ecological pressure is constructed,which contains 9 element layers:landscape structure,vigor,function,topographic factor,the earth's surface factor,meteorological factor,soil factor,population activity pressure and social environment pressure.Ultimately,an index layer consisting of 14 constraint indexes is adopted to complete the ecological fragility of Fuxin grading evaluation system,and these constraint indexes are landscape diversity index,bio-abundance,mining point disturbance,settlement disturbance,slope,aspect,elevation,vegetation coverage,annual precipitation,annual temperature,average annual relative humidity,soil erosion intensity,population density and GDP density.Secondly,Judging from the area changes of five ecological vulnerability levels in four different years,from 2000 to 2015,mainly caused by the severe drought and the excessive reclamation of cultivated land in Fuxin,the micro vulnerability region in Fuxin was spreading to the northeast,whose area had increased from 13.37%to 34.09%;the area of mild vulnerable region was decreasing,from 62.93%to 34.84%;the change of moderate vulnerable region was relatively modest,the area of this region had increased from 4.38%to 7.89%;the area of severe vulnerable region changed obviously as it had increased from 6.07%to 10.45%then gradually decreased to 4.89%;the area of extreme vulnerability region had increased from 13.38%to 18.29%,which is not obvious but the overall trend was upward.The main reason of it is that decline of the mining industry,besides natural factors.In Fuxin,the eastern part was mainly mild vulnerable,the western part is mainly severe vulnerable;with good ecological carrying capacity,the central part was mainly mild and micro vulnerable;the northeast part was mainly severe vulnerable and in the transition to extreme vulnerable.Thirdly,the regional difference of ecological restoration,ecological sensitivity,and ecological pressure intensity are obvious,these factors synthetically reflect the ecological fragility characteristics of Fuxin.In this city,the micro vulnerable region are mainly distributed in Guohua township,Daban town,Pingandi town and Laomiao town in Fumeng county;Mild vulnerable region are mainly distributed in Jiumiao town,Pingandi town and the Paozi town of Funmeng county and Sibaozi township in Zhangwu county;Moderately vulnerable region are mainly distributed in Daleng Mongolian township,Qianfuxing township,Mantanghong township,Wushan township in Fumeng County;Severe vulnerable area are mainly distributed in Aerxiang town,Zhanggutai town in Zhangwu county,Fuxin town and Shihuage township in Fumeng county.Extremely vulnerable region are mainly distributed in Taiping district,Xinqiu district,Fuxin town,Huashige town and Dongliang town in Fumeng County,Zhangwu town,Zhanggutai town and Aerxiang town in Zhangwu County etc.In short,the ecological vulnerability issue of Fuxin is very conspicuous,different vulnerability types have their own problem,notably the area of severe vulnerability region is large,while the micro vulnerable region has a tendency to deteriorate further.