Dynamic flash flood simulation method based on irregular unstructured grid model

Abstract

The invention discloses a dynamic flash flood simulation method based on an irregular unstructured grid model. The simulation method comprises the following steps: selecting a simulation area, and collecting data; performing grid division aiming at a complex computational domain and an irregular terrain by adopting an irregular unstructured grid; describing water flow by adopting a two-dimensionalunsteady flow shallow water equations, and solving the equations by using a finite volume method and a Riemann approximate solver; calculating flood arrival time, flood inundation time, maximum floodinundation water depth, maximum flood level and maximum flood flow velocity of each grid unit; and obtaining flood arrival time isograms, flood inundation time isograms, maximum flood inundation water depth isograms, maximum flood level isograms and maximum flood flow velocity isograms. According to the method disclosed by the invention, dynamic simulation and simulation of flood inundation processes in flash flood susceptible areas based on the complex computational domain and the irregular terrain can be realized, the flood inundation range, inundation water depth, flow field and other flood elements are simulated and calculated in real time, and the visualized simulation of the flood inundation process is realized.

Description

technical field [0001] The invention relates to a dynamic simulation calculation method of mountain torrents, in particular to a dynamic simulation method of mountain torrents based on an irregular and unstructured grid model. Background technique [0002] Mountain torrent disasters are natural disasters that occur due to special topographic and geological conditions under certain intensity or continuous rainfall in hilly areas. Destructive disasters, resulting in significant loss of life and property. In order to conduct dynamic analysis and timely warning of flash flood generation to development trend, as well as predict and analyze and evaluate the disaster situation caused by flash flood, the dynamic evolution simulation of flash flood based on physical process can effectively achieve this goal, and can provide water level, flow velocity, Important information such as inundation range can be used to accurately simulate flood evolution. [0003] At present, research met...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art, aiming at the simulation problem of torrent evolution in complex calculation domain and strong irregular terrain, the present invention provides a dynamic simulation method of torrent based on irregular unstructured grid model, which is suitable for strong Irregular terrain is processed with grid encryption and subdivision, and the two-dimensional non-steady flow shallow water equations are used to describe the flow of water. The finite volume method and the Riemann approximation solution are used to numerically solve the coupled equations, thereby simulating the dynamic evolution process of torrents

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