Landslide surge impact pontoon disaster chain estimation method and system

Abstract

The invention provides a landslide surge impact pontoon disaster chain estimation method and system, and relates to the technical field of disaster chain estimation, and the method comprises the steps: carrying out the coordinate pairing of a digital elevation model (DEM) generated by a satellite remote sensing image and aerial survey data with geological drilling monitoring data, and obtaining the three-dimensional terrain information and rock-soil physical property parameters of a research area; multi-level numerical simulation is adopted in the links of surge propagation, flood inundation, structural impact and the like, a whole-process closed-loop monitoring and early warning system of landslide-surge-structural impact-dam fracture-downstream flood is formed, wave propagation is accurately solved by means of a Boussinesq equation, the dam bearing capacity is dynamically matched with outburst simulation, and the early warning accuracy is improved. And the Morison rule impact evaluation is carried out on a target structure such as a pontoon or a wharf, so that the downstream submerging range, the maximum impact force and the structure safety state can be obtained in real time and are intuitively presented in a risk level map layer form.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of disaster chain estimation, in particular to a landslide surge impact on floating ship disaster chain estimation method and system. BACKGROUND

[0002] In coastal and inland lake areas, landslides in geological disasters are prone to collapse into water bodies under certain conditions, forming a large-scale sliding body into water process, and the sliding body into water will instantaneously generate a huge kinetic energy, which rapidly forms a high-amplitude surge (wave surge) in the shallow water area. Such surges have the characteristics of strong impact force, fast propagation speed and concentrated energy. Once the landslide surge acts on the floating body (such as barge, floating pier, floating platform, etc.), the impact load may exceed the design strength of the floating body, causing structural damage of the floating body, failure of the mooring system and position drift, and further leading to a series of chain disasters such as collision accidents, cargo displacement and sinking, etc. The generation process of landslide surge is jointly affected by multiple complex factors, including the size and shape of the collapsed body, the water entry speed, the shore slope topography and underwater topography, the boundary conditions of the reservoir or sea area, etc. Existing research mainly relies on traditional measurement methods or local flume experiments to obtain landslide body physical parameters and high-precision three-dimensional terrain information, which is difficult to achieve overall data integration of a large-scale study area, and cannot obtain landslide precursor information in time and give early warning for slope activity. SUMMARY

[0003] The present application aims to provide a landslide surge impact on floating ship disaster chain estimation method and system. This method uses multi-level numerical simulation in the links of surge propagation, flood inundation and structure impact, forming a whole-process closed-loop monitoring and early warning system of landslide-surge-structure impact-dam break-downstream flood. With the accurate solution of wave propagation by Boussinesq equation, dynamic matching of dam bearing capacity and breaching simulation, and impact evaluation of Morison law for target structures such as floating ships or piers, the downstream inundation range, maximum impact force and structure safety state can be obtained in real time, and the risk level diagram is presented in a intuitive way.

[0004] In order to realize the above technical features, the purpose of the present application is realized as follows: a landslide surge impact on floating ship disaster chain estimation method, comprising S1, coordinate pairing the digital elevation model (DEM) generated by satellite remote sensing images and aerial survey data with geological drilling monitoring data to obtain three-dimensional terrain information and rock-soil physical parameters of the study area; S2, identify the landslide body on the three-dimensional terrain information, call Voellmy block model, iterate and output the sliding body into the water velocity Us, total volume Vs and kinetic energy Ekin on the three-dimensional terrain information of the landslide body; use the water velocity Us, total volume Vs and kinetic energy Ekin to calculate the initial wave height H0 and wavelength λ0 of the surge wave according to the kinetic energy formula; S3, using Boussinesq model, set the initial wave height H0 and wavelength λ0 of the surge wave as input data, calculate the instantaneous pressure distribution and water level height distribution of the surge wave along the river channel by using shallow water equation, match the water level height distribution with the dam structure data to obtain the overflow height of the overflow surge wave; S4, input the overflow height of the surge wave and the dam volume into the one-dimensional flood numerical model to calculate the downstream inundation depth and range; for the downstream floating ship or wharf target simplified as a cylindrical or flat plate structure, calculate the surge impact force distribution by Morison formula, and compare it with the structure damage threshold to judge the safety state; S5, match the instantaneous pressure diagram in step S3 with the dam structure data to evaluate the bearing capacity of each region; when the bearing capacity of a region is insufficient, determine that the dam is unstable, generate a flood peak flow curve according to the dam breach model; input the flood peak flow curve into the one-dimensional flood model to calculate the downstream flood inundation depth and range.

[0005] Preferably, through satellite images and airborne LiDAR point clouds, a digital elevation model DEM is generated by stereo image matching and point cloud filtering, drill holes are arranged in the landslide high-risk area, rock sample parameters are collected according to depth layering to obtain drill hole profile information; the DEM and drill hole GPS positioning are unified in coordinates, each DEM grid node is associated with the corresponding drill hole profile information to obtain the rock and soil physical property parameters of the node, including rock and soil type, density, friction angle, cohesion, porosity, and the three-dimensional terrain information and rock and soil physical property parameters are stored in the landslide parameter database.

[0006] Preferably, on the digital elevation model DEM, the landslide body boundary is extracted with a slope threshold m, and the area A and corresponding elevation change Δh of the boundary region are calculated accordingly; the total volume V of the landslide body is obtained by integrating the area and elevation difference of each grid element in the boundary region, and the volume of each grid element is combined with the corresponding rock and soil density P to calculate the density, friction angle and cohesion of the sliding body.

[0007] Preferably, Voellmy block model is called, the sliding body is discretized into multiple elements in the finite element software, each element is given mass, friction angle, cohesion, damping coefficient and viscous drag coefficient, and the force update acceleration and velocity of each element are iteratively solved in time step increments to obtain the center of gravity velocity Us of the landslide body and the total volume V of the landslide body, and the kinetic energy Ekin is calculated. ​; the kinetic energy Ekin is calculated according to the formula: V, Us, and Ekin are used to calculate the initial surge wave height H0 and the wavelength lambda0 according to the formula: ; ; wherein: 、 is an empirical coefficient of calibration, B is the width of the landslide entrance, g is the acceleration of gravity, and h is the water depth at the entrance.

[0008] Preferably, the initial surge wave height H0 and the wavelength lambda0 are taken as the entrance boundary, and the river propagation domain is meshed: an encryption grid is used in the surge source area and upstream of the dam, and an absorption layer is set on the far-field boundary to prevent wave reflection; the time step is adjusted according to the CFL condition, and the instantaneous pressure p(x, t) and water level height eta(x, t) of each time step are iteratively solved, the instantaneous pressure distribution map and the water level height distribution map are generated, the water level height distribution map is matched with the artificial dam geometric model, and the overflow surge overflow height Hx of each node along the surface of the dam is calculated.

[0009] Preferably, the surge overflow height Hx in step 3, the artificial dam volume V, the dam material roughness coefficient n, and the riverbed cross-section data are input into a one-dimensional flood numerical model to solve the one-dimensional Saint-Venant equation, the water depth h(x, t) and flow velocity u(x, t) of each cross-section downstream under given overflow conditions are calculated, the downstream submerged depth and range map is generated, and for a floating ship or a wharf downstream, the target structure is simplified as a cylindrical or flat structure, the projected area As, the additional water volume Vs, the drag coefficient CD, and the additional mass coefficient CM are determined, the impact force F(t) of the surge on the structure is calculated according to the Morison equation: and compared with the structure failure threshold Fcrit: if F(t)>Fcrit, it is determined that the target structure has a risk of damage; otherwise, it is determined that the target structure is safe.

[0010] Preferably, the maximum pressure max(x) of each position along the dam line is extracted from the instantaneous pressure distribution map, and the unit width bearing capacity sigma_cap(x) of the artificial dam is combined, when p_max(x)≥sigma_cap(x), it is determined that the dam region is unstable and the dam break simulation is performed.

[0011] Preferably, in the dam-break simulation, according to the breach width B and the breach height H of the instability area, and the dam-break flow coefficient Cb, the Marchi breach equation is used to generate the dam-break flood peak flow time history Q_peak(t), and Q_peak(t) is taken as an input boundary to call the one-dimensional flood model again to calculate the downstream flood inundation depth h(x, t) and range after the dam-break, generate the dam-break inundation depth map, and then perform Monte Carlo perturbation on the landslide total volume V, water entry velocity Us and landslide water entry depth h critical parameters, randomly sample to generate multiple sets of parameters, and repeat steps 2 to 4 for each set of parameters, record the downstream inundation depth, and calculate the probability distribution of damage to the key target downstream.

[0012] Preferably, the instantaneous pressure distribution map, the downstream inundation depth map and the structure impact risk map generated in step 3 are imported into a GIS platform to generate a risk level layer; the risk level layer is dynamically updated in combination with real-time monitoring data; and when the downstream flood depth exceeds Q or the surge impact force exceeds OP, the risk level layer is pushed to the emergency management department.

[0013] Another aspect of the present application provides a landslide surge impact floating boat disaster chain estimation system, which is used to implement the landslide surge impact floating boat disaster chain estimation method, and comprises: A data acquisition and parameter library module is used to construct a high-precision DEM, and combine with borehole monitoring to obtain rock-soil physical parameters, and store all three-dimensional terrain and physical information in a parameter library. A landslide dynamics simulation module is used to extract a landslide body and calculate the volume and physical properties, and call a block or particle model to simulate the sliding process of the sliding body, respectively, to obtain the water entry velocity, volume and kinetic energy of the sliding body. A wave propagation simulation module is used to perform grid refinement and absorbing boundary processing in the river channel by using the shallow water equation to simulate wave propagation. A downstream flood inundation and structure impact evaluation module is used to input the dam overflow wave height into a one-dimensional flood model to calculate the downstream flood inundation depth and range. A dam stability determination and dam-break simulation module is used to evaluate the bearing capacity of each area of the dam according to the surge pressure, and if instability is determined, a dam-break model is called to generate a flood peak flow and perform one-dimensional flood simulation again.

[0014] The present application has the following beneficial effects: 1、The application adopts multi-level numerical simulation in the links of surge propagation, flood submersion and structure impact, etc., forms a whole-process closed-loop monitoring and early warning system of landslide-surge-structure impact-dam break-downstream flood, and can obtain the downstream submersion range, the maximum impact force and the structure safety state in real time by means of the accurate solution of wave propagation by the shallow water equation, the dynamic matching of dam bearing capacity and break simulation, and the impact evaluation of the Morison law for target structures such as floating ships or wharfs, and intuitively presents in the form of risk level layers, and finally realizes the rapid issuance of early warning information through radio when the flood depth or impact force reaches the early warning threshold, thereby greatly improving the emergency response speed of floating ship operators and river residents, effectively reducing disaster losses and improving disaster resistance.

[0015] 2、The application can not only accurately restore the three-dimensional geometric shape of the landslide body by the digital elevation model DEM and the geological drilling physical property parameters, but also can obtain key parameters such as the density, friction angle, cohesion and underground water level of the rock-soil layer at different depths, thereby providing more real and reliable initial conditions for dynamic simulation, and the method makes up for the defects of limited accuracy of traditional single remote sensing or single drilling data, greatly reduces the evaluation error of landslide volume and physical properties, and significantly improves the subsequent sliding behavior of the landslide body and the estimation of surge source parameters. BRIEF DESCRIPTION OF DRAWINGS

[0016] The application will be further described below in combination with the drawings and embodiments.

[0017] Figure 1 The application is a perspective structural view. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the drawings of the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0019] Embodiment 1: Please refer to Figure 1 The application provides a landslide surge impact floating ship disaster chain estimation method, which comprises the following steps: S1, coordinate pairing is performed on the digital elevation model DEM generated by satellite remote sensing images and aerial survey data and geological drilling monitoring data to obtain three-dimensional terrain information and rock-soil physical property parameters of the research area; S2, identify the landslide body on the three-dimensional terrain information, call Voellmy block model, iteratively solve the three-dimensional terrain information of the landslide body and output the sliding body into water velocity Us, total volume Vs and kinetic energy Ekin; use the water velocity Us, total volume Vs and kinetic energy Ekin to calculate the initial wave height H0 and wavelength λ0 of the surge wave according to the kinetic energy formula; S3, using Boussinesq model, set the initial wave height H0 and wavelength λ0 of the surge wave as input data, calculate the instantaneous pressure distribution and water level height distribution of the surge wave along the river channel by using shallow water equation, match the water level height distribution with the dam structure data to obtain the overflow height of the overflow surge wave; S4, input the overflow height of the surge wave and the dam volume into the one-dimensional flood numerical model to calculate the downstream inundation depth and range; for the floating ship or wharf target simplified as a cylindrical or flat plate structure, calculate the surge impact force distribution by Morison formula, and compare it with the structure damage threshold to judge the safety state; S5, match the instantaneous pressure diagram in step S3 with the dam structure data to evaluate the carrying capacity of each region; when the carrying capacity of a region is insufficient, determine that the dam is unstable, generate a flood peak flow curve according to the dam breach model; input the flood peak flow curve into the one-dimensional flood model to calculate the downstream flood inundation depth and range.

[0020] Further, through satellite images and airborne LiDAR point clouds, a digital elevation model DEM is generated by stereo image matching and point cloud filtering, drill holes are arranged in the high-risk area of landslide, rock sample parameters are collected according to depth layering, and drill section information is obtained; unify the coordinates of DEM and drill GPS positioning, associate each DEM grid node with the corresponding drill section information to obtain the rock and soil physical property parameters of the node, including rock and soil type, density, friction angle, cohesion, porosity, store the three-dimensional terrain information and rock and soil physical property parameters in the landslide parameter database.

[0021] Further, on the digital elevation model DEM, the landslide body boundary is extracted with a slope threshold m, and the area A and the corresponding elevation change Δh of the boundary region are calculated; by integrating the area and elevation difference of each grid element in the boundary region, the total volume V of the landslide body is obtained, combined with the volume of each grid element and the corresponding rock and soil density P, the sliding body density, friction angle and cohesion are calculated.

[0022] Further, the area A of the boundary region is calculated as follows: the landslide boundary polygon is mapped to the DEM raster coordinate system, and the number of raster cells N contained within the boundary is counted; combined with the DEM raster resolutions Δx and Δy (unit: m), the total area of ​​the region is calculated as A = N × Δx × Δy; if the boundary is irregular in shape, a high-precision polygon area formula (such as the Gaussian area formula) can be used to calculate the vertex coordinates of the boundary polygon to correct the area error introduced by rasterization.

[0023] Further, the determination of the elevation change Δh in the boundary area: Extract the original DEM elevation value h1 of each edge raster cell on the boundary polygon; extend along the normal direction of the landslide front and extract the reference elevation h2 at the corresponding location, using... Calculate the local elevation changes of each edge grid cell; combine this with the horizontal projected area Area_j of each grid cell, and then calculate a weighted average. Calculate the overall elevation change of the boundary region.

[0024] Using the Voellmy block model, the landslide body was discretized into multiple elements in the finite element method software. Each element was assigned mass, friction angle, cohesion, damping coefficient, and viscous drag coefficient. The forces, accelerations, and velocities of each element were iteratively solved using a time-step incremental approach to obtain the landslide's center-of-gravity velocity Us and the total volume V of the landslide. The kinetic energy was also calculated. ; Calculate the initial wave height H0 and wavelength lambda0 of the surge using V, Us, and kinetic energy Ekin according to the formula: ; ; in: , , where is the calibrated empirical coefficient, B is the width of the landslide entrance, g is the gravitational acceleration, and h is the water depth at the point of entry.

[0025] Furthermore, the initial wave height H0 and wavelength lambda0 of the surge are used as the inlet boundary, and the mesh is divided within the river propagation domain: a finer mesh is used in the surge source area and upstream of the dam, and an absorption layer is set at the far-field boundary to prevent wave reflection; the time step is adjusted according to the CFL condition, and the instantaneous pressure p(x,t) and water level height eta(x,t) of each time step are solved iteratively to generate instantaneous pressure distribution map and water level height distribution map. The water level height distribution map is matched with the geometric model of the artificial dam, and the overflow surge height Hx of each node along the dam surface is calculated.

[0026] This invention establishes geometric models of the surge source region, upstream region of the embankment, and far-field region within a two-dimensional river propagation domain, incorporating actual topographic and embankment cross-sectional information. Within the core region of interest, a finer mesh is used, with the mesh cell size refined based on the characteristic length of the surge. In the far-field region, the mesh size is progressively increased to reduce computational load, and an absorbing layer is placed at the far-field boundary to weaken surge reflection. The initial wave height and wavelength calculated from landslide inflow are used as upstream inlet boundary conditions, mapped to spatially distributed initial water level disturbances and corresponding velocity fields. The initial water level within the domain is selected from the normal operating depth of the river channel, and the initial flow velocity is set to zero or the background flow field velocity. The sidebank boundary adopts a solid-wall no-flux condition, while the upstream and downstream far-field boundaries adopt an open zero-gradient condition. Based on dynamic calculations... For high flow velocities and local water depths, the time step is adjusted in real time to meet the Courant–Friedrichs–Lewy stability requirements. Spatially, finite difference or finite volume discretization methods are used to discretize the nonlinear shallow water equation or the improved Boussinesq equation, and iterative solutions are performed using methods such as second-order central difference and explicit Runge–Kutta time-domain integral. In each time step, the inlet and far-field boundary conditions are updated first, and then the instantaneous velocity field and water level distribution are obtained through prediction-correction or pressure correction methods. The water level height is spatially matched with the three-dimensional geometric model of the artificial dam, and the correspondence between the dam boundary nodes and the grid nodes is realized through affine transformation or direct superposition, and the water level height at each node is extracted.

[0027] Furthermore, the surge height Hx, artificial embankment volume V, embankment material roughness coefficient n, and riverbed cross-section data from step 3 are input into a one-dimensional flood numerical model to solve the one-dimensional Saint-Venant equation. The water depth h(x,t) and flow velocity u(x,t) of each downstream cross-section under given overflow conditions are calculated, generating a downstream inundation depth and extent map. For downstream floating vessels or docks that can be simplified to cylindrical or flat structures, their projected area As, additional water volume Vs, drag coefficient CD, and additional mass coefficient CM are determined. Based on the Morison equation, the impact force F(t) of the surge on the structure is calculated and compared with the structural failure threshold Fcrit. If F(t) > Fcrit, the target structure is deemed to be at risk of failure; otherwise, the target structure is deemed safe.

[0028] Further, parameter input and one-dimensional flood numerical model setup: The surge overflow height Hx, total volume V of the artificial embankment, Manning roughness n of the embankment material, and riverbed cross-section data obtained in step 3 are input parameters into the one-dimensional flood numerical model. The riverbed cross-section data includes the shape parameters of each cross-section, the bottom elevation curve, and boundary condition information. A one-dimensional Saint-Venant equation model is constructed based on the parameters. The equation considers the conservation of incompressible flow and momentum, and introduces the Manning formula to reflect the influence of riverbed roughness on velocity attenuation.

[0029] Solving for downstream cross-section water depth and velocity: In the one-dimensional Saint-Venant equation model, with the surge overflow node as the upstream boundary, time-domain iterative calculations are performed using explicit or implicit numerical schemes (e.g., fourth-order Runge-Kutta or finite volume high-precision schemes). Under the given overflow time history, the water depth h(xi,t) and velocity u(xi,t) at each downstream cross-section position xi and time t are calculated. During the calculation process, the time step is dynamically adjusted to satisfy the Courant-Friedrichs-Lewy stability condition and the boundary water level is corrected in real time. The calculation is terminated when the model iterates to a predetermined time range or the surge amplitude decays below the threshold, and the water depth and velocity data in the form of a spatiotemporal sequence are output.

[0030] Generating downstream inundation depth and extent maps: Based on the obtained spatiotemporal sequence water depth h(x,t), combined with downstream topographic elevation DEM or riverbank geomorphological data, spatial interpolation and rasterization are performed using Geographic Information System (GIS) or similar visualization tools to generate inundation depth maps and inundation extent outlines for the downstream area at each time point; the inundation distribution at key times (such as the time when the maximum water level occurs) is marked on the map, and the coordinates of the inundation boundary are extracted to provide accurate spatial information for subsequent calculation of hydrodynamic loads on target structures.

[0031] The maximum pressure max(x) at each location along the dam is extracted from the instantaneous pressure distribution map. Combined with the bearing capacity per unit width of the artificial dam sigma_cap(x), if p_max(x) ≥ sigma_cap(x) at a certain location, the dam area is determined to be unstable and a dam failure simulation is performed.

[0032] In the dam break simulation, based on the breach width B and breach height H of the unstable region, as well as the dam break flow coefficient Cb, the Marchi dam break equation is used to generate the dam break flood peak flow time history Q_peak(t). Q_peak(t) is then used as the input boundary to call the one-dimensional flood model again to calculate the downstream flood inundation depth h(x,t) and range after the dam break, generating an inundation depth map after the dam break. Subsequently, Monte Carlo perturbations are performed on key parameters such as the total volume V of the landslide body, the ingress velocity Us, and the ingress depth h of the landslide body. Multiple sets of parameters are randomly sampled and generated. Steps 2 to 4 are repeated for each set of parameters to record the downstream inundation depth and calculate the probability distribution of damage to key downstream targets.

[0033] The model incorporates river cross-section information to dynamically simulate the evolution of a dam-break flood along the river channel, calculating the downstream cross-section water depth h(x,t) and flow velocity u(x,t) at each moment, thereby generating an inundation depth map and inundation range outline for the downstream area after the dam break. Subsequently, for key parameters—the total volume V of the landslide body, the landslide entry velocity Us, and the landslide entry depth h—random sampling is performed using the Monte Carlo perturbation method, generating multiple sets of input parameters based on the probability distribution characteristics of each parameter. For each set of parameters, the entire process from surge generation to one-dimensional flood simulation (i.e., the dam-break flood peak generation and downstream inundation calculation described in the previous step) is repeated, recording the corresponding spatiotemporal distribution results of downstream inundation depth. Based on the results of multiple simulations, the maximum inundation depth of downstream key targets (such as floating vessels, wharves, and dike nodes) affected by the flood is statistically analyzed in the risk assessment system, and the failure probability distribution of each key target under different parameter perturbation combinations is calculated in conjunction with the structural flood resistance capacity or design inundation limit.

[0034] Import the instantaneous pressure distribution map, downstream inundation depth map, and structural impact risk map generated in step 3 into the GIS platform to generate a risk level layer; dynamically update the risk level layer in conjunction with real-time on-site monitoring data; and push the risk level layer to the emergency management department when the downstream flood depth exceeds Q or the surge impact force exceeds the OP warning threshold.

[0035] Example 2: This invention provides a landslide surge impact floating vessel disaster chain estimation system, comprising: The data acquisition and parameter library module constructs a high-precision DEM and combines borehole monitoring to obtain soil and rock physical parameters, storing all three-dimensional topographic and physical property information in the parameter library; The landslide dynamics simulation module extracts the landslide body and calculates its volume and physical properties. It then calls either the block model or the particle model to simulate the sliding process of the landslide body and obtains the landslide body's entry velocity, volume, and kinetic energy into the water. The wave propagation simulation module uses shallow water equations to refine the mesh and process absorbing boundaries within the river channel to simulate swell propagation. The downstream flood inundation and structural impact assessment module inputs the dam overflow wave height into a one-dimensional flood model to calculate the downstream flood inundation depth and extent. The dam stability assessment and dam break simulation module evaluates the bearing capacity of each area of ​​the dam based on the surge pressure. If instability is determined, the dam break model is called to generate the peak flow and a one-dimensional flood simulation is performed again.

[0036] This invention employs multi-level numerical simulations of wave propagation, flood inundation, and structural impact to form a closed-loop monitoring and early warning system covering the entire process from landslide to wave propagation, structural impact, dam rupture, and downstream flooding. Utilizing the shallow water equation for precise wave propagation solutions, dynamic matching of dam bearing capacity and breach simulations, and Morison's law impact assessment for target structures such as floating boats or wharves, it can provide real-time information on downstream inundation range, maximum impact force, and structural safety status, presented intuitively in a risk level layer. Combined with probability distributions obtained from Monte Carlo perturbations, it ultimately enables rapid radio dissemination of early warning information when flood depth or impact force reaches the warning threshold. This significantly improves the emergency response speed for floating boat operators and riverside residents, effectively reducing disaster losses and enhancing disaster resilience.

[0037] Some of the data in the above formulas are numerical calculations with dimensions removed, and the contents not described in detail in this specification are all prior art known to those skilled in the art.

[0038] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for estimating the disaster chain of landslide surge impacting floating vessels, characterized in that, include S1. The digital elevation model (DEM) generated from satellite remote sensing images and aerial survey data is matched with geological borehole monitoring data to obtain three-dimensional topographic information and soil and rock physical parameters of the study area. S2. Identify landslide bodies from three-dimensional terrain information, call the Voellmy block model, iteratively solve the three-dimensional terrain information of the landslide body and output the landslide body's entry velocity Us, total volume Vs and kinetic energy Ekin; use the entry velocity Us, total volume Vs and kinetic energy Ekin to calculate the initial wave height H0 and wavelength λ0 of the inrush wave according to the kinetic energy formula. S3. Using the Boussinesq model, the initial wave height H0 and wavelength λ0 of the surge are set as input data. The shallow water equation is used to calculate the instantaneous pressure distribution map and water level distribution map of the surge along the river channel. The water level distribution map is matched with the dam structure data to obtain the overflow height of the overflow surge. S4. Input the surge overflow height and dam volume into the one-dimensional flood numerical model to calculate the downstream inundation depth and range; for downstream floating vessels or docks, simplify them to cylindrical or flat structures, calculate the surge impact force distribution using the Morison formula, and compare it with the structural failure threshold to determine the safety status. S5. Match the instantaneous pressure map from step S3 with the dam structure data to assess the bearing capacity of each region; When a certain area is deemed to be unable to bear the load, the dam is determined to be unstable. A flood peak flow curve is generated based on the dam failure model. The flood peak flow curve is then input into a one-dimensional flood model to calculate the downstream flood inundation depth and range.

2. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, Using satellite imagery and airborne LiDAR point clouds, a digital elevation model (DEM) is generated through stereo image pair matching and point cloud filtering. Boreholes are deployed in high-risk landslide areas, and rock sample parameters are collected layer by layer according to depth to obtain borehole profile information. The DEM is then unified with the GPS positioning of the boreholes, and each DEM grid node is associated with the corresponding borehole profile information to obtain the soil and rock physical properties of that node, including soil and rock type, density, friction angle, cohesion, and porosity. The three-dimensional topographic information and soil and rock physical properties are stored in a landslide parameter database.

3. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, On the Digital Elevation Model (DEM), the landslide boundary is extracted using a slope threshold m, and the area A and corresponding elevation change Δh of the boundary region are calculated accordingly. The total landslide volume V is obtained by integrating the area and elevation difference of each grid cell within the boundary region, combined with the volume of each grid cell. Calculate the density, friction angle, and cohesion of the sliding body using the corresponding soil and rock density P.

4. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, Using the Voellmy block model, the landslide body was discretized into multiple elements in the finite element method software. Each element was assigned mass, friction angle, cohesion, damping coefficient, and viscous drag coefficient. The forces, accelerations, and velocities of each element were iteratively solved using a time-step incremental approach to obtain the landslide's center-of-gravity velocity Us and the total volume V of the landslide. The kinetic energy was also calculated. ; Calculate the initial wave height H0 and wavelength lambda0 of the surge using V, Us, and kinetic energy Ekin according to the formula: ； ； in: , , where is the calibrated empirical coefficient, B is the width of the landslide entrance, g is the gravitational acceleration, and h is the water depth at the point of entry.

5. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, Using the initial wave height H0 and wavelength lambda0 as the inlet boundary, a grid is generated within the river propagation domain: a finer grid is used in the wave source area and upstream of the dam, and an absorption layer is set at the far-field boundary to prevent wave reflection; the time step is adjusted according to the CFL condition, and the instantaneous pressure p(x,t) and water level eta(x,t) at each time step are solved iteratively to generate instantaneous pressure distribution map and water level distribution map. The water level distribution map is matched with the geometric model of the artificial dam, and the overflow wave height Hx of each node along the dam surface is calculated.

6. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, Input the surge overflow height Hx, artificial embankment volume V, embankment material roughness coefficient n, and riverbed cross-section data from step 3 into a one-dimensional flood numerical model to solve the one-dimensional Saint-Venant equation. Calculate the water depth h(x,t) and flow velocity u(x,t) at each downstream cross-section under given overflow conditions, generating a downstream inundation depth and extent map. For downstream floating vessels or wharves, simplify to cylindrical or flat target structures, determine their projected area As, additional water volume Vs, drag coefficient CD, and additional mass coefficient CM. Based on the Morison equation, calculate the surge impact force F(t) on the structure and compare it with the structural failure threshold Fcrit: if F(t) > Fcrit, the target structure is deemed to be at risk of failure; otherwise, the target structure is deemed safe.

7. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, The maximum pressure max(x) at each location along the dam is extracted from the instantaneous pressure distribution map. Combined with the bearing capacity per unit width of the artificial dam sigma_cap(x), if p_max(x) ≥ sigma_cap(x) at a certain location, the dam area is determined to be unstable and a dam failure simulation is performed.

8. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 7, characterized in that, In the dam break simulation, based on the breach width B and breach height H of the unstable region, as well as the dam break flow coefficient Cb, the Marchi dam break equation is used to generate the dam break flood peak flow time history Q_peak(t). Q_peak(t) is then used as the input boundary to call the one-dimensional flood model again to calculate the downstream flood inundation depth h(x,t) and range after the dam break, generating an inundation depth map after the dam break. Subsequently, Monte Carlo perturbations are performed on the key parameters of the landslide body total volume V, water entry velocity Us, and landslide body water entry depth h. Multiple sets of parameters are randomly sampled and generated. Steps 2 to 4 are repeated for each set of parameters to record the downstream inundation depth and calculate the probability distribution of damage to key downstream targets.

9. The method for estimating the disaster chain of landslide surge impacting floating vessels according to claim 1, characterized in that, Import the instantaneous pressure distribution map, downstream inundation depth map, and structural impact risk map generated in step 3 into the GIS platform to generate a risk level layer; The risk level layer is dynamically updated based on real-time on-site monitoring data; when the downstream flood depth exceeds Q or the surge impact force exceeds the OP warning threshold, the risk level layer is pushed to the emergency management department.

10. A landslide surge impact floating vessel disaster chain estimation system, characterized in that, The system is used to implement the landslide surge impact floating vessel disaster chain estimation method according to any one of claims 1-9, including: The data acquisition and parameter library module is used to construct a high-precision DEM and combine borehole monitoring to obtain soil and rock physical parameters, storing all three-dimensional topographic and physical property information in the parameter library; Landslide dynamics simulation module: used to extract landslide bodies and calculate their volume and physical properties, call block or particle models respectively to simulate the sliding process of the landslide body, and obtain the landslide body's entry velocity, volume and kinetic energy into the water; Wave propagation simulation module: Employs shallow water equations to refine the mesh and handle absorbing boundaries within the river channel to simulate swell propagation; Downstream flood inundation and structural impact assessment module: Input the overflow wave height of the dam into the one-dimensional flood model to calculate the depth and extent of downstream flood inundation; The dam stability assessment and dam break simulation module evaluates the bearing capacity of each area of ​​the dam based on the surge pressure. If instability is determined, the dam break model is called to generate the peak flow and a one-dimensional flood simulation is performed again.

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