Analysis of Water Balance in Poyang Lake Basin and Subsequent Response to Climate Change

Abstract

Xu, L.G.; Zhu, M.L.; He, B.; Wang, X.L.; Zhang Q.; Jiang J.H., and Razahindrabe B.H.N., 2014. Analysis of water balance in Poyang Lake basin and subsequent response to climate change.The runoff in Poyang Lake Basin has a reversal decreasing phenomenon in 1997. Moreover, recent drought-prone pattern and low-flow events have been a serious threat to the water resource and water security in Poyang Lake in China. The water resource change is affected by regional climate change, human activities and water conservancy projects within the basin. The Poyang Lake and its watershed are selected as study sites to investigate the influence of key driving factors such as precipitation, temperature and water usage. The runoff and water level change of Poyang Lake were explored and analyzed based on the System Dynamic (SD) method. Monthly flow and water depth in lake was simulated and compared with observed values for both calibration periods from 1978 to 1997 and validation periods from1998 to 2007.The results demonstrated that SD method can acquire an ideal performance on basin runoff yielding and water resource exchanging between rivers and lake. Furthermore, 10% decrement and increment of precipitation, temperature and water usage scenario for climate change analysis showed that the proportion of impact from water use, temperature and precipitation is about 1:3:10. The changing trends of water balance in the Poyang Lake Basin are basically consistent with the effect of temperature and precipitation, but due to the function of outflow and smaller impact from the inflow during July to September, the changing trends of water level are different before and after July. Findings of this paper provide an important scientific basis for the development of integrated watershed management measures for water security in Poyang Lake.