Total variation decreasing method for improving riverway calculation stability

Abstract

The invention discloses a total variation decreasing method for improving the riverway calculation stability. The method is mainly used for riverway calculation in hydrological forecasting. Accordingto the total variation decreasing method, a monotonous and non-oscillating first-order form and a non-monotonous and high-precision second-order form are combined by introducing a limiter, so that thesimulated river cross section flow keeps the second-order precision as much as possible in a relatively gentle water volume increase and decrease time period, and a first-order form is introduced ina time period when the water quantity is greatly increased or decreased to maintain the stability of corresponding riverway calculation. After the riverway calculation method is combined with the total variation decreasing format, the riverway calculation efficiency is higher, the result is more stable, oscillation or diffusion is not generated, and good simulation precision can be kept. Therefore, the total variation decreasing method can promote the development of a hydrological forecasting model and reservoir scientific management, can be used for real-time flood forecasting, and improves the forecasting period and the simulation precision.

Description

technical field [0001] The invention belongs to the technical field of hydrology, and in particular relates to a total variation decreasing method for improving the stability of channel calculation. Background technique [0002] The drainage area of ​​our country is 200 to 3000km 2 There are nearly 9,000 small and medium-sized watersheds in China. Most of these small and medium-sized watersheds are located in mountainous areas. The water and soil conditions along the coast of the watershed are good, with a lot of cultivated land and dense population. Once a flood occurs, it will seriously threaten the safety of people's lives and property. At present, the prediction and forecasting ability of local sudden heavy rainfall in small and medium-sized rivers is not strong, the overall level of short-duration flood forecasting and early warning is not high, the scheduling of flood control projects is difficult, and the emergency response technology system is weak, which makes it di...

AI Technical Summary

Problems solved by technology

At present, the only way to solve this phenomenon of oscillation or overshooting is to shorten the time step of the river routing, but the required calculation time will increase accordingly, which reduces the calculation efficiency and will affect the accuracy of the simulation to a certain extent, resulting in the confluence of the river channel. The calculation is time-consuming and inaccurate, which leaves hidden dangers for the prevention and control of mountain torrent disasters in small and medium-sized rivers in mountainous areas

Images