Critical rainfall estimation method based on rainfall spatial distribution

Abstract

The invention discloses a critical rainfall estimation method based on rainfall spatial distribution. The critical rainfall estimation method comprises the steps that firstly, estimating the confluence flow velocity in each grid unit in a hydrological response unit secondly, on the basis of the confluence flow velocity in each grid unit, obtaining a confluence time grid in the drainage basin; performing spatial interpolation on the time-interval rainfall data observed by the station to obtain a rainfall spatial distribution grid, and combining the convergence time grid to obtain a time-interval dynamic rainfall index; counting an accumulated dynamic rainfall index before a flood peak occurs in the flood process; then counting the tension water content saturation, namely the initial soil water content saturation, of the day before the flood process begins; finally, whether the flood is an over-alarm flood is judged, and making a cumulative dynamic rainfall indicator - initial soil watercontent saturation scattering point graph on the basis of multiple floods and i, marking points corresponding to the overwanted flood, and drawing a critical rainfall line in combination with the points corresponding to the overwanted flood.

Description

technical field [0001] The invention relates to the technical field of hydrology, in particular to a critical rainfall estimation method based on the spatial distribution of rainfall. Background technique [0002] There are many rivers in my country, with a drainage area of ​​200 to 3000 km 2 There are nearly 9,000 small and medium watersheds in China. In recent years, affected by climate change, sudden floods of small and medium-sized rivers caused by local heavy rainfall have occurred frequently, and have become the main disasters causing casualties. Because small and medium-sized watersheds are usually located in remote mountainous areas with complex terrain and steep slopes, rapidly rising floods can easily cause flood disasters that endanger the personal safety of local residents and the social economy. Early warning has become an important issue to be solved urgently. [0003] The critical rainfall method is a method widely used at home and abroad. Critical rainfal...

AI Technical Summary

Problems solved by technology

However, in the current process of estimating critical rainfall, the spatial distribution characteristics of rainfall and watershed topography are often not considered

The heavy rainfall process in which the center of the storm is close to the downstream often causes sudden floods in the downstream rivers. Such flash floods rise very quickly, leaving short reaction time for personnel and property transfers, which easily cause large economic losses.

However, such floods are easily ignored by the current critical rainfall method, thus leaving hidden dangers for the prevention and control of mountain torrents in small and medium-sized watersheds.

[0006] Therefore, ignoring the spatial distribution characteristics of rainfall is not conducive to the development of early warning of flash floods using the critical rainfall method.

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