The Analysis Of The Influnce Of China’s Inland Giant Dams On The Regional Climate

Dam construction engineering has made a contribution to the development of social economy, however in recent years, extreme weather in multiple local are frequent, its influence on the ecological climate gradually cause people to take seriously. There are many researches limited in the vicinity of reservoirs. Given this, the basic climate data for this thesis, which come from National Meteorological Information Center, is the 1990-2012 data about national precipitation and air temperature of more than 2,400 nation- leveled meteorological stations. And the focus of this article is to study the influence on areal climate, which is brought out typically by the construction of two huge dams, the Three Gorges Dam and the Xiaolangdi Dam. The study is developed from the following sides:(1) At the angle of special influence of an area and using methods in geostatistics, this thesis analyzes both of time and space distribution of the Yellow River Basin and the Yangtze River Basin by Kriging interpolation and difference value. And the result shows that despite the air temperature’s obvious decline at reservoirs and increase at the basin’s lower parts, the rainfall at the upper river about 200 km far from the dam gets increased, while at the lower river declined.(2) From the standpoint of relativity analysis, this paper has done individual research on the Three Gorges Dam and the Xiaolangdi Dam by Pearson correlation analysis with time-space analysis. And the result shows a clear negative correlation between water level changes of the reservoir and its air temperature and a clear positive correlation between changes of the rainfall at the upper river and water level of the reservoir, with some other weak correlations.(3) Based on mathematical statistics, the results of previous study are further analyzed and verified. And it shows that air temperature differences of the reservoir in both summer and winter are lessened, and that for the area 200 km away upper from the dam, its fitting trend line goes high obviously.(4) From the catastrophe point, this article has analyzed the climate change points of the two basins through wavelet analysis and Yamamoto Method. And it shows that the rainfall change points of Mountain Daba and Mountain Q inling, which are at the upper part of the Three Gorge Dam, and those of Mountain Lüliang and Mountain Baiyu, which are at the upper part of the Xiaolangdi Dam, all appear around the year when the dams were constructed.This thesis has analyzed and verified the influence of building dams on climate change, using many methods and from many aspects in order to remove the effects of errors. From the above conclusions, it is safe to say the construction of huge dam can increase the rainfall of the area 200 km upper the dam, decrease the air temperature of the whole reservoir, and lessen the temperature differences. All in all, constructing huge dam will influence the regional climate of a wide area.