A landslide body blocks river determination method based on double-layer SPH model

Abstract

This invention provides a method for judging river channel blockage caused by landslides based on a two-layer SPH model. Addressing the current problem that the application of the two-layer SPH model to the analysis of landslide entry into water requires manual analysis and calculation of deposition results to determine whether a landslide has blocked a river, this invention proposes a method for judging river channel blockage caused by landslides based on a two-layer SPH model. This method establishes a local coordinate system for the landslide body by using a river blockage control vector and control points at both ends of the river channel. Based on this, an automatic method for judging river blockage based on the overflow channel of the control section is established. This enables automatic judgment of the river blockage process caused by landslides and accurate analysis of the degree of river blockage, which is of great significance for landslide-induced river blockage disaster assessment and risk early warning.

Description

Technical Field

[0001] This invention belongs to the technical fields of geological disaster simulation, landslide blocking river disaster analysis and prevention, and specifically relates to a method for judging landslide blocking river channels based on a two-layer SPH model. Background Technology

[0002] When landslides occur in high mountain and canyon areas, they can block river channels, forming barrier lakes. Once the barrier collapses, it will impact downstream water conservancy, transportation facilities, and other structures along the riverbanks, and may trigger a series of secondary disasters such as landslides. Therefore, the ability to quickly analyze and determine whether a landslide has completely blocked the river channel and formed a barrier is of great significance for landslide-related river blockage disaster assessment and risk warning.

[0003] Smoothed particle hydrodynamics (SPH) is widely used in the analysis of geological hazards such as high-speed, long-distance landslides involving large deformations and free surfaces. Existing research has applied a two-layer SPH model, considering soil-water interaction, to the analysis of landslide entry into water. However, whether a landslide has blocked a river often requires manual analysis of calculated deposition results, which introduces subjectivity and hinders rapid analysis and assessment. Therefore, there is an urgent need for a landslide-based method for determining river channel blockage, based on a two-layer SPH model, to automatically assess the landslide's blocking process and accurately analyze the degree of blockage. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the existing double-layer SPH model, when applied to the study of landslide blocking river problems, requires manual analysis and calculation of the accumulation results to determine whether the landslide is blocking the river. This results in a certain degree of subjectivity and is not conducive to rapid analysis and evaluation of the problem. This invention proposes a method for judging landslide blocking of river channels based on the double-layer SPH model, which realizes automatic judgment of the landslide blocking process and accurate analysis of the degree of river channel blockage.

[0005] The scheme includes the following steps: 1) Generate SPH particles for landslide body and water body based on geological survey data, obtain control vectors based on the coordinates of control points at both ends of the river channel according to the defined landslide direction, and calculate the normal vector of the control vector according to the right-hand rule; 2) In each calculation step, obtain the coordinates of the landslide body SPH particles in the local coordinate system based on the control vectors and the coordinates of the control points at both ends of the river channel, and record the maximum and minimum values ​​of the relative coordinates of the landslide body SPH particles in the ξ and η directions as the grid control values ​​of the local coordinate system; 3) Based on the relationship between the maximum value of the relative coordinates of the SPH particles in the x direction and the magnitude of the control vector, determine whether the landslide body has moved into the river. If the opposite bank is not reached, then no river blockage has occurred at that time step; if it is reached, proceed to the next step. 4) Generate local coordinate system grid coordinates based on the local coordinate system grid control values ​​and the intervals in the x and y directions of the local coordinate system grid. 5) Cycle through the landslide body SPH particles and interpolate the landslide body depth values ​​to the local coordinate system grid nodes to form the landslide body elevation information in the local coordinate system. 6) Cycle through each control section along the η-axis direction of the local coordinate system and determine the lowest elevation point of each section of the landslide body. When each control section has a lowest elevation point below the horizontal plane, it is considered that an overflow channel exists and a complete river blockage has not formed; otherwise, a complete river blockage has formed. This invention establishes a local coordinate system for the landslide dam body based on a double-layer SPH model, enabling rapid determination of the elevation of the control section, and thus accurate determination of the landslide blocking situation.

[0006] The specific technical solution adopted by this invention to solve its technical problem is as follows:

[0007] A method for judging landslide blocking river channels based on a two-layer SPH model: By establishing a local coordinate system of the landslide dam based on the two-layer SPH model, the elevation of the control section can be quickly determined, thereby enabling the judgment of landslide blocking the river.

[0008] Furthermore, SPH particles for the landslide body and water body are generated based on geological survey data. Control vectors are obtained from the coordinates of control points at both ends of the river channel according to the defined landslide direction. The normal vector of the control vector is calculated using the right-hand rule. In each calculation step, the coordinates of the landslide body SPH particles in the local coordinate system are obtained based on the control vectors and the coordinates of the control points at both ends of the river channel. The maximum and minimum values ​​of the relative coordinates of the landslide body SPH particles in the ξ and η directions are recorded as the grid control values ​​of the local coordinate system. Based on the relationship between the maximum value of the relative coordinates of the SPH particles in the ξ direction and the magnitude of the control vector, it is determined whether the landslide body has moved to the opposite side of the river channel. If the riverbank is not reached, then no river blockage has occurred at that time step; if it is reached, proceed to the next step. Based on the local coordinate system grid control value and the intervals of the local coordinate system grid ξ and η directions, generate local coordinate system grid coordinates. Circulate the landslide body SPH particles and interpolate the landslide body depth value onto the local coordinate system grid nodes to form the landslide body elevation information in the local coordinate system. Circulate each control section along the local coordinate system η axis direction and determine the lowest elevation point of each section of the landslide body. When each control section has a lowest elevation point below the horizontal plane, it is considered that an overflow channel exists and a complete river blockage has not been formed; otherwise, a complete river blockage has been formed.

[0009] Furthermore, the process of generating landslide and water body SPH particles based on geological survey data, obtaining control vectors based on the coordinates of control points at both ends of the river channel according to the defined landslide direction, and calculating the control vector normal vector using the right-hand rule are as follows:

[0010] Define the intersection point between the landslide source center in the terrain model and the river channel boundary along the potential landslide direction as the control point. Calculate the river channel width ld_length based on the control point coordinates ld_x(:,:).

[0011]

[0012] Where **2 represents square; , , , These are index accesses to different coordinates in the ld_x array;

[0013] Calculate and standardize the length-direction control vector ld_tv(:) of the landslide body:

[0014]

[0015] The control vector normal vector is calculated using the right-hand rule, corresponding to the landslide width direction control vector ld_tn(:), and then standardized.

[0016]

[0017] .

[0018] Furthermore, in each calculation step, the coordinates of the landslide SPH particles in the local coordinate system are obtained based on the control vector and the coordinates of the control points at both ends of the river channel. The maximum and minimum values ​​of the relative coordinates of the landslide SPH particles in the ξ and η directions are recorded as the local coordinate system grid control values. Specifically:

[0019] Define the control point closest to the landslide source as the origin P1 of the local coordinate system among the intersection points of the landslide source center along the potential landslide direction and the river boundary. By traversing the SPH particles of the landslide body, calculate the vector ip2p1(2) formed by the SPH particles of the landslide body and the origin P1 of the local coordinate system based on the coordinate values ​​x(:,:) of the SPH particles of the landslide body in the global coordinate system:

[0020]

[0021]

[0022] Where ipoin is the particle number.

[0023] Based on this, the projections of vector ip2p1(2) onto the ξ and η directions in the local coordinate system are calculated to obtain the local coordinate values ​​relx(:,:) of the SPH particles in the landslide body:

[0024]

[0025] Where dot_product() is the dot product operation; the ξ direction corresponds to the direction of the control vector ld_tv(:), and the η direction corresponds to the direction of the landslide width control vector ld_tn(:);

[0026] Record the local coordinate values ​​relx(:,:) of each landslide SPH particle, and compare them to obtain the maximum value xrelmaxg and minimum value xrelming in the ξ direction, and the maximum value yrelmaxg and minimum value yrelming in the η direction, which are used for the subsequent generation of local meshes of the landslide body.

[0027] Furthermore, based on the relationship between the maximum value of the relative coordinates of the SPH particles in the ξ direction and the magnitude of the control vector, it is determined whether the landslide has moved to the opposite bank of the river. If it has not reached the opposite bank, then no river blockage has occurred at this time step. If it has, the next step is to compare the maximum value of the relative coordinates of the landslide's SPH particles in the ξ direction (xrelmaxg) with the river width (ld_length) at the current time step. If the former is greater than the latter, it indicates that the landslide has reached the opposite bank of the river and there is a possibility of river blockage; if the former is less than the latter, there is no possibility of river blockage, and the current program is exited, waiting for the calculation and execution of the next time step before making a judgment. Based on the above, a river blockage degree threshold factor (DDF) is introduced, which is calculated... This is to adjust the threshold for determining the actual river-blocking procedure in engineering projects, thereby improving the accuracy of the judgment. The judgment formula is as follows:

[0028] .

[0029] Further, the step of generating local coordinate system grid coordinates based on the local coordinate system grid control values ​​and the intervals in the ξ and η directions of the local coordinate system grid specifically involves: calculating the coordinate values ​​of the local coordinate system grid nodes coorgrel(1:2,:) using the maximum and minimum values ​​of the landslide body SPH particles in the local coordinate system, including the maximum value xrelmaxg and minimum value xrelming in the ξ direction, the maximum value yrelmaxg and minimum value yrelming in the η direction, and the tangent intervals deta_sec_tv and deta_sec_tn in the ξ and η directions.

[0030] Calculate the number of mesh divisions (npoigxrel and npoigyrel) in the local coordinate system along the ξ and η directions, and from this, obtain the total number of mesh nodes (npoigrel) and the actual mesh intervals (deltxgrel and deltygrel) after subdivision:

[0031]

[0032] in , These represent the intervals in the local coordinate grid directions ξ and η, respectively.

[0033] Loop through each grid node and calculate the coordinates of each grid node in the local coordinate system: coorgrel(1:2,:).

[0034]

[0035] Based on the local coordinates of the grid node coorgrel(1:2,:), multiply by the transformation matrix tr_mat(:,:), and add the coordinates of the local coordinate system origin P1 in the global coordinate system ld_x(:,1), we obtain its coordinates in the global coordinate system coord_glb(:), and then assign the elevation value to coorgrel(3,:). The transformation process of coord_glb(:) is as follows:

[0036] .

[0037] Furthermore, the cyclic landslide SPH particles interpolate the landslide depth value onto the local coordinate system grid nodes to form the landslide elevation information in the local coordinate system. The landslide SPH particles are cyclically processed, and the local grid is determined based on its local coordinate value relx(:,:), and the four node numbers and local coordinate values ​​of the grid are obtained. Based on the distance relationship, the landslide accumulation depth information carried by the landslide SPH particles is interpolated onto the nodes of the local grid. The original surface elevation value coorgrel(3,:) of the local coordinate system grid node is added to obtain the landslide elevation information of the local coordinate system grid node, and it is stored in coorgrel(4,:).

[0038] Furthermore, the step of cyclically checking each control section along the η-axis of the local coordinate system and determining the lowest elevation point of each section of the landslide body specifically involves defining a judgment control value for each section and assigning an initial value of chk_sec(:)=0.0;

[0039] The local coordinate system mesh of the landslide body is looped along the η direction for each control section i_sec, and then each node of the control section is looped. If the elevation of the landslide body coorgrel(4,ipoig) is less than the elevation of the horizontal plane SWL, it is considered that there is an overflow channel in the section, chk_sec(i_sec)=1 is assigned, and the loop of control section i_sec is exited to check the next section.

[0040] The control value chk_sec(:) for judging the cross section is summed. When sum(chk_sec) is equal to the number of cross sections npoigyrel, that is, each cross section has an overflow point below the horizontal elevation, it is considered that there is an overflow channel and the river blockage cannot be formed. Otherwise, it is judged that the river blockage has been formed.

[0041] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of a landslide-blocked river channel judgment method based on a two-layer SPH model as described above.

[0042] A non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of a landslide-blocked river channel determination method based on a two-layer SPH model as described above.

[0043] Compared to existing technologies, this invention and its preferred embodiment address the problem that current applications of the double-layer SPH model in analyzing the water entry process of landslides require manual analysis and calculation of deposition results to determine whether a landslide has blocked a river. This invention proposes a method for judging river blockage by landslides based on the double-layer SPH model. A local coordinate system for the landslide is formed by using a river blockage control vector and control points at both ends of the river channel. Based on this, an automatic method for judging river blockage based on the overflow channel of the control section is established. This enables automatic judgment of the river blockage process by landslides and accurate analysis of the degree of river blockage, which is of great significance for landslide-induced river blockage disaster assessment and risk warning. Attached Figure Description

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0045] Figure 1 This is a flowchart of a method according to an embodiment of the present invention.

[0046] Figure 2 This is a schematic diagram of a landslide blocking a river according to an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram illustrating the activation particle determination process based on the background mesh absorption layer boundary application process in an embodiment of the present invention.

[0048] Figure 4 This is a schematic diagram of the if_out_domain list indicating whether a particle is within the computational domain in the initial state of an embodiment of the present invention. Detailed Implementation

[0049] To make the features and advantages of this patent more apparent and understandable, specific embodiments are provided below for detailed explanation:

[0050] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0051] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0052] This invention addresses the problem that current applications of the two-layer SPH model in analyzing landslide entry processes require manual analysis and calculation of deposition results to determine whether a landslide has blocked a river. It proposes a method for judging river blockage caused by landslides based on the two-layer SPH model. This method establishes a local coordinate system for the landslide body using a river blockage control vector and control points at both ends of the river channel. Based on this, an automatic method for judging river blockage based on the overflow channel of the control section is established. This enables automatic judgment of the river blockage process caused by landslides and accurate analysis of the degree of river blockage, which is of great significance for landslide-induced river blockage disaster assessment and risk early warning. The specific implementation flowchart is shown below. Figure 1 As shown. It mainly includes the following 6 steps:

[0053] Step 1: Generate SPH particles for landslide body and water body based on geological survey data. Obtain control vector based on the coordinates of control points at both ends of the river channel according to the defined landslide direction. Calculate the normal vector of the control vector according to the right-hand rule.

[0054] Step 2: In each calculation step, the coordinates of the landslide SPH particles in the local coordinate system are obtained based on the control vector and the coordinates of the control points at both ends of the river channel. The maximum and minimum values ​​of the relative coordinates of the landslide SPH particles in the directions of ξ and η are recorded as the grid control values ​​of the local coordinate system.

[0055] Step 3: Based on the relationship between the maximum value of the relative coordinates of the SPH particles in the ξ direction and the magnitude of the control vector, determine whether the landslide has moved to the opposite bank of the river. If it has not, then the river blockage has not occurred at this time step. If it has, proceed to the next step.

[0056] Step 4: Generate local coordinate system grid coordinates based on the local coordinate system grid control values, the intervals of the local coordinate grid ξ and η directions;

[0057] Step 5: Circulate the SPH particles of the landslide body and interpolate the landslide body depth value onto the local coordinate system grid nodes to form the landslide body elevation information in the local coordinate system;

[0058] Step 6: Along the η-axis of the local coordinate system, cycle through each control section and determine the lowest elevation point of each section of the landslide body. If each control section has a lowest elevation point below the horizontal plane, it is considered that there is an overflow channel and the complete blockage of the river has not been formed; otherwise, the complete blockage of the river has been formed.

[0059] Choose a landslide blocking river case study (see schematic diagram of the case study). Figure 2 ), according to Figure 1 The method and process shown will be explained in detail:

[0060] Step 1: Generate SPH particles for the landslide body and water body based on geological survey data. Obtain the control vector based on the coordinates of the control points at both ends of the river channel according to the defined landslide direction. Calculate the normal vector of the control vector using the right-hand rule. This includes the following steps:

[0061] S1.1: Using the intersection point of the landslide source center along the potential landslide direction and the river boundary in the terrain model as the control point, calculate the river width ld_length based on the coordinates of the control point ld_x(:,2):

[0062] (1)

[0063] S1.2: Calculate the control vector ld_tv(2) along the length direction of the landslide body and standardize it:

[0064] (2)

[0065] S1.3: Calculate the control vector ld_tn(2) in the width direction of the landslide body and standardize it:

[0066] (3)

[0067] Step 2: In each calculation step, based on the control vector and the coordinates of the control points at both ends of the river channel, obtain the coordinates of the landslide SPH particles in the local coordinate system, and record the maximum and minimum values ​​of the relative coordinates of the landslide SPH particles in the ξ and η directions as the local coordinate system grid control values. This includes the following steps:

[0068] S2.1: Traverse the SPH particles of the landslide body. Taking the particle with number ipoin=1 in the first time step as an example, calculate the vector ip2p1(2) formed by it and the origin P1 of the local coordinate system according to its coordinate value x(xx,yy) in the global coordinate system:

[0069] (4)

[0070] S2.2: Calculate the projection of this vector onto the ξ and η directions in the local coordinate system, i.e., the local coordinate values ​​relx(:,:) of the SPH particles in the landslide body:

[0071] (5)

[0072] S2.3: Record the local coordinate values ​​relx(:,:) of each landslide SPH particle, and compare them to obtain the maximum value xrelmaxg and minimum value xrelming in the ξ direction, and the maximum value yrelmaxg and minimum value yrelming in the η direction. The calculation results of the maximum and minimum values ​​of the local coordinates of the landslide SPH particles in the current time step are as follows: xrelmaxg=180.8804, xrelming=-483.4163, yrelmaxg=255.8297, yrelming=-209.2590.

[0073] Step 3: Based on the relationship between the maximum value of the relative coordinates of the SPH particles in the ξ direction and the magnitude of the control vector, determine whether the landslide has moved to the opposite bank of the river. If it has not, then no river blockage has occurred in this time step; if it has, proceed to the next step. In the current time step, the maximum value of the relative coordinates of the landslide's SPH particles in the ξ direction, xrelmaxg, is 180.8804. The calculated river width, ld_length, is 275.1812. Taking the DDF factor as 1.05, then... If the discriminant is false, then there is no possibility of blocking the river; the discriminant remains initially negative. Exit the current time step and proceed to the next time step. If the discriminant is true, then there is a possibility of blocking the river; the discriminant is true. Proceed to step 4 of the calculation.

[0074] Step 4: Generate local coordinate system grid coordinates based on the local coordinate system grid control values ​​and the intervals in the ξ and η directions of the local coordinate system grid (see local grid diagram). Figure 3 Based on the maximum and minimum values ​​of the landslide SPH particles obtained in step 2 in the local coordinate system (xrelmaxg=180.8804, xrelming=-483.4163, yrelmaxg=255.8297, yrelming=-209.2590), and according to the tangent intervals deta_sec_tv=10.0000 and deta_sec_tn=10.0000 read from the program, the coordinate values ​​of the local coordinate system grid nodes are formed as coorgrel(1:2,3149). The corresponding coordinate values ​​in the global coordinate system are then obtained by transforming the local coordinate system grid nodes. The original surface elevation value of this point is calculated and assigned to coorgrel(3, 3149). This process includes the following steps:

[0075] S4.1: Calculate the number of mesh divisions in the local coordinate system along the ξ and η directions: npoigxrel=67, npoigyrel=47. From this, we obtain the total number of mesh nodes: npoigrel=3149 and the actual mesh intervals after subdivision: deltxgrel=10.0651, deltygrel=10.1106.

[0076] (7)

[0077] in , These represent the intervals in the local coordinate grid directions ξ and η, respectively.

[0078] S4.2: Loop through each grid node and calculate the coordinates of each grid node in the local coordinate system, coorgrel(1:2,3149). Taking grid node 1 as an example, its local coordinates are calculated as follows:

[0079] (8)

[0080] S4.3: The local coordinate value of the grid node, coorgrel(1:2,1), is multiplied by the transformation matrix tr_mat(:,:), and then the coordinate value of the local coordinate system origin P1 in the global coordinate system, ld_x(:,1), is added to obtain its coordinate value coord_glb(:) in the global coordinate system. The calculated elevation value 180.4984 is then assigned to coorgrel(3,:). Taking grid node 1 as an example, the calculation process of coord_glb(:) is as follows:

[0081] (9)

[0082] Step 5: Loop through the landslide SPH particles and interpolate the landslide depth values ​​to the local coordinate system grid nodes to form the landslide elevation information in the local coordinate system. Loop through the landslide SPH particles. Taking the particle with number ipoin=1 in the first time step as an example, based on its local coordinate value relx(:,:)=[-3.7679, 645.1250], determine its local grid location and obtain the four grid node numbers (1, 3, 47, 48) and local coordinate values. Based on the distance relationship, interpolate the landslide accumulation depth information carried by the landslide SPH particles to the nodes of the local grid. Add the original surface elevation value coorgrel(3,:) = -5.8589 obtained in Step 4 to obtain the landslide elevation information of the local coordinate system grid node, which is stored in coorgrel(4,:) = -0.4722.

[0083] Step 6: Along the η-axis of the local coordinate system, iterate through each control section i_sec, determining the lowest elevation point of each section of the landslide. If each control section has at least one lowest elevation point below the horizontal plane, it is considered that an overflow channel exists and a complete dam has not yet formed; otherwise, a complete dam has formed (see schematic diagram of control sections). Figure 4 Define the judgment control value for each section and initialize it to chk_sec(:) = 0.0, including the following steps:

[0084] S6.1: For each control section i_sec, iterate along the η direction in the local coordinate system mesh of the landslide body. Then, iterate through each node of the control section. If the landslide elevation coorgrel(4,ipoig) is less than the horizontal elevation SWL, then the section is considered to have an overflow channel. Assign chk_sec(i_sec) = 1, and exit the loop for control section i_sec to check the next section. Taking the control section i_sec = 1 at the current time step as an example, this section has 67 control points. At control point 67, coorgrel(4,ipoig) = -1.3353 is less than the horizontal elevation SWL = 0.0, therefore, the section is considered to have an overflow point.

[0085] S6.2 Summing the control value chk_sec(:) for each cross-section, when sum(chk_sec) equals the number of cross-sections npoigyrel, it means that each cross-section has an overflow point below the horizontal elevation. In this case, an overflow channel is considered to exist, and river blockage cannot be formed. Otherwise, river blockage can be formed. Taking this time step as an example, there are 47 control cross-sections. The sum of the elements of chk_sec(47) is 47, which is equal to the number of control cross-sections 47. Therefore, an overflow channel is considered to exist, and river blockage cannot be formed. The next time step is then proceeded for judgment.

[0086] Based on the same inventive concept, this invention also provides a computer device, comprising: one or more processors, and a memory for storing one or more computer programs; the programs include program instructions, and the processor executes the program instructions stored in the memory. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, used to implement one or more instructions, specifically for loading and executing one or more instructions stored in a computer storage medium to implement the above-described method.

[0087] It should be further explained that, based on the same inventive concept, the present invention also provides a computer storage medium storing a computer program, which, when executed by a processor, performs the above-described method. This storage medium can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0088] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

[0090] This patent is not limited to the above-described preferred embodiment. Anyone can derive other forms of landslide-based river channel blockage judgment method based on the double-layer SPH model under the guidance of this patent. All equivalent changes and modifications made within the scope of this patent application shall be covered by this patent.

Claims

1. A method for determining river channel blockage by landslides based on a two-layer SPH model, characterized in that: By establishing a local coordinate system for the landslide dam based on the double-layer SPH model, the elevation of the control section can be quickly determined, thereby enabling the assessment of the landslide blocking the river. Based on geological survey data, SPH particles for landslide bodies and water bodies are generated. The intersection point between the landslide source center in the terrain model and the river boundary along the potential landslide direction is defined as the control point. The control vector along the length of the landslide body is obtained from the coordinates of the control point, and the normal vector of the control vector is calculated using the right-hand rule. At each time step, the coordinates of the landslide body SPH particles in the local coordinate system are obtained based on the control vector and the coordinates of the control points at both ends of the river channel. The maximum and minimum values ​​of the relative coordinates of the landslide body SPH particles in the ξ and η directions are recorded as the grid control values ​​of the local coordinate system. Based on the relationship between the maximum value of the relative coordinates of the SPH particles in the ξ direction and the magnitude of the control vector, it is determined whether the landslide body has moved to the opposite bank of the river channel. If it has not reached the opposite bank, then at that time step... If no river blockage occurs at the next step, proceed to the next judgment. Based on the local coordinate system grid control values ​​and the intervals of the local coordinate system grid directions ξ and η, generate local coordinate system grid coordinates. The ξ direction corresponds to the direction of the control vector along the length of the landslide body, and the η direction corresponds to the direction of the control vector along the width of the landslide body. Loop through the landslide body SPH particles, interpolating the landslide depth value onto the local coordinate system grid nodes to form the landslide elevation information in the local coordinate system. Loop through each control section along the η axis of the local coordinate system, determining the lowest elevation point of each control section. If each control section has a lowest elevation point below the horizontal plane, it is considered that an overflow channel exists, and a complete river blockage has not formed; otherwise, a complete river blockage has formed.

2. The method for determining river channel blockage by landslides based on a two-layer SPH model according to claim 1, characterized in that: The process involves generating SPH particles for landslide bodies and water bodies based on geological survey data. A control vector is obtained based on the coordinates of control points at both ends of the river channel along the defined landslide direction. The normal vector of the control vector is then calculated using the right-hand rule. Define the intersection point between the landslide source center in the terrain model and the river channel boundary along the potential landslide direction as the control point. Calculate the river channel width ld_length based on the control point coordinates ld_x(:,:). where **2 represents square; , , , are index accesses to different coordinates in the ld_x array, respectively; Calculate and standardize the length-direction control vector ld_tv(:) of the landslide body: The control vector normal vector is calculated using the right-hand rule, corresponding to the landslide width direction control vector ld_tn(:), and then standardized. 。 3. The method for determining river channel blockage by landslides based on a two-layer SPH model according to claim 2, characterized in that: At each time step, the coordinates of the landslide SPH particles in the local coordinate system are obtained based on the control vector and the coordinates of the control points at both ends of the river channel. The maximum and minimum values ​​of the relative coordinates of the landslide SPH particles in the ξ and η directions are recorded as the local coordinate system grid control values. Specifically: Define the control point closest to the landslide source as the origin P1 of the local coordinate system among the intersection points of the landslide source center along the potential landslide direction and the river boundary. By traversing the SPH particles of the landslide body, calculate the vector ip2p1(2) formed by the SPH particles of the landslide body and the origin P1 of the local coordinate system based on the coordinate values ​​x(:,:) of the SPH particles of the landslide body in the global coordinate system: Where ipoin is the particle number; Based on this, the projections of vector ip2p1(2) onto the ξ and η directions in the local coordinate system are calculated to obtain the local coordinate values ​​relx(:,:) of the SPH particles in the landslide body: Where dot_product() is the dot product operation; the ξ direction corresponds to the direction of the control vector ld_tv(:), and the η direction corresponds to the direction of the landslide width control vector ld_tn(:); Record the local coordinate values ​​relx(:,:) of each landslide SPH particle, and compare them to obtain the maximum value xrelmaxg and minimum value xrelming in the ξ direction, and the maximum value yrelmaxg and minimum value yrelming in the η direction, which are used for the subsequent generation of local meshes of the landslide body.

4. The method for determining river channel blockage by landslides based on a two-layer SPH model according to claim 3, characterized in that: The process involves determining whether a landslide has moved to the opposite bank of the river based on the relationship between the maximum value of the relative coordinates of the SPH particles in the ξ direction and the magnitude of the control vector. If it hasn't, then no river blockage has occurred at that time step. If it has, the next step involves comparing the maximum value of the relative coordinates of the landslide's SPH particles in the ξ direction (xrelmaxg) with the river width (ld_length) at the current time step. If the former is greater than the latter, it indicates that the landslide has reached the opposite bank of the river, and there is a possibility of river blockage. If the former is less than the latter, there is no possibility of river blockage, and the current program exits, waiting for the next time step to be calculated and determined. Based on this, a river blockage degree threshold factor (DDF) is introduced, which is calculated... This is to adjust the threshold for determining the actual river-blocking procedure in engineering projects; the determination formula is as follows: 。 5. The method for determining river channel blockage by landslides based on a two-layer SPH model according to claim 4, characterized in that: The process of generating local coordinate system grid coordinates based on the local coordinate system grid control values ​​and the intervals in the ξ and η directions of the local coordinate system grid is as follows: Using the maximum and minimum values ​​of the landslide body SPH particles in the local coordinate system, including the maximum value xrelmaxg and minimum value xrelming in the ξ direction, the maximum value yrelmaxg and minimum value yrelming in the η direction, and the tangent intervals deta_sec_tv and deta_sec_tn in the ξ and η directions, the coordinate values ​​of the local coordinate system grid nodes, coorgrel(1:2,:), are calculated. Calculate the number of mesh divisions (npoigxrel and npoigyrel) in the local coordinate system along the ξ and η directions, and from this, obtain the total number of mesh nodes (npoigrel) and the actual mesh intervals (deltxgrel and deltygrel) after subdivision: wherein , respectively represent the interval in the local coordinate grid ξ and η directions; Loop through each grid node and calculate the coordinates of each grid node in the local coordinate system: coorgrel(1:2,:). Based on the local coordinates of the grid node coorgrel(1:2,:), multiply by the transformation matrix tr_mat(:,:), and add the coordinates of the local coordinate system origin P1 in the global coordinate system ld_x(:,1), we obtain its coordinates in the global coordinate system coord_glb(:), and then assign the elevation value to coorgrel(3,:). The transformation process of coord_glb(:) is as follows: 。 6. The method for determining river channel blockage by landslides based on a double-layer SPH model according to claim 5, characterized in that: The cyclic landslide SPH particles interpolate the landslide depth value onto the local coordinate system grid nodes to form the landslide elevation information in the local coordinate system. The landslide SPH particles are cyclically processed, and the local grid is determined based on its local coordinate value relx(:,:), and the four node numbers and local coordinate values ​​of the grid are obtained. Based on the distance relationship, the landslide accumulation depth information carried by the landslide SPH particles is interpolated onto the nodes of the local grid. The original surface elevation value coorgrel(3,:) of the local coordinate system grid node is added to obtain the landslide elevation information of the local coordinate system grid node, which is then stored in coorgrel(4,:).

7. The method for determining river channel blockage by landslides based on a two-layer SPH model according to claim 6, characterized in that: The specific steps of iterating along the η-axis of the local coordinate system to determine the lowest elevation point of each control section of the landslide body are as follows: define the judgment control value for each control section and assign an initial value chk_sec(:)=0.0; The local coordinate system mesh of the landslide body is looped along the η direction for each control section i_sec, and then each node of the control section is looped. If the elevation of the landslide body coorgrel(4,ipoig) is less than the elevation of the horizontal plane SWL, it is considered that there is an overflow channel in the control section, chk_sec(i_sec)=1 is assigned, and the loop of control section i_sec is exited to check the next control section. The control values ​​chk_sec(:) of the control sections are summed. When sum(chk_sec) is equal to the number of control sections npoigyrel, that is, each control section has an overflow point below the horizontal elevation, it is considered that there is an overflow channel and the river blockage cannot be formed. Otherwise, it is judged that the river blockage has been formed.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method for judging landslide blockage of river channels based on a double-layer SPH model as described in any one of claims 1-7.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of a method for determining river channel blockage by landslides based on a two-layer SPH model as described in any one of claims 1-7.

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