Study On Land Suitability Evaluation In Karst Area Supported With RS And GIS

In recent decades, with the development of social economy, the problems among population, resources and environment crop up frequently, so that land utilization in all walks of life competes fiercely. Wherefore the land resources cry for being evaluated scientifically, which can offer scientific basis for better tactics of protecting and using land resources. It's even more important in the frail karst area where the contradiction between population and land resources is prominent. This paper wants through exploring the combination by the remote sensing, GIS technologies and the compositive model in the evaluation of land suitability for the representative and frail karst area, to providing the basic data and decision-making gist for the land programming and father.In this paper, central part of Huaxi borough as the study area, which is part of Guizhou Province's metropolis Guiyang City, belongs to the representative karst area, and represents prominently the contradiction between population and land resources. As for different land utilization type, the natural and socioeconomic condition should be analyzed to determine the sort system and build the indices system under the direction of the basic theories. The rocky desertification grade is considered as a index in this especial area. And the weight of each factor is calculated by the measure of Analytic Hierarchy Process. Specifically, the article utilizes the remote sensing images as information sources to process and capture the land information. Then, supporting by GIS, the land information's spatial database and attribute database are set up. At the same time, the article builds the compositive model that aggregating gray correlative degree, expert experience, limit condition and vector repeated addition threshold value synthetical model. Finally, using the model and GIS to conduct land suitability evaluation in the study area and classing the results, the paper works out the land suitability degree of agricultural land, holt, garden plot, grassland, constructive land in the study area, for adjusting configuration of the land resources.The result shows: the combination by which the remote sensing, GIS technologies and the compositive model can make the land suitability evaluation for the representative and frail karst area being more fast and exact. In the study area, the area proportions of the best suitability degree of agricultural land, holt, garden plot, grassland, constructive land are 9.32%, 23.11%, 18.07%, 20.20%, 32.93%. Their distribution accords with the fact.