Watershed Scale Flood Forecasting Method Based on Coupled Meteorological Hydrological Hydrodynamic Model:A Case Study of Beijiang River Basin
In light of the existing challenges in forecasting runoff and inundation with limited accuracy within small to medium-sized river basins,taking Beijiang River basin serves as the subject of investigation,a model for predicting rainfall-runoff and flood inunda-tion was constructed.Under non-coupled conditions,the hydrological model for the Beijiang River basin was developed using the WRF-Hydro model.Through parameter calibration,the WRF-Hydro hydrological model was optimized,key water cycle components such as runoff generation and confluence within the basin was simulated.Under the coupled scenario,the runoff simulations generated by the WRF-Hydro model were utilized as input for the CaMa-Flood model,the simulation of flood inundation across the entirety of the basin was enablied.Research findings indicate that within the parameter-calibrated WRF-Hydro hydrological model,the Pearson correlation coefficient surpasses 0.8 for five representative flood events during the validation period.The Nash efficiency coefficient falls within the range of 0.52 to 0.71.For three flood events during the forecast period,the average error in predicting flood peaks amounts to 22.2％.Through the coupling of hydrological and hydrodynamic models,the intricate relationship between flood inundation,rainfall intensity,and fluctuations in flood discharge is accurately captured.This,in turn,provides crucial insights into the depth and extent of floodplain inundation following a flood event.The rainfall-runoff flood inundation model developed through this study finds applicability in regions such as the Beijiang River basin,characterized by complex topography and uneven spatiotemporal rainfall distribution.It of-fers valuable reference for flood prediction in analogous semi-humid basins while also laying a robust foundation for the exploration of coupled hydro-hydrodynamic models.
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维普
