| The land ecological safety influences and constrains the condition of natural environment and the healthy development of social economy.In recent years,with the increase of human activity intensity,land erosion and desertification,mining area pollution and surface subsidence become more and more serious,which threaten the land ecological safety of study area.The DongSheng district is one of the typical areas of fragile ecological environment in Inner Mongolia,where energy development of DongSheng district is dense,the economic development is fast.Therefore,land ecological security evaluation research has great practical significance on scientific management of land,coordinating land ecological construction and protection,and optimizing the ecological spatial layout of land.In this paper,took the typical area of energy development-DongSheng district as research area,used remote sensing data,DEM data,land use status data and some thematic data,analyzed the influence factors of land ecological security.Based on the natural economic social framework model,the evaluation index system of land ecological security is established,and the entropy weight method is used to determine the index weight.Then used GIS space superposition method and comprehensive index model,calculated the comprehensive index and classified the state of land ecological security to evaluate and analyze land eco-security of study area.Finally,analyzed the ecological security changes of different factors by combining with the evaluate results and the land use types,natural factors and social economic data.The main conclusions are as follows:(1)The influence factors analysis results of land eco-security are: The change of land use leads to the change of carbon storage in the soil,thus affecting the safety of the whole ecosystem.In the period 1993-2015,the increase of construction land or urban expansion in study area caused the reduction of carbon storage.To certain extent,topography determines the status of land ecological utilization and soil erosion,the amount of soil erosion increase when slope increase,but the trend of increase is slow,the erosion degree of urban area is the largest.Desertification of the study area is mainly distributed near towns,densely populated areas and roads,which is greatly influenced by social development and economic construction.Mining activities are the main causes for surface subsidence and cracks,and regional ecological pollution.The mining industry of the study area has been developing rapidly during 1993-2015,as the mining area in TongChuan town has increased by four times.(2)The result of land ecological security evaluation is:In the period 1993-2015,the land ecological security status of Dongsheng district shows a good trend,but it is still in the unsafe range,and it also shows great volatility in time and space.In 1993,2005 and 2015,the comprehensive values of land ecological safety was seperately 0.383747,0.506635 and 0.452324.The safety grade was unsafe,general and unsafe.The land ecological security level of Dongsheng district increase at first,and then decrease,the land area proportion of ecological safety grade is 37.21%,45.15% and 41.32%.In space,the ecological unsafe areas are mainly distributed in the southern parts of HanTai Town,city proper and Tong Chuan town,and the ecological safety zones are mainly located in the east of BoJiangHaizi town and the northwest of HanTai town.(3)The ecological security changes analysis results of different land use types,natural factors and social economic are: grassland,forest and water area are the main contributors to the state of land ecological environment in Dongsheng district,while construction land and other land use are indispensable factors of the rational allocation and sustainable utilization of land resources.The land ecological unsafe areas of study area are mainly distributed in the low vegetation cover areas with vegetation coverage less than 20%,while the safety areas are mainly distributed in the medium or high vegetation coverage areas.The land with low elevation and low slope has largest proportion in safe area.The greater the elevation and the slope,the more unsafe the corresponding land ecological security level is.Mining areas,traffic roads,cities and towns are mainly distributed in the unsafe areas.The closer to the mining areas and traffic areas,the greater the land ecological unsafe area is,the greater the damage to the land along the line.The city has the greatest pressure on the land ecosystem,and the rural residential area is the smallest.The land ecological security status in the cities and towns or surrounding areas is relatively poor.The conclusions can provide some reference for the rational distribution of land use,the coordinated development of human and land,the optimization of land ecology and formulation of ecological risk prevention strategy. |
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