Suitability Assessment, Land Based Gis Mountain Areas In Yunnan Province

Land suitability evaluation is the process of evaluation of land suitability,and for the purpose of a specific land use.With the development of social economic, the problems among population, resources and environment crup up frequently, so it is an urgent need to conduct a scientific evaluation of land suitability.It's even more important in the alpine and gorge region where the contradiction between population and land resources is prominent. We must adhere to the road of sustainable development because the study area's ecological environment is fragile and with a non-renewable resources. This paper wants through exploring GIS technology and compositive model in the evaluation of land suitability for the alpine and gorge region,to provid the basic data and the development proposal for Lancang County.In this paper, Lancang County as the study area, which has a fragile ecology environment. We chose farmland, woodland, grassland and constructiveland as evaluation objects and an accuracy of 50×50 raster data as the evaluation unit. We selected the impact factors which are suitable for alpine and gorge region. By the surport of GIS thchnology,we established the database of suitability evaluation.By using GIS's powerful Spacial Analyst:Overlay, Digital Terrain Analysis and so on,we have got the special data of the study areas'evaluation factor-s.Finally the author used the Delphi,mathematical model,AHP and Synthesis Index techniqu-e,we carried out the land suitability degree of farmland,woodland,grassland and constructivela-nd in the study area, to support land resources development in alpine and gorge region.We obtained the following conclusions:(1) From the Lancang County's present situation of land use in 2005, the county woodland accounted for 62.58% of the total area, only 25.80% of other land area has been used;A little grassland which seriously hampered the scale of cattle and sheep's development.The area of condtructiveland is too small to satisfy urbanization and industrializati-on.The result shouws:land use structure in Lancang County is single and irrational.(2) From spacial distribution of the results, we can see, highly suitable for farmland and constructiveland areas are located in and around the administrative center near the State Road 214.Highly suitable areas for woodland and moderately suitable areas are located in the main roads.Grassland is widely distributed in the far distance from the administrative center, lying flat in the southeastern region. From the numerical we can see,in the study area,the area proportions of the best suitability degree of farmland, woodland,grassland and constructiveland are 18.15%,17.57%,23.8%,14.21%,the four proportions are all very small.(3) We compared the results of the analysis and the land-use of Lancang County in 2005,the highly suitable areas for grassland are concentrated,but in fact,the distribution of it is decentralization,so we should develop some grassland in suitable place to to support the development of eco-tourism.Thruogh analyse the numerical value,the total of Lancang County's woodland area is 1523.3km2,and the heighly suitable area is 1320.5km2,91% constructive land belongs to heighly suitable.For one thing,it shows Lancang County has a better ecological environment in the present moment,for an other, in study area, the site of woodland and constructiveland are reasonable.The result shows:the combination of GIS technology and the positive model can make the land suitbility evaluation for the fragile alpine and gorge region being more fast and exact. Evaluation results can be used for adjusting configuration of the land resourses especially for the alpine and gorge region.