Application Of HEC-HMS Model And Airborne Lidar Radar Technology In River Basin Flood Simulation

The river basin flood process is one of the physical processes of nature,and it is affected by the spatial differences between rainfall and underlay conditions.The objective and efficient implementation of the flood process is not only required to select the appropriate hydrological model,but also the accuracy of the spatial information of the input model.The former is the analysis of the flood process with hydrological and physical related theoretical knowledge,and the latter is a quantitative description of the impact of the flood process from the spatial and temporal perspective of the basin.Therefore,the accurate measurement and accurate description of the spatial information is the basis for the quantitative analysis of the hydrological model.This paper explores its influence on the simulation of flood process from the selection of hydrological model and the selection of spatial information(focusing on DEM).In this study,the distributed flood forecasting model of Luan chuan is selected as the research area to carry out flood simulation and analysis.In order to better evaluate the simulation results of the distributed hydrological model,the lumped hydrological model was selected to simulate the flooding in the Luan chuan basin.The Xin'anjiang model is widely adapted to the wet semi-humid areas and has achieved good simulation results.The selection of the Xin'anjiang model as a reference for the selected study area to evaluate the adaptability of the distributed hydrological model(HCE-HMS)in the Luanchuan basin is the best choice.At the same time,airborne lidar(LIDAR)technology is the only feasible technology to measure the ground elevation of forest cover area.The high precision DEM generated by airborne lidar(LIDAR)technology can accurately provide rich spatial data for distributed hydrological model,Airborne lidar(LIDAR)technology as a basic data can improve the distributed hydrological model of the simulation results is also worth exploring the problem.In this study,the influence of LIDAR technique and distributed hydrological model on the simulation results of distributed hydrological model flooding was carried out in the Tao wan basin in Luanchuan basin.The main conclusions are:(1)In this study,the 14-stage flood process was simulated and the simulation results of the lumped model were used as reference.It was found that the simulation results of the distributed model were better.According to the requirements of the ?Water Regime Forecasting?,the number of qualified fields of the HEC hydrological model and the HEC hydrological model is 6,13,and the number of field runs is 10,12,and the peak Qualified the number of sessions were 12 games,14 games,peak current qualified time were 9 games,14 games.The flow rates and peak flow simulations of the two hydrological models are all good,and the flood time difference of the distributed hydrological model is generally within 3 hours,while the lumped hydrological model is lagging behind,usually within 1-5 h.On the whole,the distributed hydrological model has good adaptability in Luanchuan basin.(2)In this study,the 1m × 1m DEM data obtained by airborne lidar were used as the basic data of distributed hydrological model for flood simulation.At the same time select the NASA ASTER GDEM resolution of 30 m × 30 m DEM data for the same operation as a comparative analysis.In the ARCGIS platform,two kinds of DEM data sources are extracted.Extracting watershed information is to make the DEM data needed for the model.From the perspective of watershed boundary,water system,watershed gradient and watershed elevation,we compare and analyze the difference between the two kinds of data extracted by the two kinds of data.When DEM changes from high precision to low precision,the gradient of the river basin is reduced,the terrain tends to be flat,the length of the river network is reduced,and the area of the river basin is changed,but it is not obvious.(3)Taking the Tao wan Basin as the research area,we analyze the effect of two DEM data sources on the hydrological analog output during the six rainfall runoff processes.Due to the lack of Taowan basin export measured flow process,the difference between runoff simulation results of ASTEM GDEM and LIDAR was analyzed from three aspects: peak flow,flood time and runoff depth.The conclusion is that the difference between runoff depth simulated by the two DEM data is not very large.Peak flow changes significantly,LIDAR simulation results are generally greater than the ASTER GDEM simulated peak flow,the size of the difference of about 10 ~ 20 m 3 / s.The peak time of the LIDAR data simulation is earlier than the peak time of the ASTER GDEM data simulation is about 1 ~ 4h.