A dynamic simulation method for dam-break scenarios based on a two-dimensional coupled model

Abstract

The application provides a kind of dynamic simulation method of dike breach scene based on two-dimensional coupling model, the method first obtains relevant data in research area, constructs one-dimensional river network model and two-dimensional hydrodynamics model and is coupled, sets simulation parameter and scene change trigger flag;Separate breach parameter as independent dynamically updated structure, allocate shared memory and define atomic access rule;In simulation, determine time step according to CFL condition to promote hydrodynamics calculation, detect whether user submits new breach parameter after each time step ends, if yes, update parameter and trigger flag;Main program non-blocking check flag, trigger after modification dike height simulation breach, reset flag and continue calculation.The method of the application realizes dynamic injection and hot update of breach scene, without restarting calculation, improves timeliness of emergency decision, saves computing resources, strengthens decision support capability, and balances simulation efficiency and accuracy.

Description

Technical Field

[0001] This invention belongs to the field of flood simulation and flood control and disaster reduction technology, and specifically relates to a dynamic simulation method for levee breach scenarios based on a one- or two-dimensional coupled model. Background Technology

[0002] Floods are among the most common and devastating natural disasters globally, with floods caused by levee breaches often resulting in enormous casualties and economic losses. To effectively address flood risks, flood evolution simulation technology has become a crucial technical support tool for flood prevention and disaster reduction efforts.

[0003] Currently, flood simulation mainly relies on hydrodynamic models, including one-dimensional river network models and two-dimensional hydrodynamic models. One-dimensional river network models, by solving the Saint-Venant equations, can efficiently simulate the evolution of river floods, but struggle to depict the complex inundation processes within floodplains. Two-dimensional hydrodynamic models, by solving two-dimensional shallow water equations, can precisely characterize the inundation range and water depth distribution of floodplains, but their computational efficiency is relatively low. To balance computational efficiency and simulation accuracy, researchers have developed a coupled one-dimensional and two-dimensional hydrodynamic model. This model generalizes the river channel into a one-dimensional model and the floodplain into a two-dimensional model, achieving full-basin flood evolution simulation through coupled computation.

[0004] However, existing flood evolution simulation methods have significant limitations when dealing with sudden scenarios such as levee breaches. In traditional simulation processes, key parameters such as the timing, location, and geometry of the breach are typically set as initial conditions or static parameters before the simulation begins. In traditional models, once the simulation program starts, these breach parameters are fixed within the model and cannot be dynamically changed during the calculation. This "static preset" mode leads to many inconveniences:

[0005] First, it lacks flexibility and timeliness. In real emergency rescue decision-making, decision-makers need to quickly assess the differences between various breach scenarios. Traditional methods require interrupting the current simulation, modifying the input file, and recalculating from scratch for each possible scenario. This entire process is time-consuming and labor-intensive, failing to meet the high timeliness requirements of emergency decision-making.

[0006] Second, there is a waste of computational resources. Flood evolution simulation, especially two-dimensional simulation for large areas, involves a huge amount of computation and can take hours or even days. Traditional methods require restarting the calculation for each breach scenario, rendering a large amount of completed computational work useless and causing a serious waste of computational resources.

[0007] Third, the decision support capabilities are limited. The inability to dynamically introduce hypothetical scenarios based on the real-time evolution of the flood during the simulation limits the simulation system's potential as an interactive decision support tool. For example, when the simulation shows that a levee is under immense pressure, decision-makers may want to immediately simulate the consequences of a breach at that location, but current technology cannot achieve this "instant response" simulation.

[0008] Therefore, how to overcome the shortcomings of static pre-setting of breach scenarios in traditional flood simulation methods and realize a flood simulation method that can dynamically, in real time and efficiently introduce and adjust breach events during the simulation process, thereby providing stronger support for flood control emergency decision-making, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] To address the shortcomings of existing flood simulation methods, such as poor flexibility, low timeliness, and lack of dynamic interaction when handling breach scenarios, this invention aims to provide a dynamic simulation method for breach scenarios based on a one-dimensional coupled model. This method can respond to user commands in real time and dynamically during the flood evolution simulation process, introducing or modifying the flood evolution simulation of breach scenarios, achieving "hot updates" of the simulation calculation, and allowing users to dynamically inject new breach events during the simulation, thereby significantly improving the efficiency of simulation analysis and emergency decision support capabilities.

[0010] The objective of this invention is achieved through the following technical solution:

[0011] This invention provides a dynamic simulation method for levee breach scenarios based on a one- or two-dimensional coupled model, comprising the following steps:

[0012] Step 1, Obtain Data

[0013] Acquire digital elevation models, river network cross-section data, river network embankment elevation data, land use type data, and flood forecast data within the study area;

[0014] Step 2, Construct a coupling model

[0015] First, based on the digital elevation model and land use type data obtained in step 1, a two-dimensional hydrodynamic model of the study area is constructed; based on the river network cross-section data and river network embankment elevation data obtained in step 1, a one-dimensional river network model of the study area is constructed.

[0016] Then, based on the spatial relationship, the two-dimensional hydrodynamic model and the one-dimensional river network model are coupled by lateral connection to complete the construction of the one- and two-dimensional coupled model of the study area;

[0017] Step 3, Simulation Parameter Settings

[0018] The flood forecast data obtained in step 1 is used as the inflow boundary condition of the one-dimensional coupled model. The simulation calculation parameters are set, including the calculation start time, calculation end time, and output time step. An integer variable is set in the shared memory space as the "scenario change" trigger flag, with the initial value set to "0".

[0019] Step 4, Create the rupture parameter structure

[0020] During the initialization phase of the simulation system, the dike breach parameters are separated from the static data structure of the core algorithm and designed as an independent, dynamically updatable "breach parameter structure". A shared memory region that can be read and written by the interactive control program is allocated in memory for this structure, and atomic access rules are defined for read and write operations.

[0021] Step 5: Hydrodynamic Calculation and Result Output

[0022] The calculation time step is determined based on the flow field state at the current time t. The main program calculates the flow field data based on time t, performs hydrodynamic deduction with a time step of dt, obtains the flow field results at time t+dt, updates the flow field state of the computational domain based on the calculation results, and determines whether to output the results based on the output time step described in step 3. The flow field state and output results include the water depth, x-direction velocity, and y-direction velocity data of each grid cell in the two-dimensional hydrodynamic model, as well as the water level and flow rate data of each river cross-section in the one-dimensional river network model.

[0023] Step 6, Update breach parameters and trigger flags

[0024] After each calculation step, it checks whether the user set and submitted new vulnerability parameters through the graphical user interface or command-line tool during this calculation step. If the user submits new vulnerability parameters, the interactive control program receives the new parameters and writes them to the vulnerability parameter structure described in step 4 through an atomic operation, while setting the "scenario change" trigger flag described in step 3 to "1". If no user submission is detected, the "scenario change" trigger flag is kept at "0".

[0025] Step 7, Check the scenario change flag.

[0026] The "scenario change" trigger flag set in step 3 is checked in a non-blocking manner. If the value of the flag is detected as "1", the simulation calculation main program immediately pauses the current calculation and executes step 8; if the value of the flag is detected as "0", then step 11 is executed.

[0027] Step 8, Reading Ulcer Parameters

[0028] After the simulation calculation main program obtains access to shared memory, it reads all parameter values ​​from the updated rupture parameter structure in step 6.

[0029] Step 9, Dike Elevation Correction and Breach Simulation

[0030] Based on the coordinates of the breach center point recorded in the breach parameter structure, the location of the river embankment where the breach occurred is determined according to the spatial relationship; at the same time, based on the breach width and the bottom elevation information of the breach, the elevation of the river embankment is corrected in the one-dimensional river network model to simulate the breach state.

[0031] Step 10, Flag Reset and Calculation Recovery

[0032] Reset the "Scenario Change" trigger flag to "0", release access permissions to shared memory, and continue to step 5 to perform the calculation for the next time step;

[0033] Step 11, Simulate termination judgment

[0034] Determine if the current simulation time is greater than the calculation termination time set in step 3; if the current time is not greater than the termination time, return to step 5 to continue the time progression loop; if the current time is greater than the termination time, execute the simulation program termination step.

[0035] Step 12, the simulation program terminates.

[0036] Release all memory and terminate the simulation program.

[0037] Furthermore, in step 1, the data obtained must be in a unified geographic coordinate system and elevation datum.

[0038] Furthermore, in step 2, the finite volume method is used to solve the two-dimensional shallow water equations in the construction of the two-dimensional hydrodynamic model; the finite element method is used to solve the one-dimensional Saint-Venant equations in the construction of the one-dimensional river network model; and the weir flow formula is used to calculate the exchange of water between the one-dimensional river channel and the two-dimensional surface in the construction of the one-dimensional coupled model.

[0039] Furthermore, in step 4, the dike breach parameter structure includes the coordinates of the breach center point, the breach width, and the breach bottom elevation; the atomic access rule uses a mutex lock mechanism to protect the shared memory, ensuring that only one process or thread can access the shared memory area at any given time, thereby guaranteeing the mutual exclusion and consistency of data access.

[0040] Furthermore, in step 5, the time step... The calculation formula is as follows:

[0041]

[0042] In the formula, For safety reasons, , , , represent the spatial step size of the grid in the x and y directions, respectively; u and v represent the flow velocities in the x and y directions, respectively; g represents the gravitational acceleration; The water is deep.

[0043] Furthermore, in step 7, the non-blocking mode check means that after each calculation step, the main program reads the value of the scenario change trigger flag to determine whether there is a new breach scenario that needs to be processed, without interrupting the current calculation process.

[0044] Furthermore, step 9, which involves correcting the elevation of the dike and simulating the breach, specifically includes: modifying the elevation value of the corresponding river dike location to the bottom elevation of the breach, and establishing a hydraulic connection between the one-dimensional river channel and the two-dimensional surface within the breach width range.

[0045] Furthermore, the method supports the dynamic introduction of different breach scenarios multiple times during the simulation process, and steps 6 to 10 are repeated each time a new breach scenario is introduced.

[0046] The advantages of this invention compared to the prior art are as follows:

[0047] 1. The dynamic simulation method for levee breach scenarios described in this invention breaks through the limitations of traditional static preset breach parameters, realizes dynamic injection and real-time adjustment of breach scenarios during the simulation process, without the need to restart the calculation, and improves the timeliness of emergency decision-making.

[0048] 2. The dynamic simulation method for levee breach scenarios described in this invention can avoid redundant calculations, significantly save computational resources for large-area flood simulation, and improve simulation efficiency;

[0049] 3. The dynamic simulation method for dike breach scenarios described in this invention supports interactive decision-making and can flexibly introduce multiple breach scenarios according to the real-time evolution of floods, thereby enhancing the flood control emergency decision support capability.

[0050] 4. The dynamic simulation method for levee breach scenarios described in this invention is based on a one-dimensional coupled model. The one-dimensional coupled model takes into account both computational efficiency and simulation accuracy, ensuring accurate depiction of the evolution process of levee breach floods (river discharge and floodplain inundation). Attached Figure Description

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0052] Figure 1 This is a flowchart illustrating the dynamic simulation method for levee breach scenarios based on a one- or two-dimensional coupled model as described in Example 1.

[0053] Figure 2This is a schematic diagram of the shared memory and mutex lock mechanism described in Example 1;

[0054] Figure 3 This is a schematic diagram illustrating the effect of dynamic updating of breach parameters and correction of dike elevation as described in Example 1. Detailed Implementation

[0055] The embodiments described are provided to better illustrate the present invention, but are not intended to limit the scope of the invention to the embodiments described. Therefore, non-essential improvements and adjustments made to the embodiments by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0056] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0057] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are only used to exemplify and further explain and illustrate the content of the present invention, and are not intended to limit the present invention.

[0058] Example 1

[0059] like Figure 1 As shown, this embodiment provides a dynamic simulation method for levee breach scenarios based on a one- or two-dimensional coupled model, including the following steps:

[0060] Step 1, Obtain Data

[0061] Acquire digital elevation models, river network cross-section data, river network embankment elevation data, land use type data, and flood forecast data for the study area; all acquired data must be in a unified geographic coordinate system and elevation datum.

[0062] Step 2, construct the coupling model

[0063] First, the study area is meshed using an unstructured grid. Based on the digital elevation model and land use data obtained in step 1, elevation interpolation and roughness assignment are performed on the two-dimensional grid to construct a two-dimensional hydrodynamic model of the study area. This model uses the finite volume method to calculate the two-dimensional shallow water equations.

[0064] The river channel is generalized into a one-dimensional river network. Based on the river network cross-sectional data and river network embankment elevation data obtained in step 1, a one-dimensional river network model of the study area is constructed. The one-dimensional Saint-Venant equations are solved using the finite element method.

[0065] Then, based on the spatial relationship, the two-dimensional hydrodynamic model and the one-dimensional river network model are coupled by lateral connection to complete the construction of the one- and two-dimensional coupled model of the study area.

[0066] Specifically, a lateral connection method is used to spatially match the bank lines of the one-dimensional river network model with the boundaries of the two-dimensional model. The water exchange between the one-dimensional river channel and the two-dimensional floodplain is calculated using the weir flow formula. When the water level in the one-dimensional river channel is higher than the bank elevation, water overflows through the bank into the two-dimensional region; conversely, the water level is lower. This completes the construction of the one-dimensional and two-dimensional coupled model for the study area.

[0067] Step 3, Simulation Parameter Settings

[0068] The flood forecast data obtained in step 1 is used as the upstream inflow boundary condition for the one-dimensional coupled model, and the downstream outlet of the model is set as a free outflow boundary. Simultaneously, simulation calculation parameters are set, including the calculation start time, calculation end time, and result output time step. An integer variable -SCENARIO_FLAG - is set in the program's shared memory space as a "scenario change" trigger flag, with an initial value of "0". This flag is visible to both the main calculation program and the external interactive control program.

[0069] Step 4, Create the rupture parameter structure

[0070] During the initialization phase of the simulation system, the dike breach parameters are separated from the static data structure of the core algorithm and designed as an independent, dynamically updatable "breach parameter structure". A shared memory region that can be read and written by the interactive control program is allocated in memory for this structure, and atomic access rules are defined for read and write operations.

[0071] The dike breach parameter structure includes the coordinates of the breach center point, the breach width, and the breach bottom elevation; for example... Figure 2 As shown, the atomic access rule uses a mutex lock mechanism to protect shared memory, ensuring that only one process or thread can access the shared memory area at any given time, thereby guaranteeing the mutual exclusion and consistency of data access.

[0072] Specifically, in the C++ code, a BreachParams structure is defined to encapsulate all dynamic parameters related to the breach, as shown in the example below:

[0073] structBreachParams {

[0074] double centerX; / / X-coordinate of the breach center point (CGCS2000)

[0075] double centerY; / / Y-coordinate of the breach center point (CGCS2000)

[0076] double width; / / Ulcers width (meters)

[0077] double bottomElev; / / Breach bottom elevation (1985 National Elevation System)

[0078] `long long breachTime;` / / The time the breach occurred (Unix timestamp)

[0079] bool isActive; / / Whether the vulnerability is active

[0080] };

[0081] The mmap system call is used to create a shared memory region large enough to hold the BreachParams structure. Simultaneously, a pthread_mutex_t mutex is initialized to protect this shared memory region, ensuring that access to this region by the interactive control program (the writer) and the simulation program (the reader) is atomic, thus avoiding data races.

[0082] Step 5: Hydrodynamic Calculation and Result Output

[0083] The main program then enters a time-progression loop. The calculation time step is determined based on the flow field state at the current time t. The main program calculates the flow field data based on time t, performs a hydrodynamic derivation with a time step of dt, obtains the flow field results at time t+dt, and updates the flow field state of the computational domain based on the calculation results. Whether to output the results is determined according to the output time step described in step 3. The flow field state and output results include the water depth, x-direction velocity, and y-direction velocity data of each grid cell in the two-dimensional hydrodynamic model, and the water level and flow rate data of each river cross-section in the one-dimensional river network model.

[0084] Among them, time step The calculation is based on the CFL (Courant-Friedrichs-Lewy) condition, and the formula is as follows:

[0085]

[0086] In the formula, For safety reasons, , , , represent the spatial step size of the grid in the x and y directions, respectively; u and v represent the flow velocities in the x and y directions, respectively; g represents the gravitational acceleration; The water is deep.

[0087] At this point, since the user has not performed any operation, SCENARIO_FLAG remains "0". The simulation proceeds according to the preset river evolution process, with floodwaters flowing downstream along the main channel without any breach.

[0088] Step 6, Update breach parameters and trigger flags

[0089] After each calculation step, it checks whether the user set and submitted new vulnerability parameters through the graphical user interface or command-line tool during this calculation step. If the user submits new vulnerability parameters, the interactive control program receives the new parameters and writes them to the vulnerability parameter structure described in step 4 through an atomic operation, while setting the "scenario change" trigger flag described in step 3 to "1". If no user submission is detected, the "scenario change" trigger flag is kept at "0".

[0090] Specifically, after 10 hours of simulation, the simulation results show that the water level at a certain section of the river is close to the top of the levee, and the risk of levee breach is high. At this time, the user inputs the coordinates of the center point of the breach, the width of the breach, and the elevation parameters of the bottom of the breach through the graphical user interface, assuming that the levee breach has occurred.

[0091] At this point, the program detects that the user has set and submitted the breach parameters through the graphical user interface during this calculation step. The parameters are then written to the breach parameter structure described in step 4 through an atomic operation, and the "scenario change" trigger flag described in S3 is set to "1".

[0092] Step 7, Check the scenario change flag.

[0093] The "scenario change" trigger flag set in step 3 is checked in a non-blocking manner. If its value is detected as "1", the simulation calculation main program immediately pauses the current calculation and executes step 8.

[0094] If the flag bit value is detected as "0", then proceed to step 11.

[0095] Step 8, Reading Ulcer Parameters

[0096] After the simulation calculation main program obtains access to shared memory, it reads all parameter values ​​from the updated rupture parameter structure in step 6.

[0097] Step 9, Dike Elevation Correction and Breach Simulation

[0098] Based on the coordinates of the breach center point recorded in the breach parameter structure, the location of the river embankment where the breach occurred is determined according to the spatial relationship. At the same time, based on the breach width and the bottom elevation information of the breach, the elevation of the river embankment is corrected in the one-dimensional river network model to simulate the breach state.

[0099] Specifically, based on the coordinates of the breach center point, the corresponding levee section is located in the one-dimensional river network data. Then, the levee crest elevation within the breach width parameter range of that levee section is modified to the breach bottom elevation parameter value, and a hydraulic connection between the one-dimensional river channel and the two-dimensional land surface is established within the breach width range.

[0100] Step 10, Flag Reset and Calculation Recovery

[0101] The SCENARIO_FLAG flag is reset to "0", the mutex is released, and then step 5 is executed seamlessly to begin the calculation of the next time step.

[0102] Step 11, Simulate termination judgment

[0103] After 38 hours, the simulation reaches the calculation termination time set in step 3, and the simulation program terminates.

[0104] Step 12, the simulation program terminates.

[0105] Release all memory, terminate the simulation program, and the simulation ends.

[0106] Application examples:

[0107] In this application example, step 1 involves acquiring a digital elevation model with a spatial resolution of 5 meters within the study area, data on 230 river network cross-sections within the study area, elevation data of the top of the dikes on both sides of the river, land use type data, and data on the process line of a "once-in-50-year" flood event.

[0108] Specifically, in step 9, the effects of dike elevation correction and breach simulation are as follows: Figure 3 As shown, in the case of a breach, the solid rectangular boxes on the shoreline represent the breach (top view), and the area within the dashed lines is a schematic diagram of the breach (side view).

[0109] The simulation log of a levee breach scenario was obtained by using the method described in Example 1:

[0110] [INFO] Simulation System Initializing...

[0111] [INFO] Setting up shared memory space for dynamic breach parameters.

[0112] [INFO] Shared memory 'SCENARIO_FLAG' initialized to 0.

[0113] [INFO] Loading upstream boundary condition: “50-year flood event”.

[0114] [INFO] Simulation starting.

[0115] [RUNNING] Sim Time: 2023-08-01 08:00:00 Checking flag... [0]

[0116] [RUNNING] Sim Time: 2023-08-01 10:30:00 Checking flag... [0]

[0117] [RUNNING] Sim Time: 2023-08-01 14:00:00 Checking flag... [0]

[0118] [INFO] writing output files...

[0119] ……

[0120] [EVENT] Interactive controller has written scenario to shared memory.

[0121] [EVENT] 'SCENARIO_FLAG' has been set to 1.

[0122] [RUNNING] Sim Time: 2023-08-01 18:00:00 Checking flag... [1]

[0123] [SYSTEM] Scenario change detected! Pausing main computation loop.

[0124] [SYSTEM] Acquiring mutex lock on shared memory... Acquired.

[0125] [SYSTEM] Reading new breach parameters:

[0126] [SYSTEM] Modifying levee elevation profile.

[0127] [SYSTEM] Model update successful.

[0128] [SYSTEM] Resetting 'SCENARIO_FLAG' to 0.

[0129] [SYSTEM] Releasing mutex lock.

[0130] [SYSTEM] Resuming simulation.

[0131] [RUNNING] Sim Time: 2023-08-01 18:00:02 Checking flag... [0]

[0132] [RUNNING] Sim Time: 2023-08-01 20:00:00 Checking flag... [0]

[0133] [INFO] writing output files...

[0134] ...

[0135] [RUNNING] Sim Time: 2023-08-03 07:59:59 Checking flag... [0]

[0136] [INFO] Simulation end time reached.

[0137] [INFO] Finalizing simulation...

[0138] [COMPLETE] Simulation Finished.

[0139] Finally, it should be noted that the above is only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention (such as the application of formulas, the order of steps, etc.) without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dynamic simulation method for levee breach scenarios based on a one- or two-dimensional coupled model, characterized in that, The method includes the following steps: Step 1, Obtain Data Acquire digital elevation models, river network cross-section data, river network embankment elevation data, land use type data, and flood forecast data within the study area; Step 2, Construct a coupling model First, based on the digital elevation model and land use type data described in step 1, a two-dimensional hydrodynamic model of the study area is constructed; based on the river network cross-section data and river network embankment elevation data described in step 1, a one-dimensional river network model of the study area is constructed. Then, based on the spatial relationship, the two-dimensional hydrodynamic model and the one-dimensional river network model are coupled by lateral connection to complete the construction of the one- and two-dimensional coupled model of the study area; Step 3, Simulation Parameter Settings The flood forecast data obtained in step 1 is used as the inflow boundary condition of the one-dimensional coupled model. The simulation calculation parameters are set, including the calculation start time, calculation end time, and output time step. An integer variable is set in the shared memory space as the "scenario change" trigger flag, with the initial value set to "0". Step 4, Create the rupture parameter structure During the initialization phase of the simulation system, the dike breach parameters are separated from the static data structure of the core algorithm and designed as an independent, dynamically updatable "breach parameter structure". A shared memory region that can be read and written by the interactive control program is allocated in memory for this structure, and atomic access rules are defined for read and write operations. Step 5: Hydrodynamic Calculation and Result Output The calculation time step is determined based on the flow field state at the current time t. The main program calculates the flow field data based on time t, performs hydrodynamic deduction with a time step of dt, obtains the flow field results at time t+dt, updates the flow field state of the computational domain based on the calculation results, and determines whether to output the results based on the output time step described in step 3. The flow field state and output results include the water depth, x-direction velocity, and y-direction velocity data of each grid cell in the two-dimensional hydrodynamic model, as well as the water level and flow rate data of each river cross-section in the one-dimensional river network model. Step 6, Update breach parameters and trigger flags After each calculation step, it checks whether the user set and submitted new vulnerability parameters through the graphical user interface or command-line tool during this calculation step. If the user submits new vulnerability parameters, the interactive control program receives the vulnerability parameters and writes them to the vulnerability parameter structure described in step 4 through an atomic operation, while setting the "scenario change" trigger flag described in step 3 to "1". If no user submission is detected, the "scenario change" trigger flag is kept at "0". Step 7, Check the scenario change flag. The "scenario change" trigger flag set in step 3 is checked in a non-blocking manner. If its value is detected as "1", the simulation calculation main program immediately pauses the current calculation and executes step 8; if the flag value is detected as "0", then step 11 is executed. Step 8, Reading Ulcer Parameters After the simulation calculation main program obtains access to shared memory, it reads all parameter values ​​from the updated rupture parameter structure in step 6. Step 9, Dike Elevation Correction and Breach Simulation Based on the coordinates of the breach center point recorded in the breach parameter structure, the location of the river embankment where the breach occurred is determined according to the spatial relationship; at the same time, based on the breach width and the bottom elevation information of the breach, the elevation of the river embankment is corrected in the one-dimensional river network model to simulate the breach state. Step 10, Flag Reset and Calculation Recovery Reset the "Scenario Change" trigger flag to "0", release access permissions to shared memory, and continue to step 5 to perform the calculation for the next time step; Step 11, Simulate termination judgment Determine if the current simulation time is greater than the calculation termination time set in step 3; if the current time is not greater than the termination time, return to step 5 to continue the time progression loop; if the current time is greater than the termination time, execute the simulation program termination step. Step 12, the simulation program terminates. Release all memory and terminate the simulation program.

2. The dynamic simulation method for levee breach scenarios according to claim 1, characterized in that, In step 1, all data obtained must be in a unified geographic coordinate system and elevation datum.

3. The dynamic simulation method for levee breach scenarios according to claim 1, characterized in that, In step 2, the two-dimensional hydrodynamic model is constructed using the finite volume method to solve the two-dimensional shallow water equations; the one-dimensional river network model is constructed using the finite element method to solve the one-dimensional Saint-Venant equations. In the construction of the one-dimensional coupled model, the weir flow formula is used to calculate the water exchange volume between the one-dimensional river channel and the two-dimensional surface.

4. The dynamic simulation method for levee breach scenarios according to claim 1, characterized in that, In step 4, the breach parameter structure includes the coordinates of the breach center point, the breach width, and the breach bottom elevation; the atomic access rule uses a mutex lock mechanism to protect the shared memory, ensuring that only one process or thread can access the shared memory area at any given time, thereby guaranteeing the mutual exclusion and consistency of data access.

5. The dynamic simulation method for levee breach scenarios according to claim 1, characterized in that, In step 5, the time step The calculation formula is as follows: In the formula, For safety reasons, , , , represent the spatial step size of the grid in the x and y directions, respectively; u and v represent the flow velocities in the x and y directions, respectively; g represents the gravitational acceleration; The water is deep.

6. The dynamic simulation method for levee breach scenarios according to claim 1, characterized in that, In step 7, the non-blocking mode check means that after each calculation step, the main program reads the value of the scenario change trigger flag to determine whether there is a new breach scenario that needs to be processed, without interrupting the current calculation process.

7. The dynamic simulation method for levee breach scenarios according to claim 1, characterized in that, Step 9, the elevation correction and breach simulation, specifically includes: modifying the elevation value of the corresponding river embankment location to the bottom elevation of the breach, and establishing a hydraulic connection between the one-dimensional river channel and the two-dimensional surface within the breach width range.

8. The dynamic simulation method for levee breach scenarios according to any one of claims 1 to 7, characterized in that, The method supports the dynamic introduction of different breach scenarios multiple times during the simulation process, and steps 6 to 10 are repeated each time a new breach scenario is introduced.

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