Impact Of Climate Change On Water Resources In Dongting Lake Basin

Water is the source of life, and is the major factor of production, is also the foundation in the ecological system. The dramatically change of time and space distribution of water resources brings out a series of ecological problems, resource problems and environmental concerns. In the meanwhile, the change of water resources, in turn, reacts on human activities, causes the Butterfly Effect, and drives further climate change.Therefore, the prediction of water resources which based on climate change is a specific and systematic work. Only with full consideration of meteorological elements and hydrology elements, programming water resources allocation in advance, and making scientific evaluation of regional water resources bearing capacity, can we fix water problems and make plans for the development of regional economy.This paper selects Dongting Lake water system as the object of study.Through the analysis of the historical relationship between water resources allocation and climate change, we can understand the impact of climate change on regional water resources. Based on scientific data collected from meteorological measurement and hydrological observation,and simulated data collected from a new generation of scenario CMIP5 climate model, adopting the statistical analysis method and the hydrology simulation method, this paper analyzes the transit water change and variation of water resources within the scope of Dongting Lake watersystem in the future. The main achievements and conclusions are as follows:This paper analyzes precipitation and temperature change trend of Dongting Lake water system as well as variation trend of its water resources, relies on which, this paper estimates the influence of climate change on water resources. It turns out that water resources always change with climate, while human activities has a little influence on its change.This paper studies the correlation among climate change of Dongting Lake water system, global ocean temperature, and geopotential height at500 h Pa and identifies the anomalies of water-related meteorological factors corresponding to the abnormal area. The results showed that the amount of precipitation in Dongting Lake water system have good relationship with sea surface temperature of certain area, especially in dry season, some correlation coefficients between them even have reached0.7 of relevant data. Specific area including the Pacific Ocean area, the Gulf of Thailand Indian Ocean area, Bay of Bengal area, When the Western Pacific Ocean bears a low ocean temperature, water inflow of Dongting Lake region is higher than average in January; Otherwise is lower. If water inflow in the summer of the year is much higher than average, the North Pacific Ocean shows a higher temperature, while water inflow is lower of the year, the East Pacific Ocean shows a highertemperature. The summer monsoon is affected by both Pacific Subtropical High and trade-wind zone. In the meanwhile, abnormality of geopotential height at 500 hpa Siberia Eurasian continent, South Asia and Antarctica regions close related with drought and floods in Dongting Lake water system.This paper collects CMIP5 multiple models, climate patterns of rainfall and temperature in Dongting Lake water system simulation capability assessment and puts forward the model of considering the climate similarity model selection method, and use the equidistant matching method, the cumulative distribution function using the history of the measured data, the model simulation results are corrections after correction data as input, put to Dongting Lake Basin hydrology calculation model, calculation of Dongting Lake Basin under the condition of high emissions scenario in the low 60 years, the change of the water resources in the future The results show that the mode in different situation, the future of Dongting Lake Basin water resources may further increase in the number of years and annual distribution more uneven. Overall, the Dongting Lake regional water resources will increase slowly and the water distribution will further uneven. Human activity will intensify this process.In addition to local rainfall, transit water from Yangtze River is also part of Dongting Lake’s water resources. Using CMIP5 GCMs as input,this paper considers reservoirs regulation of the upper reaches of Yangtze River and the evolution of the three ports to calculate the future inflow of the three ports. In conclusion, the inflow showing significant decay trend which is about 21% reduce in total. A slightly increase inflow in dry season and dramatic reduction in flood season while it comes into seasonal distribution.