Investigation method for no historical data small-watershed flood recurrence interval

Abstract

The invention relates to a method for investigating no historical data small watershed through a flood frequency curve. The method comprises the following steps that: determining the boundary of a design drainage basin on a work map, selecting one or a plurality of design sections in the design drainage basin, and calculating drainage basin feature values including the area of each design section, a river length gradient and the like; using a rainfall contour line and a variation coefficient contour line to calculate the design storm of each design section in the drainage basin; adopting a reasoning formula method to investigate design flood according to the rainstorm of the design section, and calculating the flood of the design section; drawing the frequency calculation achievement point of each design section on Haisen frequency paper to obtain the flood frequency curve of each design section in the small watershed of a no-data area; and according to existing flood, checking a flood frequency curve, and determining the flood recurrence interval. By use of the method, a basis is provided for carrying out next computer programming, conveniently determining the design flood and determining the flood recurrence interval.

Description

technical field [0001] The invention relates to the technical field of water conservancy calculation, and relates to a method for calculating the return period of a flood in a small watershed, in particular to a method for calculating the return period of a flood in a small watershed in an area without data. Background technique [0002] A small watershed refers to a watershed with an area of ​​less than 300 km 2 For watersheds, the return period of floods in small watersheds in existing data-free areas is determined. Generally, a trial algorithm is used. The hydrological comparison method or design rainstorm is used to calculate the design flood of the section, and the return period is determined by comparing it with the flood in small watersheds and performing multiple trials. [0003] Hydrological analogy method, select the same watershed or a nearby watershed with similar rainfall and runoff conditions and a relatively close watershed area with a hydrological station, us...

AI Technical Summary

Problems solved by technology

With the development of computer software programming, it is necessary to program the frequency curve and put it into the computer software to quickly and automatically check the line according to the flood flow to obtain the flood frequency and determine the flood return period. Therefore, the existing empirical methods in the past are difficult to meet the new requirements. The need for technological development

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