Method for generalizing vegetation resistance in tide-wave coupling scene

Abstract

The invention relates to a method for generalizing vegetation resistance in a tide-wave coupling scene. The method comprises the following steps: parameterizing vegetation characteristics; hydrodynamic environment parameterization: collecting tide characteristic parameters and wave element parameters of a target water area; modeling the vegetation effect of the tidal hydrodynamic field: according to the characteristics of vegetation, calculating a corresponding Manning coefficient considering the vegetation effect by using a Manning coefficient formula considering the plant effect; the obtained Manning coefficient considering the vegetation effect is applied to a tidal water power numerical model, then the influence of the vegetation is embedded into a bed friction force item of the model, simulation of the resistance reduction effect of the vegetation on the tide is completed, and a tide simulation result considering the vegetation resistance effect is obtained; and wave field vegetation resistance coupling simulation.

Description

Technical Field

[0001] The patent of this invention relates to a method for generalizing vegetation resistance in tide-wave coupling scenarios, which belongs to the fields of environmental engineering and marine engineering. Background Art

[0002] The interaction between aquatic vegetation and tides and waves involves complex hydrodynamic processes and has become one of the important topics in marine and coastal research. The interaction between vegetation and tides and waves involves complex hydrodynamic processes. Therefore, studying the hydrodynamic characteristics of tides and waves under the influence of vegetation is one of the hot issues in current research. Traditional simulation methods often use simple generalization methods to consider the effects of tides, waves and vegetation in isolation. It is difficult to truly reflect the interaction between vegetation and hydrodynamic elements in a complex dynamic environment and cannot meet engineering needs. With the advancement of coastal ecological protection and restoration projects, there is an urgent need for a scientific and reasonable generalization method to accurately generalize and simulate the vegetation resistance effect in a multi-dynamic coupling environment, so as to improve the scientific nature of engineering design and the accuracy of effect evaluation. Summary of the Invention

[0003] This patent provides a method for generalizing vegetation resistance in tide-wave coupling scenarios. By constructing a simulation framework for tide-wave-vegetation multi-physics field coupling, it solves the problem that traditional methods are difficult to accurately simulate vegetation resistance effects in complex environments, and provides a reliable technical means for the planning, design and effect evaluation of coastal ecological projects.

[0004] To achieve the above-mentioned purpose of the invention patent, the invention patent provides a method for generalizing vegetation resistance in a tidal-wave coupling scenario, comprising the following steps:

[0005] S1: Vegetation characteristic parameterization: Determine the key characteristic parameters of vegetation based on field measurements or remote sensing data;

[0006] S2: Hydrodynamic environment parameterization: Based on field measurements or remote sensing data, collect tidal characteristic parameters and wave element parameters of the target water area;

[0007] S3: Modeling the vegetation effect on tidal hydrodynamics: Based on vegetation characteristics, the corresponding Manning coefficient, which takes vegetation into account, is calculated using the Manning coefficient formula. The obtained Manning coefficient, which takes vegetation into account, is applied to the tidal hydrodynamic numerical model. The influence of vegetation is then embedded in the bottom friction term of the model to simulate the drag reduction effect of vegetation on tides, and tidal simulation results that take vegetation resistance into account are obtained.

[0008] S4: Wave field vegetation resistance coupling simulation: Based on the morphological characteristics of vegetation, the friction coefficient C is used to consider the effect of plants. fvegThe formula is used to calculate the corresponding bottom friction resistance coefficient; the obtained bottom friction coefficient is applied to the bottom friction condition in the wave model. At the same time, the tidal field data obtained in the third step are coupled to construct a composite model considering the interaction of multiple factors such as tide, wave and vegetation, so as to realize the dynamic simulation of the vegetation's attenuation effect on waves.

[0009] Furthermore, in step S1, the key characteristic parameters of the vegetation include vegetation type, planting density, water-contact diameter, height and morphology.

[0010] Furthermore, in step S2, the tidal characteristic parameters include tidal water level and tidal period, and the wave element parameters include wave height, wave frequency, and wave direction.

[0011] Furthermore, step S3 is performed as follows:

[0012] S31, Manning coefficient n considering plant effects veg The formula is as follows

[0013]

[0014] Where N v is the vegetation density, C Dv is the drag coefficient of vegetation on tidal current, h v is the plant height, h is the water depth, b v is the plant diameter, n is the Manning coefficient of the seabed, and g is the acceleration due to gravity.

[0015] S32, based on field measurements or remote sensing data, opens an engineering drawing in CAD software and uses closed polylines to demarcate vegetation areas and non-vegetation areas of different plants.

[0016] S33, importing the CAD drawing with the vegetation and non-vegetation areas into ArcGIS software, exporting the surface layer in the CAD drawing as a surface feature file, and assigning a corresponding Manning coefficient value to each area by modifying the attribute values in the surface feature file. The assigned surface feature file is converted into a raster file, and then the raster file is converted into a point feature file.

[0017] S34, converting the point feature file obtained in S33 into a .xyz file.

[0018] S35, building a model, including drawing a grid, setting terrain, setting model parameters, and setting model boundary conditions.

[0019] S36, create a file containing the Manning coefficient of vegetation effect based on the .xyz file.

[0020] S37, use the file containing the Manning coefficients for vegetation effects in the model settings.

[0021] S38, run the model to obtain tidal simulation results that take into account the vegetation resistance effect.

[0022] Furthermore, step S4 is performed as follows:

[0023] S41, roughness coefficient C considering plant effects fveg Calculated by the following formula:

[0024]

[0025] Among them, C Dw is the drag coefficient of vegetation on waves

[109] , d s is the stem diameter of the plant, T p is the wave period, C f is the friction coefficient of the seabed, k is the wave number, g is the acceleration due to gravity, N v is the vegetation density, h is the water depth, f is the average wave frequency, E tot is the total wave energy per unit area, H rms is the effective wave height, E(f,θ) is the function relationship between energy density, frequency f and wave direction θ, h v is the vegetation height.

[0026] S42, based on field measurements or remote sensing data, open the engineering drawing in CAD software and use closed polylines to demarcate vegetation areas and non-vegetation areas for different plants.

[0027] S43: Import the CAD drawing that divides the vegetation and non-vegetation areas into ArcGIS software, export the surface layer in the CAD drawing as a surface feature file, and assign a corresponding friction coefficient value to each area by modifying the attribute values in the surface feature file. Convert the assigned surface feature file into a raster file, and then convert the raster file into a point feature file.

[0028] S44, converting the point feature file obtained in S43 into a .xyz file.

[0029] S45, building a model, including drawing a grid, setting terrain, setting model parameters, and setting model boundary conditions.

[0030] S46, creating a file containing the bottom friction coefficient of vegetation based on the .xyz file.

[0031] S47, use the file containing the bottom friction coefficient of vegetation effect in the model settings.

[0032] S48, the tidal flow simulation result data obtained by coupling S3 in the model settings.

[0033] S49, run the model to obtain wave simulation results that take into account the vegetation resistance effect.

[0034] Compared with the existing technology, the beneficial effects achieved by the patent of this invention are:

[0035] This patent provides a method for generalizing vegetation resistance in tide-wave coupling scenarios. By constructing a simulation framework for tide-wave-vegetation multi-physics field coupling, it can simulate the interaction between vegetation and hydrodynamic elements in complex dynamic environments, solving the problem that traditional methods are difficult to accurately simulate the vegetation resistance effect in complex environments, and providing a reliable technical means for the planning, design and effect evaluation of coastal ecological projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Flowchart of the steps in a method to generalize vegetation resistance in tidal-wave coupled scenarios.

[0037] Figure 2 This is a comparison of tidal flow velocities at a monitoring point in the study area in specific embodiment 1 of the present invention in certain time periods with and without vegetation planting.

[0038] Figure 3 This is a comparison of tidal water levels at a monitoring point in the study area in specific embodiment 1 of the present invention in some time periods with and without vegetation planting.

[0039] Figure 4 This is a comparison of the effective wave height at a monitoring point in the study area in specific embodiment 1 of the present invention, with and without vegetation planting during part of the time period. DETAILED DESCRIPTION

[0040] The present invention will be further described below by way of specific example 1. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and that these equivalent forms also fall within the scope defined by the appended claims.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and Table 1 in combination with embodiments.

[0042] Table 1

[0043]

[0044] Reference Figure 1This embodiment 1 provides a flowchart of the steps of a method for generalizing vegetation resistance in a tidal-wave coupling scenario. Taking the simulation of tidal and wave changes in a certain offshore waters with and without vegetation as an example, the technical solution of the present invention is further illustrated by comparing the differences in tidal water level, tidal flow velocity, and significant wave height at a monitoring point in the sea area with and without vegetation, which specifically includes the following steps:

[0045] S1: Parameterization of vegetation characteristics. Determine key vegetation characteristics such as species, planting density, water-contact diameter, height, and morphology based on field measurements or remote sensing data.

[0046] S2: Hydrodynamic environment parameterization: Based on field measurements or remote sensing data, collect tidal characteristic parameters (such as tidal level and tidal period) and wave element parameters (such as wave height, wave frequency, and wave direction) of the target waters.

[0047] S3: Modeling the vegetation effect on tidal hydrodynamics. Based on the characteristics of vegetation, the corresponding Manning coefficient, which takes into account the effect of vegetation, is calculated using the Manning coefficient formula. The obtained Manning coefficient, which takes into account the effect of vegetation, is applied to the tidal hydrodynamic numerical model. The effect of vegetation is then embedded in the bottom friction term of the model to complete the simulation of the drag reduction effect of vegetation on tides and obtain the tidal simulation results that take into account the vegetation resistance effect. The specific steps are as follows:

[0048] S31, Manning coefficient n considering plant effects veg The formula is as follows

[0049]

[0050] Where N v is the vegetation density, C Dv is the drag coefficient of vegetation on tidal current, h v is the plant height, h is the water depth, b v is the plant diameter, n is the Manning coefficient of the seabed, and g is the acceleration due to gravity.

[0051] S32, based on field measurements or remote sensing data, opens an engineering drawing in CAD software and uses closed polylines to demarcate vegetation areas and non-vegetation areas of different plants.

[0052] S33, importing the CAD drawing with the vegetation and non-vegetation areas into ArcGIS software, exporting the surface layer in the CAD drawing as a surface feature file, and assigning a corresponding Manning coefficient value to each area by modifying the attribute values in the surface feature file. The assigned surface feature file is converted into a raster file, and then the raster file is converted into a point feature file.

[0053] S34, converting the point feature file obtained in S33 into a .xyz file.

[0054] S35, building a model, including drawing a grid, setting terrain, setting model parameters, and setting model boundary conditions.

[0055] S36, create a file containing the Manning coefficient of vegetation effect based on the .xyz file.

[0056] S37, use the file containing the Manning coefficients for vegetation effects in the model settings.

[0057] S38, run the model to obtain tidal simulation results that take into account the vegetation resistance effect.

[0058] S4: Coupled simulation of wave field and vegetation resistance. Based on the morphological characteristics of vegetation, the friction coefficient C is used to consider the effect of plants. fveg Formula, calculate the corresponding bottom friction resistance coefficient. The obtained bottom friction coefficient is applied to the bottom friction condition in the wave model. At the same time, coupled with the tidal field data obtained in the third step, a composite model considering the interaction of tides, waves, and vegetation is constructed to achieve a dynamic simulation of the vegetation's effect on wave attenuation. The specific steps are as follows:

[0059] S41, roughness coefficient C considering plant effects fveg Calculated by the following formula:

[0060]

[0061] Among them, C Dw is the drag coefficient of vegetation on waves

[109] , d s is the stem diameter of the plant, T p is the wave period, C f is the friction coefficient of the seabed, k is the wave number, g is the acceleration due to gravity, N v is the vegetation density, h is the water depth, f is the average wave frequency, E tot is the total wave energy per unit area, H rms is the effective wave height, E(f,θ) is the function relationship between energy density, frequency f and wave direction θ, h v is the vegetation height.

[0062] S42, based on field measurements or remote sensing data, open the engineering drawing in CAD software and use closed polylines to demarcate vegetation areas and non-vegetation areas for different plants.

[0063] S43: Import the CAD drawing that divides the vegetation and non-vegetation areas into ArcGIS software, export the surface layer in the CAD drawing as a surface feature file, and assign a corresponding friction coefficient value to each area by modifying the attribute values in the surface feature file. Convert the assigned surface feature file into a raster file, and then convert the raster file into a point feature file.

[0064] S44, converting the point feature file obtained in S43 into a .xyz file.

[0065] S45, building a model, including drawing a grid, setting terrain, setting model parameters, and setting model boundary conditions.

[0066] S46, creating a file containing the bottom friction coefficient of vegetation based on the .xyz file.

[0067] S47, use the file containing the bottom friction coefficient of vegetation effect in the model settings.

[0068] S48, the tidal flow simulation result data obtained by coupling S3 in the model settings.

[0069] S49, run the model to obtain wave simulation results that take into account the vegetation resistance effect.

[0070] Figure 2 This comparison shows tidal velocity at a monitoring point in the study area during certain time periods, with and without vegetation. It shows that the presence of vegetation reduces tidal velocity by approximately 60%, which is consistent with records in related studies.

[0071] Figure 3 This comparison shows tidal levels at a monitoring point in the study area during certain time periods with and without vegetation. It shows that, because tides are long-wave transmissions, vegetation has little effect on tidal levels, consistent with existing conclusions. Figure 4 This comparison shows significant wave heights at a monitoring point in the study area during selected time periods, with and without vegetation. It shows that the presence of vegetation reduces tidal velocity by approximately 64%, consistent with findings from related research. This demonstrates the high feasibility of this patent.

[0072] In summary, this patent, by constructing a simulation framework for the coupling of tide-wave-vegetation multi-physics fields, can generalize and simulate the interaction between vegetation and hydrodynamic elements in complex dynamic environments, solving the problem that traditional methods are difficult to accurately simulate the resistance effect of vegetation in complex environments, and providing a reliable technical means for the planning, design and effect evaluation of coastal ecological projects.

Claims

1. A method for generalizing vegetation resistance in tide-wave coupling scenarios, characterized by The following steps are involved: S1: Vegetation characteristic parameterization: Determine the key characteristic parameters of vegetation based on field measurements or remote sensing data; S2: Hydrodynamic environment parameterization: Based on field measurements or remote sensing data, collect tidal characteristic parameters and wave element parameters of the target water area; S3: Modeling the vegetation effect on tidal hydrodynamics: Based on vegetation characteristics, the corresponding Manning coefficient, which takes vegetation into account, is calculated using the Manning coefficient formula. The obtained Manning coefficient, which takes vegetation into account, is applied to the tidal hydrodynamic numerical model. The influence of vegetation is then embedded in the bottom friction term of the model to simulate the drag reduction effect of vegetation on tides, and tidal simulation results that take vegetation resistance into account are obtained. S4: Wave field vegetation resistance coupling simulation: Based on the morphological characteristics of vegetation, the friction coefficient C is used to consider the effect of plants. fveg The formula is used to calculate the corresponding bottom friction resistance coefficient; the obtained bottom friction coefficient is applied to the bottom friction condition in the wave model. At the same time, the tidal field data obtained in the third step are coupled to construct a composite model considering the interaction of multiple factors such as tide, wave and vegetation, so as to realize the dynamic simulation of the vegetation's attenuation effect on waves.

2. The method for generalizing vegetation resistance in tide-wave coupling scenarios according to claim 1, characterized in that: In step S1, the key characteristic parameters of the vegetation include vegetation type, planting density, water-contact diameter, height and morphology.

3. The method for generalizing vegetation resistance in tide-wave coupling scenarios according to claim 1, characterized in that: In step S2, the tidal characteristic parameters include tidal water level and tidal period, and the wave element parameters include wave height, wave frequency, and wave direction.

4. The method for generalizing vegetation resistance in tide-wave coupling scenarios according to claim 1, characterized in that: Step S3 is specifically as follows: S31, Manning coefficient n considering plant effects veg The formula is calculated by formula (1): Where N v is the vegetation density, C Dv is the drag coefficient of vegetation on tidal current, h v is the plant height, h is the water depth, b v is the plant diameter, n is the Manning coefficient of the seabed, and g is the acceleration due to gravity; S32, based on field measurements or remote sensing data, open an engineering drawing in CAD software and use closed polylines to demarcate vegetation areas and non-vegetation areas for different plants; S33, importing the CAD drawing with the vegetation area and the non-vegetation area divided into ArcGIS software, outputting the surface layer in the CAD drawing as a surface feature file, and assigning the corresponding Manning coefficient value to each area by modifying the attribute value in the surface feature file; converting the assigned surface feature file into a raster file, and then converting the raster file into a point feature file; S34, converting the point feature file obtained in S33 into a .xyz file; S35, building a model, including drawing a grid, setting terrain, setting model parameters, and setting model boundary conditions; S36, create a file containing the Manning coefficient of vegetation effect based on the .xyz file; S37, use the file containing the Manning coefficients for vegetation effects in the model settings; S38, run the model to obtain tidal simulation results that take into account the vegetation resistance effect.

5. The method for generalizing vegetation resistance in tide-wave coupling scenarios according to claim 1, characterized in that: Step S4 is specifically as follows: S41, roughness coefficient C considering plant effects fveg Calculated by formula (2): Among them, C Dw is the drag coefficient of vegetation on waves, d s is the stem diameter of the plant, T p is the wave period, C f is the friction coefficient of the seabed, k is the wave number, g is the acceleration due to gravity, N v is the vegetation density, h is the water depth, f is the average wave frequency, E tot is the total wave energy per unit area, H rms is the effective wave height, E(f,θ) is the function relationship between energy density, frequency f and wave direction θ, h v is the vegetation height; S42, based on field measurements or remote sensing data, open the engineering drawing in CAD software and use closed polylines to delineate vegetation areas and non-vegetation areas for different plant species; S43, importing the CAD drawing with the vegetation area and the non-vegetation area divided into ArcGIS software, outputting the surface layer in the CAD drawing as a surface feature file, and assigning a corresponding friction coefficient value to each area by modifying the attribute value in the surface feature file; converting the assigned surface feature file into a raster file, and then converting the raster file into a point feature file; S44, converting the point feature file obtained in S43 into a .xyz file; S45, building a model, including drawing a grid, setting terrain, setting model parameters, and setting model boundary conditions; S46, creating a file containing the bottom friction coefficient of vegetation based on the .xyz file; S47, use the file containing the bottom friction coefficient of vegetation effect in the model settings; S48, the tidal flow simulation result data obtained by coupling S3 in the model setting; S49, run the model to obtain wave simulation results that take into account the vegetation resistance effect.

Images