Solving method applied to design flood hydrograph of small watershed

Abstract

The invention relates to a solving method applied to a design flood hydrograph of a small watershed. The method comprises the steps of inputting hydrological parameters according to basin data; carrying out regional design rainstorm calculation and confluence calculation; calculating and verifying the flood peak flow by utilizing a Newton iteration method; acquiring a confluence time and a confluence speed, and checking the rationality of a calculation result by using the two; determining a drainage basin instantaneous unit line according to drainage basin instantaneous unit line parameters, and solving design flood peak flow according to net rain depth hourly distribution and a comparative reasoning formula method; and calculating and designing a flood hydrograph according to a basin instantaneous unit line nonlinear solving technical principle. The method is suitable for solving the same-frequency time-history rainfall distribution process of the comprehensive rain type of the smallwatershed, is reasonable in design and small in error, and can be applied to design flood hydrograph calculation.

Description

technical field [0001] The invention relates to the field of engineering hydrology, in particular to a solution method applied to the design flood process line of a small watershed. Background technique [0002] Under the joint influence of global climate warming and the dynamic changes of the underlying surface of the watershed, the probability of heavy rainstorms will increase, and the magnitude and intensity will increase, which will lead to more and more severe disasters such as flash floods, waterlogging, landslides, and debris flows. The underlying surface of the watershed changes dynamically, and their overall effect and cumulative effect will lead to more serious flash floods, waterlogging, landslides, and debris flows caused by the same heavy rain, and the task of preventive measures will be heavier. [0003] The small watershed usually refers to the watershed below the secondary and tertiary tributaries and the outlet section of the downstream channel as the bounda...

AI Technical Summary

Problems solved by technology

The design flood calculation method for this watershed is usually the generalized hydrograph method, but few flood hydrographs are triangular. As a simplified method, it is more suitable for small watersheds where the shape of the flood is not particularly important, but the accuracy will be reduced. will be lost

If the basic equation of the instantaneous unit line is used to design the flood process line, and because it is a linear equation, it will be affected by its homogenization, so that the calculated design flood peak discharge is too small, and there is a deviation

In addition, in actual engineering, due to insufficient data, empirical methods or manual calculations are often used to calculate design floods in small watersheds. The calculation efficiency and accuracy are low, and it is difficult to meet the current water and soil conservation production project construction spoil yard design flood peak flow calculation requirements

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