Study On The Suitability Evaluation Of Construction Land Of Haitong In Dali Based On

Yunnan province is a mountainous province. The mountainous area of it is accounting for ninety-four percent of the total area. The dams(include basin and river valley) area of it is just only accounting for six percent of the total area. Besides, the number of level ground that the area are more than 1 square kilometers are about 1557, the total area is 25100 square kilometers. The number of level grounds that the areas are more than 100000 square kilometers are about 375, the total area is 22000 square kilometers. The ground resources that can be used are quite limited. With the continuous development of economic and society, the need of urban and rural construction land continue increasing, and the cultivated land resources continues to decline, the contradiction between land development and protection is more and more prominent. According to the statistic data of relevant departments, more than thirty percent of the dams that the area are more than 10 square kilometers are been used for construction. The high quality cultivated land will reduce further if those dams are not timely protected. The dams are surrounded by lots of barren hills and of great potential, many of the are gentle rolling hills. The geological conditions, the ecological environment and the ecological landscape effect are superior. To realize the goal of the protection of basic farmland, build towns in the hills and leave the fertile land for our descendant. The land use suitability assessment in low-slope hilly regions becomes the principal work.This article takes the center area of Dali-Haidong as an example, under the principle of the ecological priority, sustainable development, intensive and adjust measures to local conditions. Establish a set of evaluation index system combine with 12 evaluation factors that are selected from the natural factors, social economic and ecological sensitivity factors. Combined with analytic hierarchy process(AHP) and Delphi Method(Delphi Method) to determine evaluation index weights and scores, using the spatial analysis and overlay analysis function of ArcGIS, and use build model in ArcGIS ModelBuilder. Using comprehensive index evaluation model for grid computing on grid scale. The land suitability is divided into suitable, more suitable,poor suitability and not suitable for foue levels according to the mutation of the grid score. And to offer a scientific basis for reasonable planning land use.The main research results of this paper are as follows:(1) The investigation of the land resources of the low-slope hilly regions. Combining with the actual conditions of Yunnan province, low-slope hilly commonly defined as the regions of under 3000 m above sea level, and the slope between 8 ° and 25 °.The total area of dams(include basin and river valley) in Dali is 48954.74 hectares, accounting for 28.15% of the total area of the Dali. The area of the mountain resources that the slope is greater than 8 degrees is 124891.30 hectares, accounting for 71.83% of the total area of the land. The total amount area of the low-slope hilly land resources is 85606.33 hectares, accounting for 49.22% of the total area that has great development potential and mainly distribution in Fengyi town, Shuanglang town and Haidong town.(2) The land use suitability assessment in low-slope hilly regions.Set up the evaluation index system and build the model in ArcGis ModelBuilder.Then use the comprehensive index evaluation model to to evaluate the land use suitability assessment in low-slope hilly regions.From the result we can see, the area of more suitable construction is 4.61 square kilometers, accounting for 15.1% of the total area of the study area, the area of suitable construction is 3.54 square kilometers, accounting for 11.5% of the total area of the study area, the area of poor suitable construction is 19.64 square kilometers, accounting for 64.0% of the total area of the study area, the area of not suitable construction is 2.89 square kilometers, accounting for 9.4% of the total area of the study area.(3)The analysis of evaluation results. According to the map of the land use suitability assessment in low-slope hilly regions. The regions of more suitable and suitable are mainly distributed in the milling area and more gentle slope area, these areas are with relatively flat topography and the ecological sensitivity degree is low, and with highly supply security degree of water and electricity. The external traffic is convenient, and with no distribution of important mineral resources, combined with the stability of the tectonic and lower development costs. These regions are suitable for construction. The regions of poor suitable and suitable are mainly distributed in the area with higher slope. And the main limiting factors include the topography, water environment, vegetation distribution and the possibility of induced geological hazard. That need the full study of various limiting factors, combine with the necessary engineering methods after research to reduce the limits of the these factors on the development and construction;The regions of not suitable and suitable are mainly distributed in the area that along the Erhai lake wetland area and the basic farmland protection areas, these areas are with higher ecological sensitivity. After the destruction is not easy to recover, so those areas need focus on the protection, and should be banned all development and construction activities in addition to moderate for tourism development.