A method and system for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics

Abstract

This invention relates to the field of hydrodynamic spatial distribution technology and discloses a method and system for assessing the spatial distribution of hydrodynamic forces on reefs caused by protective engineering projects. The method comprises: obtaining coral parameter data and protective engineering parameter data for the target reef area; performing hydrodynamic simulation based on the coral parameter data and protective engineering parameter data; determining hydrodynamic factor differences based on the hydrodynamic simulation results; and generating a composite impact index based on the hydrodynamic factor differences and classifying the impact of protective engineering projects. This solution enables high-precision simulation of the spatial distribution of hydrodynamic forces on reefs, providing a basis for precise, coordinated decision-making for engineering optimization and ecological protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrodynamic spatial distribution, and in particular relates to a method and system for evaluating the impact of protective engineering on the hydrodynamic spatial distribution of islands and reefs. Background Art

[0002] Coral reef ecosystems naturally mitigate wave energy and maintain landform stability. Protective engineering projects, by altering the wave and current structure, may weaken or enhance this function, thereby impacting the ecological security and resource sustainability of reefs. Current research focuses primarily on the wave-dissipating performance of the engineering structures themselves, lacking in-depth understanding of the coupling mechanisms between coral reef topography, ecology, and hydrodynamics. This has led to conflicts between engineering layout and ecological protection objectives.

[0003] Traditional methods typically employ simplified constant roughness coefficients and homogenized terrain models, making it difficult to reflect the dynamic impacts of complex bottom morphology and biological communities in coral reef areas on hydrodynamics. Traditional hydrodynamic models often ignore the variations in frictional effects caused by differences in coral types and set the Manning coefficient based solely on coral substrate type, failing to accurately characterize the differentiated blocking effects of branching and massive corals. Impact assessments of wave-breaking projects are often limited to a single project type or fixed wave conditions, lacking a systematic analysis of project location, structural permeability, and multiple wave conditions. Hydrodynamic impact grading often relies on a single parameter threshold, failing to consider the coupled effects of wave height, flow velocity, and water depth, resulting in insufficient spatial resolution in assessment results. These deficiencies make existing methods difficult to meet the demands of refined design for island and reef protection projects, easily leading to project outcomes that deviate from expectations or negative ecological impacts.

[0004] Therefore, there is an urgent need to develop a method for evaluating the impact of protective projects on the spatial distribution of island and reef hydrodynamics, which can achieve high-precision simulation of the spatial distribution of island and reef hydrodynamics and provide a basis for accurate collaborative decision-making for engineering optimization and ecological protection. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a method for evaluating the impact of protective projects on the spatial distribution of island and reef hydrodynamics, which can achieve high-precision simulation of the spatial distribution of island and reef hydrodynamics and provide a basis for accurate collaborative decision-making for engineering optimization and ecological protection.

[0006] The present invention provides a method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics, the method comprising the following steps:

[0007] S1. Obtain coral parameter data and protective engineering parameter data of the target island and reef area;

[0008] S2. Conduct hydrodynamic simulation based on coral parameter data and protective engineering parameter data;

[0009] S3. Determine the difference value of the hydrodynamic factor based on the hydrodynamic simulation results;

[0010] S4. Generate a composite impact index based on the difference values of hydrodynamic factors and classify the impact of protective projects.

[0011] Furthermore, in S1, coral parameter data include coral type, coral cover, and coral substrate type;

[0012] The parameter data of the protection project include the height, length, porosity and location of the protection project.

[0013] Furthermore, in S2, the hydrodynamic simulation based on coral parameter data and protective engineering parameter data includes:

[0014] S21. Determine the dynamic Manning coefficient based on coral parameter data;

[0015] S22, generalizing the terrain of the target island and reef area into a two-dimensional terrain profile function;

[0016] S23, modifying the two-dimensional terrain profile function according to the dynamic Manning coefficient and protective engineering parameter data;

[0017] S24. Divide the computational grid based on the modified two-dimensional terrain profile function, define the wave boundary conditions, and run the hydrodynamic model to perform hydrodynamic simulation.

[0018] Furthermore, in S21, determining the dynamic Manning coefficient based on the coral parameter data includes:

[0019] S211, determining the corresponding Manning coefficient of the base according to the coral substrate type, weighting the coral cover according to the coral type, and generating the Manning coefficient of spatial distribution;

[0020] S212. Obtain the dynamic Manning coefficient by summing the base Manning coefficient and the spatially distributed Manning coefficient.

[0021] Furthermore, in S24, the wave boundary conditions include wave height and period;

[0022] The results of the hydrodynamic simulation include instantaneous wave height, current velocity, and water depth.

[0023] Furthermore, in S3, determining the difference value of the hydrodynamic factor according to the hydrodynamic simulation results includes:

[0024] S31. Calculate the time-averaged wave height, time-averaged flow velocity, and time-averaged water depth under the conditions with and without the project based on the hydrodynamic simulation results;

[0025] S32. Determine the difference in hydrodynamic factors based on the time-averaged wave height, time-averaged flow velocity, and time-averaged water depth under the conditions with and without the project.

[0026] Furthermore, in S3, the difference values of the hydrodynamic factors include: wave height attenuation rate, flow velocity change rate, and water depth change rate.

[0027] Furthermore, in S4, the composite impact index is generated based on the difference in hydrodynamic factors and the impact of protective engineering is graded, including:

[0028] S41. Generate a composite impact index based on the weighted sum of the difference values of the hydrodynamic factors;

[0029] S42. Obtain the impact classification of the protective project based on the composite impact index and the preset threshold range.

[0030] The present invention also provides a system for evaluating the spatial distribution of hydrodynamic forces of islands and reefs caused by protective engineering, which is used to implement any of the above-mentioned methods for evaluating the spatial distribution of hydrodynamic forces of islands and reefs caused by protective engineering. The system includes the following modules:

[0031] Data acquisition module, used to obtain coral parameter data and protection engineering parameter data of the target island and reef area;

[0032] The working condition simulation module is connected to the data acquisition module and is used to perform hydrodynamic simulation based on coral parameter data and protective engineering parameter data;

[0033] The impact factor calculation module is connected to the working condition simulation module and is used to determine the difference value of the hydrodynamic factor according to the hydrodynamic simulation results;

[0034] The evaluation module is connected to the impact factor calculation module and is used to generate a composite impact index based on the difference values of the hydrodynamic factors and to perform a classification of the impact of the protective project.

[0035] The embodiments of the present invention have the following technical effects:

[0036] This approach dynamically parameterizes coral roughness and wave-breaking engineering features, constructs a two-dimensional coral reef topographic profile model, and improves the hydrodynamic equations, enabling high-precision simulation of the spatial distribution of island and reef hydrodynamics. First, dynamic Manning coefficient calculations based on coral type and coverage accurately quantify the differentiated impact of coral communities on water flow resistance, overcoming the errors caused by fixed roughness parameters in traditional methods. Second, a multi-dimensional combination of wave-breaking engineering location, structural characteristics, and wave conditions within the engineering parameter matrix systematically reveals the effects of different protection layouts on the wave and flow field. Finally, through a composite impact index and grading rules for wave height, flow velocity, and water depth variations, the scope and extent of engineering disturbances on the hydrodynamic environment can be spatially identified, providing a quantitative basis for optimizing engineering layout. Compared to existing technologies, this method explicitly couples ecological parameters with hydrodynamic models, enabling synergistic analysis of coral reef topographic characteristics, ecological friction effects, and protective engineering structures, enhancing the ecological rationality and engineering guidance value of the simulation results. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 This is a flow chart of a method for evaluating the impact of protective engineering on the spatial distribution of hydrodynamic forces on islands and reefs, provided by an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the generalized terrain of islands and reefs provided by an embodiment of the present invention;

[0040] Figure 3 It is a structural schematic diagram of a system for evaluating the impact of protective engineering on the spatial distribution of hydrodynamics of islands and reefs provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0042] The embodiment of the present invention provides a method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics. Figure 1 This is a flow chart of a method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics, provided by an embodiment of the present invention. Figure 1 , the method comprises the following steps:

[0043] S1. Obtain coral parameter data and protective engineering parameter data in the target island and reef area.

[0044] In some embodiments, the coral parameter data includes coral type, coral coverage, and coral substrate type; the protective engineering parameter data includes the height, length, porosity, and location parameters of the protective engineering location.

[0045] Coral types include branching corals (such as staghorn corals) and massive corals (such as brain corals); coral cover refers to the proportion of coral cover to the total area of the surveyed area; coral substrate types include rocky, sandy, or debris-based substrates, which are used to determine the Manning coefficient. The height of the protective structure determines the height of the wave overtopping; the length of the protective structure refers to the length of the protective structure along the reef flat, which affects the wave-breaking range; porosity, for example, ranges from 0 for solid structures (such as concrete dikes) to 0.2 to 0.5 for permeable structures (such as ecological reefs); and the location parameter of the protective structure refers to its distance from the reef edge.

[0046] S2. Perform hydrodynamic simulation based on coral parameter data and protective engineering parameter data.

[0047] In some embodiments, step S2 includes the following sub-steps:

[0048] S21. Determine the dynamic Manning coefficient based on coral parameter data.

[0049] S211. Determine the corresponding Manning coefficient based on the coral substrate type, and weight the coral coverage based on the coral type to generate a spatially distributed Manning coefficient.

[0050] S212. Obtain the dynamic Manning coefficient by summing the base Manning coefficient and the spatially distributed Manning coefficient.

[0051] Specifically, the formula for the dynamic Manning coefficient is as follows:

[0052] ;

[0053] Where n represents the dynamic Manning coefficient, n base The Manning coefficient represents the basement roughness when there is no coral cover. The parameter can be calibrated through experiments. For example, the reef is 0.03, the sand is 0.02, and K coral Indicates the type of coral. For example, branching corals can take 0.04 (high friction), blocky corals can take 0.02 (low friction), and C cover Indicates coral coverage, with a value range of 0-1.

[0054] S22. Generalize the terrain of the target island and reef area into a two-dimensional terrain profile function.

[0055] Figure 2 This is a schematic diagram of the generalized terrain of islands and reefs provided by an embodiment of the present invention. Figure 2 , generalize the island-reef terrain into a two-dimensional model of reef flat-lagoon-rift, and the two-dimensional terrain profile function is as follows:

[0056] ;

[0057] Where z(x,y) represents the bottom elevation at position (x,y), which changes with the coordinate x, z0 represents the initial elevation of the reef edge, γ represents the slope of the reef flat, δ represents the slope of the rift zone, and z lagoon represents the bottom elevation of the lagoon area, x1 represents the boundary between the lagoon area and the rift area, and x 礁坪区 Indicates the x-coordinate range of the reef flat area, x 潟湖区 Indicates the x-coordinate range of the lagoon area, x 裂口区 Indicates the x-coordinate range of the rift, determined by the measured topography.

[0058] S23. Modify the two-dimensional terrain profile function according to the dynamic Manning coefficient and protective engineering parameter data.

[0059] Specifically, the height of the protective project is superimposed at the position parameter D of the protective project, that is, on the basis of z(x,y), x=D, the height of the protective project is superimposed according to the length of the protective project to obtain the corrected two-dimensional terrain profile function.

[0060] S24. Divide the computational grid based on the modified two-dimensional terrain profile function, define the wave boundary conditions, and run the hydrodynamic model to perform hydrodynamic simulation.

[0061] Among them, the wave boundary conditions include wave height H and period T.

[0062] The results of the hydrodynamic simulation include the instantaneous wave height H s (x,y,t), flow velocity u(x,y,t) and water depth h(x,y,t); where (x,y) represents the spatial position coordinates and t represents time.

[0063] For example, the parameters shown in Table 1 can be used as input to define the porosity of the protective structure (affecting permeability) and the dynamic Manning coefficient, and to define the coral bottom shear stress term in the momentum equation (i.e., τ b ), run the hydrodynamic model to perform hydrodynamic simulation. In the table, L represents the reef flat length and W represents the atoll circumference.

[0064] Among them, τ b The calculation formula is as follows:

[0065] ;

[0066] Among them, τ b represents the shear stress at the bottom of the coral, ρ represents the density of seawater, g represents the acceleration of gravity, n represents the dynamic Manning coefficient, u represents the flow velocity, and h represents the water depth.

[0067] Table 1 Simulation working conditions

[0068]

[0069] In addition, a set of simulation results of unprotected projects need to be simulated on this basis.

[0070] S3. Determine the difference value of the hydrodynamic factor based on the hydrodynamic simulation results.

[0071] S31. Based on the hydrodynamic simulation results, calculate the time-averaged wave height, time-averaged flow velocity, and time-averaged water depth with and without the project.

[0072] In some embodiments, the time-averaged wave height H avg The calculation formula is as follows:

[0073] ;

[0074] Time-averaged flow velocity U avg The calculation formula is as follows:

[0075] ;

[0076] Hourly average water depth h avg The calculation formula is as follows:

[0077] .

[0078] Among them, H avg (x,y) represents the time-averaged wave height at the spatial coordinate (x,y), U avg (x,y) represents the time-averaged velocity at the spatial coordinate (x,y), h avg (x,y) represents the time-averaged water depth at the spatial coordinate (x,y).

[0079] S32. Determine the difference in hydrodynamic factors based on the time-averaged wave height, time-averaged flow velocity, and time-averaged water depth under the conditions with and without the project.

[0080] In some embodiments, the hydrodynamic factor difference value includes: wave height attenuation rate, flow velocity change rate, and water depth change rate.

[0081] The calculation formula of wave height attenuation rate is as follows:

[0082] ;

[0083] Among them, ΔH(x,y) represents the wave height attenuation rate at the spatial position coordinate (x,y), H avg,1 (x,y) represents the time-averaged wave height when there is a project at the spatial coordinate (x,y), H avg,0 (x,y) represents the time-averaged wave height at the spatial coordinate (x,y) without engineering work;

[0084] The flow rate change rate is calculated as follows:

[0085] ;

[0086] Among them, Δu(x,y) represents the wave height attenuation rate at the spatial coordinate (x,y), U avg,1 (x,y) represents the time-averaged velocity at the spatial coordinate (x,y) when there is an engineering project, U avg,0 (x,y) represents the time-averaged flow velocity at the spatial coordinate (x,y) without engineering;

[0087] The calculation formula of water depth change rate is as follows:

[0088] ;

[0089] Among them, Δh(x,y) represents the wave height attenuation rate at the spatial position coordinate (x,y), h avg,1 (x,y) represents the time-averaged water depth at the spatial coordinate (x,y) when there is a project, h avg,0 (x,y) represents the time-averaged water depth at the spatial coordinate (x,y) without engineering works.

[0090] S4. Generate a composite impact index based on the difference values of hydrodynamic factors and classify the impact of protective projects.

[0091] In some embodiments, step S4 includes the following sub-steps:

[0092] S41. Generate a composite impact index based on the weighted sum of the difference values of the hydrodynamic factors.

[0093] In some embodiments, the calculation formula of the composite impact index is as follows:

[0094] ;

[0095] Among them, I(x,y) represents the composite influence index at the spatial position coordinate (x,y), which is used to comprehensively reflect the degree of hydrodynamic disturbance. w1, w2, and w3 represent weight coefficients, and w1+w2+w3=1. It can be set according to methods such as expert experience. For example, it can be set to 0.5, 0.3, and 0.2.

[0096] S42. Obtain the impact classification of the protective project based on the composite impact index and the preset threshold range.

[0097] In some embodiments, the preset threshold value of nine can be determined through methods such as calibration of ecological-hydrodynamic response data from historical engineering cases, expert experience weight allocation, and physical mechanism coupling analysis. For example, based on measured data from existing protective engineering cases (such as the correlation between wave height attenuation, flow velocity changes, water depth disturbances, and changes in coral cover), the distribution range of the composite impact index I(x, y) is statistically analyzed, and the 75th percentile of the distribution of the composite impact index corresponding to a significant decrease in coral cover or damage to geomorphic stability is used as the lower threshold of the high-impact zone. For example, it is assumed that the lower threshold of the high-impact zone is set to 0.25, and the upper threshold of the low-impact zone is set to 0.15.

[0098] Based on the above preset thresholds and composite impact index, the impact classification of protective engineering is obtained:

[0099] ;

[0100] Level(x,y) represents the impact classification of the protective engineering at location (x,y). High-impact areas indicate that the protective engineering has significantly altered local hydrodynamic conditions, resulting in changes in wave height, flow velocity, or water depth exceeding the natural recovery threshold of the ecosystem or critical values for geomorphic stability. Such areas may experience problems such as coral larval attachment failure, abnormal sediment transport, or increased bottom erosion, necessitating optimization of engineering layout or implementation of ecological restoration measures. Medium-impact areas indicate that the degree of hydrodynamic disturbance is manageable but has already had observable impacts on coral growth, benthic habitat, or sediment balance. Long-term monitoring of the correlation between hydrodynamic parameters and ecological indicators is required in these areas to prevent cumulative disturbances from triggering secondary environmental risks. Low-impact areas indicate that hydrodynamic changes are within the natural range and have not significantly disturbed coral reef ecosystem functions or geomorphic processes. These areas can be considered safe zones for engineering layout, but sensitive habitats (such as dense coral areas) must still be avoided during construction.

[0101] This approach dynamically parameterizes coral roughness and wave-breaking engineering features, constructs a two-dimensional coral reef topographic profile model, and improves the hydrodynamic equations, enabling high-precision simulation of the spatial distribution of island and reef hydrodynamics. First, dynamic Manning coefficient calculations based on coral type and coverage accurately quantify the differentiated impact of coral communities on water flow resistance, overcoming the errors caused by fixed roughness parameters in traditional methods. Second, a multi-dimensional combination of wave-breaking engineering location, structural characteristics, and wave conditions within the engineering parameter matrix systematically reveals the effects of different protection layouts on the wave and flow field. Finally, through a composite impact index and grading rules for wave height, flow velocity, and water depth variations, the scope and extent of engineering disturbances on the hydrodynamic environment can be spatially identified, providing a quantitative basis for optimizing engineering layout. Compared to existing technologies, this method explicitly couples ecological parameters with hydrodynamic models, enabling synergistic analysis of coral reef topographic characteristics, ecological friction effects, and protective engineering structures, enhancing the ecological rationality and engineering guidance value of the simulation results.

[0102] The embodiment of the present invention provides a system for evaluating the impact of protective engineering on the spatial distribution of hydrodynamic forces on islands and reefs, which is used to implement the method for evaluating the impact of protective engineering on the spatial distribution of hydrodynamic forces on islands and reefs described in the above embodiment. Figure 3 This is a schematic diagram of a system for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics, provided by an embodiment of the present invention. Figure 3 , the system includes the following modules:

[0103] Data acquisition module, used to obtain coral parameter data and protection engineering parameter data of the target island and reef area;

[0104] The working condition simulation module is connected to the data acquisition module and is used to perform hydrodynamic simulation based on coral parameter data and protective engineering parameter data;

[0105] The impact factor calculation module is connected to the working condition simulation module and is used to determine the difference value of the hydrodynamic factor according to the hydrodynamic simulation results;

[0106] The evaluation module is connected to the impact factor calculation module and is used to generate a composite impact index based on the difference values of the hydrodynamic factors and to perform a classification of the impact of the protective project.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics, characterized by: The method comprises the following steps: S1. Obtain coral parameter data and protective engineering parameter data of the target island and reef area; The coral parameter data include coral type, coral coverage and coral substrate type; The protective engineering parameter data includes the height, length, porosity and location of the protective engineering; S2. performing a hydrodynamic simulation based on the coral parameter data and the protective engineering parameter data; Specifically include: S21. determining a dynamic Manning coefficient based on the coral parameter data; S211, determining a corresponding Manning coefficient according to the coral substrate type, and weighting the coral coverage according to the coral type to generate a spatially distributed Manning coefficient; S212. Obtain the dynamic Manning coefficient by summing the base Manning coefficient and the spatially distributed Manning coefficient; S22, generalizing the terrain of the target island and reef area into a two-dimensional terrain profile function; S23, modifying the two-dimensional terrain profile function according to the dynamic Manning coefficient and the protective engineering parameter data; S24, dividing the computational grid based on the modified two-dimensional terrain profile function, defining the wave boundary conditions and running the hydrodynamic model to perform hydrodynamic simulation; S3. Determine a hydrodynamic factor difference value according to the hydrodynamic simulation result; The hydrodynamic factor difference values include: wave height attenuation rate, flow velocity change rate and water depth change rate; S4. Generate a composite impact index based on the difference values of the hydrodynamic factors and perform a protective engineering impact classification.

2. The method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics according to claim 1 is characterized in that: In said S24, said wave boundary conditions include wave height and period; The results of the hydrodynamic simulation include instantaneous wave height, flow velocity and water depth.

3. The method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics according to claim 2 is characterized in that: In S3, determining the hydrodynamic factor difference value according to the hydrodynamic simulation result includes: S31, calculating the time-averaged wave height, time-averaged flow velocity, and time-averaged water depth under the conditions with and without the project according to the hydrodynamic simulation results; S32. Determine the difference in hydrodynamic factors based on the time-averaged wave height, time-averaged flow velocity, and time-averaged water depth under the conditions with and without the project.

4. The method for evaluating the impact of protective engineering on the spatial distribution of island and reef hydrodynamics according to claim 1 is characterized in that: In S4, generating a composite impact index based on the hydrodynamic factor difference value and performing a protective engineering impact grading step includes: S41, generating a composite impact index based on the weighted sum of the hydrodynamic factor difference values; S42. Obtaining a protective engineering impact rating based on the composite impact index and a preset threshold range.

5. A system for evaluating the spatial distribution of hydrodynamic forces of islands and reefs caused by protective engineering, used to implement the method for evaluating the spatial distribution of hydrodynamic forces of islands and reefs caused by protective engineering as described in any one of claims 1 to 4, characterized in that: The system includes the following modules: Data acquisition module, used to obtain coral parameter data and protection engineering parameter data of the target island and reef area; A working condition simulation module, connected to the data acquisition module, for performing a hydrodynamic simulation based on the coral parameter data and the protective engineering parameter data; An impact factor calculation module, connected to the working condition simulation module, for determining a hydrodynamic factor difference value based on the hydrodynamic simulation result; An evaluation module is connected to the impact factor calculation module and is used to generate a composite impact index based on the difference value of the hydrodynamic factors and perform a protective engineering impact classification.

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