Flood Prediction In Ungauged Small Basin

In the hilly area,due to the limitation of the basin area,the capacity of the river channel is small,which leads to the short duration of the flood,the increase is high and the flood peak is high,and the flash flood disaster is sudden,the forecast period is short,the water concentration is concentrated and the destructive power is large And other characteristics,has become China's flood control work in the weak link.Due to the complexity of the small watershed in the hilly area and the influencing factors,coupled with the difficulties in the hydrological infrastructure construction and the shortage of hydrological data,the accuracy of the flood forecasting in the small watershed is difficult to meet the requirements,and the disaster prevention and control work in the hilly area is difficult to be carried out Therefore,it is very important to carry out the study of flash flood forecasting method with out data small watershed.(1)Based on the VG model and the terrain index,the water storage capacity of the basin is extracted,and then the spatial distribution characteristics of the basin water storage capacity are analyzed.For the first time,the Erlang distribution is used to fit the reservoir water storage capacity curve and applied in several differe nt types of watersheds.The results show that the curve type has good adaptability in small watershed,and can express the inhomogeneity of spatial distribution of water storage capacity well.(2)Based on the accumulation flow theory,the calculation formula of the basin runoff is deduced based on the water storage capacity curve of Erlang distribution.Based on the Xin'anjiang model,the basin runoff based on Erlang distribution water storage capacity curve is established Model,and applied in the Qingyang River Basin.The results show that the model has high prediction accuracy and can be popularized in other small watershed.(3)On the basis of.NET platform,with two times the development of WPF technology,GIS,construction of the interactive forecast system,the system mainly consists of the introduction,information extraction,flood forecasting and other functions,the hydrological model in this paper is further applied to practice,providing important reference for hydrological forecasting.