Water storage capacity estimation for a large complex lake system incorporating the water levels during flooding season

Study region: Dongting Lake, ChinaStudy focusWater storage capacity (WSC) of a large lake system plays a crucial role in flood control decision-making during the flood season. Dongting Lake, located downstream of Three Gorges Dam, has a significant influence over flood control in the middle and lower reaches of the Yangtze River (MLYR). To have a better WSC estimation of Dongting Lake, a multiple linear regression model was developed based on hydrodynamic simulation data of the typical flood processes in the past 3 decades.New hydrological insights for the regionThe multiple linear regression (MLR) model is developed by integrating of hydrodynamic simulation. Also, the effect of the water level (WL) at Chenglingji station and the WL difference in the lake (Yangliutan-Chenglingji) were investigated. The model can accurately estimate the WSC of Dongting Lake with an R2 of 0.984. The observation indicates that the WL difference within the lake has a great influence on the WSC and the flood regulation capacity ability with the same WL at Chenglingji station. The results of the study can provide a real-time estimation of the WSC of Dongting Lake which can provide useful information for flood control management