Construction method and device of sandy river reach bed sand grading model and electronic equipment
By constructing a bed sediment gradation model for sandy river sections and dynamically calculating the bed sediment exchange process, the problem of low simulation accuracy of traditional methods under complex water and sediment conditions is solved, thereby improving the stability of river morphology and flood control safety of river sections.
Patent Information
- Application Number
- CN202510746884.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-05
- Publication Date
- 2025-09-16
AI Technical Summary
Traditional riverbed monitoring and prediction methods have low simulation accuracy under complex water and sediment conditions, making it difficult to meet engineering and scientific research needs. In particular, after the Three Gorges Project reduced the amount of sediment discharged, the stability of the river section and flood control safety were affected.
A bed-sand gradation model for sandy river sections was constructed. By obtaining the sand wave height and bed-sand exchange rate, the thickness of the active bed-sand exchange layer, the scour thickness, the sedimentation thickness, and the total scour-sedimentation thickness were dynamically calculated. Combined with the sediment balance equation, the bed-sand gradation was dynamically obtained.
It enables accurate prediction of riverbed scouring and deposition changes under complex water and sediment conditions, improving the stability of river sections and flood control safety.
Smart Images
Figure CN120654604A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of hydraulics and river kinematics, and in particular to a method, device and electronic equipment for constructing a bed sand gradation model for a sandy river section. Background Art
[0002] After the Three Gorges Project began impounding and operating, the amount of sediment discharged from the project decreased by nearly 90%. The downstream channel experienced limited bed sediment replenishment and spatial scouring, seriously impacting river stability and flood control safety in this section. Analysis shows that under certain flow conditions, bed sediment, bed load, and suspended load exchange with each other. During this process, the coarser surface sediment is washed away, exposing the finer sediment and sediment particles in the subsurface layer, which then become surface bed sediment. This surface sediment continues to exchange with bed load and suspended load, repeating the cycle and gradually moving sand waves forward.
[0003] Traditional riverbed monitoring and prediction primarily rely on empirical formulas or local observational data, which are limited by low simulation accuracy and poor adaptability, making them inadequate for engineering and scientific research under complex water and sediment conditions. For example, alluvial rivers, due to their complex water and sediment conditions, frequent riverbed adjustments, and the massive annual investment required for related regulation projects, are characterized by high sediment transport intensity and significant changes in riverbed erosion and deposition, making traditional static models incapable of meeting accurate prediction requirements. Summary of the Invention
[0004] In view of this, it is necessary to provide a method, device and electronic equipment for constructing a bed sediment gradation model for a sandy river section, so as to solve the problem of predicting riverbed gradation through static models in the prior art.
[0005] In order to solve the above problems, in a first aspect, the present invention provides a method for constructing a bed sediment gradation model for a sandy river section, comprising: When the relative water depth of the target sandy river section is not less than a first preset threshold, obtaining the sand wave height and bed-sand exchange rate of the target sandy river section; Based on the sand wave height and the bed-sand exchange rate, the thickness of the bed-sand exchange active layer of the target sandy river section in the current step of an exchange step is obtained; The bed scour thickness of the current step is obtained based on the thickness of the bed-sand exchange active layer, sand wave height and bed-sand exchange rate of the current step; The bed sediment deposition thickness of the current step is obtained based on the bed sediment exchange active layer thickness of the current step and the preset three-state transition probability; Get the thickness of incoming sand accumulation in the current step; The total scouring and silting thickness of the current step is obtained based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; Based on the preset sediment balance equation, the bed sediment gradation at each step of the suspended sediment-bed sediment exchange process in the target sandy river section is obtained; The bed sediment gradation model of the target sandy river section is obtained based on the total scouring and silting thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
[0006] In one possible implementation, when the critical sand shear stress is not less than the second preset threshold, the expression for the sand wave height is:
[0007]
[0008] The expression of bed sand exchange rate is:
[0009]
[0010] When the critical sand shear stress is greater than the second preset threshold, the expression of the bed sand exchange rate is:
[0011] The expression of sand wave height is:
[0012] Where, V sy represents the bed sand exchange rate, Indicates the height of the wave sand, represents the dimensionless sand grain shear stress, , Indicates water density, represents the bulk density of sediment, represents the hydraulic radius of sand particles, J represents the water surface gradient, h Indicates water depth. represents the median particle size of bed sand, g represents the acceleration due to gravity, 、 Relative water depth The relevant coefficients.
[0013] In a possible implementation, the thickness of the bed-sand exchange active layer in the current step is expressed as:
[0014] Where, represents the thickness of the active layer of bed-sand exchange in the sandy riverbed at step n, H s represents the height of sand waves, T represents the period of sand wave movement, is the computational step size relative to one exchange process, and , is the actual calculation step size, The time required to complete one bed sand exchange.
[0015] In a possible implementation, the expression for the bed scour thickness at the current step is:
[0016]
[0017] Where, Indicates the n Step bed surface scouring thickness, represents the bed sand exchange rate, represents the speed of sand wave movement, Indicates the n-1 Step bed sand grading, 、 Both represent the probability of sediment state transition.
[0018] In a possible implementation, the bed sand accumulation thickness of the current step is The expression is:
[0019] The thickness of the incoming sand deposition in the current step The expression is:
[0020] The expression of the total scouring and silting thickness of the current step is:
[0021] Where, Indicates the n Step bed scouring thickness, Indicates the n The thickness of bed sand deposition at the beginning of the step, Indicates the n The thickness of the incoming sand deposition, Indicates the n-1 Step by step bed load grading, Q S is the sediment transport rate per width (kg / s), ρ s is the sediment density, e s is the porosity of bed sand.
[0022] In a possible implementation, the preset sand balance equation is expressed as:
[0023] Where: Indicates sandy riverbed n Thickness of the active layer of bed sand exchange, For the n Total scouring and silting thickness, For the n -1 step bed sand scouring thickness, is the thickness of bed sand accumulation at step n-1, For the n Bulai sand deposition thickness, 、 Both represent the probability of sediment state transition, For the n Bulai sand gradation indicates that the sediment particle size is smaller than d i The percentage of sand weight, Indicates the n Step bed sand grading, express n Step-by-step bed load grading, Indicates the n The step-sand carrying capacity gradation represents the sediment particle size smaller than d k The percentage of sand weight, represents the initial bed sand gradation.
[0024] In a possible implementation, the bed sediment gradation model of the target sandy river section is expressed as:
[0025] Where, Indicates the first n Step bed sand grading, , , , , , Indicates the bed load gradation and the sand entrainment gradation, Indicates that the sediment particle size is smaller than d k Percentage of sand weight; is the initial bed sand gradation, 、 represents the probability of sediment state transition, Indicates the n Step sediment thickness, Indicates the n The speed of sand wave movement, Indicates the n The bed sand exchange rate is the step, T represents the sand wave motion period, represents the computational step size relative to one exchange process, and ; is the actual calculation step size, The time required to complete one bed sand exchange.
[0026] In a second aspect, the present invention further provides a device for constructing a bed sediment gradation model for a sandy river section, comprising: a sand wave height and exchange rate acquisition module, configured to acquire the sand wave height and bed sand exchange rate of the target sandy river section when the relative water depth of the target sandy river section is not less than a first preset threshold; An active layer thickness acquisition module is used to obtain the bed sand exchange active layer thickness of the target sandy river section in the current step of an exchange step based on the sand wave height and the bed sand exchange rate; The bed scour thickness acquisition module is used to obtain the bed scour thickness of the current step based on the thickness of the bed-sand exchange active layer, sand wave height and bed-sand exchange rate of the current step; A bed sand accumulation thickness acquisition module is used to obtain the bed sand accumulation thickness of the current step based on the bed sand exchange active layer thickness of the current step and the preset three-state transition probability; The incoming sand deposition thickness acquisition module is used to obtain the incoming sand deposition thickness of the current step; A total scouring and silting thickness acquisition module is used to obtain the total scouring and silting thickness of the current step based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; The bed sediment gradation acquisition module is used to obtain the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process of the target sandy river section based on the preset sediment balance equation; The bed sediment gradation model determination module is used to obtain the bed sediment gradation model of the target sandy river section based on the total scouring and silting thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
[0027] In a third aspect, the present invention further provides an electronic device comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is configured to execute the program stored in the memory to implement the steps of the method for constructing a bed sediment grading model for a sandy river section described in any one of the above implementations.
[0028] In a fourth aspect, the present invention also provides a computer-readable storage medium for storing computer-readable programs or instructions, which, when executed by a processor, can implement the steps in a method for constructing a bed sand grading model for a sandy river section described in any of the above-mentioned implementation methods.
[0029] The beneficial effects of the present invention are as follows: the present invention provides a method for constructing a bed sand gradation model for a sandy river section, firstly, when the relative water depth of the target sandy river section is not less than a first preset threshold, obtaining the sand wave height and the bed sand exchange rate of the target sandy river section; obtaining the thickness of the bed sand exchange active layer of the target sandy river section in an exchange step based on the sand wave height and the bed sand exchange rate; further obtaining the bed surface scour thickness of the current step based on the thickness of the bed sand exchange active layer, the sand wave height and the bed sand exchange rate; obtaining the bed surface scour thickness in each exchange step; further obtaining the bed surface scour thickness in each exchange step based on the thickness of the bed sand exchange active layer and the preset three-state The transfer probability obtains the bed sand accumulation thickness of the current step, and the bed sand accumulation thickness within each exchange step can be obtained. The incoming sand accumulation thickness of the current step can be obtained, and the incoming sand accumulation thickness within each exchange step can be obtained. The total scouring and silting thickness is obtained based on the bed surface scouring thickness, the bed sand accumulation thickness, and the incoming sand accumulation thickness. The total scouring and silting thickness is obtained dynamically. The bed sand gradation of each step in the riverbed suspended sand-bed sand exchange process of the target sandy river section is obtained based on the preset sediment balance equation. The bed sand gradation model of the target sandy river section is further obtained based on the total scouring and silting thickness and the bed sand gradation of each step in the riverbed suspended sand-bed sand exchange process. The present invention obtains the total scouring and silting thickness of the target sandy river section and combines it with the preset sediment balance equation and the bed sand gradation of each step to dynamically obtain the bed sand gradation model of the target sandy river section. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 A flow chart of an embodiment of a method for constructing a bed sediment gradation model for a sandy river section provided by the present invention; Figure 2 A schematic diagram of wave sand movement in one embodiment of a method for constructing a sandy riverbed gradation model provided by the present invention; Figure 3 A schematic diagram of a calculation model for adjusting the bed sediment in a sandy river section according to an embodiment of a method for constructing a bed sediment grading model for a sandy river section provided by the present invention; Figure 4 A schematic diagram of the calculation results of the bed sediment gradation in Shashi in 2009 in a specific embodiment of a method for constructing a bed sediment gradation model for a sandy river section provided by the present invention; Figure 5 A schematic diagram of the calculation results of the bed sediment gradation in Shashi in 2011 in a specific embodiment of a method for constructing a bed sediment gradation model for a sandy river section provided by the present invention; Figure 6 A schematic diagram of the calculation results of the bed sediment gradation in Shashi in 2010 in a specific embodiment of a method for constructing a bed sediment gradation model for a sandy river section provided by the present invention; Figure 7A schematic diagram of the calculation results of the bed sediment gradation in Shashi in 2011 in a specific embodiment of a method for constructing a bed sediment gradation model for a sandy river section provided by the present invention; Figure 8 A schematic flow chart of an embodiment of a device for constructing a sandy riverbed gradation model provided by the present invention; Figure 9 This is a schematic structural diagram of an embodiment of the electronic device provided by the present invention. DETAILED DESCRIPTION
[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.
[0032] In the description of the embodiments of the present invention, unless otherwise specified, "plurality" means two or more. "And / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone.
[0033] The terms "first," "second," and so on, used in the embodiments of the present invention are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, technical features designated as "first" or "second" may explicitly or implicitly include at least one such feature.
[0034] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0035] Before presenting the embodiments, the following terms are explained.
[0036] Bed sediment gradation refers to the distribution of sediment particles of different sizes within a riverbed. Specifically, it describes the proportions and distribution characteristics of various sediment sizes within the riverbed. Bed sediment gradation is crucial for understanding river erosion and deposition processes, changes in riverbed morphology, and the patterns of sediment movement. Bed load, also known as bed load, bottom load, push load, or traction load, refers to sediment particles that roll, move, jump, or layer along the riverbed during flow, frequently exchanging with surface sediment (referred to as bed sediment) during this movement.
[0037] The present invention provides a method, device and electronic equipment for constructing a bed sediment grading model for a sandy river section, which are respectively described below.
[0038] Figure 1 A flow chart of an embodiment of a method for constructing a sandy riverbed gradation model provided by the present invention is shown in FIG. Figure 1 As shown in FIG, the method for constructing the bed sediment gradation model for a sandy river section includes: S101, when the relative water depth of the target sandy river section is not less than a first preset threshold, obtaining the sand wave height and bed-sand exchange rate of the target sandy river section; It should be noted that a sandy riverbed is one whose surface is primarily composed of sand. This type of riverbed is characterized by coarse sediment particles that move in a manner known as propulsion or saltation. The formation and development of a sandy riverbed are influenced by the intensity of the current. As the current intensity changes, the riverbed surface undergoes various morphological changes, such as flatness, sand ripples, ridges, and waves.
[0039] In addition, relative water depth is a special term in this field, which refers to the ratio of water depth to the median particle size of bed sand.
[0040] The first preset threshold is the critical value between natural rivers and non-natural rivers, that is, when the relative water depth is greater than the first preset threshold, the model calculation will continue according to the method steps of this application.
[0041] S102, obtaining the thickness of the bed-sand exchange active layer of the target sandy river section in the current step within an exchange step based on the sand wave height and the bed-sand exchange rate; It should be noted that sand wave height refers to the maximum height of a sand wave perpendicular to the direction of water flow. Sand waves are wavy micro-topography formed by the movement of sediment particles in the riverbed under the action of flowing water. The bed-sand exchange rate is the vertical velocity of the sand wave movement.
[0042] S103, obtaining the bed surface scour thickness of the current step based on the thickness of the bed-sand exchange active layer, the sand wave height, and the bed-sand exchange rate of the current step; It should be noted that bed scour thickness refers to the scour depth formed by the erosion of the riverbed by water flow.
[0043] S104, obtaining the bed sand accumulation thickness of the current step based on the bed sand exchange active layer thickness of the current step and the preset three-state transition probability; It should be noted that the bed sand accumulation thickness refers to the thickness of sediment accumulated due to water erosion.
[0044] S105, obtaining the thickness of incoming sand deposition in the current step; S106, obtaining the total scouring and silting thickness of the current step based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; S107, obtaining the bed sediment gradation at each step of the suspended sediment-bed sediment exchange process in the target sandy river section based on a preset sediment balance equation; S108. Obtain a bed sediment gradation model for the target sandy river section based on the total scouring and silting thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
[0045] Compared with the prior art, the present embodiment provides a method for constructing a bed-sand gradation model for a sandy river section. First, when the relative water depth of the target sandy river section is not less than a first preset threshold, the sand wave height and the bed-sand exchange rate of the target sandy river section are obtained; based on the sand wave height and the bed-sand exchange rate, the thickness of the bed-sand exchange active layer of the target sandy river section in one exchange step is obtained; further, based on the thickness of the bed-sand exchange active layer, the sand wave height and the bed-sand exchange rate, the bed scour thickness of the current step is obtained; the bed scour thickness within each exchange step can be obtained; further, based on the thickness of the bed-sand exchange active layer and the preset three-state The transfer probability obtains the bed sand accumulation thickness of the current step, and the bed sand accumulation thickness within each exchange step can be obtained. The incoming sand accumulation thickness of the current step can be obtained, and the incoming sand accumulation thickness within each exchange step can be obtained. The total scouring and silting thickness is obtained based on the bed surface scouring thickness, the bed sand accumulation thickness, and the incoming sand accumulation thickness. The total scouring and silting thickness is obtained dynamically. The bed sand gradation of each step in the riverbed suspended sand-bed sand exchange process of the target sandy river section is obtained based on the preset sediment balance equation. The bed sand gradation model of the target sandy river section is further obtained based on the total scouring and silting thickness and the bed sand gradation of each step in the riverbed suspended sand-bed sand exchange process. The present invention obtains the total scouring and silting thickness of the target sandy river section and combines it with the preset sediment balance equation and the bed sand gradation of each step to dynamically obtain the bed sand gradation model of the target sandy river section.
[0046] In the specific embodiment of the present invention, first, in order to better understand the content of the present invention, the following content introduces the motion characteristics of Bosha, specifically, Figure 2As shown in the figure, during the movement of sand waves, the bed surface morphology changes with the intensity of sand transport, and has randomness and periodicity. In addition, during the movement of sand waves, an active exchange layer is formed on the surface of the bed sand, which makes the upper and lower layers of bed sand, sandy bed load, and suspended load exchange with each other, prompting the surface bed sand gradation to be continuously adjusted. Among them, the distance between two adjacent troughs, or between two adjacent crests is the wavelength; the vertical distance from the trough to the crest is the wave height. H s .
[0047] Some domestic scholars have analyzed flume tests and river sand wave data to plot different relative water depths. h / d 50 When the sand wave moves at a speed of V sx Sand resistance and summarize the sand wave movement speed V sx The calculation relationship is: (1) (2) In formulas (1) and (2): is the dimensionless sand shear stress, and ; is the water specific gravity; is the bulk density of sediment; is the hydraulic radius of the sand particle; J is the water surface gradient; h For water depth; is the median particle size of bed sand; g is the acceleration due to gravity. According to formula (2), in this embodiment, the first preset threshold is 7000.
[0048] For natural rivers ( 7000~10000), sand wave movement period T It can be expressed as: (3) Where: 、 Relative water depth The relevant coefficients; when hour, , .
[0049] At the same time, Shabobogao Hs ( 7000~10000) can be expressed as: (4) (5) Combining equations (3)-(5), we can get Vertical velocity of sand wave motion (bed sand exchange rate) V sy for: (6) In addition, by observing the flume test and analyzing the measured data, it was found that the sand wave movement period of the natural river is much longer than that in the flume, and the bed sand exchange rate during the sand wave movement was given. V sy expression: (7) Where: is the critical sand shear stress, and ;when When, take ,at this time .
[0050] Therefore, in formula (7), when When the bed sand exchange rate V sy It can be expressed as: (8) In summary, when ,and When the wave height is between 7000 and 10000, the wave height of sand wave can be obtained by combining equations (6) and (8): H s for: (9) In some embodiments of the present invention, when the critical sand shear stress is not less than the second preset threshold, the expression for the sand wave height is:
[0051]
[0052] The expression of bed sand exchange rate is:
[0053]
[0054] When the critical sand shear stress is greater than the second preset threshold, the expression of the bed sand exchange rate is:
[0055] The expression of sand wave height is:
[0056] Where, Vsy represents the bed sand exchange rate, Indicates the height of the wave sand, represents the dimensionless sand grain shear stress, , Indicates water density, represents the bulk density of sediment, represents the hydraulic radius of sand particles, J represents the water surface gradient, h Indicates water depth. represents the median particle size of bed sand, g represents the acceleration due to gravity, 、 Relative water depth In this embodiment, the second preset threshold is equal to 2.
[0057] It's important to note that for a gravel-and-sand riverbed, the amount of sand washed down each step in the active layer during bed-sand exchange cannot be replenished by an equal amount of the original bed sand below. This is because during the sorting and transport of the surface bed sand, the surface bed sand gradually coarsens, differing significantly from the composition of the underlying bed sand, causing the scouring process to become increasingly slow. In this case, if the replenishment of the original bed sand below is taken into account, the thickness of the active layer is increased, making the coarsening process relatively easier.
[0058] However, the composition of the bed sand of a sandy riverbed and a gravel-sand riverbed is quite different. The upper and lower layers of the bed sand are relatively uniform, with a small range of particle sizes. The bed sand exchange process is mainly maintained by the movement of sand waves. During the movement of sand waves, an active exchange layer is formed on the surface of the bed sand, which promotes the continuous adjustment of the surface bed sand gradation. Therefore, for the sandy riverbed downstream of the Three Gorges Project, the amount of sand washed down in the active layer should be replenished by an equal amount of the original bed sand in the lower layer. Figure 3 As shown, in some embodiments of the present invention, the expression of the preset sand balance equation is: (10) Where: Sandy riverbed n Thickness of the active layer of bed sand exchange; For the n Total scouring and silting thickness, For the n -1 step bed sand scouring thickness, For the n -1 step bed sand accumulation thickness; For the n Bulai sand deposition thickness; 、 is the probability of sediment state transition; For the n Bulai sand gradation, representing sediment particle size smaller thand i Percentage of sand weight; 、 、 Respectively n Bed sand gradation, bed load gradation and sand entrainment gradation represent sediment particle size smaller than d k Percentage of sand weight; is the initial bed sand gradation, and there is ; Among them, the second term on the left side of the equation is the incoming sand supply term, the third term is the scouring term, the fourth term is the siltation term, and the fifth term is the lower layer original bed sand supply term (the main difference from the sand balance equation of the pebble-sand river section).
[0059] Formula 11 is adjusted to consider the influence of sediment from the middle and upper reaches of alluvial rivers. n Step bed sand grading It can be calculated using the following formula: (11) Where: , .
[0060] It should be noted that under certain water flow conditions, bed sand, sandy bed load, and suspended load exchange with each other; at this time, the coarser bed sand on the surface of the bed is washed away, and the finer sediment and sediment particles in the subsurface are exposed, thus becoming the surface bed sand, which continues to exchange with the sandy bed load and suspended load, and the cycle repeats, and the sand wave gradually moves forward. Therefore, within the calculation period dt , thickness of bed sand exchange active layer With the n Bed sand exchange rate Related, and the maximum value does not exceed the sand wave height H s In some embodiments of the present invention, the expression for the thickness of the bed-sand exchange active layer in the current step is: (12) Where, represents the thickness of the active layer of bed-sand exchange in the sandy riverbed at step n, H s represents the height of sand waves, T represents the period of sand wave movement, is the computational step size relative to one exchange process, and , is the actual calculation step size, The time required to complete one bed sand exchange.
[0061] In addition, during the coarsening process of the sandy riverbed, the thickness of the bed scour at the nth step is The exchange rate with bed sand and sand wave speed In some embodiments of the present invention, the expression for the bed surface scouring thickness at the current step is: (13)
[0062] Where, Indicates the n Step bed surface scouring thickness, represents the bed sand exchange rate, represents the speed of sand wave movement, Indicates the n-1 Step bed sand grading, 、 Both represent the probability of sediment state transition.
[0063] During the bed sand exchange and coarsening process, the sedimentation mechanism of bed load and suspended sediment in sandy river sections is the same as that in pebble-sand river sections, i.e. and transition probability 、 In some embodiments of the present invention, the bed sand accumulation thickness The expression is: (14) The thickness of the incoming sand deposition in the current step The expression is:
[0064] The expression of the total scouring and silting thickness of the current step is: (15) Where, Indicates the n Step bed scouring thickness, Indicates the n The thickness of bed sand deposition at the beginning of the step, Indicates the n The thickness of the incoming sand deposition, Indicates the n-1 Step by step bed load grading, Q S is the sediment transport rate per width (kg / s), ρ s is the sediment density, e s is the porosity of bed sand.
[0065] In some embodiments of the present invention, the bed sediment gradation model of the target sandy river section is expressed as:
[0066] Where, Indicates the first n Step bed sand grading, , , , , , Indicates the bed load gradation and the sand entrainment gradation, It indicates the percentage of sediment weight with sediment particle size smaller than dk; is the initial bed sand gradation, 、 represents the probability of sediment state transition, Indicates the n Step sediment thickness, Indicates the n The speed of sand wave movement, Indicates the n The bed sand exchange rate is the step, T represents the sand wave motion period, represents the computational step size relative to one exchange process, and ; is the actual calculation step size, The time required to complete one bed sand exchange.
[0067] In order to further verify the bed sand gradation model of this embodiment, a specific example is given below to illustrate.
[0068] Since the verification results are relatively complex and there are many calculation process curves in the year, the representative bed sand gradation calculation results of 2009 (balanced-coarsening-fineness) and 2011 (fineness-coarsening) are selected from the Shashi section to illustrate the calculation accuracy of the probability model in this paper. Figure 4 As shown. Figure 4 It can be seen that the calculated results of bed sand gradation in 2009 are in good agreement with the measured data, and the bed sand exchange process is: (ii) equilibrium-coarsening-fineness; among them, the bed sand gradation on March 27 is close to the initial gradation on January 15 (approximately equilibrium state), and the coarsening is completed before the end of the flood season (September 25), after which the bed sand gradually fines. Figure 5 It can be seen that the calculation results of the bed sand exchange process in 2011 are as follows: (i) refinement-coarsening; among them, January 24 was the initial bed sand, and the refinement was completed on May 9, after which the bed sand gradually coarsened.
[0069] The Jianli section selected some calculation nodes in 2010 (balance-refinement-coarsening) and 2011 (refinement-coarsening) to illustrate the verification results of the bed sand exchange process in this paper. Figure 6 As shown. Figure 6It can be seen that the calculated results of the bed sand gradation in 2010 are in good agreement with the measured data, and the bed sand exchange process is as follows: (iii) equilibrium-refinement-coarsening; among them, the bed sand gradation on May 9 (the beginning of the flood season) is close to the initial gradation on January 15 (approximately equilibrium state), and the refinement is completed until August 22, after which the bed sand gradually coarsens. Figure 7 The calculated results of the 2011 bed-sand exchange process show the following characteristics: (ii) refinement-coarsening, which agrees well with the measured data. The initial bed-sand occurred on January 24th, and refinement was complete by May 6th, after which the bed-sand gradually coarsened. Furthermore, the total scour thickness calculated for the Shashi section during a certain calculation period at the end of the 2009 flood season (October 15th to 28th) was 0.09 m, and the total scour thickness calculated for the Jianli section during a certain calculation period at the end of the 2009 flood season (October 13th to 27th) was 0.34 m.
[0070] From the above analysis, we can see that the results of bed sediment exchange at the Shashi and Jianli sections are divided into two categories: (1) the coarsening and refinement of bed sediment coexist within the year, which may be related to factors such as the vertical change of bed sediment composition, the change of water and sediment inflow process, and the exchange of water and sediment between rivers and lakes; (2) the bed sediment shows an overall coarsening trend between years, but the degree of coarsening is not high, which is also the inevitable result of bed sediment exchange in sandy river sections; the bed sediment in the upper and lower layers of the sandy riverbed is relatively uniform, with a small range of particle sizes, and the particle size ranges of bed sediment, bed load, and suspended sediment are similar. According to the measured data at the Shashi and Jianli sections, the particle size range of bed sediment is between 0.062 mm and 2 mm, the particle size range of sandy bed load is between 0.002 mm and 2 mm (the measured data show that there is no pebble bed load at both hydrological stations), and the particle size range of suspended sediment is between 0.002 mm and 1 mm.
[0071] In order to better implement the method for constructing a sandy riverbed gradation model in an embodiment of the present invention, based on the method for constructing a sandy riverbed gradation model, correspondingly, Figure 8 As shown, an embodiment of the present invention further provides a device for constructing a sandy riverbed sediment gradation model. The device 800 for constructing a sandy riverbed sediment gradation model includes: The sand wave height and exchange rate acquisition module 801 is used to acquire the sand wave height and bed sand exchange rate of the target sandy river section when the relative water depth of the target sandy river section is not less than a first preset threshold; An active layer thickness acquisition module 802 is configured to obtain the active layer thickness of the bed-sand exchange at the current step of the target sandy river section within an exchange step based on the sand wave height and the bed-sand exchange rate; The bed scour thickness acquisition module 803 is used to obtain the bed scour thickness of the current step based on the thickness of the bed-sand exchange active layer, the sand wave height and the bed-sand exchange rate of the current step; The bed sand accumulation thickness acquisition module 804 is used to obtain the bed sand accumulation thickness of the current step based on the bed sand exchange active layer thickness of the current step and the preset three-state transition probability; The incoming sand deposition thickness acquisition module 805 is used to obtain the incoming sand deposition thickness of the current step; Total scouring and silting thickness acquisition module 806, for obtaining the total scouring and silting thickness of the current step based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; The bed sediment gradation acquisition module 807 is used to obtain the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process of the target sandy river section based on a preset sediment balance equation; The bed sediment gradation model determination module 808 is used to obtain the bed sediment gradation model of the target sandy river section based on the total scouring and deposition thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
[0072] The device 800 for constructing a sandy river section bed grading model provided in the above embodiment can implement the technical solution described in the above embodiment of the method for constructing a sandy river section bed grading model. The specific implementation principles of the above modules or units can be found in the corresponding contents in the above embodiment of the method for constructing a sandy river section bed grading model, which will not be repeated here.
[0073] like Figure 9 As shown, the present invention also provides an electronic device 900. The electronic device 900 includes a processor 901, a memory 902 and a display 903. Figure 9 Only some of the components of the electronic device 900 are shown, but it should be understood that implementation of all of the shown components is not required, and more or fewer components may be implemented instead.
[0074] In some embodiments, the processor 901 can be a central processing unit (CPU), a microprocessor, or other data processing chip, used to run the program code or process data stored in the memory 302, such as the method for constructing a bed sediment grading model for a sandy river section in the present invention.
[0075] In some embodiments, the processor 901 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 901 may be local or remote. In some embodiments, the processor 901 may be implemented on a cloud platform. In some embodiments, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, multiple clouds, or any combination thereof.
[0076] In some embodiments, the memory 902 may be an internal storage unit of the electronic device 900, such as a hard disk or memory of the electronic device 900. In other embodiments, the memory 902 may also be an external storage device of the electronic device 900, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 900.
[0077] Furthermore, the memory 902 may include both an internal storage unit of the electronic device 900 and an external storage device. The memory 902 is used to store application software installed in the electronic device 900 and various data.
[0078] In some embodiments, the display 903 can be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. The display 903 is used to display information on the electronic device 900 and to display a visual user interface. Components 901-903 of the electronic device 900 communicate with each other via a system bus.
[0079] In one embodiment, when the processor 901 executes a program for constructing a bed sediment gradation model for a sandy river section in the memory 902, the following steps may be implemented: When the relative water depth of the target sandy river section is not less than a first preset threshold, obtaining the sand wave height and bed-sand exchange rate of the target sandy river section; Based on the sand wave height and the bed-sand exchange rate, the thickness of the bed-sand exchange active layer of the target sandy river section in the current step of an exchange step is obtained; The bed scour thickness of the current step is obtained based on the thickness of the bed-sand exchange active layer, sand wave height and bed-sand exchange rate of the current step; The bed sediment deposition thickness of the current step is obtained based on the bed sediment exchange active layer thickness of the current step and the preset three-state transition probability; Get the thickness of incoming sand accumulation in the current step; The total scouring and silting thickness of the current step is obtained based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; Based on the preset sediment balance equation, the bed sediment gradation at each step of the suspended sediment-bed sediment exchange process in the target sandy river section is obtained; The bed sediment gradation model of the target sandy river section is obtained based on the total scouring and silting thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
[0080] It should be understood that, when the processor 901 executes a program for constructing a sandy riverbed gradation model in the memory 902 , in addition to the above functions, it can also implement other functions. For details, please refer to the description of the corresponding method embodiment above.
[0081] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 900 mentioned. The electronic device 900 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, or a laptop computer. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 900 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).
[0082] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random access memory.
[0083] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.
Claims
1. A method for constructing a bed sediment gradation model for a sandy river section, characterized in that: include: When the relative water depth of the target sandy river section is not less than a first preset threshold, obtaining the sand wave height and bed-sand exchange rate of the target sandy river section; Based on the sand wave height and the bed-sand exchange rate, the thickness of the bed-sand exchange active layer of the target sandy river section in the current step of an exchange step is obtained; The bed scour thickness of the current step is obtained based on the thickness of the bed-sand exchange active layer, sand wave height and bed-sand exchange rate of the current step; The bed sediment deposition thickness of the current step is obtained based on the bed sediment exchange active layer thickness of the current step and the preset three-state transition probability; Get the thickness of incoming sand accumulation in the current step; The total scouring and silting thickness of the current step is obtained based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; Based on the preset sediment balance equation, the bed sediment gradation at each step of the suspended sediment-bed sediment exchange process in the target sandy river section is obtained; The bed sediment gradation model of the target sandy river section is obtained based on the total scouring and silting thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
2. The method for constructing a sandy riverbed sediment gradation model according to claim 1, wherein: When the critical sand shear stress is not less than the second preset threshold, the expression of sand wave height is: The expression of bed sand exchange rate is: When the critical sand shear stress is greater than the second preset threshold, the expression of the bed sand exchange rate is: The expression of sand wave height is: Where, V sy represents the bed sand exchange rate, Indicates the height of the wave sand, represents the dimensionless sand grain shear stress, , Indicates water density, represents the bulk density of sediment, represents the hydraulic radius of sand particles, J represents the water surface gradient, h Indicates water depth. represents the median particle size of bed sand, g represents the acceleration due to gravity, 、 Relative water depth The relevant coefficients.
3. The method for constructing a sandy riverbed sediment gradation model according to claim 1, wherein: The expression of the thickness of the bed sand exchange active layer in the current step is: Where, represents the thickness of the active layer of bed-sand exchange in the sandy riverbed at step n, H s represents the height of sand waves, T represents the period of sand wave movement, is the computational step size relative to one exchange process, and , is the actual calculation step size, The time required to complete one bed sand exchange.
4. The method for constructing a sandy riverbed sediment gradation model according to claim 3, wherein: The expression of the bed surface scouring thickness at the current step is: Where, Indicates the n Step bed surface scouring thickness, represents the bed sand exchange rate, represents the speed of sand wave movement, Indicates the n- 1-step bed sand grading, 、 Both represent the probability of sediment state transition.
5. The method for constructing a sandy riverbed sediment gradation model according to claim 4, wherein: The bed sand accumulation thickness of the current step The expression is: The thickness of the incoming sand deposition in the current step The expression is: The expression of the total scouring and silting thickness is: Where, Indicates the n Step bed scouring thickness, Indicates the n The thickness of bed sand deposition at the beginning of the step, Indicates the n The thickness of the incoming sand deposition, Indicates the n-1 Step by step bed load grading, Q S is the sediment transport rate per width (kg / s), ρ s is the sediment density, e s is the porosity of bed sand.
6. The method for constructing a sandy riverbed sediment gradation model according to claim 1, wherein: The expression of the preset sand balance equation is: Where: Indicates sandy riverbed n Thickness of the active layer of bed sand exchange, For the n Total scouring and silting thickness, For the n -1 step bed sand scouring thickness, is the thickness of bed sand accumulation at step n-1, For the n Bulai sand deposition thickness, 、 Both represent the probability of sediment state transition, For the n The Bulai sand gradation indicates that the sediment particle size is smaller than d i The percentage of sand weight, Indicates the n Step bed sand grading, express n Step-by-step bed load grading, Indicates the n The step-sand carrying capacity gradation represents the sediment particle size smaller than d k The percentage of sand weight, represents the initial bed sand gradation.
7. The method for constructing a sandy riverbed sediment gradation model according to claim 1, wherein: The expression of the bed sand gradation model of the target sandy river section is: Where, Indicates the first n Step bed sand grading, , , , , , Indicates the bed load gradation and the sand entrainment gradation, Indicates that the sediment particle size is smaller than d k Percentage of sand weight; is the initial bed sand gradation, 、 represents the probability of sediment state transition, Indicates the n Step sediment thickness, Indicates the n The speed of sand wave movement, Indicates the n The bed sand exchange rate is the step, T represents the sand wave motion period, represents the computational step size relative to one exchange process, and ; is the actual calculation step size, The time required to complete one bed sand exchange.
8. A device for constructing a bed sediment gradation model for a sandy river section, characterized in that: include: a sand wave height and exchange rate acquisition module, configured to acquire the sand wave height and bed sand exchange rate of the target sandy river section when the relative water depth of the target sandy river section is not less than a first preset threshold; An active layer thickness acquisition module is used to obtain the bed sand exchange active layer thickness of the target sandy river section in the current step of an exchange step based on the sand wave height and the bed sand exchange rate; The bed scour thickness acquisition module is used to obtain the bed scour thickness of the current step based on the thickness of the bed-sand exchange active layer, sand wave height and bed-sand exchange rate of the current step; A bed sand accumulation thickness acquisition module is used to obtain the bed sand accumulation thickness of the current step based on the bed sand exchange active layer thickness of the current step and the preset three-state transition probability; The incoming sand deposition thickness acquisition module is used to obtain the incoming sand deposition thickness of the current step; A total scouring and silting thickness acquisition module is used to obtain the total scouring and silting thickness of the current step based on the bed scouring thickness of the current step, the bed sand silting thickness of the current step, and the incoming sand silting thickness of the current step; The bed sediment gradation acquisition module is used to obtain the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process of the target sandy river section based on the preset sediment balance equation; The bed sediment gradation model determination module is used to obtain the bed sediment gradation model of the target sandy river section based on the total scouring and silting thickness of the current step and the bed sediment gradation of each step in the riverbed suspended sediment-bed sediment exchange process.
9. An electronic device, characterized in that: comprising a memory and a processor, wherein, The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the method for constructing a bed sediment grading model for a sandy river section as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the method for constructing a bed sediment grading model for a sandy river section as described in any one of claims 1 to 7.