The Research On Rainstorm And Flood Forecast Technology In Baogaidong Basin Of Hunan Province

The Baogaidong basin in Liuyang City,Hunan Province is located in the rainstorm area in northeastern Hunan.It belongs to a small mountain basin.Heavy rains and floods occur frequently,and have the characteristics of short duration and high intensity.The forecasting is difficult and the forecasting accuracy is lacking.Based on the ArcGIS platform,this paper constructs the HEC-HMS and TOPMODEL hydrological models in the study area to forecast floods in the basin,and use the measured rainfall and runoff data to test the applicability of the model in the basin,explore the hydrological characteristics of mountain floods,establish a flood forecasting scheme suitable for Baogaidong basin.It provides a new idea for flood forecasting in Baogaidong basin,and provides reference experience for flood forecasting in other small basin in mountainous areas.The main research results obtained in this paper are as follows:(1)Using HEC-DSSvne software,the rainfall and runoff data database in the study area was constructed,and ENVI was used to decipher the land use type data of Baogaidong basin and the soil data cut out of the basin.(2)According to the rainfall data over the years,the study found that the annual precipitation(January-December)and the flood season precipitation(March-August)in the Baogaidong basin showed an insignificant upward trend,while the non-flood season precipitation(September-February)showed an insignificant downward trend.(3)The HEC-HMS model simulation was carried out,and the results showed that the qualified rate of 10 floods during the regular period was 90%,and the qualified rate of 7 floods during the verification period was 85.7%,and the comprehensive simulation accuracy of the model was B.The TOPMODEL model selected the same flood field for calibration and verification.The results showed that the regular pass rate was 80%,the verification period was 85.7%,and the comprehensive simulation accuracy of the model was C.(4)The results of HEC-HMS and TOPMODEL model data were imported into Origin,and the runoff process diagrams simulated and measured by the two models were obtained.It can be seen from the figures that the simulation effect of the two models on single-peak floods is better than that of multi-peak floods.(5)By comparing and analyzing the simulation results of the HEC-HMS and TOPMODEL models,both models are suitable for the Baogaidong basin,but in terms of simulation accuracy,the HEC-HMS model is better than the TOPMODEL model.