A Dynamic Wave Based High-performance Distributed Hydrological Model Simulating Short Term Rainfall-flood Process

In recent years,under the influence of climate change,extreme rainfall and other factors,flood disaster has caused great loss of life and property.Rainfall numerical model is an important technical method to study flood problems.It can provide scientific basis for flood risk assessment and flood disaster prediction.Therefore,reliable numerical model of rainfall-runoff process is urgently needed to improve scientific guidance and technical support for flood prevention and control.And a high performance distributed hydrological model based on dynamic wave is introduced.In this work,A dynamic wave based high-performance distributed hydrological model is presented.The model describes runoff-generated event with rainfall intensity minus infiltration rate,evapotranspiration rate and interception rate.Infiltration,evapotranspiration and interception are considered in every cell by Hargreaves method,A.P.J.D E ROO method and Green-Ampt model,respectively.Overland flow and open channel flow simulation are described by solving the SWEs within the framework of an unstructured Godunov-type cell-centered finite volume scheme.The Harten,Lax and van Leer approximate Riemann solver with the contact wave restored(HLLC)is adopted to compute the fluxes.Aiming at the capacity of large scale high-resolution simulation,the computation is accelerated by the high-performance Graphic Processing Units(GPUs)parallel computing technique.The distributed model can accurately simulate effectively the runoff process under the high-resolution topography input data.The model uses two ideal catchments and two actual catchments.The flow simulation processes of each tests are in good agreement with the measured data.The Nash coefficient is greater than 0.5.Compared with MIKE model(2014),the accuracy of the simulation results is improved to a certain extent,which shows that the model has better stability and accuracy under the condition of high-resolution topographic data.In term s of computational efficiency,the time of calculation with GPU is different under different grid accuracy,which is about 4-7 times higher than that of CPU.The higher the mesh accuracy,the more obvious the improvement of computational efficiency.Finally,the model is applied to natural catchment and urban catchment to simulate the effects of land use and rainfall patterns on rainfall-runoff process.The most advantageous and disadvantageous land use schemes for slope flood control and the most advantageous and disadvantageous rain patterns for urban flood are obtained.Therefore,the hydrological model with important application value can guide flood control and sustainable rainflood management.