Analysis And Correlation Studies Of Water(energy) In The Three Gorges Reservoir Area Under Changing Environment

In recent years,the impact of climate warming has become one of the most important environmental issues.The impact of the construction of the Three Gorges Project and water storage on the water cycle and energy exchange process is also a hot issue of concern and research.At present,there are many studies on the changing trend of water cycle elements in the Three Gorges reservoir area,but it is still rare to study all the characteristics and relationships of water and energy elements.In order to study whether climate change and the impoundment of the Three Gorges Reservoir will affect the water and energy elements of the reservoir area,thus affecting the water cycle and energy exchange process,based on the previous research results,this paper studies the variation characteristics and influencing factors of temperature,precipitation,solar radiation,wind speed,relative humidity and actual evaporation in the Three Gorges reservoir area from 1990 to 2015.The research results can provide theoretical basis and scientific basis for the study of water cycle and energy exchange in the Three Gorges reservoir area.According to the scope of the Three Gorges reservoir area,this paper selects the relevant grid point data of water and energy in the Three Gorges reservoir area from the China meteorological Forcing Dataset,and uses the measured data of the site to test the applicability of the grid point data.This paper adopts “CLM4.5 based land surface model of the Three Gorges reservoir area”,which is constructed by the national key research and development plan “The evolution of the land water cycle and its role in global change”.the selected grid data is used as the driving data,in this mode Simulate the actual evaporation of the Three Gorges reservoir area.The trend of water and energy was analyzed by linear tendency estimation method,5a moving average method and M-K trend test.The M-K mutation test was used to determine the mutation point of the change factor.Since the influence mechanism of the actual evaporation amount is complicated,the main influence factors of the actual evaporation amount are determined by the partial correlation coefficient and the stepwise regression method.The research results are as follows:(1)The average annual is on the rise.The average annual precipitation and precipitation in spring,summer and autumn all showed an increasing trend,and the precipitation in winter was a downward trend.The annual average solar radiation and the solar radiation in spring and winter are increasing,and the solar radiation in summer and autumn is decreasing.The annual average wind speed and the wind speed in the four seasons all showed an increasing trend.The annual relative humidity and the relative humidity of the four seasons all showed a downward trend.The average annual actual evaporation and the actual evaporation in summer and autumn showed an increasing trend,and the actual evaporation in spring and winter showed a downward trend.Except for summer,the average annual land and water surface evaporation and the evaporation in spring,autumn and winter all showed a downward trend.Except for autumn,the average annual vegetation evaporation and the vegetation evaporation in spring,summer and winter showed an increasing trend.Except for spring,the annual average transpiration of vegetation and the transpiration of vegetation in summer,autumn and winter showed an increasing trend.(2)The mutated results of water and energy factors in the Three Gorges reservoir area from 1990 to 2015 are: the spring temperature change point in 2002,and the sudden change in the average temperature in winter appeared in 2000.There are two mutation points in autumn precipitation,which occurred in 1994 and 2010 respectively.The average wind speed in winter has a sudden change in 2004.The annual average relative humidity change occurred in 2003,with sudden changes in relative humidity in spring and winter,all occurring in 2004.(3)In recent years,the total actual evaporation,vegetation evaporation,and vegetation transpiration in the Three Gorges reservoir area are mainly related to factors such as temperature and solar radiation.Land surface evaporation is affected by a combination of factors such as temperature,radiation,and wind speed.Climate change is the main reason for the change of total actual evaporation,vegetation evaporation and vegetation transpiration.Climate change and underlying surface changes all play a major role in the change of land surface evaporation.