Automatic breach modeling and real-time flood risk map generation method and system based on dike polygonal range

Abstract

The invention belongs to the technical field of hydraulic engineering. A breach automatic modeling and real-time flood risk map generation method based on a dike polygon range comprises the following steps: collecting basic data, and constructing a two-dimensional coupling hydrodynamic model and a structured database containing a mapping relation between the dike polygon range and a model grid edge number; receiving hydrological boundary conditions and breach parameters sent by the front-end platform through the preset port; automatically matching the embankment section to which the breach belongs based on the embankment polygon space range, dynamically expanding the associated grid edge set according to the breach width, and reconstructing the length and elevation parameters of the corresponding hydraulic structure; and calling a solution engine to carry out hydrodynamic simulation, and pushing a result to a specified API address. The method is used for solving the key problems that in the prior art, dike breach positioning is not accurate, a model structure is statically solidified, boundary condition updating is disjointed, and breach modeling depends on manual intervention. The invention also discloses a system for realizing the method.

Description

Technical Field

[0001] This invention relates to the fields of water conservancy engineering and smart flood control technology, and in particular to a method and system for automatic breach modeling and real-time flood risk map generation based on the polygonal spatial range of dikes. It is applicable to smart water conservancy and digital twin watershed application scenarios such as watershed flood evolution simulation, dynamic response to sudden dike breach events, and emergency dispatch decision support. Background Technology

[0002] In recent years, affected by climate change and frequent extreme rainfall, the risk of regional floods and levee breaches has increased significantly. Traditional flood risk maps are mostly based on historical typical floods or preset design scenarios and are generated offline. They have shortcomings such as response lag and inability to reflect real-time operating conditions, making it difficult to support the operational needs of modern flood control command for "minute-level early warning and dynamic simulation".

[0003] To improve simulation accuracy, some studies have employed a coupling approach between one-dimensional river network models and two-dimensional hydrodynamic models for flood evolution simulation. However, existing technologies still face the following key bottlenecks:

[0004] (1) The dike structure is static and fixed, lacking dynamic adjustability: The dike in the hydrodynamic model is usually embedded in the form of a fixed building. Once the model is completed, its position, length, elevation and other parameters are difficult to modify online, and it cannot respond to sudden events such as breaches and gate opening and closing in real time.

[0005] (2) Breach modeling relies on manual pre-setting and has a low degree of automation: the location, width, elevation, etc. of the breach need to be manually embedded in specific grids or cross sections during the model building stage. If the actual breach location is offset or the parameters change, the model needs to be remodeled, and it is impossible to achieve online simulation of "arbitrary location and arbitrary parameters".

[0006] (3) Insufficient accuracy in breach location: Existing methods mostly use "nearest distance matching" to associate the breach coordinates with the model edge, but mismatch is prone to occur in dense, curved or parallel areas of dikes, resulting in the breach acting on the wrong dike section, which seriously affects the simulation realism;

[0007] (4) The computation and interaction are disconnected and lack a standardized closed-loop process: Hydrodynamic models usually run independently in local or high-performance computing environments. The front-end platform cannot directly drive the model parameter update. The results need to be manually exported and processed, making it difficult to achieve the integrated linkage of "parameter input - model reconstruction - real-time solution - result push".

[0008] Although some systems have attempted to encapsulate hydrodynamic engines through web services, the two core challenges of accurate spatial location of breaches and dynamic reconstruction of model structures have not yet been solved.

[0009] Existing methods struggle to provide rapid and high-fidelity simulations of levee breaches at arbitrary locations and sizes during sudden floods. The fundamental reasons are: a lack of refined representation of the actual spatial morphology of levees, making it impossible to accurately map breach coordinates to the corresponding physical levee sections; and the inability to dynamically adjust levee structure parameters in the hydrodynamic model, preventing online reconstruction to reflect the breach state. Summary of the Invention

[0010] The first objective of this invention is to provide an automatic modeling method for breaches and a real-time flood risk map generation method based on the polygonal spatial range of dikes, in order to solve key problems in the prior art such as inaccurate location of dike breaches, static and fixed model structure, disconnection of boundary condition updates, and reliance on manual intervention for breach modeling.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: an automatic modeling method for breaches and a dynamic real-time flood risk map generation method based on the polygonal spatial range of dikes, comprising the following steps:

[0012] S1. Collect basic data, construct a one- or two-dimensional coupled hydrodynamic mathematical model, and establish a structured database. The structured database includes the mapping relationship between the boundary condition sequence name and the hydrological station code STCD, as well as the polygonal spatial range of each section of the dike, its corresponding grid edge number and building information in the one- or two-dimensional coupled hydrodynamic mathematical model.

[0013] S2. Receive hydrodynamic model calculation parameters transmitted by the front-end interactive platform through a preset exposed port. The parameters include water level, flow rate, rainfall boundary conditions, breach coordinates, width, depth, and breach water level.

[0014] S3. Analyze the parameters, match the dike section to which the breach belongs based on the dike polygon spatial range, and dynamically adjust the parameters of the corresponding dike structures in the model according to the breach width;

[0015] S4. Call the model solver engine to perform hydrodynamic model calculations;

[0016] S5. Push the hydrodynamic model calculation results to the specified API address.

[0017] This invention achieves automatic attribution of breach coordinates by constructing a structured database containing the mapping relationship between the polygonal spatial range of the dike and the edge numbers of the model grid. Based on the breach width and depth, it dynamically expands the associated grid edge set, reallocates structure parameters, and generates breach trigger control logic, thereby completing real-time updates of the dike structure without rebuilding the model. Simultaneously, the system supports automatic mapping and updating of model boundary conditions through hydrological station codes (STCD), achieving dynamic simulation in two dimensions: "hydrologically driven + structural mutation".

[0018] This invention enables accurate identification of breach locations and automatic reconstruction of model parameters, allowing for responses to sudden breach events without human intervention, and significantly improving the real-time performance, accuracy, and emergency decision support capabilities of flood risk maps.

[0019] This invention can automatically identify the location of a breach based on the actual spatial morphology of a dike and adjust the parameters of the internal structures of the hydrodynamic model in real time to achieve a second-level response and high-fidelity simulation of sudden breach events.

[0020] To further improve the technical solution of the present invention, step S1 includes:

[0021] Collect basic data and construct a one- or two-dimensional coupled hydrodynamic mathematical model and a structured database.

[0022] The basic data includes: one-dimensional river cross-section data (including coordinates of the left and right banks and the center, cross-section spacing, connection relationship, elevation-start point distance curve, roughness), two-dimensional DEM raster data, land use type data, levee vector data (recording the spatial range, length, and top elevation of each levee segment in polygon form), and water level, flow rate, and rainfall sequence of surrounding hydrological stations.

[0023] Based on the above data, a one-dimensional river network model was constructed and its parameters were calibrated using historical flood events; a two-dimensional computational grid was divided and Manning roughness was assigned according to land use type; at the boundary between one-dimensional and two-dimensional models, the dike was generalized into a parameterizable hydraulic structure weir, and the exchange flow was calculated using the weir flow formula, where the weir width corresponds to the dike length and the weir crest elevation corresponds to the dike crest elevation.

[0024] Simultaneously, a structured database is constructed to store the mapping relationship between the sequence name corresponding to each open boundary and the actual hydrological station code (STCD), and to record the polygonal spatial range of each section of the dike, its corresponding grid edge number in the model, and the building attributes.

[0025] To further improve the technical solution of the present invention, step S2, receiving hydrodynamic model calculation parameters transmitted by the front-end interactive platform through a preset exposed port, includes:

[0026] The parameters include the water level, flow rate, or rainfall time series (with STCD encoding) of the specified hydrological station, as well as the breach coordinates, width, depth, and breach water level required for breach simulation.

[0027] To further improve the technical solution of the present invention, step S3, analyzing parameters and dynamically adjusting the calculation parameters of the hydrodynamic model, includes:

[0028] First, based on the received STCD query database, the hydrological sequence is bound to the corresponding name boundary in the model to achieve dynamic updating of the boundary conditions.

[0029] Secondly, for the breach parameters, the breach section to which the breach belongs is matched based on the spatial range of the dike polygon, and the breach treatment strategy is determined according to the type of the dike section (internal or coupled boundary).

[0030] Furthermore, based on the type of breach location, initial associated edges are selected and extended to both sides along the linear topology of the dike to form a set of associated edges with a cumulative length not less than the breach width; the original building parameters of each edge are extracted, and the breach width is reasonably allocated to each edge through a linear allocation algorithm, and the elevation of the dike crest after the breach is set; finally, a breach control file is generated, defining the triggering conditions—for internal breaches, it takes effect when the water level of the two-dimensional grid cell where the breach is located exceeds the breach water level; for boundary breaches, the water level of the nearest one-dimensional river channel section is used as the triggering criterion.

[0031] To further improve the technical solution of the present invention, step S4, calling the model solver engine to perform hydrodynamic simulation calculations, includes:

[0032] After the model parameters are dynamically updated, the solver engine is started to simulate the evolution of the flood in the river channel and the inundation area.

[0033] To further improve the technical solution of this invention, step S5, pushing the hydrodynamic model calculation results to a specified API address, includes:

[0034] The model calculation results file is automatically pushed to the API interface specified by the front-end platform via standard network protocols (such as HTTP / POST) for real-time visualization and decision analysis.

[0035] The second objective of this invention is to provide a system for implementing the method of automatic breach modeling and real-time flood risk map generation based on the polygonal spatial range of dikes, comprising:

[0036] Data acquisition and model building module: used to collect one-dimensional river cross-section, two-dimensional DEM, land use, levee vector and hydrological data, and to build a one-dimensional and two-dimensional coupled hydrodynamic mathematical model; among them, the levee is expressed in polygon form to represent its spatial range, and is generalized into a parameterizable hydraulic structure weir at the one-dimensional and two-dimensional junction.

[0037] Database construction module: Used to build a structured database, store the mapping relationship between boundary condition sequence names (name) and hydrological station codes (STCD), and record the polygonal spatial range of each section of the dike, its corresponding grid edge number in the hydrodynamic model, and the building attribute information;

[0038] Parameter receiving module: Receives hydrodynamic model calculation parameters sent by the front-end interactive platform through a preset exposed port, including hydrological boundary conditions (water level, flow rate, rainfall) with STCD, as well as breach coordinates, width, depth and breach water level;

[0039] The parameter parsing and model adjustment module is used to parse the received parameters. On the one hand, it queries the database according to STCD and dynamically binds the hydrological sequence to the open boundary of the model with the corresponding name. On the other hand, it matches the dike section to which the breach belongs based on the dike polygon spatial range, dynamically expands the associated grid edge set according to the breach width, redistributes the length and elevation of the structure, and generates a breach control file to define the water level triggering conditions.

[0040] Model Solver Module: Used to call the high-performance hydrodynamic solver engine and perform flood evolution simulation calculations after the model parameters are dynamically updated;

[0041] Results transmission module: This module encapsulates the calculation results (such as water depth field and velocity field) output by the hydrodynamic model and pushes them to the API address specified on the front end via a standard network protocol, supporting real-time visualization and emergency decision-making. Attached Figure Description

[0042] Figure 1 This is a flowchart of the method for automatic breach modeling and real-time flood risk map generation based on dike polygons in an embodiment of the present invention;

[0043] Figure 2 This is a flowchart of the sub-process of breach parameter analysis and dike side dynamic adjustment in an embodiment of the present invention; Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] I. System Overall Architecture

[0046] The system for automatic breach modeling and real-time flood risk map generation based on the polygonal range of dikes is deployed on a server or cloud platform, including a hydrodynamic model service module, a database service module, and an API communication interface; external systems send calculation parameters to the model service through standard network protocols and receive the hydrodynamic simulation results returned by it.

[0047] Specifically, the system for automatic breach modeling and real-time flood risk map generation based on the polygonal range of dikes includes:

[0048] Data acquisition and model building module: used to collect one-dimensional river cross-section, two-dimensional DEM, land use, levee vector and hydrological data, and to build a one-dimensional and two-dimensional coupled hydrodynamic mathematical model; among them, the levee is expressed in polygon form to represent its spatial range, and is generalized into a parameterizable hydraulic structure weir at the one-dimensional and two-dimensional junction.

[0049] Database construction module: Used to build a structured database, store the mapping relationship between boundary condition sequence names (name) and hydrological station codes (STCD), and record the polygonal spatial range of each section of the dike, its corresponding grid edge number in the hydrodynamic model, and the building attribute information;

[0050] Parameter receiving module: Receives hydrodynamic model calculation parameters sent by the front-end interactive platform through a preset exposed port, including hydrological boundary conditions (water level, flow rate, rainfall) with STCD, as well as breach coordinates, width, depth and breach water level;

[0051] The parameter parsing and model adjustment module is used to parse the received parameters. On the one hand, it queries the database according to STCD and dynamically binds the hydrological sequence to the open boundary of the model with the corresponding name. On the other hand, it matches the dike section to which the breach belongs based on the dike polygon spatial range, dynamically expands the associated grid edge set according to the breach width, redistributes the length and elevation of the structure, and generates a breach control file to define the water level triggering conditions.

[0052] Model Solver Module: Used to call the high-performance hydrodynamic solver engine and perform flood evolution simulation calculations after the model parameters are dynamically updated;

[0053] Results transmission module: This module encapsulates the calculation results (such as water depth field and velocity field) output by the hydrodynamic model and pushes them to the API address specified on the front end via a standard network protocol, supporting real-time visualization and emergency decision-making.

[0054] II. Basic Data Acquisition and Model Building

[0055] 1. Preparation of basic data

[0056] One-dimensional river cross-section data: including the left bank coordinates (X1,Y1), right bank coordinates (X2,Y2), centerline coordinates (Xc,Yc), cross-section spacing, upstream and downstream connection relationship, cross-section elevation-starting point distance curve and Manning roughness (usually taken as 0.025~0.045) for each cross-section;

[0057] Two-dimensional DEM data: using 30m or higher resolution raster, coordinate system CGCS2000;

[0058] Land use data: sourced from national land or remote sensing images, assigned different Manning roughness rates (e.g., 0.07 for urban areas, 0.065 for forest areas) according to category (e.g., cultivated land, forest land, urban areas, water areas);

[0059] Levee data: stored as a linear vector and expanded into a polygonal feature with width, including start / end coordinates, levee crest elevation, levee width, and material type. Each levee segment corresponds to a unique ID (levee_id).

[0060] Hydrological data: Historical or real-time water level, flow rate, and rainfall sequences for designated stations (STCD codes) obtained from hydrological databases or real-time monitoring platforms.

[0061] 2. Hydrodynamic Model Construction

[0062] One-dimensional river network model: The river network topology is constructed based on cross-sectional data and solved using the Saint-Venant equations; the parameters are calibrated using historical flood events such as 2016 and 2020 to ensure that the root mean square error between the simulated water level and the measured value is controlled within ±20cm.

[0063] Two-dimensional computational grid: Unstructured triangular mesh is used, with a grid size of approximately 50m in plains areas and approximately 20m in mountainous areas;

[0064] Embankment Structure Embedding and Type Labeling: Each embankment segment is mapped to the edge of a 2D grid. Based on its spatial location and hydraulic function, its type is manually or semi-automatically labeled during the modeling phase.

[0065] If the dike is located at the boundary between the one-dimensional river channel and the two-dimensional flood zone, it is marked as a "coupling boundary dike" (edge_type = 'coupling'), and a hydraulic coupling connection is established between the one-dimensional cross-section and the two-dimensional grid.

[0066] If the dike is entirely located within the two-dimensional computational domain (such as a dike within a polder or a sub-dike), it is marked as an "internal dike" (edge_type = 'internal') and serves only as a water-blocking structure within the two-dimensional domain.

[0067] One-dimensional coupling: A weir-type hydraulic structure is set up at the boundary between the river channel and the two-dimensional region, and the exchange flow Q is calculated according to the formula for a broad-crested weir.

[0068]

[0069] Among them, C d Here, B is the flow coefficient, B is the weir width (i.e., the length of the dike), and H is the upstream water depth. c This is the weir crest elevation (i.e., the embankment crest elevation). This is determined by setting the B and H edges of the coupling boundary. c This allows for an accurate generalization of the actual dike structure.

[0070] III. Structured Database Design

[0071] The database uses a relational database (such as PostgreSQL with PostGIS extensions) and mainly contains the following tables:

[0072] The boundary_sequence table stores the mapping relationship between the model boundary and the actual hydrological stations.

[0073] name(VARCHAR): A unique name for the sequence of boundary conditions of the model, such as "Q_yuetangshuiku";

[0074] stcd(VARCHAR): Corresponds to the hydrological station code (STCD), such as "62705450";

[0075] data_type(ENUM): Data type ("water_level", "discharge" or "rainfall").

[0076] The `levee_info` table is the core table, relating the physical levee, spatial extent, and model structure.

[0077] levee_id(INTEGER): unique ID of embankment section;

[0078] polygon(GEOMETRY(POLYGON,4326)): The spatial polygon range (including width) of this section of the embankment;

[0079] model_edge_ids(INTEGER[]): A list of edge numbers for the corresponding two-dimensional mesh;

[0080] edge_type(VARCHAR): The type identifier for the dike section, with values ​​of 'internal' (internal dike) or 'coupling' (coupling boundary dike);

[0081] crest_elev(FLOAT): crest elevation (m);

[0082] The `building_on_edge` table records the attributes of buildings on each grid edge.

[0083] edge_id(INTEGER): The edge number of the 2D mesh;

[0084] length(FLOAT): Building length (m);

[0085] crest_elev(FLOAT): Elevation of the top of the building (m);

[0086] is_breachable(BOOLEAN): Whether to allow breaches (default TRUE).

[0087] The above design allows the system to first determine the dike section to which the breach belongs through spatial query after receiving the breach coordinates, and then determine the processing strategy based on the edge_type field.

[0088] IV. Parameter Analysis and Dynamic Model Adjustment

[0089] 1. Boundary conditions are dynamically updated.

[0090] When receiving parameters from the front end (e.g., stcd = 62705450, traffic sequence [100, 120, ..., 80]m) 3 When the flow rate is / s), the system queries the boundary_sequence table, finds the corresponding name = Q_yuetangshuiku, and assigns the flow rate sequence to the boundary condition sequence with that name in the model, thus achieving precise alignment between the observed data and the model calculation.

[0091] 2. Ulcer parameter settings

[0092] When the user sets the breach parameters, such as latitude and longitude coordinates (118.5°E, 32.1°N), width 150m, depth 3m, and breach water level 7.0m, the system executes the following steps:

[0093] (1) Determination of breach attribution and type:

[0094] Iterate through all polygons in the levee_info table and determine whether the breach point falls within a certain section of the levee polygon.

[0095] If it falls within the range, it is determined that it belongs to the levee segment corresponding to the levee_id; further, the edge_type field of that segment is read:

[0096] If it is 'internal', it is determined to be an internal breach in the dike;

[0097] If it is 'coupling', it is determined to be a breach in the coupled boundary levee.

[0098] (2) Generation of the set of associated edges:

[0099] For internal breaches: obtain the model_edge_id list for the dike section, calculate the center coordinates of each edge, and select the edge closest to the breach as the initial edge; if its length is <150m, expand along the linear topology of the dike to both sides, and successively include adjacent edges until the cumulative length is ≥150m, forming a set of associated edges;

[0100] For boundary breaches: Perform the same operation on the coupled boundary edge list, and additionally calculate the Euclidean distance from the breach point to each cross section of the one-dimensional river channel to determine the nearest cross section (e.g., cross section ID = 1024).

[0101] (3) Redistribution of building parameters: Let the width of the breach be W and the original length of each side be L. i Then the length of the new building assigned to edge i is:

[0102]

[0103] The elevation of the levee crest after the breach is set as: H efter =H crest - Damage

[0104] (4) Generate the breach control file:

[0105] For internal breaches: The trigger condition is "when the water level in the two-dimensional grid cell where the breach is located is >7.0m, the elevation of the top of the building drops to H". efter ”;

[0106] For boundary breaches: The trigger condition is "the breach takes effect when the water level at the nearest one-dimensional cross-section (ID=1024) is >7.0m".

[0107] V. Model Solving and Result Processing

[0108] Call the solver engine, set the time step to 10-60 seconds, and set the total simulation time to the user's settings, for example: 2025 / 7 / 10:00 to 2025 / 7 / 10 0:00.

[0109] After the calculation is complete, the model calculation result is output. The model calculation result is stored in HDF format and sent to the specified API on the front end via a POST request, such as https: / / frontend.example.com / api / flood-result.

Claims

1. A method for automatic breach modeling and real-time flood risk map generation based on the polygonal range of a dike, characterized in that, Includes the following steps: S1. Collect basic data, construct a one- or two-dimensional coupled hydrodynamic mathematical model, and establish a structured database. The structured database includes the mapping relationship between the boundary condition sequence name and the hydrological station code STCD, as well as the polygonal spatial range of each section of the dike, its corresponding grid edge number and building information in the one- or two-dimensional coupled hydrodynamic mathematical model. S2. Receive hydrodynamic model calculation parameters transmitted from the front-end interactive platform. The parameters include water level, flow rate, rainfall boundary conditions, breach coordinates, width, depth, and breach water level. S3. Analyze the parameters, match the dike section to which the breach belongs based on the dike polygon spatial range, and dynamically adjust the parameters of the corresponding dike structures in the one-dimensional coupled hydrodynamic mathematical model according to the breach width. S4. Call the one- or two-dimensional coupled hydrodynamic mathematical model solving engine to perform hydrodynamic model calculations; S5. Push the hydrodynamic model calculation results to the specified API address.

2. The method according to claim 1, characterized in that, The basic data mentioned in step S1 includes: one-dimensional river cross-section data, two-dimensional DEM raster data, land use type data, levee data, and hydrological data; The one-dimensional river channel end face data includes the coordinates of the left and right banks and the center of the cross section, the cross section spacing, the cross section connection relationship, the cross section elevation-starting point distance data, and the roughness coefficient. The dike data includes location, length, and height; The hydrological data includes water level, flow rate, and rainfall data from hydrological stations surrounding the model area.

3. The method according to claim 1, characterized in that, Step S1, "Constructing a one- or two-dimensional coupled hydrodynamic model," includes the following sub-steps: S11, construct a one-dimensional river network model, and calibrate the model roughness and cross-sectional parameters based on historical flood data; S12, based on two-dimensional DEM data, divides two-dimensional computational grids and assigns corresponding Manning roughness coefficients to each region according to land use type; S13, at the boundary between the one-dimensional river network and the two-dimensional region, the actual dike structure is generalized as a hydraulic structure weir, and the exchange flow between the one-dimensional river network model and the two-dimensional computational grid is calculated by the weir flow formula; wherein, the width of the hydraulic structure weir corresponds to the length of the dike, and the weir crest elevation corresponds to the dike crest elevation, so that the dike is embedded in the model in a parameterizable form.

4. The method according to claim 1, characterized in that, Step S1, "Establishing a structured database", includes: setting a unique field "name" for each sequence corresponding to an open boundary, with each name corresponding to a hydrological station in the real physical world. Hydrological stations are distinguished by station codes (STCDs). A mapping relationship database between sequence names and station STCDs is established, as well as storing the polygonal spatial range of each section of the dike, its corresponding grid edge number in the hydrodynamic model, and the building attribute information.

5. The method according to claim 1, characterized in that, Step S3 also includes the parsing and mapping of hydrological boundary conditions: based on the received hydrological station code STCD, query the mapping relationship between the pre-stored boundary condition sequence name name and the hydrological station code STCD in the structured database, and assign the corresponding water level, flow rate or rainfall time series to the boundary condition sequence named name in the model to realize the dynamic update of the boundary conditions.

6. The method according to claim 1, characterized in that, Step S3 includes the analysis and adjustment of the breach parameters, specifically: Based on the database of dike polygon spatial range and building number established in step S1, the location of the dike corresponding to the breach coordinates is determined by the spatial coordinate matching algorithm. When the breach is located on a section of the dike within the two-dimensional computational domain, calculate the center coordinates of each edge in the edge number list corresponding to the dike section, and select the edge closest to the breach as the initial associated edge; if the length of the initial associated edge is less than the width of the breach, then add adjacent edges to both ends along the dike topology until the cumulative length is not less than the width of the breach, forming a set of breach associated edges. When the breach is located on the levee section at the coupling boundary between the one-dimensional river network and the two-dimensional region, calculate the center coordinates of each edge in the boundary edge number list, filter the nearest edge, and similarly expand to form a set of breach-related edges. Extract the original length and top elevation information of the buildings in the associated edge set, and adjust the length of each building on each edge using a linear allocation algorithm so that the cumulative length equals the breach width; A breach control file is generated by combining the breach water level and the post-breach levee elevation, and the trigger condition is defined: when the water level of the two-dimensional grid cell where the breach is located exceeds the breach water level, the elevation of the top of the building is automatically reduced to the post-breach levee top elevation.

7. The method according to claim 6, characterized in that, When the breach is located at the coupling boundary between a one-dimensional river network and a two-dimensional region, it also includes: Calculate the Euclidean distance between the breach coordinates and each cross-section of the one-dimensional river channel to determine the nearest cross-section; The triggering condition in the breach control document is defined as follows: if the water level at the nearest cross section is greater than the breach water level, the elevation of the top of the structure corresponding to the breach will be reduced to the elevation of the top of the dike after the breach.

8. A system for implementing the automatic breach modeling and real-time flood risk map generation method based on the polygon range of a dike as described in any one of claims 1-7, characterized in that, include: The data acquisition and model building module is used to collect basic data and build a one- or two-dimensional coupled hydrodynamic mathematical model. The database construction module is used to build a structured database, which includes the mapping relationship between the boundary condition sequence name and the hydrological station code STCD, as well as the polygonal spatial range of each section of the dike, its corresponding edge number in the model, and building information. The parameter receiving module is used to receive hydrodynamic model calculation parameters transmitted by the front-end interactive platform through a preset exposed port. The parameters include water level, flow rate, rainfall boundary conditions, breach coordinates, width, depth and breach water level. The parameter parsing and model adjustment module is used to parse the parameters, match the dike section to which the breach belongs based on the dike polygon spatial range, and dynamically adjust the parameters of the corresponding dike structures in the model according to the breach width. The model solver module is used to call the model solver engine to perform hydrodynamic simulation calculations; The results transmission module is used to push the hydrodynamic model calculation results to the specified API address.

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