Method and device for predicting levee breach flood

Abstract

The present application relates to a kind of river embankment dam break flood prediction method and device, belong to flood prediction technical field, method includes according to weather bureau forecast rainfall, using historical rainfall-river boundary fitting algorithm to predict future river boundary data, and based on future river boundary data and one-dimensional water power coupling mathematical model, future river section water level and future river section flow are predicted;Based on future river section water level and future river section flow, in combination with the algorithm of discontinuous interface, the water depth and flow rate of coupling interface are determined;The water depth and flow rate of coupling interface are used as boundary condition, act on two-dimensional water power coupling mathematical model, and in combination with momentum flux correction method, future ground flood water level is predicted, the problem of static water imbalance, unstable prediction exists when flood water level is predicted is solved, to improve flood water level prediction accuracy advantageously.

Description

Technical Field

[0001] This invention relates to the field of flash flood early warning technology, and in particular to a method and device for predicting floods caused by river embankment breaches. Background Technology

[0002] Currently, due to human error and insufficient accuracy in collecting elevation data, the simulation and prediction of dam-break floods suffer from numerical oscillations and computational instability. Furthermore, in surface flood simulations, variations in terrain elevation can lead to hydrostatic imbalances without proper handling. Summary of the Invention

[0003] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a method and apparatus for predicting river embankment breach floods, which solves the technical problems of static water imbalance and unstable prediction in flood level prediction.

[0004] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0005] The first aspect of this invention provides a method for predicting river embankment breach floods.

[0006] The method for predicting riverbank breach floods proposed in this embodiment of the invention includes:

[0007] Acquire river cross-section data, ground node data, and meteorological bureau forecast rainfall, and establish a river digital twin based on the river cross-section data, and establish a ground digital twin based on the ground node data;

[0008] A coupling interface is established based on the digital twin of the river channel and the digital twin of the ground. A one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model are established based on the digital twin of the river channel, the digital twin of the ground, and the coupling interface.

[0009] Based on the rainfall forecast from the meteorological bureau, the future river boundary data is predicted using a historical rainfall-river boundary fitting algorithm. Based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model, the future river cross-section water level and future river cross-section flow are predicted.

[0010] Based on the future river cross-section water level and the future river cross-section flow, the discontinuous interface algorithm is used to determine the water depth and flow velocity of the coupling interface;

[0011] The water depth and flow velocity at the coupling interface are used as boundary conditions for the two-dimensional hydrodynamic coupling mathematical model, and the momentum flux correction method is used to predict future surface flood levels.

[0012] In some instances, the coupling interface includes a non-dam coupling interface and a dam coupling interface, and the discontinuous interface algorithm includes a first discontinuous interface algorithm and a second discontinuous interface algorithm, wherein,

[0013] Based on the future river cross-section water level and future river cross-section flow, the discontinuous interface algorithm is used to determine the water depth and flow velocity at the coupling interface, including:

[0014] Based on the future river section water level and the future river section flow, the first discontinuous interface algorithm is used to determine the water depth and flow velocity at the non-dam coupling interface, and based on the future river section water level and the future river section flow, the second discontinuous interface algorithm is used to determine the water depth and flow velocity at the dam coupling interface; wherein, the first discontinuous interface algorithm and the second discontinuous interface algorithm are two different discontinuous interface algorithms;

[0015] The method of using the water depth and flow velocity at the coupling interface as boundary conditions of the two-dimensional hydrodynamic coupling mathematical model, and employing a momentum flux correction method to predict future surface flood levels, includes:

[0016] The water depth and velocity at least one of the non-dam coupling interfaces and the dam coupling interfaces are used as boundary conditions for the two-dimensional hydrodynamic coupling mathematical model, and the momentum flux correction method is used to predict future surface flood levels.

[0017] In some instances, before determining the water depth and flow velocity at the coupling interface using a discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow, the method includes:

[0018] Obtain real-time river cross-section water level data and real-time river cross-section flow data;

[0019] The real-time river cross-section water level data and real-time river cross-section flow data are processed into time-water level data pairs and time-flow data pairs, respectively.

[0020] The predicted future river section water level and future river section flow are corrected using the time-water level data pairs and time-flow data pairs to obtain the corrected future river section water level and future river section flow.

[0021] The step of determining the water depth and flow velocity at the coupling interface using a discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow includes:

[0022] Based on the corrected future river cross-section water level and future river cross-section flow, the discontinuous interface algorithm is used to determine the water depth and flow velocity at the coupling interface.

[0023] In some instances, the determination of the water depth and flow velocity at the non-dam coupling interface using the first discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow includes:

[0024] Based on the future river cross-section water level and the water level calculation model of the coupled interface nodes, the water level of the coupled interface nodes is obtained; wherein, the coupled interface nodes are the ground nodes in the coupled interface.

[0025] Based on the water level of the coupling interface nodes, the water level of the coupling interface edge is determined; wherein, the edge formed by every two adjacent coupling interface nodes is the coupling interface edge.

[0026] The water depth at the non-dam coupling interface is obtained by subtracting the virtual elevation of the coupling interface edge from the water level at the coupling interface edge; wherein, the virtual elevation of the coupling interface edge is determined by the virtual elevation of the coupling interface node.

[0027] The future river cross-section flow velocity is obtained based on the future river cross-section flow rate and the cross-sectional area corresponding to the future river cross-section water level.

[0028] Based on the flow velocity calculation model of the future river cross-section and the coupling interface edge, the flow velocity of the non-dam coupling interface is obtained.

[0029] In some instances, the determination of the water depth and flow velocity at the dam coupling interface using the second discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow includes:

[0030] Based on the future river cross-section water level and the water level calculation model of the coupled interface nodes, the water level of the coupled interface nodes is obtained; wherein, the coupled interface nodes are the ground nodes in the coupled interface.

[0031] Based on the water level of the coupling interface nodes, the water level of the coupling interface edge is determined; wherein, the edge formed by every two adjacent coupling interface nodes is the coupling interface edge.

[0032] The water depth at the dam's coupling interface is obtained by subtracting the virtual elevation of the coupling interface edge from the water level at the coupling interface edge; wherein, the virtual elevation of the coupling interface edge is determined by the virtual elevation of the coupling interface node; wherein, if the dam fails, the virtual elevation of the coupling interface node is updated based on the dam failure width and depth, and the updated virtual elevation of the coupling interface node is used to determine the virtual elevation of the coupling interface edge.

[0033] The future river cross-section flow velocity is obtained based on the future river cross-section flow rate and the cross-sectional area corresponding to the future river cross-section water level.

[0034] Based on the flow velocity calculation model of the future river cross-section and the coupling interface edge, the flow velocity of the dam coupling interface is obtained.

[0035] In some instances, the method of using the water depth and flow velocity at the coupling interface as boundary conditions applied to the two-dimensional hydrodynamic coupling mathematical model, and combining this with a momentum flux correction method to predict future surface flood levels, includes:

[0036] The water depth and flow velocity at the coupling interface are used as boundary conditions to apply to the two-dimensional hydrodynamic coupling mathematical model. Combined with the momentum flux correction method, the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh are output.

[0037] The water depth of the triangular mesh is determined based on the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh.

[0038] The future surface flood level is obtained based on the water depth and elevation of the triangular grid; wherein the elevation of the triangular grid is the average of the elevations of the three nodes of the triangular grid.

[0039] In some instances, the two-dimensional hydrodynamic coupling mathematical model includes:

[0040] Where h represents the water depth at the coupling interface; u represents the x-component of the flow velocity at the coupling interface; v represents the y-component of the flow velocity at the coupling interface; t represents time; S b Indicates the bottom slope; S f This represents the momentum loss due to frictional resistance. For the mass flux of the triangular mesh;

[0041] Let be the momentum flux of the triangular mesh in the x-direction;

[0042] Let be the momentum flux of the triangular mesh in the y-direction.

[0043] In some instances, determining the water depth of the triangular mesh based on the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh includes:

[0044] The total momentum flux of the triangular mesh is obtained by summing the momentum flux contributed by the bottom slope of the two-dimensional mesh.

[0045] The water depth of the triangular mesh is determined based on the total momentum flux and the mass flux of the triangular mesh.

[0046] In some instances, the momentum flux contributed by the bottom slope of the two-dimensional grid is output, including:

[0047] If the water level in the two-dimensional grid is greater than or equal to the maximum original elevation of the nodes in the two-dimensional grid, then the momentum flux contributed by the bottom slope term of the two-dimensional grid is determined based on the first model; the first model is:

[0048] ;

[0049] in, This represents the component of the momentum flux contributed by the bottom slope term of the two-dimensional grid in the x-direction. y represents the component of momentum flux contributed by the bottom slope term of the two-dimensional grid in the y-direction; g represents gravitational acceleration; B represents the bottom elevation of the two-dimensional grid; A represents the area of ​​the two-dimensional grid; Z represents the water level of the two-dimensional grid.

[0050] If the water level in the two-dimensional grid is less than the maximum original elevation of the nodes in the two-dimensional grid, then the momentum flux contributed by the bottom slope term of the two-dimensional grid is determined based on the second model; the second model is:

[0051] ;

[0052] in, This represents the component of the momentum flux contributed by the bottom slope term of the two-dimensional grid in the x-direction. represents the component of momentum flux contributed by the bottom slope term of the two-dimensional grid in the y-direction; g represents gravitational acceleration; , , These are the x-coordinates of nodes 1, 2, and 3 in the two-dimensional grid, respectively. , , These are the y-coordinates of nodes 1, 2, and 3 in the two-dimensional grid, respectively. , , These are the virtual elevations of edges 1, 2, and 3 of the two-dimensional grid, respectively. This is the product of the gradient of the base slope of the triangle in the x-direction and the area of ​​the triangle; This is the product of the gradient of the base slope of the triangle in the y-direction and the area of ​​the triangle; The maximum original elevation of nodes 1, 2, and 3 in the two-dimensional grid; The virtual elevation of node 1 in the two-dimensional grid; The virtual elevation of node 2 in the two-dimensional grid; The virtual elevation of node 3 in the two-dimensional grid.

[0053] A second aspect of the present invention provides a device for predicting embankment breach floods, comprising:

[0054] The data acquisition unit is used to acquire river cross-section data, ground node data and meteorological bureau forecast rainfall, and to establish a river digital twin based on the river cross-section data and a ground digital twin based on the ground node data.

[0055] The model building unit is used to establish a coupling interface based on the digital twin of the river channel and the digital twin of the ground, and to establish a one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model based on the digital twin of the river channel, the digital twin of the ground and the coupling interface.

[0056] The future river section water level and flow prediction unit is used to predict the future river boundary data based on the rainfall forecast by the meteorological bureau, using the historical rainfall-river boundary fitting algorithm, and to predict the future river section water level and future river section flow based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model.

[0057] The unit for determining the water depth and velocity at the coupling interface is used to determine the water depth and velocity at the coupling interface based on the future river cross-section water level and the future river cross-section flow rate, using an intermittent interface algorithm.

[0058] The flood level prediction unit is used to use the water depth and flow velocity at the coupling interface as boundary conditions of the two-dimensional hydrodynamic coupling mathematical model, and to predict future surface flood levels using a momentum flux correction method.

[0059] This invention discloses a method for predicting embankment breach floods, comprising: acquiring river cross-section data, ground node data, and meteorological forecast rainfall; establishing a river digital twin based on the river cross-section data and a ground digital twin based on the ground node data; establishing a coupling interface based on the river digital twin and the ground digital twin; establishing a one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model based on the river digital twin, the ground digital twin, and the coupling interface; predicting future river boundary data using a historical rainfall-river boundary fitting algorithm based on the meteorological forecast rainfall; predicting future river cross-section water level and future river cross-section flow based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model; determining the water depth and velocity of the coupling interface based on the future river cross-section water level and future river cross-section flow, combined with a discontinuous interface algorithm; and using the water depth and velocity of the coupling interface as boundary conditions applied to the two-dimensional hydrodynamic coupling mathematical model, combined with a momentum flux correction method, to predict the future surface flood level. In this application, the water depth and velocity of the coupling interface are determined by combining the future river cross-section water level and future river cross-section flow with the discontinuous interface algorithm. The water depth and velocity of the coupling interface are used as boundary conditions to act on the two-dimensional hydrodynamic coupling mathematical model, and combined with the momentum flux correction method, the future surface flood level is predicted. This solves the problems of static water imbalance and prediction instability in flood level prediction, thereby improving the accuracy of flood level prediction. Attached Figure Description

[0060] Figure 1 A flowchart illustrating a method for predicting embankment breach floods provided in an embodiment of the present invention;

[0061] Figure 2 The digital twin of the river channel, the digital twin of the ground, and the schematic diagram of the river channel cross-section are provided in the embodiments of the present invention.

[0062] Figure 3 A schematic diagram of a riverbank breach flood prediction system provided in an embodiment of the present invention;

[0063] Figure 4 This is a schematic diagram of the structure of a flood prediction device for riverbank breaches provided in an embodiment of the present invention. Detailed Implementation

[0064] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0065] The method for predicting embankment breach floods proposed in this invention addresses the problems of static water imbalance and prediction instability in flood level prediction. By using the future cross-sectional water level and future cross-sectional flow rate of the river channel, combined with the discontinuous interface algorithm, the water depth and velocity at the coupling interface are determined. The water depth and velocity at the coupling interface are then used as boundary conditions to apply to a two-dimensional hydrodynamic coupling mathematical model, and combined with the momentum flux correction method, the future surface flood level is predicted, thereby improving the accuracy of flood level prediction.

[0066] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0067] Figure 1 This is a flowchart illustrating a method for predicting embankment breach floods, provided as an embodiment of the present invention. Figure 1 As shown in the embodiment of the present invention, the method for predicting river embankment breach floods includes:

[0068] Step 100: Obtain river cross-section data, ground node data and meteorological bureau forecast rainfall, and establish a river digital twin based on the river cross-section data, and establish a ground digital twin based on the ground node data;

[0069] Step 110: Establish a coupling interface based on the digital twin of the river channel and the digital twin of the ground, and establish a one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model based on the digital twin of the river channel, the digital twin of the ground, and the coupling interface.

[0070] Step 120: Based on the rainfall forecast from the meteorological bureau, use the historical rainfall-river boundary fitting algorithm to predict the future river boundary data, and based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model, predict the future river cross-section water level and the future river cross-section flow.

[0071] Step 130: Based on the future river section water level and the future river section flow rate, use the discontinuous interface algorithm to determine the water depth and flow velocity of the coupling interface;

[0072] Step 140: Use the water depth and flow velocity at the coupling interface as boundary conditions for the two-dimensional hydrodynamic coupling mathematical model, and use the momentum flux correction method to predict the future surface flood level.

[0073] In this exemplary embodiment, the river cross-section data includes river cross-section coordinate data, river cross-section scatter point coordinate data, and river cross-section scatter point elevation data; the ground node data includes ground non-dam node coordinate data, ground non-dam node elevation data, ground dam node coordinate data, and ground dam node elevation data.

[0074] In this exemplary embodiment, the coupling interface refers to the transition section between the river channel and the ground. The coupling interface includes two river channel cross sections and a string of points consisting of a series of ground nodes. The ground nodes in the coupling interface are hereinafter referred to as coupling interface nodes, and the edge formed by every two adjacent ground nodes in the coupling interface is hereinafter referred to as a coupling interface edge. If the ground nodes in the coupling interface are non-dam nodes, the coupling interface is called a non-dam coupling interface; if the ground nodes in the coupling interface are dam nodes, the coupling interface is called a dam coupling interface.

[0075] In this exemplary embodiment, Figure 2 The images show a digital twin of a river channel, a digital twin of the ground, and a schematic diagram of a river channel cross-section, provided as embodiments of the present invention. Figure 2 As shown, the digital twin of the river channel contains multiple river cross-sections, each composed of a series of scattered points. The outermost scattered points of each river cross-section represent the levee points. The location of each river cross-section is obtained from the river cross-section coordinate data collected in the river cross-section data set. The coordinates and elevations of the scattered points for each river cross-section are obtained from the river cross-section scattered point coordinate data and river cross-section scattered point elevation data collected in the river cross-section data set.

[0076] In this exemplary embodiment, the ground digital twin includes a series of ground nodes, the coordinates and elevation of which are obtained from the collected ground node data. Three ground nodes form a triangular mesh, and two ground nodes form an edge; the ground digital twin is composed of a series of triangular meshes.

[0077] In this application, the water depth and velocity of the coupling interface are determined by combining the future river cross-section water level and future river cross-section flow with the discontinuous interface algorithm. The water depth and velocity of the coupling interface are used as boundary conditions to act on the two-dimensional hydrodynamic coupling mathematical model, and combined with the momentum flux correction method, the future surface flood level is predicted. This solves the problems of static water imbalance and prediction instability in flood level prediction, thereby improving the accuracy of flood level prediction.

[0078] In some instances, the coupling interface includes a non-dam coupling interface and a dam coupling interface; the discontinuous interface algorithm includes a first discontinuous interface algorithm and a second discontinuous interface algorithm.

[0079] The step of determining the water depth and flow velocity at the coupling interface using a discontinuous interface algorithm based on the future river cross-section water level and future river cross-section flow includes:

[0080] Based on the future river section water level and the future river section flow, the first discontinuous interface algorithm is used to determine the water depth and flow velocity at the non-dam coupling interface, and based on the future river section water level and the future river section flow, the second discontinuous interface algorithm is used to determine the water depth and flow velocity at the dam coupling interface; wherein, the first discontinuous interface algorithm and the second discontinuous interface algorithm are two different discontinuous interface algorithms;

[0081] The step of inputting the water depth and flow velocity at the coupling interface into a two-dimensional hydrodynamic coupling mathematical model, and combining it with a momentum flux correction method, to predict future surface flood levels includes:

[0082] The water depth and velocity at the non-dam coupling interface and at least one of the water depth and velocity at the dam coupling interface are input into a two-dimensional hydrodynamic coupling mathematical model, and combined with the momentum flux correction method, to predict the future surface flood level.

[0083] In this exemplary embodiment, based on the future river cross-section water level and future river cross-section flow, the water depth and flow velocity at the non-dam coupling interface are calculated using a first discontinuous interface algorithm, and the water depth and flow velocity at the dam coupling interface are calculated using a second discontinuous interface algorithm. The water depth and flow velocity at the non-dam coupling interface and the dam coupling interface are used as boundary conditions for the two-dimensional hydrodynamic coupling mathematical model. Here, the water depth at the coupling interface refers to the water depth at each edge of the coupling interface, and the flow velocity at the coupling interface refers to the flow velocity at each edge of the coupling interface.

[0084] Based on time-water level data pairs and time-flow data pairs, the future river cross-section water level and future river cross-section flow are corrected.

[0085] In some instances, before determining the water depth and flow velocity at the coupling interface using a discontinuous interface algorithm based on the future river cross-section water level and future river cross-section flow, the method includes:

[0086] Obtain real-time river cross-section water level data and real-time river cross-section flow data;

[0087] The real-time river cross-section water level data and real-time river cross-section flow data are processed into time-water level data pairs and time-flow data pairs, respectively.

[0088] The predicted future river section water level and future river section flow are corrected using the time-water level data pairs and time-flow data pairs to obtain the corrected future river section water level and future river section flow.

[0089] The determination of the water depth and flow velocity at the coupling interface based on the future river cross-section water level and future river cross-section flow, combined with the discontinuous interface algorithm, includes:

[0090] Based on the corrected future river cross-section water level and future river cross-section flow, and combined with the discontinuous interface algorithm, the water depth and flow velocity at the coupling interface are determined.

[0091] In this exemplary embodiment, the collected real-time river cross-section water level data is usually the real-time water level data of a portion of the river cross-section, and the collected real-time river cross-section flow data is usually the real-time flow data of a portion of the river cross-section.

[0092] The specific implementation of predicting future river boundary data based on forecasted rainfall using a historical rainfall-river boundary fitting algorithm includes the following steps:

[0093] Step (1): Obtain historical rainfall data and corresponding river boundary data;

[0094] Step (2): Calculate the deviation rate between the forecast rainfall and the historical rainfall. The formula for calculating the deviation rate is:

[0095] ;

[0096] in, y is the deviation rate; n is the number of data points; i For forecasting rainfall; Y i Historical rainfall;

[0097] Step (3): Select the river boundary corresponding to the rainfall with the smallest deviation rate between the forecast rainfall and the historical rainfall as the data for predicting the future boundary of the river.

[0098] The establishment of the one-dimensional and two-dimensional hydrodynamic coupling mathematical models includes the following steps:

[0099] Step (1): Establish a one-dimensional hydrodynamic coupling mathematical model. Specifically, the one-dimensional hydrodynamic coupling mathematical model is a one-dimensional river channel mathematical model. The governing equations are the Saint-Venant equations.

[0100] Step (2): Establish a two-dimensional hydrodynamic coupling mathematical model, and adopt two-dimensional shallow water equations as the governing equations;

[0101] Step (3): Perform the coupling of the one-dimensional and two-dimensional mathematical models of the river channel and the ground based on the one-dimensional river channel mathematical model and the two-dimensional hydrodynamic coupling mathematical model.

[0102] Furthermore, in step (1) above, a one-dimensional river channel mathematical model is established, and the governing equations are as follows:

[0103] ;

[0104] Wherein, B represents the width of the water surface at the river cross-section; Z represents the water level at the river cross-section; Q represents the flow rate at the river cross-section; A represents the cross-sectional area of ​​the river; t represents time; x represents the distance along the river; q represents the source term; g represents the gravitational acceleration; S f This represents the momentum loss due to frictional resistance.

[0105] This invention employs the Godunov finite volume method to solve the one-dimensional river channel control equations. Hancock predictive correction ensures a second-order temporal scheme for the solution, while MUSCL linear reconstruction ensures a second-order spatial scheme. An approximate Riemannian solver with an HLL scheme is used to calculate the numerical flux at the cell interface. These methods demonstrate excellent shock wave capture capabilities and can simulate water flow under complex terrain conditions. Furthermore, this invention utilizes OpenMP parallel computing technology to improve the computational speed of the one-dimensional river channel mathematical model. Since the techniques and methods used to establish the one-dimensional river channel mathematical model are already known in the academic community, they will not be described in detail here.

[0106] The specific calculation method for simulating and predicting future river cross-sectional water levels and future river cross-sectional flows based on a one-dimensional river mathematical model, using future river boundary data, is known in academia and will not be detailed here. The method for correcting future river cross-sectional water levels and future river cross-sectional flows based on time-water level data pairs and time-flow data pairs includes the following steps:

[0107] Step (1): Obtain the water level and future river section water level in the time-water level data pair at the same cross section and the same time; obtain the flow rate and future river section flow rate in the time-flow data pair at the same cross section and the same time.

[0108] Step (2): Calculate the difference between the water level at the time-water level data point and the future water level at the river section, and calculate the average value of the water level difference; calculate the difference between the flow rate at the time-flow rate data point and the future flow rate at the river section, and calculate the average value of the flow rate difference.

[0109] Step (3): Increase the average of the water level differences of all future river sections to obtain the corrected future river section water level, and increase the average of the flow differences of all future river sections to obtain the corrected future river section flow.

[0110] The two-dimensional shallow water equation mathematical model established in this invention employs a tilted triangular mesh, which can well adapt to two-dimensional boundary shapes. The governing equations are solved using Godunov finite volume, and Hancock prediction correction ensures a second-order temporal scheme. Linear reconstruction ensures a second-order spatial scheme, and an approximate Riemannian solver with HLLC scheme is used to calculate numerical flux at the cell interface. These methods exhibit good shock wave capture capabilities and can simulate water flow under complex terrain conditions. Furthermore, this invention employs GPU parallel computing and OpenMP parallel computing techniques to improve the model's computational speed when establishing the two-dimensional hydrodynamic coupling mathematical model. Since the techniques and methods used to establish the two-dimensional hydrodynamic coupling mathematical model are well-known in academia, they will not be described in detail here.

[0111] In some instances, determining the water depth and flow velocity at the non-dam coupling interface based on the future river cross-section water level and future river cross-section flow, combined with the first discontinuous interface algorithm, includes:

[0112] Based on the future river cross-section water level and the water level calculation model of the coupling interface node, the water level of the coupling interface node is obtained.

[0113] Based on the water level of the nodes at the coupling interface, determine the water level at the edge of the coupling interface;

[0114] The water depth at the non-dam coupling interface is obtained by subtracting the virtual elevation of the coupling interface edge from the water level at the coupling interface edge; wherein, the virtual elevation of the coupling interface edge is determined by the virtual elevation of the coupling interface node.

[0115] The future river cross-section flow velocity is obtained based on the future river cross-section flow rate and the cross-sectional area corresponding to the future river cross-section water level.

[0116] Based on the flow velocity calculation model of the future river cross-section and the coupling interface edge, the flow velocity of the non-dam coupling interface is obtained.

[0117] In this exemplary embodiment, the step of determining the water depth and flow velocity at the dam coupling interface using the second discontinuous interface algorithm based on the future river cross-section water level and future river cross-section flow includes:

[0118] Based on the future river cross-section water level and the water level calculation model of the coupling interface node, the water level of the coupling interface node is obtained.

[0119] Based on the water level of the nodes at the coupling interface, determine the water level at the edge of the coupling interface;

[0120] The water depth at the dam's coupling interface is obtained by subtracting the virtual elevation of the coupling interface edge from the water level at the coupling interface edge; wherein, the virtual elevation of the coupling interface edge is determined by the virtual elevation of the coupling interface node; wherein, if the dam fails, the virtual elevation of the coupling interface node is updated based on the dam failure width and depth, and the updated virtual elevation of the coupling interface node is used to determine the virtual elevation of the coupling interface edge.

[0121] The future river cross-section flow velocity is obtained based on the future river cross-section flow rate and the cross-sectional area corresponding to the future river cross-section water level.

[0122] Based on the flow velocity calculation model of the future river cross-section and the coupling interface edge, the flow velocity of the dam coupling interface is obtained.

[0123] In this exemplary embodiment, it is assumed that the two river sections of the coupling interface are river section A and river section B, and the coupling interface nodes are coupled interface node 1, coupled interface node 2, ... coupled interface node m in connection order. The embankment of river section A is connected to coupled interface node 1, and the embankment of river section B is connected to coupled interface node m.

[0124] The first discontinuous interface algorithm is a method proposed in this invention for calculating the water depth and flow velocity at the coupling interface when the elevation of the levee point at the river cross section differs from the elevation of the nodes at the coupling interface in non-dam coupling interfaces. Due to human error in the collected river cross section data or insufficient accuracy of the collected ground node data, the elevation of the levee point at the river cross section is usually inconsistent with the elevation of the nodes at the coupling interface, which is either higher or lower than the elevation of the nodes at the coupling interface.

[0125] If the elevation of the levee point at the river cross-section is higher than the elevation of the coupling interface node, a large drop will occur when the river flow overflows the levee point and flows to the ground, leading to a dam-break wave. This will cause instability in the two-dimensional hydrodynamic coupling mathematical model simulation, resulting in oscillations and inaccuracies in the predicted future surface flood level. Conversely, if the elevation of the levee point at the river cross-section is lower than the elevation of the coupling interface node, the water will still flow to the ground even when it overflows the levee point but not the ground node, which is unrealistic. The first discontinuous interface algorithm can eliminate the aforementioned large drop, making the prediction results more stable, accurate, and consistent with reality. The specific steps of the first discontinuous interface algorithm include:

[0126] Step (1): Calculate the virtual elevation of the coupling interface node. Since the elevation of the river cross-section embankment point at the coupling interface is different from the elevation of the coupling interface node, the virtual elevation of the coupling interface node can be selected based on either the river cross-section embankment point or the coupling interface node elevation.

[0127] If the elevation of the coupling interface node is selected as the standard, then the virtual elevation of the coupling interface node is equal to the elevation of the coupling interface node.

[0128] If the levee point of the river channel cross-section is selected as the reference, then the virtual elevation of node 1 of the coupling interface is equal to the levee point elevation of river channel cross-section A, the virtual elevation of node m of the coupling interface is equal to the levee point elevation of river channel cross-section B, and the virtual elevation calculation formulas for the other coupling interface nodes are as follows:

[0129] ;

[0130] Where bi represents the virtual elevation of node i at the coupling interface, i = 2~m-1; L i b represents the distance between node i and node i+1 of the coupled interface; A Indicates the elevation of the levee point at river section A; b B L represents the elevation of the levee point at point B on the riverbed surface. j This represents the distance between node j and node j+1 of the coupled interface;

[0131] Step (2): Calculate the water level at the coupling interface nodes. The water level at coupling interface node 1 is equal to the future water level at river section A, and the water level at coupling interface node m is equal to the future water level at river section B. The formulas for calculating the water levels at the remaining coupling interface nodes are as follows:

[0132] ;

[0133] Among them, Z i L represents the water level at node i of the coupling interface, where i = 2 ~ m-1; i Z represents the distance between node i and node i+1 of the coupled interface; A Z represents the future water level at river section A; B Indicates the future water level at the river cross-section B; L j This represents the distance between node j and node j+1 of the coupled interface;

[0134] Step (3): Calculate the virtual elevation and water level of the coupling interface edge. The virtual elevation of the coupling interface edge is equal to the average value of the virtual elevation of the coupling interface node, and the water level of the coupling interface edge is equal to the average value of the water level of the coupling interface node.

[0135] Step (4): Calculate the water depth at the coupling interface edge. The water depth at the coupling interface edge is equal to the water level at the coupling interface edge minus the virtual elevation of the coupling interface edge.

[0136] Step (5): Calculate the flow velocity at the coupling interface edge. The formula for calculating the flow velocity at the coupling interface edge is:

[0137] ;

[0138] Among them, u i This represents the water level at edge i of the coupling interface, where i = 1 to m-1. Edge i of the coupling interface is the edge formed by node i and node i+1 of the coupling interface. i U represents the distance between node i and node i+1 of the coupled interface; A U represents the future cross-sectional velocity of the river at section A; B This represents the future cross-sectional velocity of the river at the surface of the river channel, B.

[0139] Furthermore, in step (5) above, the future river cross-section flow velocity can be obtained from the future river cross-section water level and the future river cross-section flow rate. The future river cross-section water area can be calculated based on the future river cross-section water level. The future river cross-section flow velocity is equal to the future river cross-section flow rate divided by the future river cross-section water area.

[0140] In some instances, the method of using the water depth and flow velocity at the coupling interface as boundary conditions applied to the two-dimensional hydrodynamic coupling mathematical model, and combining this with a momentum flux correction method to predict future surface flood levels, includes:

[0141] The water depth and flow velocity at the coupling interface are used as boundary conditions to apply to the two-dimensional hydrodynamic coupling mathematical model. Combined with the momentum flux correction method, the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh are output.

[0142] The water depth of the triangular mesh is determined based on the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh.

[0143] The future surface flood level is obtained based on the water depth and elevation of the triangular grid; wherein the elevation of the triangular grid is the average of the elevations of the three nodes of the triangular grid.

[0144] In this exemplary embodiment, the two-dimensional hydrodynamic coupling mathematical model includes:

[0145] Where h represents the water depth at the coupling interface; u represents the x-component of the flow velocity at the coupling interface; v represents the y-component of the flow velocity at the coupling interface; t represents time; S b Indicates the bottom slope; S f This represents the momentum loss due to frictional resistance. For the mass flux of the triangular mesh;

[0146] Let be the momentum flux of the triangular mesh in the x-direction;

[0147] Let be the momentum flux of the triangular mesh in the y-direction.

[0148] In some instances, determining the water depth of the triangular mesh based on the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh includes:

[0149] The total momentum flux of the triangular mesh is obtained by summing the momentum flux contributed by the bottom slope of the two-dimensional mesh.

[0150] The water depth of the triangular mesh is determined based on the total momentum flux and the mass flux of the triangular mesh.

[0151] In this exemplary embodiment, the second discontinuous interface algorithm is a method proposed by the present invention for calculating water depth and flow velocity at the dam coupling interface. The dam coupling interface includes ground dam nodes. When the dam fails, the elevation of the ground dam nodes within the dam failure range will decrease. The second discontinuous interface algorithm can find the ground dam nodes whose elevation needs to be reduced and update their elevations. The specific steps of the second discontinuous interface algorithm include:

[0152] Step (1): Determine whether the dam has collapsed. In this invention, the determination is based on the average future water level of the river section in the coupling interface. When the average future water level of the river section is greater than the dam collapse threshold, the dam collapses. If the dam collapses, the dam collapse width dx and depth dh are calculated, and the elevation of the coupling interface nodes is updated. The elevation of the coupling interface nodes included by the width dx extending from the center of the coupling interface to both sides is updated to minus dh. If the dam has not collapsed, the elevation of the coupling interface nodes does not need to be updated.

[0153] Step (2): Calculate the water level of the coupled interface node. The calculation method of the water level of the coupled interface node is the same as that of the first discontinuous interface algorithm, and will not be repeated here.

[0154] Step (3): Calculate the elevation and water level of the coupling interface edge. The elevation of the coupling interface edge is equal to the average elevation of the coupling interface nodes, and the water level of the coupling interface edge is equal to the average water level of the coupling interface nodes.

[0155] Step (4): Calculate the water depth at the coupling interface edge. The water depth at the coupling interface edge is equal to the water level at the coupling interface edge minus the elevation of the coupling interface edge.

[0156] Step (5): Calculate the flow velocity at the coupled interface edge. The calculation method for the flow velocity at the coupled interface edge is the same as that in the first discontinuous interface algorithm, and will not be repeated here.

[0157] Furthermore, in step (1) above, the formula for calculating the dam failure depth dh is:

[0158] ;

[0159] Among them, K d The erosion coefficient; For water flow shear stress; dt represents the critical shear stress of the dam material; dt is the calculation time step of the model.

[0160] Furthermore, in step (1) above, the dam breach width dx is twice the dam breach depth.

[0161] In step (5) above, the specific calculation method for simulating and predicting future surface flood levels based on the boundary conditions of the two-dimensional hydrodynamic coupling mathematical model is known in the academic community, so this invention will not elaborate further.

[0162] In some instances, the momentum flux contributed by the bottom slope of the two-dimensional grid is output, including:

[0163] If the water level in the two-dimensional grid is greater than or equal to the maximum original elevation of the nodes in the two-dimensional grid, then the momentum flux contributed by the bottom slope term of the two-dimensional grid is determined based on the first model; the first model is:

[0164] ;

[0165] in, This represents the component of the momentum flux contributed by the bottom slope term of the two-dimensional grid in the x-direction. y represents the component of momentum flux contributed by the bottom slope term of the two-dimensional grid in the y-direction; g represents gravitational acceleration; B represents the bottom elevation of the two-dimensional grid; A represents the area of ​​the two-dimensional grid; Z represents the water level of the two-dimensional grid.

[0166] If the water level in the two-dimensional grid is less than the maximum original elevation of the nodes in the two-dimensional grid, then the momentum flux contributed by the bottom slope term of the two-dimensional grid is determined based on the second model; the second model is:

[0167] ;

[0168] in, This represents the component of the momentum flux contributed by the bottom slope term of the two-dimensional grid in the x-direction. represents the component of momentum flux contributed by the bottom slope term of the two-dimensional grid in the y-direction; g represents gravitational acceleration; , , These are the x-coordinates of nodes 1, 2, and 3 in the two-dimensional grid, respectively. , , These are the y-coordinates of nodes 1, 2, and 3 in the two-dimensional grid, respectively. , , These are the virtual elevations of edges 1, 2, and 3 of the two-dimensional grid, respectively. This is the product of the gradient of the base slope of the triangle in the x-direction and the area of ​​the triangle; This is the product of the gradient of the base slope of the triangle in the y-direction and the area of ​​the triangle; The maximum original elevation of nodes 1, 2, and 3 in the two-dimensional grid; The virtual elevation of node 1 in the two-dimensional grid; The virtual elevation of node 2 in the two-dimensional grid; The virtual elevation of node 3 in the two-dimensional grid.

[0169] In this exemplary embodiment, the momentum flux correction method is a method for calculating the momentum flux of a two-dimensional grid, proposed by the present invention for the static imbalance problem of a two-dimensional hydrodynamic coupled mathematical model, and includes the following steps:

[0170] Step (1): Calculate the virtual elevation of the two-dimensional grid edge. If the water level of the two-dimensional grid is greater than or equal to the maximum original elevation of the two-dimensional grid node, then the virtual elevation of the two-dimensional grid edge is equal to the average elevation of the two-dimensional grid edge node. If the water level of the two-dimensional grid is less than the maximum original elevation of the two-dimensional grid node, then the virtual elevation of the two-dimensional grid edge is equal to the maximum original elevation of the two-dimensional grid node minus the water depth of the two-dimensional grid edge after variable reconstruction.

[0171] Step (2): Based on the virtual elevation of the two-dimensional grid edge and the water depth and flow velocity of the two-dimensional grid edge after variable reconstruction, the momentum flux of the two-dimensional grid edge is calculated using the approximate Riemann solver in HLLC format.

[0172] Step (3): Calculate the momentum flux contributed by the bottom slope term of the two-dimensional grid. If the water level of the two-dimensional grid is greater than or equal to the maximum original elevation of the two-dimensional grid node, the formula for calculating the momentum flux contributed by the bottom slope term of the two-dimensional grid is the first model.

[0173] If the water level in the two-dimensional grid is less than the maximum original elevation of the two-dimensional grid nodes, then the formula for calculating the momentum flux contributed by the bottom slope term of the two-dimensional grid is the second model.

[0174] Step (4): Calculate the momentum flux of the two-dimensional grid, and sum the momentum flux of the two-dimensional grid edge in step (2) and the momentum flux contributed by the two-dimensional grid bottom slope term in step (3) to obtain the momentum flux of the two-dimensional grid.

[0175] Furthermore, in step (1) above, since the two-dimensional shallow water equation mathematical model established by this invention uses a tilted triangular mesh, the two-dimensional mesh consists of three two-dimensional mesh nodes, with each pair of two two-dimensional mesh nodes forming a two-dimensional mesh edge. The water level of the two-dimensional mesh is obtained by setting an initial value at the beginning of the simulation of the two-dimensional hydrodynamic coupling mathematical model, and thereafter obtained by the future surface flood water level predicted by the simulation of the two-dimensional hydrodynamic coupling mathematical model. The elevation of the two-dimensional mesh nodes is obtained from the collected surface node elevation data.

[0176] Furthermore, in step (2) above, the water depth and velocity of the two-dimensional grid edges are obtained by MUSCL linear reconstruction. The method for reconstructing the water depth and velocity of the two-dimensional grid edges and the method for calculating the momentum flux of the two-dimensional grid edges using the approximate Riemann solver in HLLC format are both known in the academic community, so the present invention will not elaborate on them.

[0177] Furthermore, in step (3) above, the x and y coordinates of the two-dimensional grid nodes are obtained from the collected ground node coordinate data.

[0178] Figure 3 This is a schematic diagram of a riverbank breach flood prediction system provided in an embodiment of the present invention.

[0179] This invention provides a riverbank breach flood prediction system, comprising: surveying equipment, monitoring equipment, a modeling cloud platform 01, a flood prediction platform 02, and a flood control platform 03. The modeling cloud platform 01 includes a digital twin construction module, a monitoring data receiving and processing module, and a river boundary prediction module; the flood prediction platform 02 includes a mathematical model construction module, a water level and flow rate correction module, and a coupled calculation module.

[0180] The surveying equipment is used to collect river cross-section data and ground node elevation data, and transmits the collected data to the digital twin construction module of the modeling cloud platform. The surveying equipment consists of a total station, an echo sounder, a multibeam echo sounder system, and a drone. The total station, echo sounder, and multibeam echo sounder system are used to collect river cross-section data; the total station and the drone are used to collect ground node data.

[0181] The monitoring equipment is used to collect real-time river cross-section water level data and real-time river cross-section flow data, which are transmitted in real-time to the monitoring data receiving and processing module of the modeling cloud platform via a 4G communication card. The monitoring equipment consists of data sensing devices, RTU data acquisition devices, and a 485 bus module. The 485 bus module connects the data sensing devices and the RTU data acquisition devices, which have built-in 4G communication cards. The monitoring equipment is deployed as fixed cameras at river level and flow stations, and also utilizes drones and unmanned vessels for patrol and monitoring at various locations along the river.

[0182] The digital twin construction module of the modeling cloud platform is used to receive river cross-section data and ground node data collected by surveying equipment, build a river digital twin based on the river cross-section data, build a ground digital twin based on the ground node data, further build a coupling interface, and transmit the river digital twin, ground digital twin and coupling interface to the mathematical model construction module of the flood prediction platform.

[0183] The monitoring data receiving and processing module of the modeling cloud platform is used to receive real-time river cross-section water level data and real-time river cross-section flow data collected by monitoring equipment, process the real-time river cross-section water level data into time-water level data pairs, process the real-time river cross-section flow data into time-flow data pairs, and transmit them to the water level and flow correction module of the flood prediction platform.

[0184] The river boundary prediction module of the modeling cloud platform receives rainfall forecasts from the meteorological bureau, uses a historical rainfall-river boundary fitting algorithm to predict future river boundary data based on these forecasts, and then transmits the future river boundary data to the coupled calculation module of the flood prediction platform. Rainfall forecasts from the meteorological bureau are typically obtained from urban municipal departments.

[0185] The mathematical model building module of the flood prediction platform is used to receive the river digital twin, ground digital twin and coupling interface transmitted from the modeling cloud platform to establish a one- or two-dimensional hydrodynamic coupling mathematical model.

[0186] The coupled calculation module of the flood prediction platform receives future river boundary data transmitted from the modeling cloud platform, calculates future river cross-sectional water level and future river cross-sectional flow based on a one-dimensional river mathematical model; it also calculates the water depth and velocity at the non-dam coupling interface based on the future river cross-sectional water level and future river cross-sectional flow using a first discontinuous interface algorithm; it further calculates the water depth and velocity at the dam coupling interface based on the future river cross-sectional water level and future river cross-sectional flow using a second discontinuous interface algorithm; it also calculates the future surface flood level based on the water depth and velocity at the coupling interface using a two-dimensional hydrodynamic coupled mathematical model combined with a momentum flux correction method; and it transmits the future river cross-sectional water level data, future river cross-sectional flow data, and future surface flood level data to the flood control platform.

[0187] The water level and flow rate correction module of the flood prediction platform is used to receive time-water level data pairs and time-flow rate data pairs transmitted from the modeling cloud platform, and to correct the future river cross-section water level and future river cross-section flow rate.

[0188] The flood control platform is used to receive and visualize data on future river cross-section water levels, future river cross-section flow rates, and future surface flood levels transmitted from the flood forecasting platform.

[0189] This invention provides a device for predicting river embankment breach floods. Figure 4 This is a schematic diagram of the structure of a riverbank breach flood prediction device provided in an embodiment of the present invention. Figure 4 As shown, the device for predicting levee breach floods includes:

[0190] The data acquisition unit 40 is used to acquire river cross-section data, ground node data and meteorological bureau forecast rainfall, and to establish a river digital twin based on the river cross-section data and a ground digital twin based on the ground node data.

[0191] Model building unit 41 is used to establish a coupling interface based on the digital twin of the river channel and the digital twin of the ground, and to establish a one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model based on the digital twin of the river channel, the digital twin of the ground and the coupling interface.

[0192] The future river section water level and flow prediction unit 42 is used to predict the future river boundary data based on the rainfall forecast by the meteorological bureau, using the historical rainfall-river boundary fitting algorithm, and to predict the future river section water level and future river section flow based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model.

[0193] The water depth and velocity determination unit 43 of the coupling interface is used to determine the water depth and velocity of the coupling interface based on the future river section water level and the future river section flow rate, using an intermittent interface algorithm.

[0194] The flood level prediction unit 44 is used to use the water depth and flow velocity at the coupling interface as boundary conditions of the two-dimensional hydrodynamic coupling mathematical model, and to use the momentum flux correction method to predict the future surface flood level.

[0195] Since the systems / devices described in the above embodiments of the present invention are systems / devices used to implement the methods of the above embodiments of the present invention, those skilled in the art can understand the specific structure and modifications of the systems / devices based on the methods described in the above embodiments of the present invention, and therefore will not be repeated here. All systems / devices used in the methods of the above embodiments of the present invention fall within the scope of protection of the present invention.

[0196] This invention provides a computer-readable storage medium storing a flood prediction program for river embankment breaches. When the flood prediction program for river embankment breaches is executed by a processor, it implements the flood prediction methods for river embankment breaches described in the above embodiments.

[0197] This invention provides an electronic device, including a memory, a processor, and a river embankment breach flood prediction program stored in the memory and executable on the processor. When the processor executes the river embankment breach flood prediction program, it implements the river embankment breach flood prediction method described in the above embodiments.

[0198] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0199] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0200] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0201] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0202] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for predicting embankment breach floods, characterized in that, include: Acquire river cross-section data, ground node data, and meteorological bureau forecast rainfall, and establish a river digital twin based on the river cross-section data, and establish a ground digital twin based on the ground node data; A coupling interface is established based on the digital twin of the river channel and the digital twin of the ground. A one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model are then established based on the digital twin of the river channel, the digital twin of the ground, and the coupling interface. The coupling interface refers to the transition section between the river channel and the ground, and includes two river channel cross-sections and a string of points composed of a series of ground nodes. The digital twin of the river channel includes multiple river channel cross-sections, each composed of a series of scattered points, with the outermost scattered points of each cross-section being the river channel embankment point. The digital twin of the ground includes a series of ground nodes; three ground nodes form a triangular mesh, and two ground nodes form an edge. The digital twin of the ground is composed of a series of triangular meshes. Based on the rainfall forecast from the meteorological bureau, the future river boundary data is predicted using a historical rainfall-river boundary fitting algorithm. Based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model, the future river cross-section water level and future river cross-section flow are predicted. Based on the future river cross-section water level and the future river cross-section flow, the discontinuous interface algorithm is used to determine the water depth and flow velocity of the coupling interface; The water depth and flow velocity at the coupling interface are used as boundary conditions for the two-dimensional hydrodynamic coupling mathematical model, and the momentum flux correction method is used to predict future surface flood levels.

2. The method for predicting levee breach floods according to claim 1, characterized in that, The coupling interface includes a non-dam coupling interface and a dam coupling interface, and the discontinuous interface algorithm includes a first discontinuous interface algorithm and a second discontinuous interface algorithm, wherein... Based on the future river cross-section water level and future river cross-section flow, the discontinuous interface algorithm is used to determine the water depth and flow velocity at the coupling interface, including: Based on the future river section water level and the future river section flow, the first discontinuous interface algorithm is used to determine the water depth and flow velocity at the non-dam coupling interface, and based on the future river section water level and the future river section flow, the second discontinuous interface algorithm is used to determine the water depth and flow velocity at the dam coupling interface; wherein, the first discontinuous interface algorithm and the second discontinuous interface algorithm are two different discontinuous interface algorithms; The method of using the water depth and flow velocity at the coupling interface as boundary conditions of the two-dimensional hydrodynamic coupling mathematical model, and employing a momentum flux correction method to predict future surface flood levels, includes: The water depth and velocity at least one of the non-dam coupling interfaces and the dam coupling interfaces are used as boundary conditions for the two-dimensional hydrodynamic coupling mathematical model, and the momentum flux correction method is used to predict future surface flood levels.

3. The method for predicting levee breach floods according to claim 1, characterized in that, Based on the future river cross-section water level and the future river cross-section flow, before determining the water depth and flow velocity at the coupling interface using the discontinuous interface algorithm, the method includes: Obtain real-time river cross-section water level data and real-time river cross-section flow data; The real-time river cross-section water level data and real-time river cross-section flow data are processed into time-water level data pairs and time-flow data pairs, respectively. The predicted future river section water level and future river section flow are corrected using the time-water level data pairs and time-flow data pairs to obtain the corrected future river section water level and future river section flow. The step of determining the water depth and flow velocity at the coupling interface using a discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow includes: Based on the corrected future river cross-section water level and future river cross-section flow, the discontinuous interface algorithm is used to determine the water depth and flow velocity at the coupling interface.

4. The method for predicting embankment breach floods according to claim 2, characterized in that, The step of determining the water depth and flow velocity at the non-dam coupling interface using the first discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow includes: Based on the future river cross-section water level and the water level calculation model of the coupled interface nodes, the water level of the coupled interface nodes is obtained; wherein, the coupled interface nodes are the ground nodes in the coupled interface. Based on the water level of the coupling interface nodes, the water level of the coupling interface edge is determined; wherein, the edge formed by every two adjacent coupling interface nodes is the coupling interface edge. The water depth at the non-dam coupling interface is obtained by subtracting the virtual elevation of the coupling interface edge from the water level at the coupling interface edge; wherein, the virtual elevation of the coupling interface edge is determined by the virtual elevation of the coupling interface node. The future river cross-section flow velocity is obtained based on the future river cross-section flow rate and the cross-sectional area corresponding to the future river cross-section water level. Based on the flow velocity calculation model of the future river cross-section and the coupling interface edge, the flow velocity of the non-dam coupling interface is obtained.

5. The method for predicting embankment breach floods according to claim 2, characterized in that, The step of determining the water depth and flow velocity at the dam coupling interface using the second discontinuous interface algorithm based on the future river cross-section water level and the future river cross-section flow includes: Based on the future river cross-section water level and the water level calculation model of the coupled interface nodes, the water level of the coupled interface nodes is obtained; wherein, the coupled interface nodes are the ground nodes in the coupled interface. Based on the water level of the coupling interface nodes, the water level of the coupling interface edge is determined; wherein, the edge formed by every two adjacent coupling interface nodes is the coupling interface edge. The water depth at the dam's coupling interface is obtained by subtracting the virtual elevation of the coupling interface edge from the water level at the coupling interface edge; wherein, the virtual elevation of the coupling interface edge is determined by the virtual elevation of the coupling interface node; wherein, if the dam fails, the virtual elevation of the coupling interface node is updated based on the dam failure width and depth, and the updated virtual elevation of the coupling interface node is used to determine the virtual elevation of the coupling interface edge. The future river cross-section flow velocity is obtained based on the future river cross-section flow rate and the cross-sectional area corresponding to the future river cross-section water level. Based on the flow velocity calculation model of the future river cross-section and the coupling interface edge, the flow velocity of the dam coupling interface is obtained.

6. The method for predicting embankment breach floods according to claim 2, characterized in that, The step of using the water depth and flow velocity at the coupling interface as boundary conditions, applying them to the two-dimensional hydrodynamic coupling mathematical model, and combining them with a momentum flux correction method to predict future surface flood levels includes: The water depth and flow velocity at the coupling interface are used as boundary conditions to apply to the two-dimensional hydrodynamic coupling mathematical model. Combined with the momentum flux correction method, the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh are output. The water depth of the triangular mesh is determined based on the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh. The future surface flood level is obtained based on the water depth and elevation of the triangular grid; wherein the elevation of the triangular grid is the average of the elevations of the three nodes of the triangular grid.

7. The method for predicting embankment breach floods according to claim 6, characterized in that, The two-dimensional hydrodynamic coupling mathematical model includes: Where h represents the water depth at the coupling interface; u represents the x-component of the flow velocity at the coupling interface; v represents the y-component of the flow velocity at the coupling interface; t represents time; S b Indicates the bottom slope; S f This represents the momentum loss due to frictional resistance. Here, g represents the mass flux of the triangular mesh; g represents the acceleration due to gravity. Let be the momentum flux of the triangular mesh in the x-direction; Let be the momentum flux of the triangular mesh in the y-direction.

8. The method for predicting levee breach floods according to claim 7, characterized in that, The determination of the water depth in the triangular mesh based on the mass flux and momentum flux of the triangular mesh and the momentum flux contributed by the bottom slope of the two-dimensional mesh includes: The total momentum flux of the triangular mesh is obtained by summing the momentum flux contributed by the bottom slope of the two-dimensional mesh. The water depth of the triangular mesh is determined based on the total momentum flux and the mass flux of the triangular mesh.

9. The method for predicting embankment breach floods according to claim 6, characterized in that, Output the momentum flux contributed by the bottom slope of the two-dimensional grid, including: If the water level in the two-dimensional grid is greater than or equal to the maximum original elevation of the nodes in the two-dimensional grid, then the momentum flux contributed by the bottom slope term of the two-dimensional grid is determined based on the first model; the first model is: ； in, This represents the component of the momentum flux contributed by the bottom slope term of the two-dimensional grid in the x-direction. y represents the component of momentum flux contributed by the bottom slope term of the two-dimensional grid in the y-direction; g represents gravitational acceleration; B represents the bottom elevation of the two-dimensional grid; A represents the area of ​​the two-dimensional grid; Z represents the water level of the two-dimensional grid. If the water level in the two-dimensional grid is less than the maximum original elevation of the nodes in the two-dimensional grid, then the momentum flux contributed by the bottom slope term of the two-dimensional grid is determined based on the second model; the second model is: ； in, , , These are the x-coordinates of nodes 1, 2, and 3 in the two-dimensional grid, respectively. , , These are the y-coordinates of nodes 1, 2, and 3 in the two-dimensional grid, respectively. , , These are the virtual elevations of edges 1, 2, and 3 of the two-dimensional grid, respectively. This is the product of the gradient of the base slope of the triangle in the x-direction and the area of ​​the triangle; This is the product of the gradient of the base slope of the triangle in the y-direction and the area of ​​the triangle; The maximum original elevation of nodes 1, 2, and 3 in the two-dimensional grid; The virtual elevation of node 1 in the two-dimensional grid; The virtual elevation of node 2 in the two-dimensional grid; The virtual elevation of node 3 in the two-dimensional grid.

10. A device for predicting embankment breach floods, characterized in that, include: The data acquisition unit is used to acquire river cross-section data, ground node data and meteorological bureau forecast rainfall, and to establish a river digital twin based on the river cross-section data and a ground digital twin based on the ground node data. The model building unit is used to establish a coupling interface based on the river channel digital twin and the ground digital twin, and to establish a one-dimensional hydrodynamic coupling mathematical model and a two-dimensional hydrodynamic coupling mathematical model based on the river channel digital twin, the ground digital twin, and the coupling interface. The coupling interface refers to the transition section between the river channel and the ground, and includes two river channel cross-sections and a string of points composed of a series of ground nodes. The river channel digital twin includes multiple river channel cross-sections, each composed of a series of scattered points, with the outermost scattered points of the river channel cross-section being the river channel embankment points. The ground digital twin includes a series of ground nodes; three ground nodes form a triangular mesh, two ground nodes form an edge, and the ground digital twin is composed of a series of triangular meshes. The future river section water level and flow prediction unit is used to predict the future river boundary data based on the rainfall forecast by the meteorological bureau, using the historical rainfall-river boundary fitting algorithm, and to predict the future river section water level and future river section flow based on the future river boundary data and the one-dimensional hydrodynamic coupling mathematical model. The unit for determining the water depth and velocity at the coupling interface is used to determine the water depth and velocity at the coupling interface based on the future river cross-section water level and the future river cross-section flow rate, using an intermittent interface algorithm. The flood level prediction unit is used to use the water depth and flow velocity at the coupling interface as boundary conditions of the two-dimensional hydrodynamic coupling mathematical model, and to predict future surface flood levels using a momentum flux correction method.

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