The Study On Longitudinal Evaluation Of Eco-environmental Quality In Lanzhou City Based On GIS And RS

In recent years, with the boost of economic, the economic and social level have elevated to a new level. However, ecological problems have also emerged along with economic development. Landslide, drought etc have attracted people's attention to ecological problem. People gradually realized that it is very important to adjust the relationship among society, economic and ecology to maintain the sustainable development of this country.This paper describes ecological environment quality assess theory and method. It contains the relevant concepts, styles, method and index system etc, which is the theory foundation of this paper. It also includes the advantages and applications of GIS and RS in assessment, which plays the role of technical and experience foundation.Lanhou City, capital of Gansu province, is located in the overlap of Tibet plateau, Mongolia-Xinjing plateau and eastern plateau, having complex and typical terrain and climate characters. At the same time, it is one of the earliest industry city founded in northwestern region because it is also the typical valley city in northwestern drought region.Lanzhou is selected as the target, referring index system and evaluation criteria published by《Technical criterion for eco-environmental status evaluation》, using stratify and export consulting method to optimize its items. The new system is more suitable for Lanzhou, based on which, over 20 years data is used to analysis ecological environmental quality, among which,1986,1995,2000 and 2007 representing the trend. Using the platform of GIS and RS, data gained from remote image, basic geographic data, year book and other published materials is under analyzed. Further, evaluations of ecological environment quality in 1986,1995,2000 and 2007 are provided. The evolve trend over the last 20 years of Lanzhou City is given. In the end, the driven factors are analyzed from nature and humanity aspects. The paper also provides suggestions and strategies as references for further ecological environment construction of Lanzhou.