Calibration method of initial bed sand gradation in a two-dimensional water-sediment mathematical model

Abstract

The invention discloses a calibration method of initial bed material gradation of a two-dimensional water and sediment mathematical model, comprising the following steps: step S1, dividing bed material gradation zones according to bed characteristics, and calculating an initial bed material gradation calibration value of each unknown grid point of each gradation in each zone; step S2: calculating a calculation value of the scouring and silting thickness of each grid point; step S3: calculating the error between a scouring and silting thickness predicted value of each grid point and a known scouring and silting thickness measured value; S4, judging whether an error absolute value is less than a preset precision threshold; if so, going to step S6; if not, going to step S5; step S5, according to a sign of the error, adjusting the initial bed material gradation value of a corresponding grid point by adopting dichotomy, and going to step S2; step S6, completing the bed material gradation calibration, and preserving a bed material gradation calibration result. The method can improve the calibration efficiency of the two-dimensional water and sediment mathematical model while ensuring that the initial bed material gradation calibration value of the riverbed two-dimensional water and sediment model is reasonable.

Description

technical field [0001] The invention relates to the technical fields of hydraulics and river motion mechanics, in particular to a method for calibrating the initial bed sand gradation of a two-dimensional water-sediment mathematical model. Background technique [0002] The initial bed sand gradation is an important parameter of the two-dimensional water-sediment mathematical model of the river channel (hereinafter referred to as the "two-dimensional water-sediment model"). Sand movement elements, the acquisition of these water and sand elements can provide water and sand conditions for solving water conservancy, ecological and environmental problems. The two-dimensional water-sediment model is widely used in the scientific research of hydraulics and river dynamics, and it is also an important tool for solving various engineering sediment problems. [0003] In the study of hydraulics and river motion mechanics and the solution of engineering sediment problems, it is usually ...

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Problems solved by technology

[0019] 2) Spatial mutations that do not reflect bed sand gradation

The existing technology determines the initial value of the sand gradation ratio in the given initial bed When , no partition processing is done, which essentially assumes It is derivable everywhere in the two-dimensional space, which is an idealized assumption, and often cannot reflect the actual situation, because the sudden change of geological conditions commonly found in nature will lead to sudden changes in the bed sand gradation. The sudden change is often smoothed in the spatial interpolation method without partitioning, which leads to deviations in the bed-sand exchange and bed deformation calculated by the water-sand model

[0020] In conclusion, from the application point of view, the existing techniques for the determination of the initial bed sand gradation of the two-dimensional water flow mathematical model of the river channel have shortcomings such as being too empirical, heavy workload, and unable to reflect the spatial mutation of the bed sand gradation.

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