| In recent years,with the acceleration of urbanization,ecological space has been occupied and destroyed.The service function of urban ecosystem is reduced,and the ecological environment is serious.The study of ecological space is of great significance.This paper takes xuzhou as the research object,which based on the land use type of 1995 /2000/2005/2010/2015.Based on Arc GIS and Fragstats,the evolution of area and spatial pattern of ecological space were studied.In order to increase the connectivity of the ecological space and optimize the ecological space,this paper constructed the minimum consumption distance model to identify ecological corridors and ecological nodes.Finally,the optimization strategy is proposed.By studying the evolution of ecological space in xuzhou,the following conclusions are drawn:(1)The area of woodland decreased by 24km2;The grassland decreased by about 15km2;The waters decreased by 6km2;There was little change in the unused land.(2)By studying the transfer matrix of land use,it was found that about 20km2 woodland,6km2 grassland and 13km2 water area were converted into construction land.In the process of massive encroachment on farmland,4km2 of woodland and 13km2 of grassland were converted into farmland.(3)This paper calculated the change of ecological spatial pattern in Xuzhou.The largest patch index of woodland decreased and the split index increased,which indicated that large woodland patches were encroaching and the fragmentation degree of patch increased.The largest patch index of the grassland decreased from 0.4 to 0.07,the separation of the patches increased,and the large patch of grassland was all occupied.The remaining grass patches were small patches.The patch density of water changed little,the largest patch index rised,the separation index decreased,and the area of the largest water patch increased,but the whole was still in a delicate trend.To sum up,under the double pressure of construction land expansion and farmland protection policy,the ecological space area of Xuzhou was reduced,the large ecological patches were destroyed,and the degree of patch fragmentation was increased.Through the study of xuzhou ecological space optimization,the following conclusions are drawn:(1)When the particle size is 850 m,the connectivity of the ecological space structure is the highest,which is the optimal ecological source structure of xuzhou.Xuzhou has 45 ecological sources(15 primary sources,16 secondary sources,14 tertiary sources),and the minimum ecological area is 1.2km2.(2)There are 47 ecological corridors in Xuzhou,11 river ecological corridors and 36 green ecological corridors.By combing the ecological corridor,this paper divides into 9 important ecological corridors,4 regional corridors,3 subregional corridors and 2 connecting corridors.There are 65 ecological nodes in xuzhou,and the identified ecological nodes are constructed as park green Spaces with an area of about 5hm2.(3)The study found that,after ecological space optimization,the ecological land area increased,the connectivity of ecological patches increased significantly,the separation degree was greatly reduced,and the optimization results were good.(4)The optimization strategy of xuzhou ecological space is put forward.The primary ecological sources shall be strictly controlled and protected,and no form of development and construction shall be allowed.The secondary sources should prohibit the construction of projects and facilities that cause harm to the ecological environment,and strengthen the ecological restoration of subsidence.The tertiary sources should strengthen the protection of native vegetation,and properly develop the constructive and touristic development activities that meet local standards.Ecological corridor and ecological node should be constructed and protected according to its importance. |
PDF Full Text Request