Yellow River Basin In Rs And Gis-based Ecological Safety Evaluation Studies

Ecological security means that an ecosystem is no suffered or little suffered of being destroyed and threatened, which is an essential condition for human survival and evolution. Ecological security is an important constitute of National security and Social safety, as well as ecology guarantee of the ecology-economy system and sustainable development.The evaluation of ecological security, based on the evaluation of environment quality, evaluates the condition of ecological security including both of environment gene and the ecosystem for the service function and guarantee the social economic society sustainable development of human being.Take HuangShuihe river valley as an example for the evaluation of ecological security in the text. First, take grid as basic unit and get ecological security gene information of each grid. Then, figure out ecological security index of each grid, by operating the model of the ecological security evaluation. Finally, acquire ecological security classification. The primary research contents and research outcome as follows:1. Aim for ecological security actuality of HuangShuihe River valley, establish ecological security index system that include three aspect, State, Pressure, Response, 9 element layers and 17 index factors based on P-S-R model.2. Correct and enhance remote sensing image, then Obtain land use and cover, vegetation cover degree, degree of soil erosion and so on. With the help of GIS and weather datum, physiognomy landform and society statistic datum to acquire other Ecological security factors information.3. Establish Ecological security factor database, collect Ecological security factor datum, and input them to database according to uniform figure environment frame. The database of Ecological security includes basic element, landform physiognomy, weather element, environment actuality, society attribute and ecology stress database and so on. 4. Classification standardization of guideline factor, calculating single factor ecosafety index from three aspect, environment state, society pressure and society response. The result showed the upper stream of Huangshuihe valley was better in environment state,while the downstream of Huangshuihe river is much batter in society pressure and society response.5. The degree of Ecological security was divided into five degree according to Ecological security index. The most area of Huangshuihe valley was safety and basically safety, which was 46211 ha and 40474 ha, accounting for 45.2%and 39.6%. 5.7% specially security and 9.2% insecurity and specially insecurity only 0.3% of total area. The average Ecological security index of Huangshuihe was 69.7,belonging to basically safety.