A Study On The Ecological Environment Evaluation Of Ruoergai County Of Sichuan Province Base On RS And GIS Technology

With the world's population ceaselessly increasing, economic and social developments has stimulated a sharply increasing demand for energies and resources. Meanwhile, the over exploitation of natural resources results in severe pollutions, fury people-land conflicts and deteriorating ecological environment, threatening human survival and social development. In order to get us a deeper understanding about the earth, it's necessary to conduct ecological environment investigations and evaluations, which is an important subject concerning human sustainable development and able to provide theoretical supports and references for decision makings about regional economical developments and ecological environment protections.Ruoergai County of Sichuan Province is located in northern part of western Sichuan Plateau, the eastern edge of Qinghai-Tibet Plateau. As a water conservation district for Yangtze River and Yellow River and ecological function protected area, its location is very important. However, due to natural and human reasons, it suffers deteriorating ecological environment and growing grassland desertification and marsh degradation. Therefore, for the sake of regional social and economical sustainable development, it's of great importance to research and assess Ruoergai County's present ecological environment, explore the driving forces influencing the environment and propose some countermeasures to improve it.Depending on related theories and techniques in Remote Sensing and GIS, the thesis sets up interpreting signs corresponding to the area's characteristics with TM remote sensing pictures as main data sources, and constructs a basic database of ecological environment in researching areas. Then the thesis selects pressure-state-response model to found an index system by summarizing previous research results, and assesses Ruoergai County's present ecological environment by means of Analytic Hierarchy Process (AHP). Finally, the thesis analyses the driving forces according to the evaluation, and proposes countermeasures to protect the ecological environment.The thesis's main findings are as follow:(1) Focusing the terrain characteristics of the researching area and combining remote sensing pictures processes with local investigations, the thesis sets up interpreting signs for the remote sensing pictures of the areas with the help of the theories and techniques in Remote Sensing and GIS, and constructs a basic database of ecological environment for the areas by means of automated classification in computers as well as classification of human-computer interaction. On the basis of that, the thesis analyses the space distribution, the structures and the level of the area's land use, providing basic data and background materials for the area's ecological environment evaluations.(2) By researching and summarizing related theories on ecological environment evaluations, the thesis selects pressure-state-response model to be the evaluation's concept model. By taking Technical Specifications of Ecological Environment Evaluations as assessing criteria and selecting a number of indexes including nature, ecology, society and economy, etc, the thesis founds an assessing criteria system for the area's ecological environment. And by combining the area's characteristics with previous research results, the thesis amends some indexes in Technical Specifications, which has some reference value for other areas'ecological environment evaluations.(3)According to the evaluation, the thesis analyses the driving forces from several aspects such as nature, humanity and biology, comprehensively examines the impacts of each type of driving forces on the ecological environment, and proposes corresponding measures to improve Ruoergai County's ecological environment in consideration of practice.