Research On Landscape Pattern And Ecological Frangibility Assessment Of Chuan-Dian Farming-Pastoral Zone

As an indispensable part of China's farming-pastoral ecosystem, Chuan-Dian farming-pastoral zone is the ecological defense of the middle and lower course of the Yangtze River and it plays an important role in ecological security construction in China. However, the function of Chuan-Dian farming-pastoral ecosystem as an ecological defense did not only exert fully, but also became the district of ecological and environmental problems for the frailness itself, unreasonable exploitation and utilization of natural resources by human beings, which restricts the local social-economic development and imperils the ecological security of middle and lower course of the Yangtze River. Nowadays, economic activities are becoming more and more frequently under the background of The Grand Western Development Program, which influences the local natural ecosystem more deeply than before. Both Pressure of poverty and environment deterioration made higher ecological weakness level of the local area, greater contradiction between economic development and environmental protection as time flows. In this case, the author choose the Chuan-Dian Farming-Pastoral Zone as research district, to begin studies on ecological and environmental weakness estimations to make sense of future ecological protection and sustainable development.Main contents and results of this paper are as follows:1) This paper analyzed the relationship between natural condition, especially the climate, layout of agriculture and animal husbandry of the research area. Based on combining the agricultural climate situation, agricultural economy indicators, and land use structure, this paper finished the geographic definition of Chuan-Dian farming-pastoral zone.2) This paper analyzed the changes of landscape pattern and its environmental impact of the research area, including land use type changes, interchange of different land use types, and etc. The main result shows that although research area was a region with a vast expanse and spares population. landscape components with high ecologicalfunction, (such as natural forest, high covered grass, wetland, and etc.), reduced due to unreasonable resource exploitation and land utilization from human behavior for a long time, which led to the change of system's ecological function, such as ecosystem degradation, biodiversity reduction, the ecosystem services function decrease. At the same time, this paper analyzed the driving force on landscape pattern change and the result shows that the physiognomic factors are basis of regional landscape pattern and the level of social economy development can reflect the landscape change directly.3) This paper studied the method of eco-environment frangibility assessment. The comprehensive evaluation model of ecological assessment based on the ecological sensitivity index, the ecological elasticity index, and the ecological pressure index was put forward for the first time. At the same time, the author constructed the assessment index system of ecological frangibility, and proposed the method of assessment by combination of comprehensive index method, analytic hierarchy process and RS & GIS .Used the comprehensive assessment method, this paper finished the case analysis on the Chuan-Dian farming-pastoral zone. The results show the degree and the main influential factors of ecological frangibility in the research area. The result of assessment is accordance with the actual situation.Study on the ecological assessment frangibility in the Chuan-Dian fanning- pastoral zone has great significance both in theory and reality. On one hand, this paper can provide theory reference for other researchers to study on fragile eco- environment and ecological frangibility assessment, and on the other hand, the result of this study can provide scientific evidence for environment protection and ecological reparation in research area, which has realistic signification for promoting regional sustainable development of Chuan-Dian farming-pastoral zone and maintaining ecological security of the middle and the lower reaches of the Yangtze river.