Relationship Between Vegetation Index And Climate Factors In Three Gorges Reservoir Area

Three Gorges Reservoir Area is located at the upper and middle reaches of the Yangtze River, it’s the biodiversity conservation hot area of china even the world, also it’s the key area of ecological and environmental protection in china. It is also one of the most vulnerable areas in China’s ecological environment and how to protect the ecological construction of the reservoir area has been a common issue to governments and scientists. The Three Gorges Project is a remarkable water conservancy project that will have a tremendous impact on our social harmony, economic development and ecological environment construction,Chinese Academy of Sciences scholar give a report on "air-conditioning effecf" and Wang Hongqi, a Beijing-based geographical and environmental scholar give a report on "barrel effect" in<<he influence of three Gorges reservoir area on Chongqing temperatures>>, which caused people thinking about climatic effect induced by three Gorges reservoir area.In this thesis, the Three Gorges reservoir area of vegetation cover data, the climate data were integrated. Analyzing the spatial and temporal response mechanism between vegetation change and meteorological factors based on the technologies of Correlation Analysis, Geogr aphically Weighted Regression and Artificial Neural Network Analysis. From that, we would understand the influence of growth stage of the Three Gorges Reservoir to climate and veg etation at mechanism, and provided a reference on the study of vegetation change and clima tic effluence on the Three Gorges reservoir area, enriching the understanding and comprehen sion of reservoir climatic effluence, providing a reference the ecology construction of the res ervoir area.This study including:(1) The annual temperature large differences at spatial distribution of the Three Gorges Reservoir. The many years average precipitation also has significant regional differences at the reservoir area. The lowest Precipitation value of the reservoir area zone appeared in the northern part of the Xing Shan County, the highest precipitation value of the reservoir area are mainly distributed in the south region of the Ba Dong county, Hubei Province and the a small part of the south region at Feng Jie county.(2) The NDVI of Three Gorges Reservoir Area during the year changes showed a Inver ted U Shape, and the maximum value appeared in July, the minimum value appeared in Jan uary. The vegetation coverage showed a significant upward trend at whole in Three Gorges reservoir area, and the Reservoir Area forest distribution region is in the eastern region.(3) The temperature and precipitation accelerated the vegetation cover change of the Res ervoir Area, and the small time scale of climate change had great impact on the vegetation cover change, the time scale is significant. The temperature is the main meteorological factor s of the reservoir area vegetation cover change.(4) While analys the relationship between vegetation cover change and meteorological f actors. Simple linear correlation is a relatively simple, intuitive method, it is suited to less c onsider the the impact of the vegetation cover changes from non-climatic factors.Study the c orrelation of time series of vegetation cover change and meteorological factors.Geographically Weighted Regression considered the spatial autocorrelation and spatially nonstationary of me teorological factors, which is more applicable and reasonable in the analysis of the spatial re sponse mechanism between Vegetation cover and meteorological factors. It can achieve better results.Artificial neural network is very reasonable in the analysis of the relationship betwee n Vegetation cover and meteorological factors. Mainly because the mechanism is very compl ex between meteorological factors and vegetation change in the reservoir area. The relations hip between vegetation change and meteorological factors is not a single linear relationship. Non-climatic factors may also lead to the dynamic Change of vegetation cover. Vegetation c over based on meteorological factors is more accurate in the reflection of meteorological fact ors on regional dynamic Change of vegetation cover.