The Urban Ecological Function Regionalization In Hilly Region Of Red Soil Base On RS And GIS

The hilly region of red soil is a type of ecosystem which has poor ecological stability, great fluctuation of bio-tissue and productivity, and be sensitivity to human activity and unexpected disaster, and would appulsively be unfavorable to human. It widely distributes in south of China. The study of ecological function regionalization in hilly region of red soil has great academic and practiced significance in protecting local brittle entironment and promoting coordinated development of economy and environment.This study takes Changsha City– a typical hilly region of red soil as an example, analyzes and simulates its current status of entironment and ecological function regionalization by the methods of Remote Sensing(RS), Geographic Information System(GIS) and space simulation etc. The aim is to explore indicator system and research methods of ecological function regionalization which is suitable to hilly region of red soil. This paper takes more attention to the process of ecological function regionalization base on the methods of RS and GIS, and the method of regional urban expansion land ecological suitability evaluation.By interpreting Landsat TM/ETM+ remote sensing image, the study not only undertake an overall analysis on the current status and developing trend of entironment in the territory of Changsha City, but also evaluates the quality and sensitivity of the whole ecosystem; specifies the importance of ecosystem service functions; and also differentiates and analyses the quality and sensitivity of the ecological environment and the importance of ecosystem service functions upon their various spatial and geographic distributions. This study further markes of different ecological function zones in Changsha City and also presents relevant key tasks, goals and measures of protection and establishment of the ecological function zones.The results show that only 7% of the total land areas (approximately 827.64 km2) are maintaining at higher or the highest grades of the ecological and environmental quality in Changsha City. However, there are 52.4% of the lands (approximately 6187.14 km2) are getting worse or the worst grades of the ecological and environmental quality. Most areas of Changsha City stand in areas of ecosystem with low sensitivity. Areas with sensitivity at high-level amount to 24.19%, areas with sensitivity at middle-level and low-level respectively account for 26.87% and 18.23%. The most important ecological service functions areas around Changsha City amount to 31.91%, important and comparatively important respectively account for 41.03% and 26.09%. In ecological function zones of Changsha City, class I amount to 0.12%, and the class II III IV V respectively occupies 34.33%, 13.64%, 26.18%, 25.73%.On the basis of ecological function regionalization, this study also evaluates urban expansion land ecological suitability of Changsha City. The results show that the percentage of the highly suitable land, suitable land, moderately suitable land, unsuitable land and permanently unsuitable land are respectively 14.77%, 16.64%, 24.07%, 30.91% and 13.61%; most lands are suitable for construction(the total percentage of highly suitable, suitable and moderately suitable land is 55.48%). The result coincides with urban development current status, the controlled principle and key points of urban space structure which is one main, tow secondary and four groups put forward in Changsha Comprehensive Plan, and the expansion landuse of Changsha City.