Study On The Suitability Of Land Use In ErHai Basin Under The Perspective Of Spatital Planning

With the rapid advance of industrialization and urbanization in China,the supply of space limitations and the contradiction between the infiniteness of human society development demand increasingly prominent.Which intensifying the contradiction between the national spatial development and ecological construction.The problem of environment pollution and urban construction "booth pie" type development is becoming more and more prominent.Matching based on "the development and carrying capacity" of the concept of sustainable development,in erhai lake basin as the research object,from urban construction suitability,agricultural land suitability and ecological land use suitability,21 evaluation factors are selected to build up the erhai lake watershed land use suitability evaluation index system.Based on ArcGIS technology platform,ecological niche suitability evaluation model was applied to evaluate the suitability of urban land,agricultural land and ecological land in erhai basin.On the basis of three kinds of land suitability evaluation results,delimit the erhai lake basin by applying the method of three-dimensional rubik's cube space partition,urban space,agricultural space,ecological space.three types of space respectively put forward the direction for the development of three kinds of space and space optimization countermeasures.lt is of great significance to promote the efficient utilization of the space and optimize the spatial pattern and sustainable development of the erhai basin.The main results are as follows:Firstly,The suitable level of land use in erhai basin presents the trend of gradual decline from "ecological land-agricultural land-urban construction land",which is consistent with the territory status that is superior to the ecological base of the basin,rich in natural landform and insufficient land for development and construction.In addition,the ecological suitability levels of the land for urban construction and agricultural present high in the middle and low in the around.The first class suitable area shows the distributation trend of the belt extending southward from erhai lake.The construction land of the town is at a high level in the downstream of the erhai lake,and the agricultural land is bounded by erhai lake,the high level of agricultural land aggregated in the west and the north of erhai lake,and the low level scattered in the east of erhai.Ecological land is less restricted by topographic factors,so it is more appropriate.The high appropriate area of ecological land is mainly concentrated in the northern and southern mountainous areas,and the low-value area is mainly located in the surrounding area of erhai lake and the upper part of the river.Secondly,From the point of all kinds of land use suitability rank distribution,The total suitable area of urban construction land is 1936.51 km2,accounting for 66.22%of the total area of the basin,but it is dominated by third-class suitable area,whose total area is 972.05 km2,accounted for 50.35%of total suitable area;The area of the fourth-class is equivalent to the third-class.The second-class is suitable for the region and the first-class are only occupies 32.98%of the total area.The total suitable area of agricultural land is 2066.18 km2,accounting for 70.65%of the total area of the river basin.However,it is dominated by third-class suitable area too,accounted for 50.73%of the total rural areas,The area of the fourth-class is equivalent to the second-class,and the second-class is more advantage.The total suitable area of ecological land is 2718.29km2,accounting for 92.95%of the total area.while,the second-class and third-class suitable areas account for 75.50%of the total suitable areas,and the area of fouth-class is 206.09km2,accounted for 7.05%of the total area.According to the city and county,Dali city has absolute advantage in ecological land and urban land,and eryuan county has absolute advantage in agricultural land.Therefore,the two cities and counties should be based on their local practice,give full play to their own advantages,reasonable layout of urban construction land,and other land,to promote national spatial development benefit maximization.Thirdly,the area of urban space,agricultural space and ecological space in erhai basin is:148.35 km2,1158.97 km2 and 1616.75 km2 respectively,accounting for 5.08%,39.63%and 55.29%of the total basin area respectively.From the point of spatial distribution,urban space usually lie in the agricultural space and ecological space,as well as along the erhai lake and polo river extension,and there is a zonal extension in the southern tip of erhai lake;The agricultural space is mainly concentrated in the dam area in the middle of the basin,with erhai lake as the boundary,which shows the characteristics of haixi concentration and the distribution of east.Ecological space is mainly located in the west,south and north west mountainous area,and change with the mountains,at the same time,there is a distribution between urban space and agricuatural space in the east of erhai lake and eryuan.Fourthly,Propose space development proposals,the main idea is using "three lines" o ensure the coordination of "three zones".By demarcating the urban development boundary and regulating the intensity of space development,strictly controlling the urban construction space scale of the erhai river basin,and promoting the efficiency of the urban space intensive in the basin;We will strictly regulate the development of agricultural production space and promote the appropriate living space for agricultural space through the demarcation of permanent basic farmland and ensuring the capacity of agricultural production.In order to define the ecological protection red line and improve the ecological service level,we should strictly protect the ecological space and promote the ecological space.