Analysis Of Land Use And Ecological Environment Vulnerability In Dongjiang Watershed

With the rapid development of remote sensing technology,scholars have gradually focused their attention on the relationship between land use and ecological environment.The change of natural environment is closely related to the change of land use type,and the change of land use will bring about the change of the vulnerability intensity of the ecological environment.It is of great significance to maintain and protect the green sustainable development of regional ecological environment by studying the influence of land use on the change of ecological environment vulnerability.Dongjiang River Watershed is located in Hilly and mountainous of southern China.It plays a major role in the safety of production and living water for about 40 million people in Hong Kong and Macao.It likes its ecological barrier.Therefore,we study the impact mechanism of land use on its ecological environment vulnerability in the Dongjiang River Watershed can provide support for regional sustainable development.Aiming at the ecological environment problems in Dongjiang River Watershed,we take land use change on the ecological environment vulnerability response as a starting point of research,using GF-1 remote sensing data,DEM data,meteorological data and economic statistical data and other types of data,by means of GIS,analyzing and comprising various classification accuracy,selecting object oriented classification to draw the land use classification map by using GF-1 remote sensing image.Based on this,choosing related evaluation factors of the watershed corresponding ecological vulnerability from the ecological sensitivity and ecological pressure-ecological restoration force levels;establishing a vulnerability model of the ecological environment in the watershed,analyzing the response regularity of distribution and land use types on the ecological vulnerability of the Dongjiang River Basin in 2015,in order to provide decision support for the ecological environment of the basin,the research results are as follows:(1)In view of the land use classification in Dongjiang River Basin,the object oriented CART decision tree classification method has good extraction effect,and the overall classification accuracy is 93.19%,which can achieve the precise extraction of its land use information.(2)The ecological vulnerability of the Dongjiang River Watershed is dominated by moderate vulnerability,and the moderate and above vulnerability ratio is 61.98% in the total research area.Moderate vulnerable area mainly distributed in Xunwu,Anyuan,Heping Longchuan,Xingning,Huiyang,Shenzhen,Baoan and Huidong counties.The ecological vulnerability distribution is: the ecology of the northern Gannan is more fragile,it is mainly caused by the cultivation of navel orange,serious water erosion and disordered rare earth mining;the middle part of the basin mainly for the slight and mild vulnerability,the region has a steep terrain,and the effective implementation of Guangdong afforestation policy;so the southern part of the basin in strength and vulnerability,also the region includes Guangzhou-Shenzhen-Dongguan and other large city,its economic development is rapid and its population is densely populated.(3)There are different types of land use types in the study area,and the distribution intensity of ecological vulnerability is different.Medium strength and strength ecological vulnerability of forest land is mainly distributed in Anyuan,Xunwu,Longchuan,Dingnan,peace,Huidong,Huiyang.As Gannan is located in the upper reaches of the Dongjiang River Watershed,rare earth mining in the region destroys forests;the cities of Guangzhou and Shenzhen are located in the lower reaches of the watershed,and the population of the region is denser.The garden with medium strength and strength ecological vulnerability is mainly distributed in Longmen,Zengcheng,Boluo and other cities and counties.Because the upstream area of the basin is large area of navel orange,which has great interference on the ecological environment.The cultivated land with medium strength and middle ecological vulnerability is densely distributed in parts of Longchuan and Xunwu,and the agricultural development is rapid in this area.The grassland plants in medium strength and middle vulnerability is quite obvious,its growth is small and the distribution is scattered in Anyuan,Xunwu,Dingnan county.The construction land in Dongguan,Baoan and Huiyang is mainly about the medium strength and strength ecological vulnerability.The area of hardened area has a large proportion,which seriously destroys the ecological environment in the area.Above moderate ecological vulnerability of unused land distribution located in Huizhou,Huiyang,Baoan and Gannan,which have rare earth mining residual plots in Gannan.