Early warning system and early warning method based on influence of ecological potential dike on nearshore seabed morphology under tsunami wave action

Abstract

This invention proposes an early warning system and method for the impact of ecological submerged breakwaters on nearshore seabed morphology under tsunami wave action. The system includes: a feature extraction module that collects water pressure data inside and outside the breakwater and establishes a high-energy potential difference time window; a potential energy analysis module that retrieves data within the high-energy potential difference time window and performs differential analysis of the vertical gradient to generate the permeability per unit volume of the seabed surface; an erosion analysis module that obtains the loss coefficient and corrects the static critical initiation shear stress to establish a time-evolving erosion resistance threshold sequence; a concealment identification module that identifies concealed scour zones; and a graded early warning module that quantifies and accumulates the surplus characteristics of shear strength in concealed scour zones using sediment transport rates to obtain morphological loss characteristics, performs stability assessment of the breakwater support structure, and triggers graded collapse early warning. This invention achieves the identification and dynamic early warning of concealed scour risks under low flow velocity backgrounds by quantifying soil weakening caused by seepage.

Description

Technical Field

[0001] This invention belongs to the field of marine early warning technology, specifically relating to an early warning system and method for the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves. Background Technology

[0002] Ecological submerged breakwaters are nearshore engineering structures that combine wave protection and ecological restoration. Existing monitoring and early warning technologies focus on the strong hydrodynamic impact during the tsunami crest climbing phase, often using wave height or horizontal current velocity as the sole criterion for disaster, and typically assuming that the erosion resistance threshold of seabed sediment is a static constant.

[0003] However, tsunami waves exhibit unique long-period fluctuation characteristics, particularly during the backflow phase, which is often accompanied by a sharp drop in the external free water level. Due to the seepage-blocking effect of the submerged breakwater structure and the porous media of the seabed, the dissipation rate of internal pore water pressure lags significantly behind the rate of decline of the external water level, thus creating a huge vertical upward seepage force at the seabed interface. This uplift force directly offsets the effective self-weight of sediment particles, leading to a sharp decrease in the effective stress of the seabed soil, a nonlinear dynamic decay in its shear strength, and even localized suspension or quasi-liquefaction.

[0004] Current technologies overlook the real-time weakening effect of seepage mechanisms on seabed resistance. Even if the hydrodynamic shear value during the backflow phase has not yet reached the conventional scour threshold, the extremely vulnerable seabed, supported by seepage forces, can still be easily swept away by low-velocity flows, forming a low-energy, highly destructive, and insidious scour. The lack of monitoring mechanisms allows deep erosion to occur at the toe of submerged breakwaters without triggering conventional flow velocity warnings, leading to sudden overturning or structural instability and threatening the safety of nearshore protection systems.

[0005] Therefore, this invention proposes an early warning system and method for the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves. Summary of the Invention

[0006] The purpose of this invention is to propose an early warning system and method for the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves, so as to achieve the identification and dynamic early warning of hidden scour risks under low flow velocity background.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] An early warning system based on the impact of tsunami waves on the nearshore seabed morphology of ecological submerged dikes includes:

[0009] Feature extraction module: used to collect water pressure data inside and outside the submerged dike and perform differential feature extraction to obtain the hysteresis response characteristics of water seepage; based on the hysteresis response characteristics, time-domain analysis is performed on the pressure difference evolution during the tsunami backflow stage to obtain the high-energy potential difference time window dominated by internal high pressure; the water pressure data is acquired by data acquisition units deployed in the monitoring area, including time-series pressure data of the free water surface outside the ecological submerged dike and time-series pressure data of the internal pore core;

[0010] Potential Energy Analysis Module: Used to retrieve water pressure data within a high potential difference time window and perform differential analysis of the vertical gradient to obtain the vertical hydraulic conduction characteristics inside the seabed; based on the vertical hydraulic conduction characteristics, the permeability per unit volume of the seabed surface is generated.

[0011] Erosion Analysis Module: Used to calculate the self-weight offset of the permeability per unit volume to obtain the reduction coefficient of the effective stress of the sediment; based on the reduction coefficient, the static critical starting shear stress is corrected to establish a time-varying erosion resistance threshold sequence.

[0012] The concealed scour identification module is used to collect near-bottom fluid horizontal velocity data during the tsunami backflow phase and convert it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed. The instantaneous bottom shear stress sequence is compared with the difference of heterogeneous data to obtain the surplus characteristics of shear strength. Based on the surplus characteristics, low-velocity concealed scour analysis is performed to identify low-energy flow-high-damage concealed scour zones. The near-bottom fluid horizontal velocity data is acquired by data acquisition units deployed in the monitoring area.

[0013] Preferably, the data acquisition unit includes an external water pressure sensor, an internal pore water pressure sensor, and a flow meter;

[0014] The external water pressure sensors are evenly and equidistantly distributed on the seabed surface outside the ecological submerged dike or fixed on the water-facing structure of the dike, and are used to collect time-series pressure data of the free water surface outside the ecological submerged dike in real time.

[0015] The internal pore water pressure sensor is uniformly and equidistantly embedded in the porous medium inside the ecological submerged dike or below the seabed, and has a preset vertical burial depth from the seabed surface, for real-time acquisition of time-series pressure data at the core of the internal pores.

[0016] The flowmeters are evenly and equidistantly installed at the toe of the ecological submerged dike to acquire near-bottom fluid horizontal velocity data generated by tsunami backflow.

[0017] Preferably, the hysteresis response characteristics of the water seepage are obtained as follows:

[0018] The time-series pressure data of the external free water surface and the internal pore core of the ecological submerged dike were time-stamped and aligned.

[0019] Sliding window differential operations were performed on the two sets of time-aligned pressure data to obtain the external water level drop rate and the internal pore water pressure dissipation rate.

[0020] Directional differential processing is performed between the external water level drop rate and the internal pore water pressure dissipation rate: the external water level drop rate and the internal pore water pressure dissipation rate are compared at each time point, and only data point pairs with an external water level drop rate greater than the internal pore water pressure dissipation rate are retained. Data point pairs with an external drop rate less than or equal to the internal dissipation rate are set to zero.

[0021] The difference between the internal and external rates is calculated based on the external water level drop rate and the internal pore water pressure dissipation rate at each time point after directional differential processing. Obtain the internal and external rate difference sequence:

[0022]

[0023] in, and These represent the rate of decrease in external water level and the rate of dissipation of internal pore water pressure at the same time point;

[0024] Smoothing filters are applied to the internal and external rate difference sequences, and the resulting smooth sequence represents the hysteresis response characteristics of water seepage.

[0025] Preferably, the high-energy potential difference time window dominated by the internal high pressure is obtained as follows:

[0026] During the tsunami backflow phase, a dual-threshold envelope analysis is performed on the hysteresis response characteristics: the abrupt rising edge of the hysteresis response characteristics is identified based on the first preset threshold to obtain the non-equilibrium starting point; the relaxation decay edge of the hysteresis response characteristics is tracked based on the second preset threshold to obtain the non-equilibrium ending point.

[0027] Using the non-equilibrium starting point as the starting point and the non-equilibrium ending point as the ending point, the time span between the starting point and the ending point is extracted to establish a high-energy potential difference time window.

[0028] Preferably, the potential energy analysis module specifically performs the following steps:

[0029] The temporal pressure data of the external free water surface and the internal pore core of the ecological submerged dike within the time period corresponding to the high potential difference time window are extracted to obtain the external free water surface pressure sequence and the internal pore water pressure sequence.

[0030] The vertical burial depth of the internal pore water pressure sensor relative to the seabed surface is used as the path length of vertical seepage.

[0031] The two extracted pressure sequences were calculated point by point based on the path length of the vertical seepage: the internal pore water pressure at the same moment was subtracted from the external free water surface pressure to obtain the instantaneous vertical pressure difference; and the instantaneous vertical pressure difference was divided by the path length of the vertical seepage to obtain the vertical pressure gradient inside the seabed.

[0032] The vertical pressure gradient is used as the characteristic of vertical hydraulic conduction within the seabed and is equivalent to the permeability per unit volume of the seabed surface.

[0033] Preferably, the erosion analysis module specifically performs the following steps:

[0034] The saturated unit weight parameters of seabed sediments at the corresponding burial depth of the internal pore water pressure sensor are obtained, and the effective self-weight of the seabed soil in a still water environment is calculated and defined as buoyancy unit weight.

[0035] Obtain the depth of the buoyancy unit weight calculation point, and multiply the depth with the buoyancy unit weight to obtain the static effective stress.

[0036] Multiply the current unit volume permeability by the depth of the buoyancy calculation point to obtain the permeability uplift pressure;

[0037] The instantaneous effective stress is obtained by calculating the difference between the effective stress in still water and the pressure from seepage.

[0038] Read the average initial effective stress in still water conditions from historical monitoring data of tsunami waves;

[0039] The ratio of instantaneous effective stress to the average initial effective stress is calculated to obtain the loss coefficient;

[0040] The static critical initiation shear stress of the sea area under seepage-free environmental conditions is obtained, and the static critical initiation shear stress is input into the function relationship of dynamic attenuation mapping to obtain the dynamic erosion resistance threshold:

[0041]

[0042] in, For the current moment The dynamic erosion resistance threshold, The static critical starting shear stress. For the current moment The loss coefficient;

[0043] Obtain the dynamic anti-erosion threshold at M time points and establish an anti-erosion threshold sequence.

[0044] Preferably, the concealment identification module specifically performs the following steps:

[0045] Establishing an instantaneous seabed shear stress sequence: Using the second law of friction, the near-bottom fluid horizontal velocity data is converted into an instantaneous seabed shear stress sequence exerted by the fluid on the seabed. The values ​​in the instantaneous seabed shear stress sequence are the hydrodynamic shear values ​​at the corresponding moments.

[0046]

[0047] in, For instantaneous bed shear stress, The density of seawater, Let be the coefficient of friction of the seabed surface. This represents the measured horizontal velocity of the fluid near the bottom.

[0048] The difference between the instantaneous substrate shear stress sequence and the erosion resistance threshold sequence at each time point is calculated to obtain the surplus strength difference; if the surplus strength difference is positive, the surplus strength difference is retained and defined as the surplus characteristic of shear strength.

[0049] Set dual screening conditions: (1) the instantaneous bed shear stress is less than the preset conventional flow velocity scouring threshold, and (2) there is a surplus characteristic of shear strength.

[0050] Based on the instantaneous bed shear stress sequence and the erosion resistance threshold sequence, data segments that simultaneously meet the dual screening conditions are selected, and the corresponding spatial locations of the data segments that meet the dual screening conditions are obtained to establish the hidden scour zone.

[0051] Preferably, it also includes a graded early warning module: used to quantify and accumulate the sediment transport rate of the surplus characteristics of shear strength in the hidden scour zone to obtain the morphological missing characteristics of the submerged dike toe; based on the morphological missing characteristics, the stability of the submerged dike support structure is deduced and evaluated and graded collapse early warning is set.

[0052] Preferably, the graded early warning module specifically performs the following steps:

[0053] Using the surplus characteristics of shear strength as the independent variable and the instantaneous unit width sediment transport rate as the dependent variable, a sediment transport rate model is established to calculate the instantaneous unit width sediment transport rate.

[0054] A backflow scouring time window is constructed, which is the time interval from the start of the tsunami wave at the maximum backflow water level to the decay of the backflow velocity to below a preset threshold. The instantaneous unit width sediment transport rate is integrated to obtain the total volume of sediment loss.

[0055] The total volume of sediment loss is converted into the change in seabed elevation, i.e., the maximum scour depth at the toe of the submerged breakwater, as a feature of morphological loss:

[0056]

[0057] in This is a feature of missing morphology. This represents the total volume of sediment loss. To conceal the area of ​​erosion. Porosity of seabed soil;

[0058] To obtain the pre-embedded depth of the ecological submerged dike foundation structure and the ultimate overturning moment of the dike itself;

[0059] The ratio of the missing morphological features to the pre-embedded depth is used as the suspension ratio;

[0060] Based on the numerical range of the suspending ratio, execute the tiered early warning logic:

[0061] When the suspension ratio is less than the first threshold, it is judged as slight erosion and a blue observation warning is triggered;

[0062] When the suspension ratio is between the first and second thresholds, the passive earth pressure of the seabed soil surrounding the submerged breakwater foundation structure that participates in providing overturning restraint is recalculated. Based on the recalculated passive earth pressure and the ultimate overturning moment of the submerged breakwater itself, the remaining overturning moment of the breakwater foundation structure is calculated. Combined with the overturning moment under the tsunami backflow load, the overturning safety factor is calculated.

[0063]

[0064] in, To ensure overturning safety factor, For the remaining anti-overturning moment, The overturning moment under the action of tsunami backflow load;

[0065] If the overturning safety factor decreases but does not exceed the preset threshold, a blue observation warning is triggered; if the overturning safety factor decreases but exceeds the preset threshold, a yellow structural risk warning is triggered; wherein, the first threshold is less than the second threshold.

[0066] When the suspended ratio is greater than the second threshold, it is determined that the toe of the submerged dike has lost its anchoring ability and there is an immediate risk of collapse, triggering a red emergency evacuation warning.

[0067] An early warning method for the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves, wherein the early warning method is implemented using any of the aforementioned early warning systems, includes the following steps:

[0068] S1. Collect water pressure data inside and outside the submerged dike and extract differential features to obtain the hysteresis response characteristics of water seepage; perform time-domain analysis on the pressure difference evolution during the tsunami backflow stage based on the hysteresis response characteristics to obtain the high-energy potential difference time window dominated by internal high pressure; the water pressure data includes time-series pressure data of the free water surface outside the ecological submerged dike and time-series pressure data of the internal pore core.

[0069] S2. Retrieve instantaneous water level data within the high potential difference time window and perform differential analysis of the vertical gradient to obtain the vertical hydraulic conduction characteristics inside the seabed; generate the permeability per unit volume of the seabed surface based on the vertical hydraulic conduction characteristics.

[0070] S3. Perform self-weight offset calculation on the unit volume permeability to obtain the reduction coefficient of effective stress in sediments; based on the reduction coefficient, correct the static critical starting shear stress and establish a time-dependent erosion resistance threshold sequence.

[0071] S4. Collect near-bottom fluid horizontal velocity data during the tsunami backflow phase and convert it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed. Compare the difference between the instantaneous bottom shear stress sequence and the erosion resistance threshold sequence to obtain the surplus characteristics of shear strength. Based on the surplus characteristics, conduct hidden scour analysis at low flow velocities to identify the hidden scour zone with low energy flow and high damage.

[0072] S5. Quantify and accumulate the sediment transport rate of the surplus shear strength in the hidden scour zone to obtain the morphological missing characteristics of the submerged dike toe; based on the morphological missing characteristics, deduce and evaluate the stability of the submerged dike support structure and set graded collapse warnings.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] 1. By collecting water pressure data inside and outside the submerged breakwater and performing differential feature extraction of dissipation rates, a high-energy potential difference time window can be defined. This facilitates the extraction of internal high-pressure hysteresis response segments caused by sudden drops in external water levels from complex wave signals. This enables targeted targeting of the physical disaster time domain, concentrating computational resources on the critical stages dominated by seepage forces within the seabed, and distinguishing between conventional wave action and the unique reverse pressure differential effect during tsunami backflow.

[0075] 2. Based on the water pressure data within the high potential difference time window, the vertical gradient is differentially inverted to generate the unit volume permeability, transforming the pressure data into a vector field index with a clear vertical upward attack attribute. The quantification process reflects the supporting effect of the pore hydrodynamics within the seabed soil during the backflow period on the sediment skeleton, and at the physical level, it characterizes the dynamic mechanism by which the vertical hydraulic gradient overcomes frictional resistance and offsets the effective self-weight of the soil.

[0076] 3. The effective stress principle of seabed soil is used to calculate the self-weight offset of unit volume seepage force and generate a dynamic erosion resistance threshold sequence, constructing a bottom shear resistance model that evolves in real time with seepage intensity. This enables the characterization of the seabed's erosion resistance under extreme sensitive conditions such as semi-suspended or quasi-liquefied conditions. By capturing the near-bottom hydrodynamic shear value during the backflow stage and comparing the difference between the heterogeneous data and the dynamic erosion resistance threshold sequence, hidden erosion zones with low energy flow and high damage are identified. This helps to discover areas where external flow velocities do not reach conventional erosion thresholds but are substantially damaged due to significant weakening of internal resistance. This coupled analysis logic based on surplus characteristics reveals the nonlinear failure law under water-soil interaction, which helps to reduce the risk of missed assessments that may occur when relying solely on flow velocity indicators for disaster judgment, and to locate the most vulnerable sources of hidden erosion in submerged dike foundations.

[0077] 4. For the shear surplus strength in the concealed scour zone, integral calculations of sediment transport rates are performed, and graded collapse early warnings are triggered based on morphological loss characteristics, transforming instantaneous stress imbalance analysis into cumulative geometric deformation assessment. By calculating the suspension ratio of the maximum scour depth at the toe of the submerged dike to the pre-buried depth, differentiated emergency responses for different risk levels are achieved. Attached Figure Description

[0078] Figure 1 This is a functional module diagram of the early warning system for the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves, based on the present invention.

[0079] Figure 2 This is a flowchart for determining whether the driving force exceeds the weakened resistance in this invention. Detailed Implementation

[0080] The following is in conjunction with the appendix Figure 1-2 The technical solution of the present invention will be described in detail below.

[0081] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0082] Example 1:

[0083] like Figure 1 As shown, the early warning system for the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves includes the following modules:

[0084] Feature extraction module: used to collect water pressure data inside and outside the submerged dike and perform differential feature extraction to obtain the hysteresis response characteristics of water seepage; based on the hysteresis response characteristics, time-domain analysis of pressure difference evolution during the tsunami backflow stage is performed to obtain the high-energy potential difference time window dominated by internal high pressure.

[0085] The preferred method for collecting water pressure data inside and outside the submerged dike and extracting differential features to obtain the hysteresis response characteristics of water seepage is as follows:

[0086] The system's data acquisition unit acquires time-series pressure data of the free water surface outside the ecological submerged dike and time-series pressure data of the core of the internal pores, and timestamps the two sets of time-series pressure data.

[0087] It should be noted that the underlying environmental data relied upon by this system is acquired by data acquisition units deployed in the monitoring area. The data acquisition units include external water pressure sensors and internal pore water pressure sensors (or piezometers).

[0088] The external water pressure sensors are uniformly and equidistantly arranged on the seabed surface outside the ecological submerged dike or fixed on the water-facing structure of the dike, and are used to collect time-series pressure data of the free water surface outside the ecological submerged dike in real time; the internal pore water pressure sensors are uniformly and equidistantly embedded in the porous medium inside the ecological submerged dike or on the seabed below it, and have a specific vertical burial depth from the seabed surface, and are used to collect time-series pressure data at the core of the internal pores in real time.

[0089] Sliding window differentiation was performed on the two sets of time-aligned pressure data to calculate the instantaneous external water level drop rate and the instantaneous internal pore water pressure dissipation rate.

[0090] The external water level drop rate and the internal pore water pressure dissipation rate are subjected to directional differential processing to obtain the internal and external rate difference.

[0091] The method for directional differential processing is as follows: compare the external water level drop rate and the internal pore water pressure dissipation rate at each time point, retain only data point pairs where the external drop rate is greater than the internal dissipation rate, and set the data point pairs where the external drop rate is less than or equal to the internal dissipation rate to zero, using the formula: Obtain the difference between internal and external rates ;

[0092] It should be noted that, That is, the rate of decline of the external water level. That is, the rate at which the internal pore water pressure dissipates;

[0093] The internal and external rate difference sequence after directional differential processing is established and smoothed by filtering. The resulting smooth sequence is the hysteresis response characteristic of water seepage.

[0094] Among them, based on the time-domain analysis of the pressure difference evolution during the tsunami backflow stage using the hysteresis response characteristics, the optimal method for the high-energy potential difference time window dominated by internal high pressure is as follows:

[0095] Set a dynamic trigger threshold that is correlated with the peak value of the tsunami wave height (e.g., take 0.1 times the peak pressure as a benchmark).

[0096] During the tsunami backflow phase, a dual-threshold envelope analysis was performed on the hysteresis response characteristics to obtain the high potential difference time window;

[0097] The method for performing dual-threshold envelope analysis is as follows:

[0098] S101. Identify the abrupt rising edge of the hysteresis response characteristic to obtain the non-equilibrium starting point:

[0099] The preferred method for identifying the abrupt rising edge of the hysteresis response characteristic is: the moment when the value of the hysteresis response characteristic first exceeds the dynamic trigger threshold for three consecutive sampling points is taken as the unbalanced starting point;

[0100] S102. By tracing the relaxation decay edge of the hysteresis response characteristics, the non-equilibrium termination point is obtained:

[0101] The preferred method for tracking the relaxation decay edge of the hysteresis response feature is: as the reflux process continues, when the value of the tracking hysteresis response feature drops from the peak and first falls below 50% of the dynamic trigger threshold, it is locked as the non-equilibrium termination point.

[0102] Using the non-equilibrium starting point as the starting point and the non-equilibrium ending point as the ending point, the time span between the starting point and the ending point is extracted to establish a high-energy potential difference time window;

[0103] It should be noted that the time window is closed when the hysteresis response characteristics decay to the non-equilibrium termination point.

[0104] Understandably, the purpose of constructing an evolutionary sequence of asynchronous dissipation and defining time windows is to:

[0105] Function 1: Isolating physical disaster-causing mechanisms: By introducing sliding window differentiation and directional differential, a digital filter is constructed that only allows the residual signal of internal high pressure caused by the external water level drop to pass through, thereby eliminating false signals caused by conventional waves or sensor jitter.

[0106] Function 2: Defining the effective domain of calculus operations: The time window determined by double threshold envelope analysis delineates the work interval from the perspective of energy dissipation.

[0107] Potential Energy Analysis Module: Used to retrieve water pressure data within a high potential difference time window and perform differential analysis of the vertical gradient to obtain the vertical hydraulic conduction characteristics inside the seabed; based on the vertical hydraulic conduction characteristics, analyze the stress state of sediments and generate the permeability per unit volume of the seabed surface.

[0108] The preferred method for obtaining the vertical hydraulic conduction characteristics within the seabed by retrieving water pressure data within a high potential difference time window and performing differential analytical processing of the vertical gradient is as follows:

[0109] Based on the determined start and end time nodes of the high-energy potential difference time window, the temporal pressure data of the external free water surface and the internal pore core of the ecological submerged dike within the corresponding time period of the high-energy potential difference time window are indexed and extracted from the memory to obtain the pressure sequence of the external free water surface and the pressure sequence of the internal pore water.

[0110] The vertical burial depth distance of the internal pore water pressure sensor relative to the seabed surface, obtained from a pre-measured measurement, is used as the path length for vertical seepage.

[0111] The two extracted pressure sequences are processed point by point, that is, the internal pore water pressure at the same moment is subtracted from the external free water surface pressure to obtain the instantaneous vertical pressure difference, and the instantaneous vertical pressure difference is divided by the path length of vertical seepage to obtain the vertical pressure gradient inside the seabed.

[0112] Using the vertical pressure gradient as the transmission characteristic of vertical hydraulic forces within the seabed, a transmission characteristic sequence containing N data points is constructed (preferably, N=500).

[0113] It should be noted that the vertical hydraulic transmission characteristics are physically represented as the vertical hydraulic gradient, which reflects the head loss rate per unit vertical distance. The vertical hydraulic transmission characteristics are the direct power source that drives pore water to overcome frictional resistance and flow upward.

[0114] Among them, the method for generating the permeability per unit volume of the seabed surface layer by analyzing the stress state of sediments based on vertical hydraulic conduction characteristics is as follows:

[0115] Since the dimension of the vertical pressure gradient is the force per unit volume, for each data point in the conduction characteristic sequence, the value in the conduction characteristic sequence is directly equivalent to the vertical upward seepage hydrodynamic pressure on a unit volume of seabed soil.

[0116] Isohydrodynamic pressure is defined as the osmotic force per unit volume.

[0117] The solution lies in the fact that performing differential inversion of the vertical gradient and generating permeability per unit volume serves the purpose of:

[0118] Function 1: To realize the dimensional transformation from scalar field to vector field: that is, the original pressure data is only a scalar without direction. Through differential inversion processing (divided by vertical distance), it is transformed into a vector field with a clear vertical upward attack direction (hydraulic conduction characteristics), so that it can directly participate in subsequent mechanical synthesis calculations.

[0119] Function 2: Constructing the dynamic precursors for soil instability: During the tsunami backflow period, the seabed is not directly pushed away by the water flow, but is first lifted to a suspended or semi-suspended state by the unit volume permeability force. This generates unit volume permeability force, quantifying the degree to which the seabed soil becomes lighter.

[0120] Erosion Analysis Module: Used to calculate the self-weight offset of the permeability per unit volume to obtain the reduction coefficient of the effective stress of the sediment; based on the reduction coefficient, the static critical starting shear stress is corrected to establish a time-varying erosion resistance threshold sequence.

[0121] The preferred method for calculating the reduction coefficient of effective stress in sediments by offsetting the unit volume permeability with its own weight is as follows:

[0122] The saturated unit weight parameters of seabed sediments at the corresponding burial depth of the internal pore water pressure sensor are obtained, and the effective self-weight of the seabed soil in a still water environment is calculated and defined as buoyancy unit weight.

[0123] Obtain the depth of the buoyancy unit weight calculation point, and multiply the depth with the buoyancy unit weight to obtain the static effective stress.

[0124] Multiply the current unit volume permeability by the depth of the buoyancy calculation point to obtain the permeability uplift pressure;

[0125] The instantaneous effective stress is obtained by calculating the difference between the effective stress in still water and the pressure from seepage.

[0126] Read the historical monitoring logs of tsunami waves and extract the average initial effective stress in still water conditions from the historical monitoring data.

[0127] The effective stress at calculation points within a preset time window under still water conditions is averaged to obtain the initial mean effective stress:

[0128]

[0129] in, The initial mean effective stress, Let N be the effective stress under still water conditions at time i, and N be the total number of samples within the preset time window;

[0130] The ratio of instantaneous effective stress to the average initial effective stress is calculated to obtain the loss coefficient;

[0131] It should be noted that the value range of the loss coefficient is [0,1]. When the loss coefficient approaches 0, the surface uplift seepage force offsets the effective gravity of the soil skeleton, and the seabed surface tends to be in a critical state of suspension or quasi-liquefaction with the loss of effective stress.

[0132] Among them, the preferred method for establishing the time-evolving erosion resistance threshold sequence by correcting the static critical initiation shear stress based on the loss coefficient is as follows:

[0133] The static critical initiation shear stress of the sea area under seepage-free environmental conditions is obtained based on the Shields curve;

[0134] A functional relationship for dynamic attenuation mapping is established, and the static critical starting shear stress is input into the functional relationship to obtain the dynamic erosion resistance threshold.

[0135] The optimal functional relationship for dynamic decay mapping is: ;

[0136] in, This represents the dynamic erosion resistance threshold at the current time t. The static critical starting shear stress. The loss coefficient at the current time t;

[0137] It should be noted that the mapping relationship indicates that the seabed's ability to resist shear failure decreases linearly or quasi-linearly when the effective stress decreases;

[0138] Obtain the dynamic anti-erosion threshold at M time points and establish an anti-erosion threshold sequence (preferably, M=500).

[0139] Concealed scour identification module: used to collect near-bottom fluid horizontal velocity data during the tsunami backflow phase and convert it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed. The instantaneous bottom shear stress sequence is compared with the heterogeneous data difference of the erosion resistance threshold sequence to obtain the surplus characteristics of shear strength. Based on the surplus characteristics, low-velocity concealed scour analysis is performed to identify low-energy flow-high-damage concealed scour zones.

[0140] The preferred method for capturing near-bottom fluid horizontal velocity data during the backflow phase and converting it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed, and then comparing the difference between the instantaneous bottom shear stress sequence and the erosion resistance threshold sequence to obtain the surplus characteristics of shear strength, is as follows:

[0141] The data acquisition unit also includes flow velocity monitoring hardware, which can be an acoustic Doppler current profiler (ADCP) or a high-frequency point current meter. By uniformly and equidistantly installing the flow velocity monitoring hardware at the toe of the ecological submerged dike, the near-bottom fluid horizontal flow velocity data generated by the tsunami backflow can be obtained.

[0142] The near-bottom fluid horizontal velocity data is converted into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed using the second friction law. The values ​​in the instantaneous bottom shear stress sequence are the hydrodynamic shear values ​​at the corresponding moments.

[0143] It should be noted that the specific conversion method follows the following fluid dynamics formula:

[0144]

[0145] in, For instantaneous bed shear stress, The density of seawater, This is the coefficient of friction of the seabed surface (e.g., the Jonsson wave friction coefficient). This represents the measured horizontal velocity of the fluid near the bottom.

[0146] It should be noted that the friction coefficient is converted into an equivalent Niculaz roughness (usually 2.5 times the median grain size) by measuring the median grain size of seabed sediments. Next, the motion amplitude of near-bottom water particles is calculated based on measured flow velocity data. The relative roughness (i.e., the ratio of roughness to motion amplitude) is then substituted into a standard wave friction coefficient lookup chart for indexing, thereby retrieving the corresponding friction coefficient value under the current flow condition. The friction coefficient is set to a range of 0.005 to 0.03, with a preferred value of 0.01, which represents the average resistance level of a typical medium-roughness seabed.

[0147] A one-to-one correspondence was established between the instantaneous bed shear stress sequence and the erosion resistance threshold sequence at specific time points.

[0148] The difference between the instantaneous substrate shear stress sequence and the erosion resistance threshold sequence at each time point is calculated to obtain the surplus strength difference.

[0149] like Figure 2 As shown, the driving force is analyzed based on the difference in surplus strength to determine whether the driving force exceeds the weakened resistance.

[0150] If the surplus strength difference is positive, the surplus strength difference is retained and defined as the surplus characteristic of shear strength, that is, it is determined that the driving force exceeds the weakened resistance.

[0151] Conversely, if the difference in surplus intensity is not positive, it is determined that the corresponding time point indicates that no sediment initiation has occurred;

[0152] It should be noted that each data point in the instantaneous subsurface shear stress sequence represents the external hydrodynamic load, while the erosion resistance threshold sequence represents the internal soil and rock resistance, representing two different data sources with different physical properties. The comparison logic of the surplus strength difference is to determine whether the driving force exceeds the significantly weakened resistance.

[0153] Among them, the preferred method for identifying the low-energy-flow-high-damage hidden scour zone by conducting hidden scour analysis based on surplus characteristics is as follows:

[0154] Set a normal flow velocity scour threshold, which is the shear stress corresponding to the minimum flow velocity required to cause scour under normal conditions, without considering seepage.

[0155] For typical silty sandy seabeds, the scour threshold value of conventional flow velocity is usually between 0.15 Pa and 0.4 Pa (corresponding to a flow velocity of about 0.3 m / s to 0.5 m / s).

[0156] Data segments that satisfy both the instantaneous subsoil shear stress sequence and the erosion resistance threshold sequence are selected:

[0157] Screening criterion 1: The instantaneous bed shear stress is less than the scouring threshold of the conventional flow velocity (i.e., the flow velocity from the conventional perspective is very low and not enough to cause a disaster).

[0158] Screening criterion two: There is a surplus of shear strength, that is, failure has actually occurred;

[0159] The spatial location corresponding to the data segment that meets the above dual screening conditions is marked as the hidden scour zone.

[0160] Understandably, the purpose of identifying hidden scour zones is:

[0161] Function 1: Correcting cognitive biases based on traditional experience: During the tsunami backflow period, the seabed is extremely vulnerable due to the uplifting seepage force, and even very low backflow velocities can carry away large amounts of sediment. Identifying low-energy flow – high-damage areas can effectively prevent missed reports due to low flow velocities;

[0162] Function 2: Locating key defense targets for monitoring: Hidden scour zones are often the starting point for the hollowing out of the foundation of submerged dikes. This non-intuitive source of danger can be captured through coupled analysis.

[0163] The graded early warning module is used to quantify and accumulate the sediment transport rate by the surplus characteristics of shear strength in the hidden scour zone, and obtain the morphological missing characteristics of the submerged dike toe; based on the morphological missing characteristics, the stability of the submerged dike support structure is deduced and evaluated and graded collapse early warning is set.

[0164] Among them, the preferred method for quantifying and accumulating the sediment transport rate of the shear surplus intensity in the concealed scour zone to obtain the morphological missing characteristics of the submerged dike toe is as follows:

[0165] A sediment transport rate model was established, using the surplus characteristics of shear strength as the independent variable, to calculate the instantaneous sediment transport rate per unit width:

[0166] An exemplary approach to establishing a sediment transport model is to use a modified empirical formula for sediment transport rate: ;

[0167] in, The instantaneous unit width sediment transport rate, For time, The sediment coefficient is related to sediment particle size and settling velocity. This refers to the surplus characteristic of shear strength (i.e., surplus strength difference). The transport index (usually between 1.5 and 3.0, preferably 2.5);

[0168] It should be noted that the sediment coefficient is based on the physical property analysis of seabed sediment samples and calibrated using laboratory flume simulation experiments. The sediment coefficient is an empirical coefficient in terms of content dimensions, and its dimensions are compatible with the transport index m, ensuring consistency of physical dimensions on both sides of the equation. The sediment coefficient reflects the volume of sediment that can be driven by a unit shear surplus. For coarser, denser particles, the coefficient value is smaller, meaning a greater shear force from the water flow is required to produce the same amount of sediment transport; conversely, for fine-grained silt, the coefficient value is larger. For fine sand seabeds with a median particle size between 0.1 mm and 0.5 mm, the sediment coefficient is taken as 0.05.

[0169] A time window for backflow scouring is constructed, which is the time interval from the start of the tsunami wave at the maximum backflow water level to the decay of the backflow velocity to below a preset threshold. The instantaneous unit width sediment transport rate is calculated by definite integral to obtain the total volume of sediment loss.

[0170] The total volume of sediment loss is converted into the change in seabed elevation, i.e. the maximum scour depth at the toe of the submerged breakwater, as a feature of morphological loss.

[0171] The optimal method for converting the total volume of sediment loss into changes in seabed elevation is: using the formula... Perform calculations;

[0172] in The feature is the absence of morphological characteristics (maximum drawing depth). This represents the total volume of sediment loss. To conceal the area of ​​erosion. Porosity of seabed soil;

[0173] It should be noted that integral calculus is an accumulation process that takes into account the instantaneous intensity of destruction and the duration of destruction, reflecting the final physical change in seabed morphology.

[0174] Among them, the preferred method for extrapolating and evaluating the stability of submerged dike support structures based on morphological missing characteristics and setting graded collapse early warning is:

[0175] Obtain the pre-buried depth parameters of the ecological submerged dike foundation structure and the ultimate overturning moment of the dike itself;

[0176] The ratio of the maximum drilling depth to the pre-embedded depth, which is the missing feature of the calculation shape, is defined as the suspension ratio;

[0177] Based on the numerical range of the suspending ratio, execute the tiered early warning logic:

[0178] When the suspended ratio is less than 30%, it is judged as slight erosion, triggering a blue observation warning;

[0179] When the overhang ratio is between 30% and 60%, the passive earth pressure of the seabed soil surrounding the submerged breakwater foundation structure that provides overturning restraint is recalculated. Based on the recalculated passive earth pressure and the ultimate overturning moment of the submerged breakwater itself, the remaining overturning moment of the breakwater foundation structure is calculated. Combined with the overturning moment under the tsunami backflow load, the overturning safety factor is calculated.

[0180]

[0181] in, To ensure overturning safety factor, For the remaining anti-overturning moment, The overturning moment under the action of tsunami backflow load;

[0182] If the overturning safety factor decreases by more than 20%, a yellow structural risk warning is triggered; otherwise, a blue observation warning is triggered.

[0183] When the suspended ratio is greater than 60%, it is determined that the toe of the submerged dike has lost its anchoring ability and there is an immediate risk of collapse, triggering a red emergency evacuation warning.

[0184] It is understandable that the purpose of performing integral calculations and stability deductions is:

[0185] Function 1: Achieving a quantitative leap from micromechanics to macroscopic deformation: Transforming abstract stress data (shear surplus) into intuitive geometric data (drawing depth, overhang ratio), directly connecting with engineering maintenance indicators;

[0186] Function 2: Establishing a dynamic early warning closed loop based on physical mechanisms: Instead of relying solely on single indicators such as wave height or flow velocity, it provides accurate early warning decision support that conforms to the tsunami disaster mechanism based on the complete chain of "seepage-weakening-scouring-suspension-instability".

[0187] Example 2:

[0188] Please see Figure 2 As shown, the early warning method based on the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves includes the following steps:

[0189] S1. Collect water pressure data inside and outside the submerged dike and extract differential features to obtain the hysteresis response characteristics of water seepage; based on the hysteresis response characteristics, perform time-domain analysis on the pressure difference evolution during the tsunami backflow stage to obtain the high-energy potential difference time window dominated by internal high pressure.

[0190] S2. Retrieve water pressure data within the high potential difference time window and perform differential analysis of the vertical gradient to obtain the vertical hydraulic conduction characteristics inside the seabed; analyze the stress state of sediments based on the vertical hydraulic conduction characteristics to generate the permeability per unit volume of the seabed surface.

[0191] S3. Perform self-weight offset calculation on the unit volume permeability to obtain the reduction coefficient of effective stress in sediments; based on the reduction coefficient, correct the static critical starting shear stress and establish a time-dependent erosion resistance threshold sequence.

[0192] S4. Collect near-bottom fluid horizontal velocity data during the tsunami backflow phase and convert it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed. Compare the difference between the instantaneous bottom shear stress sequence and the erosion resistance threshold sequence to obtain the surplus characteristics of shear strength. Based on the surplus characteristics, conduct hidden scour analysis at low flow velocities to identify the hidden scour zone with low energy flow and high damage.

[0193] S5. Quantify and accumulate the sediment transport rate of the surplus shear strength in the hidden scour zone to obtain the morphological missing characteristics of the submerged dike toe; based on the morphological missing characteristics, deduce and evaluate the stability of the submerged dike support structure and set graded collapse warnings.

[0194] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. An early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves, characterized in that, include: Feature extraction module: used to collect water pressure data inside and outside the submerged dike and perform differential feature extraction to obtain the hysteresis response characteristics of water seepage; Based on the hysteresis response characteristics, a time-domain analysis of the pressure difference evolution during the tsunami backflow stage was performed to obtain a high-energy potential difference time window dominated by internal high pressure. The water pressure data was acquired by data acquisition units deployed in the monitoring area, including time-series pressure data of the free water surface outside the ecological submerged dike and time-series pressure data of the internal pore core. Potential energy analysis module: used to retrieve water pressure data within a high potential difference time window and perform differential analysis of the vertical gradient to obtain the vertical hydraulic conduction characteristics inside the seabed. The permeability per unit volume of the seabed surface is generated based on the characteristics of vertical hydraulic conduction. Erosion Analysis Module: Used to calculate the self-weight offset of the permeability per unit volume and obtain the reduction coefficient of the effective stress of the sediment; Based on the loss coefficient, the static critical starting shear stress is corrected, and a time-dependent erosion resistance threshold sequence is established. The concealed scour identification module is used to collect near-bottom fluid horizontal velocity data during the tsunami backflow phase and convert it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed. The instantaneous bottom shear stress sequence is compared with the difference of heterogeneous data to obtain the surplus characteristics of shear strength. Based on the surplus characteristics, low-velocity concealed scour analysis is performed to identify low-energy flow-high-damage concealed scour zones. The near-bottom fluid horizontal velocity data is acquired by data acquisition units deployed in the monitoring area.

2. The early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 1, characterized in that, The data acquisition unit includes an external water pressure sensor, an internal pore water pressure sensor, and a flow meter; The external water pressure sensors are evenly and equidistantly distributed on the seabed surface outside the ecological submerged dike or fixed on the water-facing structure of the dike, and are used to collect time-series pressure data of the free water surface outside the ecological submerged dike in real time. The internal pore water pressure sensor is uniformly and equidistantly embedded in the porous medium inside the ecological submerged dike or below the seabed, and has a preset vertical burial depth from the seabed surface, for real-time acquisition of time-series pressure data at the core of the internal pores. The flowmeters are evenly and equidistantly installed at the toe of the ecological submerged dike to acquire near-bottom fluid horizontal velocity data generated by tsunami backflow.

3. The early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 1, characterized in that, The hysteresis response characteristics of the water seepage were obtained as follows: The time-series pressure data of the external free water surface and the internal pore core of the ecological submerged dike were time-stamped and aligned. Sliding window differential operations were performed on the two sets of time-aligned pressure data to obtain the external water level drop rate and the internal pore water pressure dissipation rate. Directional differential processing is performed between the external water level drop rate and the internal pore water pressure dissipation rate: the external water level drop rate and the internal pore water pressure dissipation rate are compared at each time point, and only data point pairs with an external water level drop rate greater than the internal pore water pressure dissipation rate are retained. Data point pairs with an external drop rate less than or equal to the internal dissipation rate are set to zero. The difference between the internal and external rates is calculated based on the external water level drop rate and the internal pore water pressure dissipation rate at each time point after directional differential processing. Obtain the internal and external rate difference sequence: in, and These represent the rate of decrease in external water level and the rate of dissipation of internal pore water pressure at the same time point; Smoothing filters are applied to the internal and external rate difference sequences, and the resulting smooth sequence represents the hysteresis response characteristics of water seepage.

4. The early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 1, characterized in that, The high-energy potential difference time window dominated by the internal high pressure is obtained in the following specific way: During the tsunami backflow phase, a dual-threshold envelope analysis is performed on the hysteresis response characteristics: the abrupt rising edge of the hysteresis response characteristics is identified based on the first preset threshold to obtain the non-equilibrium starting point; the relaxation decay edge of the hysteresis response characteristics is tracked based on the second preset threshold to obtain the non-equilibrium ending point. Using the non-equilibrium starting point as the starting point and the non-equilibrium ending point as the ending point, the time span between the starting point and the ending point is extracted to establish a high-energy potential difference time window.

5. The early warning system for the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 2, characterized in that, The potential energy analysis module specifically performs the following steps: The temporal pressure data of the external free water surface and the internal pore core of the ecological submerged dike within the time period corresponding to the high potential difference time window are extracted to obtain the external free water surface pressure sequence and the internal pore water pressure sequence. The vertical burial depth of the internal pore water pressure sensor relative to the seabed surface is used as the path length of vertical seepage. The two extracted pressure sequences were calculated point by point based on the path length of the vertical seepage: the internal pore water pressure at the same moment was subtracted from the external free water surface pressure to obtain the instantaneous vertical pressure difference; and the instantaneous vertical pressure difference was divided by the path length of the vertical seepage to obtain the vertical pressure gradient inside the seabed. The vertical pressure gradient is used as the characteristic of vertical hydraulic conduction within the seabed and is equivalent to the permeability per unit volume of the seabed surface.

6. The early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 2, characterized in that, The erosion analysis module specifically performs the following steps: The saturated unit weight parameters of seabed sediments at the corresponding burial depth of the internal pore water pressure sensor are obtained, and the effective self-weight of the seabed soil in a still water environment is calculated and defined as buoyancy unit weight. Obtain the depth of the buoyancy unit weight calculation point, and multiply the depth with the buoyancy unit weight to obtain the static effective stress. Multiply the current unit volume permeability by the depth of the buoyancy calculation point to obtain the permeability uplift pressure; The instantaneous effective stress is obtained by calculating the difference between the effective stress in still water and the pressure from seepage. Read the average initial effective stress in still water conditions from historical monitoring data of tsunami waves; The ratio of instantaneous effective stress to the average initial effective stress is calculated to obtain the loss coefficient; The static critical initiation shear stress of the sea area under seepage-free environmental conditions is obtained, and the static critical initiation shear stress is input into the function relationship of dynamic attenuation mapping to obtain the dynamic erosion resistance threshold: in, For the current moment The dynamic erosion resistance threshold, The static critical starting shear stress. For the current moment The loss coefficient; Obtain the dynamic anti-erosion threshold at M time points and establish an anti-erosion threshold sequence.

7. The early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 2, characterized in that, The stealth detection module specifically performs the following steps: Establishing an instantaneous seabed shear stress sequence: Using the second law of friction, the near-bottom fluid horizontal velocity data is converted into an instantaneous seabed shear stress sequence exerted by the fluid on the seabed. The values ​​in the instantaneous seabed shear stress sequence are the hydrodynamic shear values ​​at the corresponding moments. in, For instantaneous bed shear stress, The density of seawater, Let be the coefficient of friction of the seabed surface. This represents the measured horizontal velocity of the fluid near the bottom. The difference between the instantaneous substrate shear stress sequence and the erosion resistance threshold sequence at each time point is calculated to obtain the surplus strength difference; if the surplus strength difference is positive, the surplus strength difference is retained and defined as the surplus characteristic of shear strength. Set dual screening conditions: (1) the instantaneous bed shear stress is less than the preset conventional flow velocity scouring threshold, and (2) there is a surplus characteristic of shear strength. Based on the instantaneous bed shear stress sequence and the erosion resistance threshold sequence, data segments that simultaneously meet the dual screening conditions are selected, and the corresponding spatial locations of the data segments that meet the dual screening conditions are obtained to establish the hidden scour zone.

8. The early warning system based on the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 1, characterized in that, It also includes a graded early warning module: used to quantify and accumulate the sediment transport rate of the surplus characteristics of shear strength in the hidden scour zone, and obtain the morphological missing characteristics of the toe of the submerged dike. Based on the morphological missing characteristics, the stability of the submerged dike support structure is simulated and evaluated, and graded collapse early warning is set.

9. The early warning system for the impact of ecological submerged dikes on nearshore seabed morphology under tsunami wave action as described in claim 8, characterized in that, The tiered early warning module specifically performs the following steps: Using the surplus characteristics of shear strength as the independent variable and the instantaneous unit width sediment transport rate as the dependent variable, a sediment transport rate model is established to calculate the instantaneous unit width sediment transport rate. A backflow scouring time window is constructed, which is the time interval from the start of the tsunami wave at the maximum backflow water level to the decay of the backflow velocity to below a preset threshold. The instantaneous unit width sediment transport rate is integrated to obtain the total volume of sediment loss. The total volume of sediment loss is converted into the change in seabed elevation, i.e., the maximum scour depth at the toe of the submerged breakwater, as a feature of morphological loss: in This is a feature of missing morphology. This represents the total volume of sediment loss. To conceal the area of ​​erosion. Porosity of seabed soil; To obtain the pre-embedded depth of the ecological submerged dike foundation structure and the ultimate overturning moment of the dike itself; The ratio of the missing morphological features to the pre-embedded depth is used as the suspension ratio; Based on the numerical range of the suspending ratio, execute the tiered early warning logic: When the suspension ratio is less than the first threshold, it is judged as slight erosion and a blue observation warning is triggered; When the suspension ratio is between the first and second thresholds, the passive earth pressure of the seabed soil surrounding the submerged breakwater foundation structure that participates in providing overturning restraint is recalculated. Based on the recalculated passive earth pressure and the ultimate overturning moment of the submerged breakwater itself, the remaining overturning moment of the breakwater foundation structure is calculated. Combined with the overturning moment under the tsunami backflow load, the overturning safety factor is calculated. in, To ensure overturning safety factor, For the remaining anti-overturning moment, The overturning moment under the action of tsunami backflow load; If the overturning safety factor decreases but does not exceed the preset threshold, a blue observation warning is triggered; if the overturning safety factor decreases but exceeds the preset threshold, a yellow structural risk warning is triggered; wherein, the first threshold is less than the second threshold. When the suspended ratio is greater than the second threshold, it is determined that the toe of the submerged dike has lost its anchoring ability and there is an immediate risk of collapse, triggering a red emergency evacuation warning.

10. An early warning method based on the impact of ecological submerged dikes on nearshore seabed morphology under the action of tsunami waves, characterized in that, The early warning method is implemented using an early warning system as described in any one of claims 1-9, and includes the following steps: S1. Collect water pressure data inside and outside the submerged dike and extract differential features to obtain the hysteresis response characteristics of water seepage; perform time-domain analysis on the pressure difference evolution during the tsunami backflow stage based on the hysteresis response characteristics to obtain the high-energy potential difference time window dominated by internal high pressure; the water pressure data includes time-series pressure data of the free water surface outside the ecological submerged dike and time-series pressure data of the internal pore core. S2. Retrieve instantaneous water level data within the high potential difference time window and perform differential analysis of the vertical gradient to obtain the vertical hydraulic conduction characteristics inside the seabed. The permeability per unit volume of the seabed surface is generated based on the characteristics of vertical hydraulic conduction. S3. Perform self-weight offset calculation on the unit volume permeability to obtain the reduction coefficient of effective stress in sediments; based on the reduction coefficient, correct the static critical starting shear stress and establish a time-dependent erosion resistance threshold sequence. S4. Collect near-bottom fluid horizontal velocity data during the tsunami backflow phase and convert it into an instantaneous bottom shear stress sequence exerted by the fluid on the seabed. Compare the difference between the instantaneous bottom shear stress sequence and the erosion resistance threshold sequence to obtain the surplus characteristics of shear strength. Based on the surplus characteristics, conduct hidden scour analysis at low flow velocities to identify the hidden scour zone with low energy flow and high damage. S5. Quantify and accumulate the sediment transport rate of the surplus characteristics of shear strength in the hidden scour zone to obtain the morphological missing characteristics of the toe of the submerged dike. Based on the morphological missing characteristics, the stability of the submerged dike support structure is simulated and evaluated, and graded collapse early warning is set.

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