Study On The Theory And Application Of Runoff Of Small Watershed In Mountain Area

In recent years,floods,drought and other problems has seriously affected the economic and social development,even lead to the safety of life and property problems for the human,especially the flood disasters will not only cause the housing collapse,environmental degradation and other issues,but also will take human life.Settling the flood issue bears on the overall development of the social economy and the vital interests of the people,important and urgent.Flood forecasting becomes the key problem to solve the flood disaster.Nowadays,little research has been done in flood disaster of small watershed in mountain area,several research results are not mature enough,the precision of flood forecasting is relatively low,resulting in when the flood disaster of a small watershed in mountain area happened,flood forecasting are not timely and reasonable,advance the flood control measures,reduce the people who living in small watershed in mountain area.If want make the flood forecast of small watershed in mountainous area more defensible,people have to increase the research on the theory of runoff yield and concentration of small watershed in mountain area.Therefore,the research on runoff yield and concentration theory of small watershed in mountain area is the key to improve the rationality of flood forecasting in small watershed in mountainous area.So far,the theory of runoff yield and concentration in the small watershed of mountain area remained to be studied.This essay is supported by the project of " Pingyao County,Jinzhong City,Shanxi Province,flood disaster warning indicators analysis" project,the project primaly through watershed model method to calculate the runoff yield and concentration of small watershed in mountainous area,this paper also include analyze the composition of the underlying surface elements and their effects on hydrological variables,and closely combined with the hydrological underlying surface to reasonably determine the various calculation models and empirical formula of the land type parameters,improving the accuracy of calculation results of runoff yield and concentration in Small Watersheds in Mountainous Areas.(1)This paper brief the background and significance of the research,summarizes the development of the theory of convergence of production at home and abroad,and realizing the research contents and technical methods.(2)Introduces the situation of the underlying surface in the study area and research the rainstorm,flood and flood control situation.(3)By replacing the piecewise log linear rainstorm formula by using the logarithmic nonlinear design rainstorm formula,solve the problem of the solution to the duration of the production flow of the piecewise logarithmic formula at the segment node;with a fixed plane relationship instead of moving point surface,improve the relationship between the surface point displacement effect;Instantaneous unit line delay time by the usual period of time geography comprehensive average net rainfall intensity to "lag" average net rain intensity.(4)Select Pingyao County as the research object under the change of the underlying surface,analyzing the effect of underlying surface factors on runoff yield and concentration,by analyzing the influence of the underlying surface on the calculation of runoff yield,introducing an improvement,so as to improve the accuracy of calculation of runoff yield and concentration of small watershed in mountain area.At last,summarize the implement of the principal research achievement in this paper,consisting the innovation of this paper.