A Calculation Method of Bed-Building Discharge in Tidal Reach

Abstract

The invention discloses a method for calculating the channel forming discharge of a tidal reach and belongs to the field of river regulation projects and channel regulation projects. The method includes the steps of firstly, building a tidal current mathematical model to calculate and research the annual hourly water level, discharge, spring tide differences of the flooding season and the dry season and the water level differences of the flooding season and the dry season of the selected section of the reach; secondly, dividing the discharge of one section of the reach into a plurality of equal discharge levels, and determining the occurrence frequency P of each discharge level; thirdly, calculating the Q<n>P product value corresponding to each discharge level; fourthly, drawing Q-Q<n>P relation curves, and finding the extreme value of a channel forming effect curve, wherein the discharge corresponding to the extreme value is the channel forming discharge; fifthly, analyzing channel forming discharge along the reach and section flooding season-dry season tide difference change, analyzing influence of tides and runoff power on the channel forming discharge, and analyzing the features of channel morphology shaped by reach water power. The method can be used for calculating the channel forming discharge of the tidal reach and provides important reference indexes for the planning and design of tidal reach riverway and channel regulation projects.

Description

technical field [0001] The invention relates to a calculation method for bed-forming flow in a tidal river section, which belongs to the field of river control and waterway engineering. Background technique [0002] At present, there are relatively few related research results on bed-forming flow in tidal reaches. For the calculation of bed-making flow, there are generally flat beach water level method, sand transport rate method, comprehensive frequency method of water and sediment, etc. Among them, the sand transport rate method is divided into Markaviev method, geomorphic work method and effective flow method. [1] . For single runoff reaches, Dong Guanying and Zhao Wenbin [2] , Yu Bangyi, etc. [3] The bed-making flow in the Xuyi reach and middle reaches of the Huaihe River was calculated using the Makaveyev method, and it was believed that the calculation results could reflect the relatively average flow and bed characteristics of the studied reach. Chu Wanqiang et al...

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Problems solved by technology

[0013] The present invention is based on the basic principle of Makaveyev's derivation of bed-making flow rate, and applies the flow-sediment rate method to the calculation of bed-making flow in tidal river sections, which solves the technical problem that the water surface gradient in tidal estuary sections is difficult to determine. A calculation method for bed-making flow in tidal reaches is proposed; for the downstream tidal-dominant reaches of tidal reaches, the concept of bed-making flow groups is proposed; combined with the water level difference in flood and dry seasons along the section, the tidal range in flood and dry seasons Analyze the relationship between bed-making flow changes and tidal and runoff dynamics, provide internal theoretical support for bed-making flow calculations, and reveal the characteristics of riverbeds shaped by hydrodynamic forces in tidal river sections where runoff is dominant and tidal is dominant

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