Dynamic Evaluation Of Eco-environmental Fragility In Guazhou County

In the context of global change, eco-environmental degradation has become a serious problem of human existence and development. The essence of population, resources, environment and economic development problem is ecological environment problem. Since the last century, with the great progress of scientific & technological and productive forces, further development of economic is facing the challenge of population explosion, resource exhaustion, environmental pollution, ecological degradation challenges. In particular, serious ecological environment problem is threatening the survival of the earth species. Although human activities lead to the original habitat degradation, lower vegetation coverage, serious land degradation and so on, these results are also the objective environment which gradually becomes the constraints of the survival and development of human beings. China's natural environment has significant characteristics: varieties and complexity, obvious regional differences, natural ecosystems vulnerable, improper development and utilization, extremely vulnerable, poor natural mediation and outstanding ecological environment problems in many regions.Guazhou County is located at the western end of Hexi Corridor, Gansu Province. Its climate is extremely arid, the sunshine duration is long and sunlight the energy is rich, the temperature difference is big between cold winter and hot summer, drought and hot, frequent natural disaster and blown sand. The land difficult to use is large and the cultivation rate is low in the county. Because of its location and climate, as well as the human activities lead to the ecological environment gets worse and the situation is extremely critical. Although the ecological environment issues of are so serve, there is no reported about ecological environment vulnerability assessment of the county so far. Therefore, assessing the ecological environment vulnerability of Guazhou County is a urgent scientific problem. This study evaluated the ecological environment fragility of the area adopting Fuzzy Comprehensive Evaluation Method. The development regularity of ecological environment was revealed, based on which, the author provided the development strategies and ecological rebuilding measures for the area. This study will contribute to regional sustainable development theoretically and practically. The thesis is organized into six parts as following:The first part presented the research background, reviewed the recent advances in ecological environment fragility assessment research at home and abroad, and then introduced the selected topic aims and meanings, theoretical basis, method and route of this study.The second part summed up the geography characteristics and the state of ecological environment of Guazhou County. At the beginning, the renamed history of Guazhou was introduced. Then, provided a brief survey of the natural environment of the area, including topography, climate, river system, soil and vegetation; and socioeconomic status, including population, GDP and per capita net income. At last, subscribed the current situation of ecological environment vulnerability of the area, from the point of vegetation, forest cover index, grass-land deterioration, land desertification and water resources decrease.The third part built an index system of ecological environment fragility assessment of Guazhou County. According to the principal of index system building and the meaning of fragility, taking in cause - result performance index system, fourteen indexes were chosen to form a series of index system of fragility assessment, meanwhile, worked out a relative standard of it.The fourth part provided a dynamic assessment of the ecological environment fragility of Guazhou County. Fuzzy Comprehensive Evaluation modelwas built Based on the principal of ecological environment fragility assessment. The results showed: from 1981 to 2005, the ecological environment fragility degree of the area had a good tendency with fluctuation change. Natural and human-induced reasons are blamed to the formation of Guazhou's ecological environment fragility.The fifth part provided 6 suggestions to improve the local vulnerable ecological environment according to the ecological environment fragility assessment results and the reasons of its formation.The last part summarized the whole thesis. Illustrated the deficiency in this research and put forward the direction of further investigation.