Author(s): Yingbiao Shi; Bingyao Lin; Youcheng Xu
Linked Author(s):
Keywords: Qiantang estuary; Mobile-bed model; Flood forecast
Abstract: Based on the observed hydrologic and topographic data, it is found that the non-linear properties of tide, runoff and topography in the estuary have a great influence on flood level. 1-D mobile-bed mathematical model for unsteady flow is developed, and calibrated by a series of measured data. Water level, cross-sectional velocity, sediment concentration and riverbed deformation computed by the model is well agree with those was measured, and even the extreme flood events in Qiantang estuary in 1997 are well simulated. In Qiantang Estuary, it is necessary to consider mobile-bed scouring process in flood forecast because the peak flood level simulated by fixed-bed model would be 0.3m to 2m higher than the measured while mobile-bed model could get more objective results. Besides for flood prediction, the 1-D mobile-bed model is also a helpful tool for decision-making of flood control. One of the important scenarios of flood control in Qiantang estuary is to generate moderate flood to scour the deposited river by regulating Xin’anjiang Reservoir upstream before flood season. Results showed that a large flushing flow over a relatively short period is more effective than providing a more constant flow over a longer period, which is very important for flood control.
Year: 2004