Application of GIS and RS technologies to the evaluation of natural suitability of human habitation in Qiannan karst area

In this paper,an evaluation model for natural suitability of human settlement,by integrating key factors as relief degree of land surface,temperature and humidity index,vegetation index,hydrology index and climate suitability,is established.Based on Geographic Information System and Remote Sensing tech-niques,the natural suitability and restrictiveness for human settlement in the Qiannan karst area were evalu-ated,respectively.Results show that 1)The human settlement in the karst area is mainly characterized by the zones of critical habitability and general habitability,which respectively hold 57% and 43% of the entire area,while the natural suitability of human settlement environment generally shows a trend of increasing ar-ea from the mountains to the hills,the valleys and the plains;2)The natural conditions of the human settle-ment in the area studied,including the features of topography,climate,hydrology together with vegetation, have the influence on the population distribution in different extent,of which land surface is most restrictive, followed by terrain conditions.Scientifically evaluating the natural suitability for human settlement of Qian-nan karst area can guide the functional location and population distribution,which has guiding significance on the coordinated development of population and environment.