Construction method of alluvial river dam downstream riverbed undercutting depth prediction model

Abstract

The invention discloses a construction method of an alluvial dike downstream riverbed undercutting depth prediction model. The construction method comprises the following steps: collecting post-flood actual measurement topographic data of each sedimentation section of an alluvial dike downstream river reach every year and hydrological data of a hydrological station; determining a main groove range of each siltation section year by year based on actually measured topographic data, and calculating an average value of riverbed elevations of all actually measured nodes in the main groove range of the siltation section every year and an accumulated riverbed undercutting depth of each siltation section; and carrying out river reach averaging on the accumulated riverbed undercutting depths of all the siltation sections, and constructing a prediction model of the undercutting depth of the downstream riverbed of the alluvial river dam. According to the method, the amplitude of the dam downstream alluvial river depth undercutting is represented by the average accumulative river bed undercutting depth of the constructed river reach, the characteristics of the river bed depth undercutting of the whole river reach can be better reflected, and the change trend of the alluvial river dam downstream depth undercutting can be better predicted by the established statistical model with less data; the method has guiding significance on river management and river regulation planning.

Description

technical field [0001] The invention relates to the technical field of water conservancy and hydropower engineering, in particular to a method for constructing a prediction model for the undercut depth of a riverbed downstream of an alluvial river dam. Background technique [0002] After the construction of reservoirs or dams in the upper reaches of alluvial rivers, the conditions of water and sediment entering the lower reaches will change, causing a series of riverbed morphological adjustments in the lower reaches. Among them, the undercut of the riverbed in the lower reaches is an important part of the longitudinal deformation of the riverbed. At present, the undercut pattern and response mechanism of the riverbed in the downstream reaches of the dam have not been fully grasped. Therefore, it is of great significance to study the prediction model of the incision depth of the riverbed downstream of alluvial river dams for river management and river regulation planning. ...

AI Technical Summary

Problems solved by technology

Although this method has a certain theoretical basis, it can only calculate the maximum incision depth of the river bed, and cannot calculate the year-by-year incision depth of the river bed during the scouring process.

The calculation method of the mathematical model of water and sediment can calculate the detailed process of downstream river bed scour, but it often requires many detailed data such as flow and sediment concentration process, suspended mass gradation, bed sand gradation, siltation section topography, etc., and the mathematical model is rough There is also a lack of a unified calculation method for parameters such as rate and recovery saturation coefficient

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