A method and system for assessing extreme environmental conditions for coastal engineering
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HOHAI UNIV
- Filing Date
- 2026-05-15
- Publication Date
- 2026-06-19
Smart Images
Figure CN122241843A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the fields of marine engineering and coastal engineering technology, and in particular to a method and system for assessing extreme environmental conditions in coastal engineering. Background Technology
[0002] The hydrodynamic environment of coastal areas has the following typical characteristics: frequent tropical cyclone activity; large tidal range; complex topography and coastline conditions; and diverse engineering types.
[0003] Currently, in coastal engineering design, extreme environmental conditions are typically determined using the following methods: single-factor extreme value statistical analysis is performed on significant wave height, peak period, high tide level, or total water level, and design values for a given return period are selected. Based on this, an empirical combination method is used to simply superimpose wave elements and tide levels with different return periods or recommended values from specifications, such as "waves are taken as a 50-year return period, and tide levels are taken as the highest tide level" or "unfavorable values are combined." A few projects have attempted to introduce joint probability analysis, but the lack of a unified data processing workflow, model selection criteria, and engineering-oriented representative working condition selection rules makes it difficult to promote and apply in practical engineering.
[0004] However, the above-mentioned technologies have the following problems in practical applications: First, the single-factor extreme value statistics and empirical combination methods fail to systematically characterize the joint upper tail correlation between wave height, period and tide level, which may produce physically rare or probabilistically distorted combination conditions, making the design results unsafe or overly conservative; Second, there is insufficient identification of typical controlling extreme combinations such as "high wave height + long period + high water level", making it difficult to timely discover the most unfavorable combination of conditions for breakwater stability, breakwater crest overtopping, harbor swaying, dynamic response of high pile structures and local scour.
[0005] Therefore, there is a lack of a method in the relevant technologies for assessing extreme environmental conditions applicable to coastal engineering, especially for coastal port engineering. Summary of the Invention
[0006] The purpose of this application is to provide a method and system for assessing extreme environmental conditions in coastal engineering. By driving the process with multi-source wave-tide data, a joint distribution model of wave height, period, and tide level is established and an environmental profile with equal exceedance probability is constructed. This enables the quantitative determination of extreme design wave conditions with clear joint probability meaning, thereby improving the scientific and economical nature of coastal engineering design.
[0007] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a method for assessing extreme environmental conditions in coastal engineering, comprising: determining a representative deep-water point and a nearshore control point in the engineering area based on engineering information of the engineering area, and establishing a wave propagation deformation conversion relationship between the representative deep-water point and the nearshore control point; acquiring multi-source wave-tide data associated with the representative deep-water point, and performing quality control on the multi-source wave-tide data to generate a significant wave height time series, a spectral peak period time series, and a total water level time series; performing tidal level decomposition on the total water level time series to obtain astronomical tidal components and non-astronomical residual components; and identifying multiple independent extreme wave-tide conditions from the significant wave height time series and the total water level time series based on preset wave height and tidal level thresholds, where the significant wave height is not lower than the wave height threshold and the total water level is not lower than the tidal level threshold. Tidal coupling events; wherein the tidal level threshold is determined based on at least one of the water level values in the total water level time series or the non-astronomical residual components; feature parameters are extracted from each independent extreme wave-tidal coupling event to form a multidimensional extreme sample set; a joint distribution model is established based on the multidimensional extreme sample set; the target probability level is determined according to the target design return period; based on the joint distribution model and the target probability level, an environmental profile with equal exceedance probability is constructed, the environmental profile representing the boundary where the joint exceedance probability in a three-dimensional space composed of wave height, period, and water level does not exceed the target probability level; at least one representative combination condition is selected on the environmental profile, and the representative combination condition is converted to the nearshore control point using the wave propagation deformation conversion relationship to obtain the design wave elements at the nearshore control point.
[0008] Optionally, determining the offshore deep-water representative point and nearshore control point of the engineering area based on the engineering information of the engineering area includes: classifying the engineering area into a preset dynamic zone; selecting a deep-water location that meets preset criteria as the offshore deep-water representative point within the dynamic zone; and determining the nearshore control point at the engineering control section.
[0009] Optionally, the multi-source wave-tide data includes buoy data, wave radar data, shore-based observation data, tide gauge station record data, reanalysis data, and typhoon process numerical post-report data.
[0010] Optionally, identifying multiple independent extreme wave-tide coupling events that satisfy the condition that the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold includes: identifying candidate events that satisfy the condition that the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold using the peak threshold method; and merging or eliminating the candidate events according to a preset minimum event interval and event duration to obtain the independent extreme wave-tide coupling events.
[0011] Optionally, the step of extracting feature parameters from each independent extreme wave-tide coupling event includes: extracting the maximum significant wave height within the event window of the independent extreme wave-tide coupling event; extracting the spectral peak period corresponding to the maximum significant wave height, or extracting the maximum value of the spectral peak period within the time window adjacent to the time when the maximum significant wave height occurs; and extracting the peak total water level within the event window of the independent extreme wave-tide coupling event.
[0012] Optionally, establishing a joint distribution model based on the multidimensional extreme sample set includes: fitting marginal distributions to the maximum significant wave height, the spectral peak period corresponding to the maximum significant wave height, and the peak total water level, respectively; mapping the samples in the multidimensional extreme sample set to uniform variables based on the marginal distributions; estimating Copula parameters based on the uniform variables, establishing a ternary joint distribution model, and using it as the joint distribution model.
[0013] Optionally, constructing an environmental profile with equal exceedance probabilities includes: generating a three-dimensional environmental profile surface that satisfies the target probability level using an analytical method or a Monte Carlo sampling method; generating equal exceedance probability curves of the three-dimensional environmental profile surface on the wave height-water level plane and / or the wave height-period plane; wherein the equal exceedance probability curves serve as a two-dimensional representation of the environmental profile and are used to select representative combined working conditions from the environmental profile.
[0014] Optionally, selecting at least one representative combination of working conditions on the environmental profile includes: selecting representative combination of working conditions from the environmental profile for stability verification, overtopping verification, hydrodynamic pressure verification, vibration response verification, scouring verification, and harbor sway verification, based on the sensitivity of the project type to wave height, period, tide level, and direction.
[0015] Optionally, the method further includes: introducing a sea-level rise scenario to correct the peak total water level in the multidimensional extreme sample set; and based on the corrected multidimensional extreme sample set, re-establishing a joint distribution model, constructing an environmental profile, and selecting representative combined working conditions to obtain the design wave elements under the future scenario.
[0016] Secondly, this application provides an assessment system for extreme environmental conditions in coastal engineering, comprising: a representative point determination module, configured to determine the offshore deep-water representative point and nearshore control point of the engineering area based on engineering information of the engineering area, and establish a wave propagation deformation conversion relationship from the offshore deep-water representative point to the nearshore control point; a data management module, configured to acquire multi-source wave-tidal data associated with the offshore deep-water representative point, and perform quality control on the multi-source wave-tidal data to generate a significant wave height time series, a spectral peak period time series, and a total water level time series; perform tidal level decomposition on the total water level time series to obtain astronomical tidal components and non-astronomical residual components; and an extreme event identification module, configured to identify multiple independent extreme wave-tidal coupling events from the significant wave height time series and the total water level time series based on preset wave height thresholds and tidal level thresholds, wherein the significant wave height is not lower than the wave height threshold and the total water level is not lower than the tidal level threshold; wherein... The tide level threshold is determined based on at least one of the water level values in the total water level time series or the non-astronomical residual components; the feature extraction module is configured to extract feature parameters from each independent extreme wave-tide coupling event and form a multidimensional extreme sample set; the joint modeling module is configured to establish a joint distribution model based on the multidimensional extreme sample set; the environmental profile generation module is configured to determine the target probability level based on the target design return period; based on the joint distribution model and the target probability level, an environmental profile with equal exceedance probability is constructed, the environmental profile representing the boundary where the joint exceedance probability in the three-dimensional space composed of wave height, period, and water level does not exceed the target probability level; the working condition recommendation module is configured to select at least one representative combined working condition on the environmental profile; the deformation conversion module is configured to use the wave propagation deformation conversion relationship to convert the representative combined working condition to the nearshore control point to obtain the design wave elements at the nearshore control point.
[0017] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a method and system for assessing extreme environmental conditions in coastal engineering. By establishing a wave propagation deformation conversion relationship from a representative point in deep water to a nearshore control point, it achieves spatial benchmark unification between extreme environmental condition assessment and engineering section design, ensuring that the subsequently constructed design wave elements accurately reflect the actual loading conditions at the engineering location. Through quality control, tidal level decomposition, and identification of independent extreme wave-tidal coupling events using multi-source wave-tidal data, it solves the problems of insufficient representativeness of single data sources and strong subjectivity in event identification in traditional methods, improving the reliability of extreme event samples. By establishing a joint distribution model based on a multi-dimensional extreme sample set, it overcomes the limitations of single-factor extreme value statistics in related technologies. This approach overcomes the limitations of assessing the joint upper tail correlation between wave height, period, and tide level, enabling a quantitative description of controlling extreme combinations such as "high wave height + long period + high water level." By constructing environmental profiles with equal exceedance probabilities, the target design return period is transformed into the boundary of an extreme environment set with clear probabilistic significance. This solves the problem of ambiguous probabilistic meanings in traditional empirical combination methods, allowing designers to intuitively identify the range of extreme environmental conditions that meet given design standards. By selecting representative combination conditions on the environmental profile and converting them to nearshore control points, the approach moves from probabilistic modeling to engineering application, ensuring that the selected combination conditions have clear joint exceedance probabilities and guaranteeing the scientific and economical nature of coastal engineering design. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments 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.
[0019] Figure 1 This is an application environment diagram of an assessment method for extreme environmental conditions in coastal engineering according to an embodiment of this application; Figure 2 A flowchart illustrating an assessment method for extreme environmental conditions in coastal engineering, provided as an embodiment of this application; Figure 3 for Figure 2 A detailed flowchart illustrating the process of determining the representative deep-water offshore points and nearshore control points of the engineering area based on engineering information of the engineering area in step S1. Figure 4 for Figure 2 A detailed flowchart illustrating the process of identifying multiple independent extreme wave-tide coupling events in step S4 that satisfy both the effective wave height and the total water level as not lower than the tide level threshold. Figure 5 for Figure 2A detailed flowchart illustrating the process of extracting feature parameters from each independent extreme wave-tidal coupling event in step S5. Figure 6 for Figure 2 A detailed flowchart illustrating the process of establishing a joint distribution model based on a multidimensional extreme sample set in step S5. Figure 7 for Figure 2 A detailed flowchart illustrating the process of constructing an environmental profile with equal transcendental probability in step S7. Figure 8 A schematic diagram of the distribution of extreme event samples on the wave height-water level plane and the equal exceedance probability curves obtained based on the Copula model, provided in an embodiment of this application; Figure 9 A schematic diagram of the three-dimensional environment contour surface under the target design recurrence period provided in an embodiment of this application; Figure 10 This is a schematic diagram showing the selection of representative combination working conditions in the design of the breakwater outside port X in one application embodiment of this application; Figure 11 This is a schematic diagram of the functional modules of an assessment system for extreme environmental conditions in coastal engineering, provided as an embodiment of this application. Detailed Implementation
[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0022] The method for assessing extreme environmental conditions in coastal engineering provided in this application can be applied to, for example... Figure 1In the application environment shown, terminal 101 communicates with server 102 via a network. The data storage system can store data that server 102 needs to process, such as multi-source wave-tidal raw data, topographic and shoreline data of the engineering area, and preset dynamic zoning information. The data storage system can be set up separately, integrated into server 102, or placed in the cloud or on other servers. Terminal 101 can send engineering information of the engineering area to server 102. After receiving the engineering information, server 102 retrieves the corresponding multi-source wave-tidal data from the data storage system and executes the coastal engineering extreme environmental condition assessment method provided in this application embodiment. Server 102 can feed back the obtained design wave elements and corresponding representative combination working condition information to terminal 101. Furthermore, in some embodiments, the coastal engineering extreme environmental condition assessment method provided in this application embodiment can also be implemented separately by server 102 or terminal 101. For example, terminal 101 can directly execute the above assessment method on the locally stored wave-tidal data to be processed, or server 102 can retrieve data from the data storage system, independently complete the assessment, and store the results in the data storage system for subsequent use.
[0023] The terminal 101 can be, but is not limited to, various desktop computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. Portable wearable devices can be smartwatches, smart bracelets, head-mounted devices, etc. The server 102 can be implemented using a standalone server or a server cluster composed of multiple servers, or it can be a cloud server.
[0024] In one exemplary embodiment, such as Figure 2 As shown, a method for assessing extreme environmental conditions in coastal engineering is provided. This method is executed by computer equipment, specifically by a terminal or server alone, or by both a terminal and a server. In this embodiment, the method is applied to... Figure 1 Taking server 102 as an example, the explanation includes the following steps: S1. Based on the engineering information of the engineering area, determine the representative point of the offshore deep water and the nearshore control point of the engineering area, and establish the wave propagation deformation conversion relationship from the representative point of the offshore deep water to the nearshore control point.
[0025] S2 acquires multi-source wave-tidal data associated with representative points in deep waters of the open ocean, performs quality control on the multi-source wave-tidal data, and generates time series of significant wave height, spectral peak period, and total water level.
[0026] S3 decomposes the total water level time series into tidal components and non-astronomical residual components.
[0027] S4, based on preset wave height and tide level thresholds, identify multiple independent extreme wave-tide coupling events from the significant wave height time series and the total water level time series that satisfy the condition that the significant wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold. The tide level threshold is determined based on at least one of the water level values in the total water level time series or non-astronomical residual components.
[0028] S5 extracts feature parameters from each independent extreme wave-tidal coupling event and forms a multidimensional extreme sample set; based on the multidimensional extreme sample set, a joint distribution model is established.
[0029] S6, determine the target probability level based on the target design return period.
[0030] S7. Based on the joint distribution model and the target probability level, an environmental profile with equal transcendence probability is constructed. The environmental profile represents the boundary in a three-dimensional space consisting of wave height, period, and water level where the joint transcendence probability does not exceed the target probability level.
[0031] S8. Select at least one representative combination of working conditions on the environmental profile, and use the wave propagation deformation conversion relationship to convert the representative combination of working conditions to the nearshore control point to obtain the design wave elements at the nearshore control point.
[0032] By implementing steps S1 to S8, step S1 establishes the wave propagation deformation conversion relationship from the representative point in offshore deep water to the nearshore control point, achieving spatial benchmark unification between extreme environmental condition assessment and engineering section design. This ensures that the subsequently constructed design wave elements accurately reflect the actual loading conditions at the project location. Steps S2 to S4 perform quality control, tidal level decomposition, and independent extreme wave-tidal coupling event identification on multi-source wave-tidal data, solving the problems of insufficient representativeness of a single data source and strong subjectivity in event identification in traditional methods, thus improving the reliability of extreme event samples. Step S5 establishes a joint distribution model based on a multi-dimensional extreme sample set, overcoming the inability of single-factor extreme value statistics to characterize wave height in related technologies. The deficiency of the joint upper tail correlation between the period and the tide level is overcome, enabling a quantitative description of controlling extreme combinations such as "high wave height + long period + high water level". By constructing environmental profiles with equal transcendence probabilities through steps S6 to S7, the target design return period is transformed into the boundary of an extreme environment set with clear probabilistic meaning, solving the problem of ambiguous probabilistic meaning of combined working conditions in traditional empirical combination methods. This allows designers to intuitively identify the range of extreme environmental conditions that meet given design standards. Through step S8, representative combined working conditions are selected on the environmental profile and converted to nearshore control points, realizing the transition from probabilistic modeling to engineering application. This ensures that the selected combined working conditions have clear joint transcendence probability meaning, guaranteeing the scientific and economical nature of coastal engineering design.
[0033] In practical implementation, the specific steps in step S1 for determining the representative deep-water point and nearshore control point of the engineering area based on the engineering information of the engineering area can be as follows: Figure 3 As shown, it includes: S11: Obtain engineering information for the engineering area and assign the engineering area to the preset power zone.
[0034] Specifically, the acquired engineering information for the project area includes basic information such as geographical location, project type, design water depth, and main injection direction. The project area is then assigned to a pre-defined dynamic zone, which can be based on ocean dynamic characteristics.
[0035] S12, within the dynamic zone, select a deep-water location that meets the preset criteria as a representative point for offshore deep water.
[0036] Specifically, within the corresponding dynamic zone, a deep-water location that meets the deep-water conditions (e.g., water depth greater than twice the design wavelength or greater than 30-50m), is far from the coastline or islands / reefs, and has available wave data (e.g., at least 20 years of available wave data or verifiable reanalysis or reproducibility data) is selected as the representative point P1 for deep-water in the open sea.
[0037] S13, determine the near-shore control point at the engineering control section.
[0038] Specifically, a nearshore control point P2 is determined at the engineering control section. This point should be aligned with the wave-affected direction of the engineering structure and should be able to obtain tidal or water level information. It is understood that in step S13, determining the nearshore control point can also be replaced with an off-harbor control point.
[0039] In practice, after determining the representative deep-water point and nearshore control point of the engineering area in step S1, based on the topography and coastline data of the engineering area, a wave propagation deformation conversion relationship is established from the representative deep-water point P1 to the nearshore control point P2 using numerical wave models, spectral deformation, energy conservation, or transfer function matrices. It can be understood that this conversion relationship is used to convert wave elements at the offshore points into design wave elements for the engineering cross-section, serving as the spatial benchmark for subsequent steps in the assessment method for extreme environmental conditions in coastal engineering in this application.
[0040] In specific implementation, step S2, obtaining multi-source wave-tide data associated with a representative point in deep water, involves: based on the geographical location of the representative point, retrieving multi-source wave-tide data associated with that point's location from a pre-stored multi-source wave-tide database. This multi-source wave-tide data includes buoy data, wave radar data, shore-based observation data, tide gauge station records, reanalysis data, and typhoon process numerical post-report data.
[0041] In the specific implementation, step S2 involves quality control of the multi-source wave-tidal data, including: time alignment and unit unification, handling of missing and duplicate records, detection of range / abrupt / rate anomalies, internal parameter consistency verification, and multi-source cross-comparison and deviation correction. Through the above quality control process, continuous effective wave height time series Hs(t), spectral peak period time series Tp(t), and total water level time series η(t) are generated.
[0042] In the specific implementation, step S3 involves decomposing the total water level time series η(t) into tidal components, specifically by using harmonic analysis least squares method to decompose the total water level time series η(t) into astronomical tidal components η. tide (t) and non-astronomical residual components η res (t), where η res (t)=η(t)-η tide (t) represents the water level change caused by non-astronomical factors such as storm surge.
[0043] In specific implementation, the wave height threshold H in step S4 thr The tide level threshold η can be preset. thr The water level value or non-astronomical residual component η can be used as the basis for the total water level time series η(t). res At least one of η(t) is determined, wherein the water level values in the total water level time series η(t) are used as the total water level η. Optionally, a wave height threshold H is selected. thr To determine the 95th percentile of the long-term distribution of significant wave height at a representative point P1 in deep ocean waters, if we take the wave height threshold H... thr =3.0m. Tide threshold η thr This is approximately the 90th percentile of the climax distribution. If we take η... thr =2.6m.
[0044] For identifying waves whose effective wave height Hs is not lower than the wave height threshold H thr And the total water level η is not lower than the tide threshold η thr Multiple independent extreme wave-tidal coupling events E i The specific process can be as follows: Figure 4 As shown, the specific steps include: S41, the peak threshold method is used to identify candidate events that satisfy the condition that the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold.
[0045] S42, according to the preset minimum event interval and event duration, merge or eliminate candidate events to obtain independent extreme wave-tide coupling events.
[0046] The minimum event interval can be 72 hours; thus, the independent extreme wave-tidal coupling event E is obtained. i It outputs the start and end times and event number of each event.
[0047] In practical implementation, the specific process of extracting characteristic parameters from each independent extreme wave-tidal coupling event in step S5 can be described as follows: Figure 5 As shown, the specific steps include: S511 extracts the maximum significant wave height within the event window of an independent extreme wave-tidal coupling event.
[0048] Specifically, each independent extreme wave-tidal coupling event E i In its event window [t s (i), t e (i)] Extraction based on the maximum effective wave height Hs max .
[0049] S512, extract the spectral peak period corresponding to the maximum significant wave height, or extract the maximum value of the spectral peak period within the time window adjacent to the time when the maximum significant wave height occurs.
[0050] Specifically, the effective wave height Hs is taken to reach the maximum effective wave height Hs. max The dominant period corresponding to the time is taken as the spectral peak period Tp corresponding to the maximum significant wave height. max If discrete sampling errors exist, the maximum significant wave height Hs can also be used. max Extract the maximum period of the spectral peak within the time window adjacent to the time of occurrence.
[0051] S513 extracts the peak total water level within the event window of an independent extreme wave-tidal coupling event.
[0052] Specifically, the peak total water level within the event window is represented as η. max .
[0053] Therefore, the characteristic parameters extracted from each independent extreme wave-tide coupling event include the maximum significant wave height, the spectral peak period corresponding to the maximum significant wave height, or the maximum value of the spectral peak period extracted within the time window adjacent to the occurrence of the maximum significant wave height, and the total peak water level within the event window. Optionally, the characteristic parameters may also include parameters such as storm surge peak, dominant wave direction, and event duration.
[0054] Therefore, by extracting the characteristic parameters from each independent extreme wave-tidal coupling event as described above, a multidimensional extreme sample set X is formed. i ={(Hs max ,Tp max ,η max This is for use in subsequent joint modeling.
[0055] In practical implementation, the specific process of establishing the joint distribution model based on the multidimensional extreme sample set in step S5 can be as follows: Figure 6 As shown, the specific steps include: S521, respectively, fits the edge distribution of the maximum significant wave height, the spectral peak period corresponding to the maximum significant wave height, and the total water level of the peak value.
[0056] Specifically, using the multidimensional extreme sample set X i ={(Hs max ,Tp max ,η max As input, the maximum significant wave height Hs is respectively... max The spectral peak period Tp corresponding to the maximum effective wave height max And the peak total water level η within the event window max By fitting the edge distribution, the edge distribution function F of the maximum effective wave height is obtained. H The edge distribution function F of the spectral peak period T The marginal distribution function F of the peak total water level η For samples of annual maximum values, the Generalized Extreme Value (GEV) distribution can be used for fitting; for samples exceeding the threshold, the Peaks Over Threshold (POT)-Generalized Pareto Distribution (GPD) distribution can be used for fitting. Parameter estimation can be performed using the maximum likelihood method or the L-moment method, and the goodness of fit can be evaluated using the Akaike Information Criterion (AIC) / Bayesian Information Criterion (BIC), quantile-quantile plots (QQ plots), and Kolmogorov-Smirnov (KS) / Anderson-Darling (AD) tests.
[0057] S522, based on marginal distribution, maps samples in a multidimensional extreme sample set to uniform variables.
[0058] Specifically, based on the fitted marginal distribution function F H (h), F T (t), F η (η), the multidimensional extreme sample set X i ={(Hs max ,Tp max ,η max Each sample in} is mapped to a uniform variable, denoted as u, the uniform variable of the maximum significant wave height. H The uniform variable u of the spectral peak period T Uniform variable u of peak total water level η.
[0059] S523, based on the estimation of Copula parameters from uniform variables, establishes a ternary joint distribution model, and uses it as the joint distribution model.
[0060] Specifically, the Copula parameter θ is estimated using the Inference Functions for Margins (IFM) method or the full likelihood method. A Copula model sensitive to upper tail correlation, such as Gumbel Copula, t-Copula, or a ternary conditional extremum model, is selected to establish a ternary joint distribution model. The model expression is as follows: F(h,t,η)=C(F H (h), F T (t), F η (η); θ).
[0061] In the formula, F(h,t,η) represents the ternary joint distribution function of the maximum significant wave height, spectral peak period, and peak total water level; C(·;θ) represents the Copula function, which is used to characterize the correlation structure among the three variables.
[0062] This model can characterize the joint upper tail correlation between wave height, period and tide level, and provide a joint transcendence probability expression for any combination.
[0063] In specific implementation, in step S6, the return period T is designed according to the target. R Determine the target probability level. The target probability level can be the annual exceedance probability p. a , and p a =1 / T R Alternatively, it can be the single sea state exceedance probability p calculated based on the sea state duration. s , and p s =1 / (T R ·N); where N represents the number of sea states in a year.
[0064] In specific implementation, such as Figure 7 As shown, the specific process of constructing the environmental profile with equal transcendence probability in step S7 can be as follows: S71 uses analytical or Monte Carlo sampling methods to generate a three-dimensional environmental contour surface that meets the target probability level.
[0065] Specifically, analytical methods (such as IFORM (Inverse FORM)) or Monte Carlo sampling methods can be used. Taking IFORM as an example: the uniform variable u... H u T u ηThe standard normal space vector U is obtained through standard normal transformation. A reliability index β is chosen, such that the probability P that the magnitude ‖U‖ of the standard normal space vector U exceeds the reliability index β is equal to the target probability level. In this embodiment, the single sea state exceedance probability p is preferably used. s As the target probability level, it satisfies: P(‖U‖>β)=p s .
[0066] Where, β 2 χ is 3 degrees of freedom 2 The distribution (chi-square distribution) is in 1-p s quantile, 1-p s Quantiles are represented as cumulative probabilities of 1-p in a chi-square distribution. s The corresponding values.
[0067] In the standard normal vector space U, an equiprobable hypersphere with radius β is generated. After inverse Rosenblatt transformation, it is mapped back to physical space to obtain the three-dimensional environment contour surface.
[0068] S72 generates equal-breakthrough probability curves of the three-dimensional environment profile surface on the wave height-water level plane and / or wave height-period plane.
[0069] Specifically, the equal exceedance probability curves serve as a two-dimensional representation of the environmental profile, used to select representative combined operating conditions from the environmental profile. The equal exceedance probability curves on the three-dimensional environmental profile surface on the wave height-water level plane and the wave height-period plane serve as a two-dimensional representation of the environmental profile. The equal exceedance probability curves serve as a two-dimensional representation of the environmental profile, used to select representative combined operating conditions from the environmental profile. In this embodiment, as... Figure 8 As shown, Figure 8 The distribution of extreme event samples on the wave height-water level plane and the equal exceedance probability curves obtained based on the Copula model are shown, reflecting the correlation between high wave height and high water level. Figure 8 Each scatter point represents an independent extreme event, corresponding to its maximum significant wave height Hs. max and peak total water level η max The Copula model, constructed based on these samples, can generate equal exceedance probability curves for different annual exceedance probability levels. In the figure, the solid curve with p=0.01 corresponds to the design standard of once in 100 years, and the dashed curve with p=0.005 corresponds to the design standard of once in 200 years. Figure 9 A schematic diagram of the three-dimensional environmental profile surface under the target design recurrence period is shown. The three dimensions are the maximum significant wave height Hs, the spectral peak period Tp, and the peak total water level η.
[0070] In specific implementation, step S8 involves selecting at least one representative combination of working conditions on the environmental profile, including: selecting representative combination of working conditions from the environmental profile for stability verification, overtopping verification, hydrodynamic pressure verification, vibration response verification, scouring verification, and harbor sway verification based on the sensitivity of the project type to wave height, period, tide level, and direction.
[0071] In the specific implementation, step S8 utilizes the wave propagation deformation conversion relationship established in step S1 to convert the representative combined working condition from the deep-water representative point P1 in the open sea to the nearshore control point P2, obtaining the design wave elements at the nearshore control point P2. These elements include design wave height, design period, and design water level, serving as inputs for engineering structure design and safety verification. The nearshore control point P2 is located at the engineering control section and is determined in step S1.
[0072] In an exemplary embodiment, based on the above assessment method for extreme environmental conditions in coastal engineering, optionally: future scenarios such as sea-level rise are introduced to evaluate the peak total water level η in the multidimensional extreme sample set in step S5. max Make corrections; for example, uniformly increase the sea-level rise value during the planning period. Based on the corrected multidimensional extreme sample set, repeat steps S6 to S8 to re-establish the joint distribution model, construct the environmental profile, and select representative combined working conditions to obtain the design wave elements under future scenarios, which are used to evaluate the safety margin of the project throughout its entire life cycle.
[0073] In an exemplary embodiment, the specific application of the method of this application is illustrated using the X-area port breakwater project as an example. The project is located in the southern coastal waters of the strait in area T, with a water depth of approximately 12-18m in front of the breakwater. The breakwater is a sloping block breakwater, and its design is based on a 100-year return period extreme sea state for stability and overtopping verification.
[0074] The project site was assigned to the "Southern Coastal Zone of the Strait in Area T". The representative deep-water point P1 was selected as the long-term statistical point of wave conditions. The wave deformation relationship between the representative deep-water point P1 and the front section of the seawall (i.e., the nearshore control point P2) was established through numerical wave model.
[0075] Based on nearly 30 years of multi-source data (including buoy data, tide gauge records, reanalysis data, and post-typhoon reports), independent extreme wave-tide coupling events were identified after quality control. Characteristic parameters were extracted, and a Copula joint distribution model was established. After constructing a 100-year return period environmental profile, representative combined operating conditions were selected from the profile.
[0076] like Figure 10 The diagram shows a representative combination of working conditions selected in the design of the breakwater of Port X. The curves in the diagram are equal exceedance probability curves, representing the boundary conditions of wave height Hs and water level η that meet the 100-year return period design standard. The following representative working conditions are selected on the 100-year return period environmental profile: Condition A (stability control of embankment body and toe): Hs=7.2m, Tp=12.5s, η=3.0m.
[0077] Condition B (overtopping of the dike and control of safety elevation): Hs=6.3m, Tp=11.0s, η=3.4m.
[0078] Operating condition C (long-period effect and local scour control): Hs=5.5m, Tp=14.5s, η=2.9m.
[0079] The above operating conditions are all determined by a joint probability model and environmental profile. Their joint occurrence probability meets or exceeds the 100-year return period design requirement, and each condition covers different control effects. Through a predetermined wave deformation conversion relationship, the sea state at the representative deep-water point P1 in the open sea is converted to the cross-section in front of the breakwater (i.e., the nearshore control point P2), and the design wave height, design period, and design water level in front of the breakwater are obtained as inputs for structural calculations.
[0080] In one exemplary embodiment, such as Figure 11 As shown, an assessment system for extreme environmental conditions in coastal engineering is provided, comprising: The partition representative point determination module 201 is configured to determine the offshore deep-water representative point and nearshore control point of the engineering area based on the engineering information of the engineering area, and to establish the wave propagation deformation conversion relationship between the offshore deep-water representative point and the nearshore control point.
[0081] The data management module 202 is configured to acquire multi-source wave-tidal data associated with the representative point in the deep sea, perform quality control on the multi-source wave-tidal data, and generate a significant wave height time series, a spectral peak period time series, and a total water level time series; and perform tidal level decomposition on the total water level time series to obtain astronomical tidal components and non-astronomical residual components.
[0082] The extreme event identification module 203 is configured to identify, based on a preset wave height threshold and tide level threshold, multiple independent extreme wave-tide coupling events from the effective wave height time series and the total water level time series, wherein the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold; wherein the tide level threshold is determined based on at least one of the water level value in the total water level time series or the non-astronomical residual component.
[0083] The feature extraction module 204 is configured to extract feature parameters from each independent extreme wave-tide coupling event and form a multidimensional extreme sample set.
[0084] The joint modeling module 205 is configured to establish a joint distribution model based on the multidimensional extreme sample set.
[0085] The environmental profile generation module 206 is configured to determine the target probability level based on the target design return period; and to construct an environmental profile with equal transcendence probability based on the joint distribution model and the target probability level, wherein the environmental profile represents the boundary in a three-dimensional space consisting of wave height, period and water level where the joint transcendence probability does not exceed the target probability level.
[0086] The operating condition recommendation module 207 is configured to select at least one representative combination of operating conditions on the environmental profile.
[0087] The deformation conversion module 208 is configured to use the wave propagation deformation conversion relationship to convert the representative combined working condition to the nearshore control point, thereby obtaining the design wave elements at the nearshore control point.
[0088] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal. The computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The I / O interfaces of the computer device are used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for evaluating extreme environmental conditions in coastal engineering.
[0089] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Furthermore, any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory.
[0090] The technical features of the above embodiments can be combined in any way. 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.
[0091] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for assessing extreme environmental conditions in coastal engineering, characterized in that, include: Based on the engineering information of the engineering area, determine the offshore deep-water representative point and nearshore control point of the engineering area, and establish the wave propagation deformation conversion relationship from the offshore deep-water representative point to the nearshore control point; Acquire multi-source wave-tide data associated with the representative deep-sea point, perform quality control on the multi-source wave-tide data, and generate time series of significant wave height, time series of spectral peak period, and time series of total water level; The total water level time series is decomposed by tide level to obtain astronomical tide components and non-astronomical residual components; Based on preset wave height thresholds and tide level thresholds, multiple independent extreme wave-tide coupling events that satisfy the condition that the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold are identified from the effective wave height time series and the total water level time series; wherein, the tide level threshold is determined based on the water level value in the total water level time series or at least one of the non-astronomical residual components; Feature parameters are extracted from each independent extreme wave-tidal coupling event, forming a multidimensional extreme sample set; Based on the aforementioned multidimensional extreme sample set, a joint distribution model is established; Determine the target probability level based on the target design return period; Based on the joint distribution model and the target probability level, an environmental profile with equal transcendence probability is constructed. The environmental profile represents the boundary in a three-dimensional space consisting of wave height, period, and water level where the joint transcendence probability does not exceed the target probability level. At least one representative combination of working conditions is selected on the environmental profile, and the wave propagation deformation conversion relationship is used to convert the representative combination of working conditions to the nearshore control point to obtain the design wave elements at the nearshore control point.
2. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, The determination of the offshore deep-water representative point and nearshore control point of the engineering area based on the engineering information of the engineering area includes: The engineering area is assigned to the pre-defined power zone; Within the dynamic zone, a deep-water location that meets preset criteria is selected as the representative point of the open ocean deep water. The nearshore control point is determined at the engineering control section.
3. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, The multi-source wave-tide data includes buoy data, wave radar data, shore-based observation data, tide gauge station records, reanalysis data, and typhoon process numerical post-report data.
4. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, The identification of multiple independent extreme wave-tide coupling events that satisfy both the effective wave height and the total water level being not lower than the tide level threshold includes: Candidate events that satisfy the condition that the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold are identified using the peak threshold method. Based on the preset minimum event interval and event duration, the candidate events are merged or eliminated to obtain the independent extreme wave-tide coupling event.
5. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, The extraction of feature parameters from each independent extreme wave-tidal coupling event includes: Extract the maximum significant wave height within the event window of the independent extreme wave-tidal coupling event; Extract the spectral peak period corresponding to the maximum significant wave height, or extract the maximum value of the spectral peak period within the time window adjacent to the time when the maximum significant wave height occurs; Extract the peak total water level within the event window of the independent extreme wave-tidal coupling event.
6. The method for assessing extreme environmental conditions in coastal engineering according to claim 5, characterized in that, The establishment of a joint distribution model based on the multidimensional extreme sample set includes: The edge distributions of the maximum significant wave height, the spectral peak period corresponding to the maximum significant wave height, and the total peak water level are respectively fitted; Based on the marginal distribution, the samples in the multidimensional extreme sample set are mapped to uniform variables; Based on the estimation of Copula parameters using the uniform variables, a ternary joint distribution model is established and used as the joint distribution model.
7. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, The construction of the environmental profile with equal transcendental probability includes: A three-dimensional environmental contour surface that satisfies the target probability level is generated using either analytical or Monte Carlo sampling methods. Generate equal-break probability curves of the three-dimensional environmental profile surface on the wave height-water level plane and / or wave height-period plane; wherein, the equal-break probability curves serve as a two-dimensional representation of the environmental profile and are used to select representative combined working conditions from the environmental profile.
8. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, Selecting at least one representative combination of working conditions on the environmental contour includes: Based on the sensitivity of the project type to wave height, period, tide level and direction, representative combination conditions are selected from the environmental profile for stability verification, overtopping verification, hydrodynamic pressure verification, vibration response verification, scouring verification and harbor sway verification.
9. The method for assessing extreme environmental conditions in coastal engineering according to claim 1, characterized in that, Also includes: A sea-level rise scenario is introduced to correct the peak total water level in the multidimensional extreme sample set; Based on the revised multidimensional extreme sample set, a joint distribution model was re-established, an environmental profile was constructed, and representative combined working conditions were selected to obtain the design wave elements under future scenarios.
10. A system for assessing extreme environmental conditions in coastal engineering, characterized in that, include: The zone representative point determination module is configured to determine the offshore deep-water representative point and nearshore control point of the engineering area based on the engineering information of the engineering area, and to establish the wave propagation deformation conversion relationship between the offshore deep-water representative point and the nearshore control point. The data management module is configured to acquire multi-source wave-tidal data associated with the representative point in the open ocean deep water, perform quality control on the multi-source wave-tidal data, and generate a significant wave height time series, a spectral peak period time series, and a total water level time series; and perform tidal level decomposition on the total water level time series to obtain astronomical tidal components and non-astronomical residual components. An extreme event identification module is configured to identify multiple independent extreme wave-tide coupling events from the effective wave height time series and the total water level time series, based on preset wave height thresholds and tide level thresholds, where the effective wave height is not lower than the wave height threshold and the total water level is not lower than the tide level threshold; wherein, the tide level threshold is determined based on at least one of the water level values in the total water level time series or the non-astronomical residual components. The feature extraction module is configured to extract feature parameters from each independent extreme wave-tidal coupling event and form a multidimensional extreme sample set; The joint modeling module is configured to establish a joint distribution model based on the multidimensional extreme sample set; An environmental profile generation module is configured to determine a target probability level based on the target design return period; and to construct an environmental profile with equal exceedance probability based on the joint distribution model and the target probability level, wherein the environmental profile represents the boundary in a three-dimensional space consisting of wave height, period, and water level where the joint exceedance probability does not exceed the target probability level. The working condition recommendation module is configured to select at least one representative combination of working conditions on the environmental profile; The deformation conversion module is configured to use the wave propagation deformation conversion relationship to convert the representative combined working condition to the nearshore control point, thereby obtaining the design wave elements at the nearshore control point.