Risk assessment method and system based on port and shipping engineering seabed erosion and deposition monitoring

Abstract

The application discloses a risk assessment method and system based on seabed scouring and silting monitoring of port and shipping engineering, and the method comprises the following steps: preprocessing scouring and silting monitoring data before and after scouring and silting, generating a target area DEM grid map, analyzing and calculating the height difference of each pixel, and generating a scouring and silting change map; a risk assessment model is built, various risk coefficients are calculated for each pixel, and different display colors are used for representation; the system comprises a seabed topography processing module, a scouring and silting space-time analysis module, a port risk assessment module and a result mapping module; the risk assessment comprises port hydraulic structure erosion risk assessment and channel silting risk assessment; the assessment method and system utilize seabed scouring and silting monitoring data to count seabed scouring and silting change data and generate a scouring and silting change grade map, so that the scouring and silting change can be intuitively understood and analyzed; the risk coefficient is output through the assessment model, and different color risk grade maps are used for representation, so that the result can be intuitively presented, risks can be found in time, the pertinence of safety measures can be improved, and the maintenance and operation cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of marine risk assessment, and in particular to a risk assessment method and system based on seabed scouring and silting monitoring of port and navigation projects. Background Art

[0002] Affected by factors such as waves, tides, and river estuaries, port waters often experience siltation and erosion, which can lead to damage to terminal facilities, channel siltation, and changes in port water depth. Seabed erosion and erosion monitoring uses sonar technology to capture subtle changes in seabed topography with high precision and density in real time, allowing for a timely understanding of the real-time topography and landforms of the seabed. Seabed erosion and erosion monitoring technology is mature and widely used. By understanding changes in seabed topography, it can promptly identify potential siltation areas, prevent ship groundings and collisions, and ensure shipping safety.

[0003] The application of submarine scouring and silting monitoring technology is still insufficient. Although real-time monitoring data can provide certain safety warnings, there is still insufficient research on the assessment of related risks based on the dynamic changes of submarine scouring and silting, such as the risk of erosion of hydraulic structures related to scouring and silting or the risk of tunnel clogging caused by scouring and silting. The application of scouring and silting monitoring data is single, and it is impossible to proactively understand the potential risks associated with submarine scouring and silting and the distribution of risks, which is not conducive to the preemptive and accurate implementation of relevant prevention and control measures.

[0004] In view of this, this method provides a risk assessment method and system based on seabed scouring and silting monitoring of port and navigation projects. The relevant risks are assessed according to the dynamic changes of scouring and silting, and the risk results are displayed in combination with the seabed topography to facilitate intuitive risk distribution. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a risk assessment method and system based on seabed scouring and silting monitoring of port and navigation engineering to solve the problems raised in the above background technology.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering includes the following steps:

[0008] S1: Data preprocessing: Preprocess the scouring and silting monitoring data before and after the scouring and silting to generate a DEM raster map of the target area, analyze and calculate the height difference of each pixel, and generate a scouring and silting change map;

[0009] S2: Conduct risk assessment; build a risk assessment model, calculate the risk coefficient for each pixel according to the erosion and siltation change map, and represent different risk coefficients through different display colors; risk assessment includes erosion risk assessment of port hydraulic structures and waterway siltation risk assessment, among which,

[0010] The method for erosion risk assessment of hydraulic structures includes: first, importing the shoreline vector data of the hydraulic structure and segmenting it into equidistant segments to generate a number of shoreline units; then, obtaining the erosion grade score corresponding to the erosion and deposition change value of each pixel; finally, introducing the erosion grade score into the erosion risk assessment model and calculating the erosion risk coefficient of each shoreline unit;

[0011] The erosion risk assessment model is:

[0012] Where, is the erosion risk coefficient of the shoreline unit, Indicates the vulnerability value of the hydraulic structure itself, is the scour grade score of each pixel, is the Euclidean distance from the pixel to the midpoint of the shoreline unit, is the regulating factor;

[0013] The method for assessing the risk of waterway siltation includes obtaining the siltation status score corresponding to the water depth point data of each pixel after scouring and silting, as well as the siltation trend score corresponding to the scouring and silting change value of each pixel, assigning weights, and calculating the waterway siltation risk coefficient for each pixel:

[0014] The waterway siltation risk assessment model is:

[0015] Where: is the channel siltation risk coefficient of the pixel, is the pixel's sedimentation status score, is the sedimentation trend score, and are weight factors, and + =1.

[0016] Furthermore, the preprocessing steps of the erosion and siltation monitoring data are as follows:

[0017] A1: Import the water depth point data from the two periods of scouring and silting monitoring results into the TIN tool, use the elevation field of the water depth point data as the height attribute, and create a Delaunay irregular triangulated mesh;

[0018] A2: Use the TIN to Raster tool to sample the triangular grid and output the seabed DEM raster of the two ports. The natural domain method is used for sampling and interpolation.

[0019] A3. Import the surface boundary vector data and clip the seabed DEM grid to obtain the DEM grids of the two target areas that meet the requirements.

[0020] Furthermore, the risk assessment also includes the evaluation of the navigation efficiency of the waterway: first, the tide levels in fixed time periods are statistically analyzed, and a conditional function is established to normalize the navigation effectiveness in each time period;

[0021] Conditional Function

[0022] in, is the effective navigation value of pixel j at time point r, is the tide level at time r, is the seabed elevation of the pixel after scouring and silting, is the maximum draft of the ship;

[0023] Then, the mean method is used to calculate the navigation efficiency of the pixel in a fixed time period. ;

[0024]

[0025] Furthermore, by graded coloring, the scouring and silting change amounts of the scouring and silting change map are divided into multiple ranges, and different colors are set to represent the height difference ranges to generate a visual scouring and silting change graded map.

[0026] Furthermore, the scour grade score ∈ The negative value of the scour change value represents the scour change value, the positive value represents the sedimentation change value, and 0 represents no scour or sedimentation change. The scour limit value is set, and the scour change value range [scour limit value, 0] is divided into several level ranges. When the scour change value is equal to or less than the scour limit value, the score is 1, and when the scour change value is equal to or greater than 0, the score is 0. Therefore, according to the corresponding relationship, the scour change value of each pixel is scored through the piecewise linear simulation function.

[0027] Furthermore, the sedimentation status score ∈ , sedimentation trend score ∈ , set the positive limit of sedimentation, divide the sedimentation change value range [0, positive limit of sedimentation] into several level ranges, when the sedimentation change value is less than or equal to 0, the sedimentation trend score When the sedimentation change value is equal to or greater than the sedimentation positive limit, the sedimentation trend score is 0. is 1, and according to the corresponding relationship, the sedimentation change value of each pixel is assigned a score through the piecewise linear simulation function;

[0028] Set the low and high values ​​of water depth, divide [low and high values ​​of water depth] into several level ranges, and assign the sedimentation status score when the water depth is less than or equal to the low value of water depth 1, when the water depth is greater than or equal to the high value of the water depth, the sedimentation status score is assigned is 0, and according to the corresponding relationship, the water depth point data of each pixel is assigned a siltation status score through a piecewise linear simulation function.

[0029] A risk assessment system includes a seabed terrain processing module, a scouring and silting spatiotemporal analysis module, a port risk assessment module and a result mapping module. The seabed terrain processing module includes a data import component, a grid division component, a raster conversion component and a clipping component. The data import component is used to import vector data, raster data and text data into the result mapping module. The grid division component is based on a TIN tool and is used to construct a Delaunay irregular triangulated grid. The raster conversion component is used to convert TIN data into standard seabed DEM raster data. The clipping component is used to clip TIN data or DEM raster data according to surface boundary vector data. The seabed terrain processing module inputs the DEM raster data of the target area into the scouring and silting spatiotemporal analysis module. The scouring and silting spatiotemporal analysis module includes a scouring and silting change analysis component. The scouring and silting change analysis component is used to count the scouring and silting change values ​​of the seabed and visually display them in the result mapping module. The port risk assessment module evaluates various risk values ​​based on the data from the scouring and silting spatiotemporal analysis module, and the result mapping module visually displays them.

[0030] Furthermore, the scouring and silting spatiotemporal analysis module also includes a scouring and silting intensity calculation component, a scouring and silting earthwork volume calculation component and a seabed three-dimensional centroid calculation component. The scouring and silting earthwork volume calculation component is used to calculate the volumetric data of scouring and silting, and the seabed three-dimensional centroid calculation component is used to calculate the three-dimensional centroid coordinates of the seabed before and after scouring and silting, as well as its planar displacement and direction.

[0031] Compared with the existing technology, the risk assessment method and system based on seabed scouring and silting monitoring of port and navigation engineering of the present invention have the following beneficial effects:

[0032] This assessment method utilizes long-term single-beam or multi-beam seabed erosion and sedimentation monitoring data, based on geographic information systems (GIS) and spatial analysis statistical methods, to comprehensively count seabed erosion and sedimentation change data and generate visual erosion and sedimentation change level maps, which facilitate intuitive understanding and analysis of the port's seabed topography erosion and sedimentation changes; at the same time, the erosion risk assessment model built based on erosion and sedimentation monitoring data can identify potential risks of hydraulic structures in advance, take preventive and repair measures, and protect the stability and integrity of hydraulic structure structures; the channel siltation risk assessment model built based on erosion and sedimentation monitoring data can assess and predict the potential risk of seabed siltation to port channel siltation, providing important data support for dredging projects; at the same time, the risk coefficient output by the assessment model is represented by setting risk level maps of different colors, and the results are presented intuitively, which is conducive to timely detection of risks and adjustment of maintenance and prevention strategies accordingly, improving the pertinence of safety measures, saving resource consumption, and reducing maintenance and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural diagram of the risk assessment system disclosed in the present invention;

[0034] Figure 2 This is an example diagram of the Delaunay irregular triangulated network of water depth points constructed based on erosion and deposition monitoring data;

[0035] Figure 3 for Figure 2 An example of a seafloor DEM grid obtained after the raster conversion operation. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only the best embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] The present invention provides a risk assessment method based on seabed scouring and silting monitoring of port and navigation projects, which is based on a geographic information system (GIS) and spatial analysis statistical methods. The method comprises the following steps:

[0039] S1: Preprocess the scouring and silting monitoring data before and after the scouring and silting to generate a DEM raster map of the target area, analyze and calculate the height difference of each pixel, and generate a scouring and silting change map;

[0040] S2: Build a risk assessment model, calculate the risk coefficient for each pixel, and represent different risk coefficients through different display colors; risk assessment includes port hydraulic structure erosion risk assessment and waterway siltation risk assessment.

[0041] In addition, the present invention also provides a risk assessment system based on seabed scouring and silting monitoring of port and navigation projects, such as Figure 1 As shown, it includes a seabed terrain processing module, a scouring and silting spatiotemporal analysis module, a port risk assessment module and a result mapping module.

[0042] Next, this embodiment combines the risk assessment system (such as Figure 1 Specific implementation methods of the risk assessment method based on seabed scouring and silting monitoring of port and navigation projects are described in detail as follows:

[0043] S1: Preprocess the seabed topography data obtained from erosion and deposition monitoring. The working steps are as follows:

[0044] A1. Import the water depth point vector data into the grid division component of the assessment system through the data import component. The data format is shp format. The grid division component is based on the TIN tool, which uses the elevation field in the water depth point vector data as the height attribute to create a Delaunay irregular triangulated network. For example, the triangulated network generation case of the water depth point is as follows: Figure 2 As shown;

[0045] A2. The raster conversion component is based on the TIN to raster tool. The triangulated network data is sampled and converted into a DEM raster by the raster conversion component. The sampling interpolation method is the natural neighbor method. The sampling grid size is 2 m × 2 m. The port seabed DEM raster is output. The seabed DEM raster generation example is as follows: Figure 3 As shown, the DEM raster data format is tif format, and the data value is floating point data;

[0046] A3. Use the data import tool to import the area boundary vector data into the clipping component. The clipping component clips the seabed DEM grid to obtain the target area DEM grid that meets the requirements. The target area DEM grid is then transferred to the erosion and deposition spatiotemporal analysis module.

[0047] A4. The Scour and Sedimentation Spatiotemporal Analysis Module's Scour and Sedimentation Change Map Generation tool uses statistics from the DEM rasters of the target area before and after the scour and sedimentation phases to generate a visual scour and sedimentation change map. This tool analyzes and calculates the height difference of each pixel. The scour and sedimentation change data is then graded using different colors to represent the height differences. The scour and sedimentation change graded map is then output in the Result Mapping Module as a floating-point raster map.

[0048] Assume that the range of scour and silt changes is divided into seven levels and colored accordingly: -5 m and below are colored blue, indicating severe scour; -1 to -5 m are colored light blue, indicating moderate scour; -1 to -0.1 m are colored green, indicating slight scour; -0.1 to 0.1 m are colored yellow, indicating no change; 0.1 to 1 m are colored orange, indicating slight siltation; 1 to 5 m are colored orange-red, indicating moderate siltation; and 5 m and above are colored red, indicating severe siltation.

[0049] S2. The port risk assessment module builds a risk assessment model to calculate and characterize the erosion risk coefficient. The specific content and steps include:

[0050] (1) The erosion risk assessment component assesses the risk of erosion damage to port hydraulic structures caused by seabed erosion, such as docks, dams, and breakwaters. The data import component is used to import the erosion and sedimentation change data and the shoreline vector data of the hydraulic structures into the erosion risk assessment component. The erosion risk assessment component performs equidistant segmentation processing on the shoreline vector data of the hydraulic structures to generate a number of shoreline units. The erosion risk assessment component retrieves the erosion grade score and assigns a score to the erosion and sedimentation change data of each pixel. The erosion risk assessment model is loaded and the erosion risk coefficient of each shoreline unit is calculated.

[0051] Specifically, the erosion risk assessment model is: ;

[0052] Where, is the erosion risk coefficient of the shoreline unit, Indicates the vulnerability value of the hydraulic structure itself, which is assigned based on experience and assessment. is the scour grade score of each pixel, ∈ , is the Euclidean distance from the pixel to the midpoint of the shoreline unit, is the adjustment factor, which takes 1 or 2, then is the weight value of each pixel;

[0053] Among them, negative values ​​in the scour and sedimentation change value represent scour change values, positive values ​​represent sedimentation change values, and 0 represents no scour or sedimentation change. The scour limit value is set based on experience or statistical data. The erosion risk assessment focuses on scour changes. Therefore, according to the piecewise linear simulation function, the scour change value range [scour limit value, 0] is mapped to the scour grade score. Scoring is done based on the above data: the flushing change value Divided into 7 levels, the scour change value hour Take 1, scour change value hour Take 0.8-1, scour change value hour Take 0.6-0.8, scour change value hour Take 0.4-0.6, scour change value hour Take 0.2-0.4, scour change value hour Take 0-0.2, erosion and siltation change value hour Take 0;

[0054] Run the erosion risk assessment model to obtain the erosion risk coefficient of each shoreline unit The erosion risk factor level map of hydraulic structures is output in the result mapping module through color differentiation and representation, which is convenient for identifying the potential risks and weak erosion locations of hydraulic structures, and is conducive to taking targeted prevention and repair measures to protect the stability and integrity of hydraulic structures.

[0055] (2) The siltation risk assessment component assesses the potential risk of seabed siltation to port and waterway siltation. Waterway siltation will reduce the water depth, making it easy for ships to run aground during passage, affecting the cargo loading and unloading and throughput capacity of the port. The waterway siltation risk assessment can provide important data support for dredging projects. The scouring and silting change map and the DEM raster of the target area after scouring and silting are imported into the siltation risk assessment component. The siltation risk assessment component retrieves the siltation trend score and assigns a score to the scouring and silting change data of each pixel. It also retrieves the siltation status score and assigns a score to the water depth data of each pixel. The siltation risk assessment model is loaded and the waterway siltation risk coefficient is calculated pixel by pixel:

[0056] The waterway siltation risk assessment model is:

[0057] Where: is the channel siltation risk coefficient of the pixel, is the pixel's sedimentation status score, ∈ , is the sedimentation trend score, ∈ , and are weight factors, and + =1, general Take 0.4, Take 0.6;

[0058] Among them, the sedimentation trend is based on the change trend of a certain period of history, such as one month or one year, to predict the future sedimentation changes. Similarly, the sedimentation positive limit is set, and the scouring and sedimentation change value range [0, sedimentation positive limit] is divided into several level ranges. For example, the scouring and sedimentation change value range is When the scouring and silting change value is less than or equal to 0, the sedimentation trend score When the scouring and silting change value is equal to or greater than 5, the sedimentation trend score is 0. =1, run the piecewise linear simulation function, and set the scouring and silting change range to and sedimentation trend score Perform linear correspondence assignment and assign sedimentation trend scores to the erosion and deposition change values ​​of each pixel ;

[0059] Similarly, set the low value and high value of water depth, and divide [low value, high value] into several level ranges. The low value of water depth indicates that the current situation is serious siltation. When the water depth is less than or equal to the low value of water depth, the siltation status score is assigned. 1, when the water depth is greater than or equal to the high value of the water depth, the sedimentation status score is assigned =0, run the piecewise linear simulation function, and compare the water depth change range [water depth low value, water depth high value] with the sedimentation status score Perform linear corresponding assignment and assign sedimentation status score to each pixel's water depth change ;

[0060] Calculate the channel siltation risk coefficient for each pixel The waterway siltation risk factor level map is output in the result mapping module through color differentiation and representation, which is convenient for identifying and predicting siltation risks, taking preventive measures in advance, or planning safe waterways.

[0061] (3) The Navigation Efficiency Assessment Component evaluates the daily or monthly navigability of port channels. Channel siltation may prevent ships from entering and leaving the port normally. Ships need to slow down or wait for high tide during navigation, which will extend the voyage and docking time, reduce shipping efficiency, and thus affect the operational efficiency of the entire supply chain. Navigation efficiency assessment can provide an important reference for the operation and maintenance management of port channels;

[0062] The DEM grid and tide level data of the target area after scouring and silting are loaded into the navigation efficiency evaluation model through the data import component to calculate the navigation efficiency of each pixel within a day or month. ;

[0063] First, statistics are collected on the tide levels within a day or month, and a conditional function is established to normalize the navigation effectiveness in each period.

[0064] Conditional Function

[0065] in, for The effective navigation value of the pixel at time point r, is the tide level at time x, is the seabed elevation of the pixel after scouring and silting, is the maximum draft of the ship;

[0066] Then, the navigation efficiency of each pixel within a day or month is calculated using the mean method. ;

[0067]

[0068] Calculate the navigation efficiency of each pixel within a day or month The navigation efficiency map is output in the result mapping module through color differentiation and representation, so as to manage the port channel.

[0069] In addition, the scouring and silting spatiotemporal analysis module also includes scouring and silting intensity calculation components, scouring and silting earthwork volume calculation components, and seabed three-dimensional centroid calculation components, providing more data support for waterway operation and maintenance management and risk prediction. Among them, the scouring and silting intensity analysis component is used to calculate the scouring and silting rate per unit time. It inputs the scouring and silting change map and the time parameters before and after scouring and silting, and calculates and outputs the scouring and silting rate per unit time for each pixel.

[0070] The scouring and silting volume calculation component can quickly calculate the volume of seabed sediment scouring and silting. The DEM rasters of the target area before and after scouring and silting are input, and the scouring volume, silting volume, and total scouring and silting volume are obtained through difference calculation and conditional statistical methods.

[0071]

[0072] Where: V represents the volume of erosion and siltation, is the seabed elevation of the pixel after scouring and silting, is the seabed mud surface elevation before scouring and silting, Indicates the pixel area; the overall erosion and deposition volume is calculated by accumulating and summing all pixels, and the deposition volume is calculated only for the elevation difference. The pixels with elevation difference greater than 0 are accumulated and summed, while the scour volume is only accumulated and summed for pixels with elevation difference less than 0. The absolute value of the summation result can be taken to obtain the scour volume. The calculation model of scour volume is realized by combining the conditional function to control the scour volume.

[0073] The Seabed 3D Centroid Calculation Component calculates the 3D centroid coordinates of the seabed before and after scouring and silting, and infers the plane displacement distance and direction of the 3D centroid, thereby reflecting the overall change trend of the seabed morphology. The DEM grid of the target area before and after scouring and silting is input, and the 3D centroid coordinates of the two periods are calculated based on the weighted average algorithm. The output data is a centroid point layer in shp format, as well as the plane coordinates, plane displacement distance and direction angle of the centroid point:

[0074]

[0075]

[0076]

[0077] Where, and are the easting and northing coordinates of the seafloor centroid, and Represent the easting and northing coordinates of any pixel, is the height difference weight, which is determined by the seabed elevation of the pixel and the lowest point elevation The height difference is determined, and after the plane coordinates of the seabed center of mass are calculated, the center of mass displacement is calculated using the Euclidean distance formula, and the displacement direction angle is calculated using the inverse tangent function.

[0078] Those skilled in the art will understand that all or part of the steps of the above-mentioned embodiment method can be implemented by instructing the relevant hardware through a software program, and the program can be applied to relevant devices and equipment and can be stored in a computer-readable storage medium.

[0079] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering, characterized by: The following steps are involved: S1: Data preprocessing: Preprocess the scouring and silting monitoring data before and after the scouring and silting to generate a DEM grid for the target area, analyze and calculate the height difference of each pixel, and generate a scouring and silting change map; S2: Conduct risk assessment; Building a risk assessment model, calculating the risk coefficient for each pixel according to the scouring and silting change map, and representing different risk coefficients by different display colors; The risk assessment includes the risk assessment of erosion of port hydraulic structures and the risk assessment of waterway siltation, among which: The method for erosion risk assessment of hydraulic structures includes: first, importing shoreline vector data of the hydraulic structure and performing equidistant segmentation processing on the shoreline vector data to generate a plurality of shoreline units; then, obtaining a scour grade score corresponding to the scour and deposition change value of each pixel; finally, introducing the scour grade score into the erosion risk assessment model and calculating the erosion risk coefficient of each shoreline unit; The erosion risk assessment model is: ; Where, is the erosion risk coefficient of the shoreline unit, represents the vulnerability value of the hydraulic structure itself, is the scour grade score of each pixel, is the Euclidean distance from the pixel to the midpoint of the shoreline unit, is the regulating factor; The method for assessing the risk of waterway siltation includes: obtaining the siltation status score corresponding to the water depth point data of each pixel after scouring and silting, and the siltation trend score corresponding to the scouring and silting change value of each pixel, assigning weights, and calculating the waterway siltation risk coefficient pixel by pixel using a waterway siltation risk assessment model: The waterway siltation risk assessment model is: ; Where: is the channel siltation risk coefficient of the pixel, is the sedimentation status score of the pixel, is the sedimentation trend score of the pixel, and are weight factors, and + =1.

2. The risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering according to claim 1 is characterized by: The preprocessing steps of the scouring and silting monitoring data are as follows: A1: Import the water depth point data from the two-phase scouring and silting monitoring results into the TIN tool, use the elevation field of the water depth point data as the height attribute, and create a Delaunay irregular triangulated mesh; A2: Use the TIN to Raster tool to sample the triangular grid and output the seabed DEM raster of the two ports. The natural field method is used for sampling and interpolation. A3. Importing the surface boundary vector data, clipping the seabed DEM grid, and obtaining the target area DEM grids of the two phases that meet the requirements.

3. The risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering according to claim 1 is characterized by: The risk assessment also includes an assessment of the navigation efficiency of the waterway: first, statistics are collected on the tide levels at fixed time periods, and a conditional function is established to normalize the navigation efficiency of each time period; The conditional function ; in, is the effective value of pixel j at time point x, is the tide level at time x, is the seabed elevation of pixel j after scouring and silting, is the maximum draft of the ship; Then, the mean method is used to calculate the navigation efficiency of the channel in the fixed time period. ; 。 4. The risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering according to claim 1 is characterized by: By grading colors, the scouring and silting change amount of the scouring and silting change map is divided into multiple ranges, and different colors are set to represent different height difference ranges to generate a visual scouring and silting change grading map.

5. The risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering according to claim 1 is characterized by: The scour grade score ∈ The negative value of the scour change value represents the scour change value, the positive value represents the siltation change value, and 0 represents no scour or siltation change. A scour limit value is set, and the scour change value range [scour limit value, 0] is divided into several level ranges. When the scour change value is equal to or less than the scour limit value, the score is 1, and when the scour change value is equal to or greater than 0, the score is 0. Therefore, according to the corresponding relationship, the scour change value of each pixel is scored through a piecewise linear simulation function.

6. The risk assessment method based on seabed scouring and silting monitoring of port and navigation engineering according to claim 5 is characterized by: The siltation status score ∈ , the sedimentation trend score ∈ , set the positive limit value of siltation, divide the siltation change value range [0, positive limit value of siltation] into several level ranges, when the siltation change value is less than or equal to 0, the siltation trend score When the sedimentation change value is equal to or greater than the sedimentation positive limit value, the sedimentation trend score is 0. is 1, and according to the corresponding relationship, the sedimentation change value of each pixel is assigned a score through a piecewise linear simulation function; Set the low and high values ​​of water depth, divide [low and high values ​​of water depth] into several level ranges, and assign the sedimentation status score when the water depth of the pixel is less than or equal to the low value of water depth 1, the assigned sedimentation status score when the water depth is greater than or equal to the high water depth value is 0, and according to the corresponding relationship, the water depth point data of each pixel is assigned the siltation status score through a piecewise linear simulation function.

7. A risk assessment system, characterized in that: It includes a seabed terrain processing module, a scouring and silting spatiotemporal analysis module, a port risk assessment module and a result mapping module. The seabed terrain processing module includes a data import component, a grid division component, a raster conversion component and a clipping component. The data import component is used to import vector data, raster data and text data into the result mapping module. The grid division component is based on the TIN tool and is used to construct a Delaunay irregular triangulated grid. The raster conversion component is used to convert TIN data into standard seabed DEM raster data. The clipping component is used to clip the TIN data or the DEM raster data according to the surface boundary vector data to generate a target area DEM raster. The seabed terrain processing module inputs the target area DEM raster map into the scouring and silting spatiotemporal analysis module. The scouring and silting spatiotemporal analysis module includes a scouring and silting change analysis component. The scouring and silting change analysis component is used to count the scouring and silting change values ​​of the seabed and visually display them in the result mapping module. The port risk assessment module evaluates various risk values ​​based on the data of the scouring and silting spatiotemporal analysis module, and the result mapping module performs visual display.

8. The risk assessment system according to claim 7, characterized in that: The erosion and siltation spatiotemporal analysis module also includes an erosion and siltation intensity calculation component, an erosion and siltation earthwork volume calculation component and a seabed three-dimensional centroid calculation component. The erosion and siltation earthwork volume calculation component is used to calculate the volumetric volume data of erosion and siltation, and the seabed three-dimensional centroid calculation component is used to calculate the three-dimensional centroid coordinates of the seabed before and after erosion and siltation and its planar displacement and direction.

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