Study On The Ecological Fragility In Minjiang Watershed Based On GIS Technology

Fragile environment is the result formed by the exploration and the utility of the natural resource under the specific natural, economical, social conditions. As the development of the social and the economical, the insufficiency of resource and the capability of the ecology was the main factors which handled the development between the human and the nature. Minjiang watershed is an important economical area whose ecological environment played a very important role on the development of the economy and the society in Fujian Province. The causes of ecological fragility in Minjiang watershed was analyzed based on the comprehension of the ecological fragility and the facts of the ecological fragility of Minjiang watershed. The index system which would estimate the ecological fragility was established in this thesis. The fragile database was established with the help of the normal data procession based on GIS. The ecological fragility of Minjiang watershed was evaluated by the comprehensive index with the help of the principal component analysis and this would provide important strategies for the conduction of the ecological environment in Minjiang watershed. The main results :1 .The fragility of Minjang watershed were caused by the natural and the personal factors. The evaluate system of fragile indexes was established with the help of the former research production and the internal causes of the ecological fragility of Minjiang watershed. The system had contained the objection, the rule and 21 indexes.2.The evaluated cell was established based on county area with the help of the analysis and the overlay of the thematic maps which were built by GIS and the standardizing data. The weigh of each index was assured under the principal component analysis and the normal procession by GIS technology.3.The 29 counties of Minjiang watershed was classified into 3 sorts with the help of the clump method. The fragility of Minjiang watershed was divided into 4 grades based on the clump result, the former researched production and the rule and the character of the fragility in the area. The results showed that Gutian, Minqing, Yongtai, Datian, Shonxi and Zhenghe county were classified as the third sort which was serious or quite serious fragility.4.The ecological fragility of the 29 counties in Minjiang watershed were evaluated by the model which was built in this thesis. The results show that the average fragility was 0.5012 and there were less differences among of the county in Minjiang watershed which was belong the medium fragility and the most severity was 0.6239 and the lest severity was 0.4014.5.The advice that would improve the ecological environment were provided in this thesis such as strategies, adjusting the industry frame and decreasing more domain which always consume the wood resources. These propose would decrease the fragile pressure and guarantee the sustainable development of the ecological environment in Minjiang watershed.