Godunov format one-dimensional and two-dimensional coupling technology-based mountain flood numerical simulation method

Abstract

The invention provides a Godunov format one-dimensional and two-dimensional coupling technology-based mountain flood numerical simulation method. The method comprises the steps of acquiring corresponding data, discretizing a slope surface of a small watershed in a mountainous and hilly area by adopting a quadrilateral unstructured grid firstly, describing a motion process of overland flow of mountain flood by adopting a complete two-dimensional shallow water equation, taking a rainfall process as a driving item of a two-dimensional model, and calculating a numerical flux at a grid interface by adopting a Roe format; discretizing a mountain flood channel by adopting a one-dimensional finite volume unit, calculating a numerical flux at a unit interface by adopting an HLL format, and performing centralized inflow processing on inflow of a two-dimensional slope surface in one dimension; and realizing water volume exchange calculation of the two-dimensional slope surface and the one-dimensional channel by adopting a weir flow formula. According to the method provided by the invention, not only water power information of the mountain flood in the channel but also detailed water power information of the mountain flood on the watershed surface can be obtained; and the method has a clear physical mechanism, and only the roughness parameter of the whole model needs to be calibrated, so that the method is still suitable for areas lack of hydrological data.

Description

technical field [0001] The invention belongs to the technical field of water conservancy engineering, in particular to the technical field of mountain torrent prevention and control engineering, in particular to a numerical simulation method of mountain torrents. Background technique [0002] Flash floods refer to stream floods caused by heavy rainfall in small watersheds in hilly areas. They have the characteristics of sudden rise and fall, and often induce landslides and mudslides at the same time, often bringing serious disasters to local areas and causing casualties. [0003] Calculation technology of storm and flood in small watersheds in mountainous areas is a core technology in the prevention and control of mountain torrents. At present, the analysis of storms and floods in small watersheds in mountainous areas mostly uses hydrological models, such as HBV model, distributed Xin'anjiang model, KINEROS (KINEROS2) model, GBHM model, CASC2D model and PIHM model, etc. The...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a numerical simulation method of mountain torrent process based on Godunov format one-dimensional and two-dimensional coupling technology, to solve the problem of poor applicability of hydrological model in the case of mountain flood in the absence of hydrological data, and can give full play to the water Using the advantages of the dynamic model to solve some complex technical problems of flash floods, this method can be used in the flood risk analysis and real-time forecasting and early warning business of small watersheds in mountainous areas

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