A general plant wave-damping prediction method considering whole-factor geometric parameters and mechanical characteristics of plant above-ground structure

Abstract

This application relates to the field of marine ecological disaster reduction technology. This application discloses a general method for predicting wave height reduction by considering the geometric parameters and mechanical properties of all aboveground structural elements of plants, which can improve the accuracy of predicting wave height reduction coefficients. The method includes determining multiple aboveground structural elements of a target plant in a target vegetation, where the target plant is any plant of one species in the target vegetation, and the multiple aboveground structural elements include stems, leaves, roots, and branches; obtaining the geometric shape and mechanical characteristics corresponding to each aboveground structural element, which at least include distribution density, length, width, thickness, elastic modulus, upper limit of vertical distribution, and lower limit of vertical distribution; and substituting all geometric shapes and mechanical characteristics into a wave height reduction coefficient prediction model to obtain the target wave height reduction coefficient of the target plant per unit propagation distance.

Description

Technical Field

[0001] This application relates to the field of marine ecological disaster reduction technology. More specifically, this application relates to a general method for predicting wave dissipation by vegetation that considers all geometric parameters and mechanical properties of aboveground plant structures. Background Technology

[0002] Ecosystems composed of coastal mangroves, salt marshes, and seagrass beds provide crucial natural protection against wave-induced floods and seabed erosion; however, their protective effectiveness varies significantly depending on hydrodynamic conditions and vegetation characteristics. Current technologies typically use wave height reduction coefficients to represent the protective effects of these vegetation types. These coefficients are calculated by considering factors such as the drag coefficient of the vegetation, vegetation density, water depth, wave number, and incident wave height. However, this method neglects the geometric characteristics and mechanical parameters of different structural elements within the vegetation, leading to inaccurate wave height reduction coefficient predictions. Summary of the Invention

[0003] The purpose of this application is to provide a general method for predicting wave height reduction by considering all geometric parameters and mechanical properties of aboveground plant structures, which can improve the accuracy of the predicted wave height reduction coefficient. This application is mainly achieved through the following technical solutions: This application provides a general method for predicting wave dissipation by plants that considers all geometric parameters and mechanical properties of aboveground plant structures, including: Identify multiple aboveground structural elements of a target plant in a target vegetation, wherein the target plant is any one plant of one species in the target vegetation, and the multiple aboveground structural elements include stems, leaves, roots and branches; Obtain the geometric shape and mechanical characteristics corresponding to each above-ground structural element. The geometric shape and mechanical characteristics include at least the distribution density, length, width, thickness, elastic modulus, upper limit of vertical distribution, and lower limit of vertical distribution. By substituting all geometric shapes and mechanical characteristics into the wave height reduction coefficient prediction model, the target wave height reduction coefficient of the target plant per unit propagation distance is obtained.

[0004] According to one embodiment of this application, the calculation formula for the wave height reduction coefficient prediction model is as follows: ; in, It is the target wave height reduction coefficient of the target plant per unit propagation distance; It refers to the number of types of the above-ground structural elements; It is the incident wave height on the seaward side of the target vegetation; It is the first Distribution density of structural elements on the farmland; It is the first Resistance coefficients corresponding to structural elements on farmland; It is the first The width corresponding to structural elements on the farmland; It is the first The lengths corresponding to structural elements on the farmland; It is the wave number; It is the first The lower limit of the vertical distribution of structural elements on the planting land; It is the first The upper limit of the vertical distribution of structural elements on the farmland; It is a hyperbolic sine function; It is the depth of the seawater where the target plant is located; It is the first The shading coefficients corresponding to structural elements on the farmland; It is the first Cross-sectional shape coefficients corresponding to structural elements on the farmland; It is the first The Cauchy number corresponding to the structural elements on the planting site represents the first... The ratio of the fluid resistance generated by structural elements on the planted surface to the restoring force caused by its elastic deformation, the third The Cauchy number corresponding to the structural elements on the ground is based on fluid velocity and the first... The length, width, thickness, and elastic modulus of the structural elements on the planting site are calculated. It is the first Length ratio coefficients corresponding to structural elements on farmland The value is equal to the first The ratio of the length of the structural elements on the planting site to the horizontal migration amplitude of wave water particles.

[0005] According to one embodiment of this application, the general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures further includes: Based on the Cauchy number of the target aboveground structural element and the ratio of the length of the target aboveground structural element to the wave trajectory displacement, the drag flexibility correction term of the target aboveground structural element is calculated. The drag flexibility correction term is used to reflect the influence of the flexibility of the target aboveground structural element on plant drag and wave energy dissipation rate. The target above-ground structural element is any one of the various above-ground structural elements.

[0006] According to one embodiment of this application, when the resistance correction term is 1, the target above-ground structural element is a rigid structural element.

[0007] According to one embodiment of this application, the Cauchy number corresponding to each aboveground structural element is calculated based on the length, width, elastic modulus, and horizontal component of the average velocity of water particles at maximum water depth corresponding to each aboveground structural element.

[0008] According to one embodiment of this application, the length ratio coefficient corresponding to each above-ground structural element is obtained based on the length of each above-ground structural element and the wave track displacement corresponding to each above-ground structural element.

[0009] According to one embodiment of this application, the general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures further includes: Obtain the width of the vegetation strip of the target vegetation; The target total wave height reduction coefficient of the target vegetation is obtained by substituting the width of the vegetation belt, the incident wave height on the seaward side of the target vegetation, and the transmitted wave height on the shoreward side of the target vegetation belt into the total wave height reduction coefficient prediction model.

[0010] According to one embodiment of this application, the calculation formula for the total wave height reduction coefficient prediction model is as follows: ; in, It is the target total wave height reduction coefficient of the target vegetation; It is the width of the vegetation strip; It is the target vegetation The transmitted wave height at the location, that is, the transmitted wave height of the vegetation belt of the target vegetation on the shore side.

[0011] According to one embodiment of this application, after substituting the width of the vegetation strip, the incident wave height on the seaward side of the target vegetation, and the transmitted wave height on the shoreward side of the target vegetation strip into the total wave height reduction coefficient prediction model to obtain the target total wave height reduction coefficient of the target vegetation, the general vegetation wave dissipation prediction method considering all geometric parameters and mechanical properties of the aboveground structure of the vegetation further includes: Substitute the target total wave height reduction coefficient into the wave height reduction rate prediction model to obtain the target wave height reduction rate at a preset distance.

[0012] According to one embodiment of this application, the calculation formula for the wave height attenuation rate prediction model is as follows: ; in, It is the target wave height attenuation rate at a preset distance; This is the preset distance. The beneficial effects of this application's embodiments include: This application embodiment determines multiple aboveground structural elements of a target plant in a target vegetation, wherein the target plant is any one plant of one variety in the target vegetation, and the multiple aboveground structural elements include stems, leaves, roots, and branches; obtains the geometric shape and mechanical characteristics corresponding to each aboveground structural element, wherein the geometric shape and mechanical characteristics include at least distribution density, length, width, thickness, elastic modulus, upper limit of vertical distribution, and lower limit of vertical distribution; substitutes all geometric shapes and mechanical characteristics into a wave height attenuation coefficient prediction model to obtain the target wave height attenuation coefficient of the target plant per unit propagation distance. Compared with existing technologies that ignore the structural characteristics and mechanical parameters of vegetation, the wave height reduction coefficient model provided in this application generalizes a plant into above-ground structural elements such as stems, leaves, roots, and branches, and considers the geometric and mechanical characteristics (which can be understood as geometric and mechanical parameters) of the plant, such as distribution density, length, width, thickness, elastic modulus, upper limit of vertical distribution, and lower limit of vertical distribution. That is, this application uses the structural characteristics and mechanical parameters of vegetation to calculate the wave height reduction coefficient. As a result, the wave height reduction coefficient prediction model can predict the wave height reduction coefficient more accurately, thereby improving the accuracy of the wave height reduction coefficient prediction. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 Flowcharts of some embodiments of the general plant wave-dissipation prediction method that takes into account all geometric parameters and mechanical properties of aboveground plant structures in this application; Figure 2 This is a simplified reference diagram of salt marsh plants in some embodiments of this application; Figure 3 This is a simplified reference diagram of seagrass plants in some embodiments of this application; Figure 4 This is a generalized reference diagram of mangrove plants in some embodiments of this application; Figure 5 This is a generalized reference diagram of mangrove plants in some other embodiments of this application; Figure 6 This is a generalized reference diagram of salt marsh plants in some other embodiments of this application; Figure 7 This is a generalized reference diagram of seagrass plants in some other embodiments of this application; Figure 8This is a generalized reference diagram of mangrove plants in some of the embodiments of this application; Figure 9 This is a data reference diagram showing the geometric shape and mechanical characteristics of the parts in this application; Figure 10 Reference figures for the energy dissipation ratio of the prior art in this application and the energy dissipation ratio of this application in some embodiments; Figure 11 Reference figures for the energy dissipation ratio of the prior art in this application and the energy dissipation ratio of this application in other embodiments; Figure 12 The reference figure shows the energy dissipation ratio of the prior art in this application and the energy dissipation ratio of this application in some other embodiments. Detailed Implementation

[0015] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0016] It should be noted that the terms "first" and "second" are used 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, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0017] The terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0018] The terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or that are inherent to such process, method, product, or apparatus.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0020] The specific embodiments of this application will be further described below with reference to the accompanying drawings.

[0021] refer to Figure 1 The diagram shown is a flowchart of a general plant wave-dissipation prediction method that considers the geometric parameters and mechanical properties of all elements of the aboveground structure of plants, provided in an embodiment of this application. Figure 1 The general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures includes the following steps S1, S2 and S3.

[0022] S1. Determine various aboveground structural elements of the target plant in the target vegetation, wherein the target plant is any one plant of one variety in the target vegetation, and the various aboveground structural elements include stem, leaf, root system and branches.

[0023] The target vegetation includes coastal mangroves, salt marsh vegetation, or seagrass beds. Among them, plants in coastal mangroves include saffron or tamarisk, plants in salt marsh vegetation include reeds, sea sedge, or Spartina alterniflora, and plants in seagrass beds include sedge or eelgrass.

[0024] In practical applications, mangroves, salt marshes and seagrass differ significantly in terms of individual plant characteristics and community density. However, any aboveground structural element corresponding to the plants of mangroves, salt marshes and seagrass can be summarized into two cross-sectional shapes: a circular cross-section (such as the stems, roots and branches of most vegetation) and a rectangular cross-section (leaves).

[0025] Salt marsh plants generally have a rigid main stem, with numerous flexible leaves distributed around its perimeter and along its axis. (See reference...) Figure 2 As shown, in Figure 2 In the diagram, the symbol 's' represents the main stem of a salt marsh plant, and the symbol 'le' represents its leaves.

[0026] Seagrass plants are similar to salt marsh plants, but their stems are much shorter (usually less than 10 cm), and their leaves typically grow at the top of the stem. (See reference...) Figure 3 As shown, in Figure 3In this document, the symbol 's' represents the stem of a seagrass plant, and the symbol 'le' represents the leaf of a seagrass plant. Although the aboveground structural elements of seagrass plants are referred to as sheaths and leaves in the prior art, in order to maintain consistency with the terminology of salt marsh plants, the embodiments of this application uniformly refer to them as stems and leaves.

[0027] Mangrove plants are quite diverse, and can be classified morphologically into monostem shrub-like mangroves and mangroves with branches and above-ground roots. Monostem shrub-like mangroves include species such as *Gnaphalium affine*, *Portulaca grandiflora*, and *Centipeda minima*. These plants have slender, upright stems with leaves arranged along the stem. (See reference...) Figure 4 As shown, in Figure 4 In this context, the symbol 's' represents the stem of a single-stemmed shrub-like mangrove plant, and the symbol 'le' represents its leaves. Mangrove plants with branches and above-ground roots, however, consist of one or more main stems (which can be understood as stems), branches, roots, and leaves. (See reference...) Figure 5 As shown, in Figure 5 In this diagram, the symbol 's' represents the stem of a mangrove plant, the symbol 'le' represents the leaf of a mangrove plant, the symbol 'b' represents the branch of a mangrove plant, and the symbol 'r' represents the root system of a mangrove plant. In other embodiments, the branches and roots of mangrove plants may exhibit multiple levels.

[0028] Based on the analysis of salt marsh plants, seagrass plants, and mangrove plants described above, this application's embodiments generalize the target plant into a plant with four aboveground structural elements: stem, leaf, root system, and branches. The branches, roots, and stem can be further classified into different levels of aboveground structural elements, such as primary, secondary, and tertiary, depending on the specific circumstances.

[0029] Stems, leaves, roots, and branches are all real components of a plant.

[0030] Furthermore, the average resistance experienced by leaves and branches facing different orientations can be equivalently represented by upright vegetation units. Accordingly, each vegetation unit can be modeled as a cantilever beam, and its deformation motion occurs only in a two-dimensional plane (vertical and wave propagation direction).

[0031] Defining the vertical distribution range of the vegetation structural elements can effectively determine whether a unit (i.e., a vegetation unit) is submerged and the number of submerged units. When the vegetation is emergent, only the submerged portion interacts with the water body; therefore, the length and upper limit of the vertical distribution of the effective unit need to be updated. The updated length is... , It is the initial length corresponding to each aboveground structural element in the vegetation. It is a function for finding the minimum value. It represents the seawater depth at which each aboveground structural element in the vegetation is located; the updated upper limit of the vertical distribution is... , This represents the initial vertical distribution upper limit for each aboveground structural element in the vegetation. The total number of vegetation units interacting with the fluid within a unit bed area of ​​a vegetation unit is: , It is the initial distribution density corresponding to each aboveground structural element in the vegetation. This represents the initial lower limit of the vertical distribution for each aboveground structural element in the vegetation. Seagrass is typically in a completely submerged state; even if the water depth is slightly less than the total upright height of the seagrass plant, its high flexibility allows the entire plant to remain submerged. Therefore, the unit length and density of seagrass are determined to remain unchanged with water depth, and only the upper limit of the seagrass' vertical distribution is updated. This is used to calculate the flow rate.

[0032] S2. Obtain the geometric shape and mechanical characteristics corresponding to each above-ground structural element. The geometric shape and mechanical characteristics include at least the distribution density, length, width, thickness, elastic modulus, upper limit of vertical distribution, and lower limit of vertical distribution.

[0033] Furthermore, the distribution density corresponding to each above-ground structural element is directly proportional to the upper and lower limits of its vertical distribution. For details, please refer to the formula: ;in, It is the updated distribution density, used to characterize the total number of each aboveground structural element within a unit bed area.

[0034] Furthermore, when the thickness and width of each above-ground structural element meet a first preset condition, it indicates that the above-ground structural element is a cylindrical structural element. The first preset condition is: ,in, It refers to the thickness corresponding to each type of above-ground structural element. It is the width corresponding to each type of above-ground structural element. It is an approximate equality symbol. When the thickness and width corresponding to each above-ground structural element meet the second preset condition, it indicates that the above-ground structural element is a flat blade. The second preset condition is: , It is much smaller than the sign.

[0035] Furthermore, the lower limit of the vertical distribution is expressed as... The upper limit of the vertical distribution For the leaves of salt marsh plants, assuming they are uniformly distributed along the stem, the lower limit of the vertical distribution of salt marsh plants can be expressed as follows: The upper limit of the vertical distribution of salt marsh plants is expressed as ,in, The length of the stem, for reference. Figure 6 As shown, in Figure 6In the diagram, the solid red line represents the upper limit of the vertical distribution of stems and leaves, and the dashed line represents the depth of seawater. For seagrass plants, if the stems grow from the substrate, the lower limit of the vertical distribution of the seagrass plant is expressed as follows: The upper limit of the vertical distribution of seagrass plants is expressed as If the leaves grow at the top of the stem, then the lower limit of the vertical distribution of seagrass plants is expressed as follows: The upper limit of the vertical distribution of seagrass plants is expressed as ,in, Refers to the length of the blade, for reference. Figure 7 As shown, in Figure 7 In the diagram, the dashed line represents the "depth of the seawater," the red solid line represents the "upper limit of the vertical distribution of leaves," and the blue solid line represents the "lower limit of the vertical distribution of leaves and the upper limit of the vertical distribution of stems." For single-stemmed shrub-like mangrove plants, the corresponding lower limit of vertical distribution is expressed as... The upper limit of the vertical distribution is expressed as For mangrove plants with branches and above-ground roots (e.g., *Mangrove*, *Avicennia*, and *Avicennia*), the upper and lower limits of their vertical distribution in the stem and root parts are expressed as follows: , As for leaves and branches of different grades ( Figure 8 In the diagram, b1 represents the first-level branch, b2 represents the second-level branch, b3 represents the third-level branch, and b4 represents the fourth-level branch, respectively. Defined by the height of the lowest branch. Defined by tree height. It should be noted that these definitions can be flexibly adjusted according to the specific plant morphology. Figure 8 In the diagram, the dashed line represents the depth of the seawater, the blue solid line represents the upper limit of the vertical distribution of leaves and branches, the red solid line represents the lower limit of the vertical distribution of leaves and branches, and the upper limit of the vertical distribution of stems, and the green solid line represents the upper limit of the vertical distribution of roots.

[0036] In practical applications, the following can be adopted: Figure 9 Based on the reference data of the geometry and mechanical characteristics in the data, the plant wave-dissipating model of the present application embodiment is derived.

[0037] S3. Substitute all geometric shapes and mechanical characteristics into the wave height reduction coefficient prediction model to obtain the target wave height reduction coefficient of the target plant per unit propagation distance.

[0038] Furthermore, the calculation formula for the wave height reduction coefficient prediction model is as follows: ; in, It is the target wave height reduction coefficient of the target plant per unit propagation distance; It refers to the number of types of the above-ground structural elements; It is the incident wave height on the seaward side of the target vegetation; It is the first Distribution density of structural elements on the farmland; It is the first Resistance coefficients corresponding to structural elements on farmland; It is the first The width corresponding to structural elements on the farmland; It is the first The lengths corresponding to structural elements on the farmland; It is the wave number; It is the first The lower limit of the vertical distribution of structural elements on the planting land; It is the first The upper limit of the vertical distribution of structural elements on the farmland; It is a hyperbolic sine function; It is the depth of the seawater where the target plant is located; It is the first The shading coefficients corresponding to structural elements on the farmland; It is the first Cross-sectional shape coefficients corresponding to structural elements on the farmland; It is the first The Cauchy number corresponding to the structural elements on the planting site represents the first... The ratio of the fluid resistance generated by structural elements on the planted surface to the restoring force caused by its elastic deformation, the third The Cauchy number corresponding to the structural elements on the ground is based on fluid velocity and the first... The length, width, thickness, and elastic modulus of the structural elements on the planting site are calculated. It is the first Length ratio coefficients corresponding to structural elements on farmland The value is equal to the first The ratio of the length of the structural elements on the planting site to the horizontal migration amplitude of wave water particles.

[0039] It should be understood that the shading coefficient is an empirical coefficient used to characterize the reduction in resistance caused by the shading effect and the interaction between different elements of vegetation structure. When there is no shading effect, the shading coefficient is 1.

[0040] In practical applications, the shading coefficient for salt marsh vegetation is 0.4, which remains unchanged regardless of hydrodynamic conditions. The shading coefficient for seagrass vegetation is 1, meaning there is no shading effect. For mangrove vegetation, the shading coefficient for leaves attached to branches is uniformly set to 0.4, while the coefficient for all other vegetation units is set to 1.

[0041] The wave height reduction coefficient prediction model provided in this application generalizes a plant into above-ground structural elements such as stems, leaves, roots, and branches, and considers the plant's distribution density, length, width, thickness, elastic modulus, upper and lower limits of vertical distribution, and other geometric and mechanical characteristics (which can be understood as geometric and mechanical parameters). In other words, this application uses the structural characteristics and mechanical parameters of vegetation to calculate the wave height reduction coefficient. As a result, the wave height reduction coefficient prediction model can predict the wave height reduction coefficient more accurately, thereby improving the accuracy of the wave height reduction coefficient prediction.

[0042] In some embodiments, the general plant wave dissipation prediction method that considers the geometric parameters and mechanical properties of all plant aboveground structural elements further includes: calculating a drag flexibility correction term for the target aboveground structural element based on the Cauchy number of the target aboveground structural element and the ratio of the length of the target aboveground structural element to the wave trajectory displacement; the drag flexibility correction term is used to reflect the influence of the flexibility of the target aboveground structural element on plant drag and wave energy dissipation rate; the target aboveground structural element is any one of the multiple aboveground structural elements.

[0043] Furthermore, when the target above-ground structural element is a flexible structural element, the resistance flexibility correction term of the flexible structural element can be expressed as follows: ,in, It is the cross-sectional shape factor of the flexible structural element. It is the Cauchy number of the flexible structural element. It is the ratio of the length of the flexible structural element to the displacement of the wave track.

[0044] Furthermore, the flexible structural element is a flat structural element ( , here It is the width corresponding to the flexible structural element. When the thickness is the thickness corresponding to the flexible structural element, The value is 1, where the flexible structural element is a cylindrical structural element ( )hour, The value is 1.2.

[0045] Furthermore, the Cauchy number is used to represent the ratio of fluid resistance to the restoring force caused by structural stiffness. It should be noted that this only applies to... Greater than 1, and When the value is greater than 1, the drag flexibility correction term of the flexible structural element conforms to theoretical derivation and experimental verification. When When the value is less than or equal to 1, the structural element can be considered rigid, and the resistance flexibility correction term... The value is 1, that is, when the resistance flexibility correction term is 1, the target above-ground structural element is a rigid structural element.

[0046] Furthermore, The calculation formula is: ; where, in this formula It is the width of the flexible structural element; It is the horizontal component of the average water particle velocity at the maximum water depth acting on the flexible structural element; It is the elastic modulus of the flexible structural element; It is the moment of inertia of the cross section of the vegetation unit corresponding to the flexible structural element; It is the length of the flexible structural element.

[0047] It should be understood that, You can refer to The calculation formula can be used to solve this problem; simply replace the flexible structural element with the first... Since the above-ground structural elements are sufficient, it can be concluded that the Cauchy number corresponding to each above-ground structural element in this application is obtained by calculating the length, width, elastic modulus and the horizontal component of the average water particle velocity at maximum water depth corresponding to each above-ground structural element.

[0048] Furthermore, the formula for calculating the moment of inertia of the cross section of the cylindrical stem is: ;in, It refers to the width. The formula for calculating the moment of inertia of a flat blade section is: ;in, It refers to thickness.

[0049] Furthermore, The calculation formula is: ;in, It is wave orbital displacement. , It is the wave angular velocity. The length of the flexible structural element.

[0050] It should be understood that, The calculation formula can be referenced. The calculation formula is as follows. Therefore, it can be determined that the length ratio coefficient corresponding to each above-ground structural element in this application is obtained based on the length of each above-ground structural element and the wave track displacement corresponding to each above-ground structural element.

[0051] It is important to note that only submerged above-ground structural elements will interact with the fluid. When the water depth... Less than hour, The value is 0. For partially submerged above-ground structural elements ( The length and upper limit of the vertical distribution of submerged above-ground structural elements need to be adjusted to reflect the actual situation. The formula for calculating the length of submerged structural elements is as follows: , That is, the initial length; the formula for calculating the upper limit of the vertical distribution of submerged above-ground structural elements is: , That is, the initial upper limit of the vertical distribution; the density of submerged above-ground structural elements is: .

[0052] In some implementations, the drag coefficient corresponding to the above-ground structural elements Depends on dimensionless parameters , .

[0053] In some implementations, the drag coefficient corresponding to the above-ground structural elements is used. The following two calculation formulas are fitted: The calculation formula for structural elements on flat ground is as follows: ; The calculation formula for cylindrical above-ground structural elements is as follows: .

[0054] It should be noted that, The derivation assumes the width of the above-ground structural elements. and the velocity of the fluid acting on it All values ​​are vertical averages, referring to the average value within the upper and lower limits of the vertical distribution of above-ground structural elements. In practical applications, the width of plant stems and roots tends to be greater near the ground and decreases upwards. Conversely, wave velocity exhibits a characteristic of being greatest at the free surface and decreasing closer to the substrate. The tendency for the results to be underestimated by using vertically averaged velocity in this model is somewhat offset by the tendency to be overestimated by using uniform width. This not only derives a simpler theoretical formula but also improves the accuracy of the predicted wave height reduction coefficient. In contrast, existing theories use vertically averaged structural element widths, considering only the vertical variation of horizontal velocity, and their predictions generally tend to overestimate the actual values.

[0055] In some embodiments, the general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of the aboveground structure of plants also combines the target wave height reduction coefficient to solve for the path wave height. The specific calculation formula is as follows: ; in, This is the current wave height. , This is the total number of vegetation grids; It is the wave height of the previous position; It is the target wave height reduction coefficient at the current location; It is the width of each grid in the vegetation.

[0056] In some embodiments, the general vegetation wave reduction prediction method that considers all geometric parameters and mechanical properties of aboveground vegetation structures further includes: obtaining the vegetation belt width of the target vegetation; substituting the vegetation belt width, the incident wave height on the seaward side of the target vegetation, and the transmitted wave height on the shoreward side of the target vegetation into the total wave height reduction coefficient prediction model to obtain the target total wave height reduction coefficient of the target vegetation.

[0057] Furthermore, the calculation formula for the total wave height reduction coefficient prediction model is as follows: ; in, It is the target total wave height reduction coefficient of the target vegetation, that is, the wave height reduction coefficient of the entire vegetation belt; It is the width of the vegetation strip. , It is the total number of grid cells. It is the width of each grid cell; It is the target vegetation The transmitted wave height at the location, that is, the transmitted wave height of the vegetation belt of the target vegetation on the shore side.

[0058] It should be understood that, in the embodiments of this application, the vegetation zone is divided into... The target wave height reduction coefficient is calculated for each grid cell, starting from the first cell at the edge of vegetation. Then, the transmitted wave height at the exit of the first grid is calculated based on the wave energy balance along the path. , The transmitted wave height at the exit of the first grid It is the incident wave height of the second grid, used to calculate the target wave height reduction factor corresponding to the second grid and the transmitted wave height at the exit of the second grid. By analogy, the transmitted wave height at the exit of each grid and the target wave height reduction coefficient corresponding to each grid can be calculated. Each grid can be understood as a vegetation unit.

[0059] In some embodiments, after substituting the width of the vegetation strip, the incident wave height on the seaward side of the target vegetation, and the transmitted wave height on the shoreward side of the target vegetation strip into the total wave height reduction coefficient prediction model to obtain the target total wave height reduction coefficient of the target vegetation, the general vegetation wave dissipation prediction method considering all geometric parameters and mechanical properties of the aboveground structure of the vegetation further includes: substituting the target total wave height reduction coefficient into the wave height reduction rate prediction model to obtain the target wave height reduction rate at a preset distance.

[0060] Furthermore, the calculation formula for the wave height attenuation rate prediction model is as follows: ; in, It is the target wave height attenuation rate at a preset distance; It is the preset distance. The calculation formula for the wave height attenuation rate prediction model has no special meaning. It is a whole used to represent the target wave height attenuation rate at a preset distance.

[0061] Furthermore, when the preset distance is 100 meters, the calculation formula for the wave height attenuation rate prediction model is as follows: In other embodiments, the specific value of the preset distance can be set by those skilled in the art according to actual needs.

[0062] In some embodiments, the general plant wave reduction prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures further includes: the derivation process of the wave height reduction coefficient prediction model, as follows: The formula for wave energy attenuation along its path can be expressed as: ;in, It is the energy dissipation rate (i.e., the value of wave energy attenuation along the path). It is the density of the water. It is gravitational acceleration; It is the wave height, along the propagation distance. Changes have occurred; It is the group velocity; Horizontal coordinates of the flow Find the partial derivative, which represents the spatial gradient along the direction of water flow; When wave energy attenuation caused by plant resistance dominates ;in, It is a wave cycle; It acts on the first The hydrodynamic resistance of structural elements on the plantation per unit length; It refers to the current moment; It is a structural element above ground. The vertically averaged horizontal velocity component of the fluid within the vertical distribution range; Individual plant structural elements The resistance can be calculated using the following formula: ;in, The flow resistance generated by rigid structures with identical structures, with the variable term in parentheses being the flexibility correction term. Shielding coefficient caused by shading and interaction between different structural elements ; ; in, above-ground structural elements The vertically averaged horizontal velocity component of the fluid within the vertical distribution range; ;in, It is the wave angular frequency; Combining the above formulas, the wave energy attenuation formula along its path can be simplified to the first derived formula, and the specific calculation formula is as follows: ;in, It is the wave height reduction factor per unit length and unit wave height, with units of . (per square meter); The first derivation formula can be solved using the following formula: ; ; ; ; in, It is a resistance-related term. It is a speed-related item. It is a periodic average correlation term. It is the drag coefficient. It is a dimensionless wavenumber. It is the speed of the wave group. , It is a hyperbolic tangent function; and the dispersion relation is applied. Therefore, we can obtain: ; then, ,Will Substitute The formula yields: ; ; ; ; in, It is a hyperbolic cosine function.

[0063] In some embodiments, the general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures also includes a model comparison process, as detailed below: This application assumes that the vegetation unit is rigid, and also considers the diameter. If the energy dissipation rate varies along the vertical direction, then the expression for the energy dissipation rate is: ; It is the length of the vegetation unit. It is the flow rate; Based on linear wave theory, In the formula, Representing elevation The maximum horizontal flow velocity at that location This represents the velocity of horizontal water particles at the bottom of the water column. Therefore, the vertical distributions of both diameter and velocity can be normalized to the energy dissipation rate, yielding: Considering diameter With flow rate With elevation The complete vertical change yields , It is the total energy dissipation rate; considering the flow rate. The vertical change, while assuming the diameter Uniform and constant along the vertical direction ,in, This refers to the energy dissipation rate proposed by scholars in 1984 (i.e., the energy dissipation rate of existing technology). Then, it is assumed that the vertical flow velocity is uniformly distributed. And diameter Uniform and constant along the vertical direction, ,in, This refers to the energy dissipation rate of an embodiment of this application, considering the rigid cylindrical structural elements, with the diameter varying linearly along the vertical direction. ,in, It is the base diameter. It is the top diameter, then the base diameter and the average diameter. The ratio is defined as , The value can be 1-2; when When the value is 1, the diameter is uniform, refer to the formula. ;when When the value is equal to 2, it forms a cone shape, refer to the formula. ;exist The diameter at that point can be expressed as Next, the energy dissipation ratio of existing technologies can be obtained. and the energy dissipation ratio of this application The energy dissipation ratios of existing technologies and this application can both be solved in MATLAB (Matrix Laboratory) using the discrete method (step size dz=0.01m).

[0064] For example, the ratio of the base diameter to the average diameter When the value is 1, the energy dissipation ratio of the prior art and the energy dissipation ratio of this application can be referenced. Figure 10 As shown; the ratio of the base diameter to the average diameter When the value is 1.5, the energy dissipation ratio of the prior art and the energy dissipation ratio of this application can be referenced. Figure 11 As shown; the ratio of the base diameter to the average diameter When the value is 2, the energy dissipation ratio of the prior art and the energy dissipation ratio of this application can be referenced. Figure 12 As shown.

[0065] It should also be noted that the general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures can be applied to terminal devices, such as computers or smartphones.

[0066] In some implementations, a general method for predicting plant wave dissipation that takes into account all geometric parameters and mechanical properties of aboveground plant structures can be stored in a computer-readable storage medium as a computer program.

[0067] The technical features of the above embodiments can be combined without changing the basic principles of this application. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A general method for predicting wave dissipation by plants that considers all geometric parameters and mechanical properties of aboveground plant structures, characterized in that, include: Identify multiple aboveground structural elements of a target plant in a target vegetation, wherein the target plant is any one plant of one species in the target vegetation, and the multiple aboveground structural elements include stems, leaves, roots and branches; Obtain the geometric shape and mechanical characteristics corresponding to each above-ground structural element. The geometric shape and mechanical characteristics include at least the distribution density, length, width, thickness, elastic modulus, upper limit of vertical distribution, and lower limit of vertical distribution. Substitute all geometric shapes and mechanical characteristics into the wave height reduction coefficient prediction model to obtain the target wave height reduction coefficient of the target plant per unit propagation distance; The calculation formula for the wave height reduction coefficient prediction model is as follows: ； in, It is the target wave height reduction coefficient of the target plant per unit propagation distance; It refers to the number of types of the above-ground structural elements; It is the incident wave height on the seaward side of the target vegetation; It is the first Distribution density of structural elements on the farmland; It is the first Resistance coefficients corresponding to structural elements on farmland; It is the first The width corresponding to structural elements on the farmland; It is the first The lengths corresponding to structural elements on the farmland; It is the wave number; It is the first The lower limit of the vertical distribution of structural elements on the planting land; It is the first The upper limit of the vertical distribution of structural elements on the farmland; It is a hyperbolic sine function; It is the depth of the seawater where the target plant is located; It is the first The shading coefficients corresponding to structural elements on the farmland; It is the first Cross-sectional shape coefficients corresponding to structural elements on the farmland; It is the first The Cauchy number corresponding to the structural elements on the planting site represents the first... The ratio of the fluid resistance generated by structural elements on the planted surface to the restoring force caused by its elastic deformation, the third The Cauchy number corresponding to the structural elements on the ground is based on fluid velocity and the first... The length, width, thickness, and elastic modulus of the structural elements on the planting site are calculated. It is the first Length ratio coefficients corresponding to structural elements on farmland The value is equal to the first The ratio of the length of the structural elements on the planting site to the horizontal migration amplitude of wave water particles.

2. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 1, characterized in that, The general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures also includes: Based on the Cauchy number of the target aboveground structural element and the ratio of the length of the target aboveground structural element to the wave trajectory displacement, the drag flexibility correction term of the target aboveground structural element is calculated. The drag flexibility correction term is used to reflect the influence of the flexibility of the target aboveground structural element on plant drag and wave energy dissipation rate. The target above-ground structural element is any one of the various above-ground structural elements.

3. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 2, characterized in that, When the resistance flexibility correction term is 1, the target above-ground structural element is a rigid structural element.

4. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 1, characterized in that, The Cauchy number for each aboveground structural element is calculated based on the length, width, elastic modulus, and horizontal component of the average velocity of water particles at maximum water depth for each aboveground structural element.

5. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 1, characterized in that, The length ratio coefficient corresponding to each above-ground structural element is obtained based on the length of each above-ground structural element and the wave track displacement corresponding to each above-ground structural element.

6. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 1, characterized in that, The general plant wave-dissipation prediction method that considers all geometric parameters and mechanical properties of aboveground plant structures also includes: Obtain the width of the vegetation strip of the target vegetation; The target total wave height reduction coefficient of the target vegetation is obtained by substituting the width of the vegetation belt, the incident wave height on the seaward side of the target vegetation, and the transmitted wave height on the shoreward side of the target vegetation belt into the total wave height reduction coefficient prediction model.

7. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 6, characterized in that, The calculation formula for the total wave height reduction coefficient prediction model is as follows: ； in, It is the target total wave height reduction coefficient of the target vegetation; It is the width of the vegetation strip; It is the target vegetation The height of the transmitted wave at the location.

8. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 7, characterized in that, After substituting the width of the vegetation strip, the incident wave height on the seaward side of the target vegetation, and the transmitted wave height on the shoreward side of the target vegetation strip into the total wave height reduction coefficient prediction model to obtain the target total wave height reduction coefficient of the target vegetation, the general vegetation wave dissipation prediction method considering all geometric parameters and mechanical properties of the aboveground structure of the vegetation further includes: Substitute the target total wave height reduction coefficient into the wave height reduction rate prediction model to obtain the target wave height reduction rate at a preset distance.

9. The general plant wave-dissipation prediction method considering all geometric parameters and mechanical properties of aboveground plant structures according to claim 8, characterized in that, The calculation formula for the wave height attenuation rate prediction model is as follows: ； in, It is the target wave height attenuation rate at a preset distance; It is the preset distance.

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