A method and system for calculating the water height of a high mountain valley reservoir landslide river blocking

Abstract

This invention relates to the field of geological disaster prediction technology, and particularly to a method and system for calculating the water dam height in the event of a landslide blocking a river in a high mountain canyon reservoir area. The method first obtains the topographic feature parameters of the target reservoir area's valley cross-section and the effective volume data of the landslide entering the river, and determines the type of the valley cross-section; it then constructs a geometric model of a landslide dam reflecting the depositional morphology of the landslide within the valley, and establishes an equivalent relationship between the effective volume data, topographic feature parameters, and the desired water dam height; based on the determined valley cross-section type, it calls the corresponding calculation logic to solve the equivalent relationship to obtain the water dam height value; and based on the water dam height value, it determines the river blocking status. If the water dam height value is greater than zero, it outputs the predicted water dam height; if the water dam height value is less than or equal to zero, it outputs a determination that the river will not be blocked. This invention significantly improves the timeliness and reliability of emergency decision-making for landslide blocking disasters in high mountain canyon reservoir areas.

Description

Technical Field

[0001] This invention relates to the field of geological disaster prediction technology, and in particular to a method and system for calculating the water damming height of landslides blocking rivers in high mountain canyon reservoir areas. Background Technology

[0002] Landslides blocking rivers are a typical highly destructive geological hazard in high mountain and canyon areas, especially in the reservoir areas of large reservoirs and hydropower stations. When a large-scale landslide occurs on the reservoir bank, a massive amount of rock and soil rushes into the river channel at high speed, forming a natural barrier dam. This drastically hinders the river's flood discharge capacity, causing the upstream water level to rise rapidly and forming a barrier lake. This type of disaster is characterized by its suddenness, rapid onset, long disaster chain, and wide impact. Its evolution process typically manifests as "landslide initiation → river blockage → water level rise (upstream inundation) → barrier dam collapse → downstream flooding (riverbank inundation)". It not only poses a fatal threat to upstream riverside towns, settlements, transportation and communication infrastructure, and the safety of residents' lives and property, but also seriously affects the safe and stable operation of downstream hydropower stations and water conservancy projects, triggering a chain reaction of secondary disasters.

[0003] In emergency response, risk assessment, and prevention and control decisions regarding landslide-induced river blockages, the maximum backwater height is a core and critical parameter. Its accuracy directly determines the scientific validity and feasibility of the upstream inundation area delineation, the quantitative assessment of disaster losses, and subsequent emergency rescue plans (such as flood discharge channel excavation, personnel relocation and resettlement, and engineering protection and reinforcement). Therefore, developing a rapid, accurate, and practically applicable method for predicting backwater height is of irreplaceable practical significance for the proactive prevention and emergency response to landslide-induced river blockages.

[0004] A search revealed that current domestic and international methods for predicting landslide-blocked river conditions (including dam height and water level) suffer from three main problems, making them unsuitable for practical applications in high mountain and canyon reservoir areas:

[0005] First, the lack of physical mechanism support limits the reliability of predictions. Most existing methods rely on empirical formulas based on historical case statistics. By collecting data on landslide-blocking cases worldwide, they establish statistical correlation models or simplified calculation formulas between landslide volume and dam height or water level. Some methods directly output the risk level of landslide-blocking. For example, Chinese patent CN120296531A discloses "A Risk Prediction Method and Related Products for Landslide-Blocking," which uses a machine learning "black box model" to directly construct the mapping relationship between blocking risk and raw data such as landslide velocity, flow depth, and channel slope angle. It does not consider the physical evolution mechanism of landslide-blocking, and its prediction results are greatly affected by the sample size and case similarity, resulting in poor applicability in high mountain and canyon areas with significantly different geological conditions.

[0006] Second, the models neglect cross-sectional topographic differences, resulting in insufficient model adaptability. High mountain and canyon areas exhibit various typical valley cross-sections, such as V-shaped, U-shaped, and T-shaped valleys, with extremely strong topographic constraints. However, most existing modified and simplified models are based on the assumption of a trapezoidal cross-section of the valley longitudinal section, failing to fully consider the impact of cross-sectional topographic variations on the depositional morphology of landslide dams and the height of the backwater, leading to limited prediction accuracy. For example, Chinese patent CN119862821B, which discloses "A prediction method and model for the geometric morphology of debris flow dam formation," only focuses on the analysis of the longitudinal cross-sectional distribution characteristics of landslide dams, lacking sufficient characterization of cross-sectional topography. Especially in scenarios with gentle slopes, it cannot adapt to the diverse valley cross-section types in high mountain and canyon areas, resulting in significant prediction errors.

[0007] Third, the methods are highly complex to operate and lack practical application in the field. While physical process-based numerical simulation methods (such as the discrete element method, finite element method, and DEM-CFD fluid-structure interaction method) can accurately depict landslide movement and deposition processes, they suffer from drawbacks such as complex modeling processes, stringent parameter input requirements (requiring a large number of topographic, geological, and geotechnical parameters), and long computation times. These methods are difficult to meet the timeliness requirements of emergency rescue for landslide-blocked river disasters (results are usually required within several hours). These methods are mostly used for post-event inversion analysis, and front-line maintenance engineers and rescue personnel cannot directly operate and apply them, thus failing to provide rapid technical support for emergency decision-making.

[0008] In summary, existing technologies cannot simultaneously meet the core requirements of "reliable physical mechanisms, adaptability to high mountain and canyon terrain, and convenient on-site operation." There is an urgent need to develop a targeted, accurate, and efficient method and system for calculating the height of landslides blocking rivers and impounding water in high mountain and canyon reservoir areas. Summary of the Invention

[0009] The present invention aims to at least partially solve one of the technical problems in the related art.

[0010] Therefore, the first objective of this invention is to propose a method for calculating the water damming height in the event of a landslide blocking a river in a high mountain canyon reservoir area, comprising the following steps: S1, Obtain the topographic feature parameters of the target reservoir area valley cross section and the effective volume data of the landslide body entering the river, and determine the type of the valley cross section; S2. Based on the principle of equivalent two-dimensional cross-sectional area and the law of volume conservation, a geometric model of a landslide dam reflecting the depositional morphology of the landslide body in the valley is constructed, and the equivalent relationship between the effective volume data, the topographic feature parameters, and the water impoundment height to be determined is established. S3, based on the determined valley cross-section type, call the corresponding calculation logic to solve the equivalent relationship to obtain the backwater height value; S4. Determine the river blockage status based on the water level value. If the water level value is greater than zero, output the predicted water level. If the water level value is less than or equal to zero, output the determination result that the river will not be blocked.

[0011] In one embodiment of the present invention, S1 includes: S11, the width of the valley bottom and the average natural slope angle of the mountains on both sides are obtained through on-site topographic survey or high-precision topographic data extraction, and the slope angle of the landslide dam surface is determined based on colluvial rock and soil mechanics test or engineering experience. S12, the effective volume of the landslide entering the river is calculated based on the total volume of the landslide and the preset proportion of the landslide entering the river, and the volume of the landslide entering the river per meter of the cross section is calculated by combining the distribution length of the landslide along the longitudinal section of the river valley. S13, Based on the extracted terrain contour features, the type of the valley cross section is determined to be one of V-shaped valley, U-shaped valley or T-shaped valley.

[0012] In one embodiment of the present invention, S13 includes: When the width B at the bottom of the valley is identified as zero or close to zero, the type of the valley cross section is determined to be a V-shaped valley. When a valley bottom is identified as having a significant width and both sides of the slope extend in a straight line, the valley cross section is classified as a T-shaped valley. When a valley bottom is identified as having a significant width and a relatively open valley shape, the valley cross-section is determined to be a U-shaped valley.

[0013] In one embodiment of the present invention, S3 includes: When the determined valley cross-section type is a T-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface, and the water backfill height is calculated. When the valley cross-section type is determined to be a V-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface. The valley bottom width is set to zero, and the water backing height is calculated. When the valley cross-section is determined to be a U-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface. The valley bottom width is set to zero, and an area correction coefficient is introduced to calculate the backwater height.

[0014] In one embodiment of the present invention, the calculation model for the T-shaped valley is as follows: ; The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. Using the quadratic formula:

[0015] The water level was calculated.

[0016] In one embodiment of the present invention, the calculation model for the V-shaped valley is as follows: ; The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. By setting the width of the valley floor to zero and substituting it into the coefficient calculation formula of the calculation model, we obtain: ; The backwater height is then calculated by reverse calculation based on the simplified volume equivalence relation.

[0017] In one embodiment of the present invention, the calculation model for the U-shaped valley is as follows: ; The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. By setting the width of the valley floor to zero and substituting the area correction factor into the coefficient calculation formula of the calculation model, the corrected volume equivalence relationship is constructed: ; Where k is the area correction factor; The water level rise is obtained by using the corrected volume equivalence formula, combined with the known volume and area correction coefficient of the landslide body entering the river per meter of cross section.

[0018] In one embodiment of the present invention, the method for determining the river blockage status based on the water level height in step S4 is as follows: The calculated water dam height is compared with the zero value. If the water dam height is greater than zero, it is determined that the landslide can block the river channel and the water dam height is output as the predicted water dam height. If the water level is less than or equal to zero, the landslide is determined to be insufficient to block the river channel and a text judgment result stating that it will not block the river is output.

[0019] To achieve the above objectives, a second aspect of the present invention proposes a system for calculating the water damming height in a high-mountain canyon reservoir area due to landslides, comprising: The basic data acquisition and cross-section type determination module is used to acquire the topographic feature parameters of the river valley cross section of the target reservoir area and the effective volume data of the landslide body entering the river, and to determine the type of the river valley cross section. The module for constructing geometric models and parameter equivalence relationships of landslide dams is used to construct geometric models of landslide dams that reflect the depositional morphology of landslide bodies in river valleys based on the principle of equivalence of two-dimensional cross-sectional area and the law of volume conservation, and to establish the equivalence relationship between the effective volume data, the topographic feature parameters, and the water impoundment height to be determined. The categorized logic module for solving the backwater height is used to call the corresponding calculation logic based on the determined river valley cross-section type to solve the equivalent relationship and obtain the backwater height value. The river blockage status determination and result output module is used to determine the river blockage status based on the water level height value. If the water level height value is greater than zero, the predicted water level height is output; if the water level height value is less than or equal to zero, the determination result that the river will not be blocked is output.

[0020] To achieve the above objectives, a third aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0021] The method, system, and storage medium of this invention can accurately calculate the backwater height under different valley types based on the principle of equivalent two-dimensional cross-sectional area, effectively solving the problems of insufficient physical mechanism support and inadequate terrain adaptability in existing technologies. Simultaneously, by simplifying parameter input and achieving rapid solutions in seconds, it significantly improves the timeliness and reliability of emergency decision-making for landslide-related river blockage disasters in high mountain canyon reservoir areas.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a flowchart of a method for calculating the water backfill height in a landslide blocking a river in a high mountain canyon reservoir according to an embodiment of the present invention; Figure 2 This is a hypothetical model of a landslide blocking a river in a high mountain canyon according to an embodiment of the present invention, wherein (a) is a schematic diagram of the cross section before the landslide; and (b) is a schematic diagram of the accumulation of the landslide dam and the backwater after the landslide. Figure 3 These are schematic diagrams of calculation models for different cross-sectional types in embodiments of the present invention, wherein (a) is a V-shaped valley cross-section and accumulation model; (b) is a U-shaped valley cross-section and accumulation model; and (c) is a T-shaped valley (trapezoidal valley) cross-section and accumulation model. Figure 4 This is a sensitivity analysis diagram of the main parameters of the backwater height in an embodiment of the present invention, where (a) is the width of the river valley. B right H (b) Influence curve of slope angle φ0 on H Influence curve; (c) Surface slope angle φ1 of the landslide dam on H The influence curve; Figure 5 This is a curve showing the change in backwater height as a function of the landslide's volume entering the river, according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the Baige landslide blocking the Jinsha River according to an embodiment of the present invention, wherein (a) is a real-life photo taken at the scene; and (b) is a cross-sectional topography and distribution of deposits. Figure 7 This is a schematic diagram of the Tangjiashan landslide blocking the river according to an embodiment of the present invention, wherein (a) is a real-life photo taken at the scene; and (b) is a cross-sectional topography and a profile of the landslide dam. Figure 8 This is a schematic diagram of the Atadeng landslide according to an embodiment of the present invention, wherein (a) is an aerial photograph of the site; and (b) is a cross-sectional topographic parameter labeling. Figure 9 This is a structural diagram of a water damming height calculation system for landslides blocking rivers in high mountain canyon reservoirs according to an embodiment of the present invention. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] The following describes, with reference to the accompanying drawings, a method and system for calculating the water damming height in a mountain canyon reservoir area caused by landslides, according to an embodiment of the present invention.

[0027] Example 1 Figure 1 This is a flowchart of a method for calculating the water damming height in a mountain canyon reservoir area during a landslide that blocks the river, according to an embodiment of the present invention.

[0028] like Figure 1 As shown, the method for calculating the water damming height of a landslide blocking a river in a high mountain canyon reservoir includes the following steps: S1, obtain the topographic feature parameters of the target reservoir area valley cross section and the effective volume data of the landslide body entering the river, and determine the type of the valley cross section.

[0029] Obtaining topographic feature parameters of the target reservoir valley cross section and effective volume data of landslide bodies entering the river, and determining the type of valley cross section, are fundamental data preparation steps for constructing the subsequent backwater height calculation model. This step aims to extract key two-dimensional feature quantities from the complex three-dimensional geological environment that can characterize the valley constraints and landslide material sources. Its core lies in abstracting the actual terrain into a computable geometric model input through parametric description.

[0030] Specifically, step S1 includes: S11, the width of the valley bottom and the average natural slope angle of the mountains on both sides are obtained through on-site topographic survey or high-precision topographic data extraction, and the slope angle of the landslide dam surface is determined based on colluvial soil and rock mechanics test or engineering experience.

[0031] S12, the effective volume of the landslide entering the river is calculated based on the total volume of the landslide and the preset proportion of the landslide entering the river, and the volume of the landslide entering the river per meter of the cross section is calculated by combining the distribution length of the landslide along the longitudinal section of the river valley.

[0032] S13, Based on the extracted terrain contour features, the type of the valley cross section is determined to be one of V-shaped valley, U-shaped valley or T-shaped valley.

[0033] Specifically, topographic feature parameters are used to define the spatial morphological constraints of the valley. These typically include geometric dimensions reflecting the width of the valley floor and angular information characterizing the natural slopes of the mountains on both sides. These parameters collectively determine the boundary conditions for landslide deposition within the river channel. The effective volume data of the landslide entering the river represents the total amount of material involved in the river blocking process. This data differs from the overall unstable volume of the landslide; it specifically refers to the volume of the rock and soil mass that actually displaced and entered the valley channel, obstructing water flow. Its value can be derived based on the total volume of the landslide combined with engineering experience proportional coefficients, or obtained through numerical simulation analysis. Based on this, determining the type of valley cross-section is a process of classifying continuously changing natural terrain into typical geometric models to match the corresponding physical calculation logic. These types encompass various cross-sectional morphologies commonly found in high mountain and canyon areas.

[0034] As one implementation method, such as Figure 2 As shown, the terrain feature parameter can be specifically selected as the width of the valley bottom. Average natural slope angle of the mountain and the slope angle of the landslide dam surface The effective volume of the landslide entering the river can be obtained by multiplying the total volume of the landslide by... to The empirical proportions are obtained, while the types of river valley cross sections can be specifically divided into V-shaped valleys, U-shaped valleys, or T-shaped valleys. For example... Figure 3 The images show V-shaped, U-shaped, and T-shaped valley accumulation models.

[0035] This step, by extracting key terrain features and effective material volume and classifying cross-section types, achieves a precise mapping of complex three-dimensional geological disaster scenarios to two-dimensional physical models. It retains the core geometric constraints and material conservation elements that affect the backwater height, while avoiding the excessive reliance of full three-dimensional numerical simulation on massive geomechanical parameters. This lays a reliable data foundation for subsequent rapid and adaptable solutions to backwater heights in different terrains.

[0036] S2. Based on the principle of equivalent two-dimensional cross-sectional area and the law of volume conservation, a geometric model of a landslide dam reflecting the depositional morphology of the landslide body in the valley is constructed, and an equivalent relationship is established between the effective volume data, the topographic feature parameters, and the desired impoundment height.

[0037] This step aims to simplify the complex three-dimensional evolution of landslide-blocked river flow into a two-dimensional geometric solution through physical modeling. Its core lies in constructing a dam geometric model that reflects the actual depositional morphology of the landslide mass within the valley, based on the principle of equivalence of two-dimensional cross-sectional area and the law of volume conservation. Specifically, this method does not rely on statistical regression or black-box machine learning of historical cases. Instead, it starts from the physical mechanism, mapping the effective volume data of the landslide mass entering the river to the depositional area within the cross-section, thereby establishing a strict equivalence relationship between the effective volume data, topographic feature parameters, and the desired impoundment height. In this process, topographic feature parameters are used to define the spatial constraints of the valley, while the dam geometric model describes the surface slope and filling range of the landslide material when it reaches a stable state under gravity. Together, they constitute the physical basis for solving the impoundment height.

[0038] This step, by constructing a physics-based geometric model, fundamentally overcomes the lack of theoretical support in traditional empirical formula methods, significantly improving the reliability and universality of the prediction results. Simultaneously, reducing the three-dimensional problem to two-dimensional cross-sectional processing preserves the crucial influence of terrain constraints on the depositional morphology while avoiding the dependence on massive parameters and computational resources in complex numerical simulations, laying a solid theoretical and data foundation for the subsequent rapid and accurate calculation of backwater height.

[0039] S3. Based on the determined river valley cross-section type, call the corresponding calculation logic to solve the equivalent relationship to obtain the backwater height value.

[0040] Based on the determined valley cross-section type, the corresponding calculation logic is invoked to solve the equivalent relationship to obtain the water backwater height value. The core of this process lies in adaptively matching a preset mathematical analytical model based on the valley cross-section type identified in previous steps, and substituting terrain feature parameters and the effective volume data of the landslide entering the river into the corresponding equivalent relationship for numerical calculation. For example... Figure 5 The curve shown is the change in water backwater height as a function of the volume of landslide entering the river.

[0041] Specifically, when the determined valley cross-section type is a T-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface, and the water backfill height is calculated.

[0042] The calculation model for the T-shaped valley is as follows: ; In the formula, the coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. Using the quadratic formula:

[0043] The water level was calculated.

[0044] When the valley cross-section type is determined to be a V-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface. The valley bottom width is set to zero, and the water backfill height is calculated.

[0045] The calculation model for the V-shaped valley is as follows: ; The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. By setting the width of the valley floor to zero and substituting it into the coefficient calculation formula of the calculation model, we obtain: ; The backwater height is then calculated by reverse calculation based on the simplified volume equivalence relation.

[0046] When the valley cross-section is determined to be a U-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface. The valley bottom width is set to zero, and an area correction coefficient is introduced to calculate the backwater height.

[0047] The calculation model for the U-shaped valley is as follows: ; The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. By setting the width of the valley floor to zero and substituting the area correction factor into the coefficient calculation formula of the calculation model, the corrected volume equivalence relationship is constructed: ; Where k is the area correction coefficient. As one implementation method, the value of k ranges from 1.1 to 1.2. The wider the valley, the closer the value of k is to 1.2.

[0048] The water level rise is obtained by using the corrected volume equivalence formula, combined with the known volume and area correction coefficient of the landslide body entering the river per meter of cross section.

[0049] This step establishes a mapping relationship between valley terrain types and computational logic, achieving precise adaptation to diverse geomorphic conditions in high mountain and canyon areas and avoiding computational errors caused by inconsistent terrain assumptions in single models. Simultaneously, the analytical method directly solves for equivalence relationships, eliminating the need for complex iterative calculations or numerical simulations, significantly improving the efficiency and timeliness of water backfill height calculations. This meets the technical requirements for rapid decision-making in emergency response to landslide-related river blockage disasters.

[0050] like Figure 4 As shown, this invention clarifies the influence of key parameters on backwater height through parameter sensitivity analysis: Valley width B: The dammed height decreases significantly as B increases. When B exceeds a certain large value, the dammed height approaches 0 (it will not block the river). Mountain slope angle φ0: The water damming height increases with the increase of φ0, that is, the steeper the mountain, the higher the risk of blocking the river; The slope angle φ1 of the landslide dam surface: the water backing height decreases as φ1 increases, that is, the higher the residual strength of the colluvium, the lower the risk of blocking the river.

[0051] This pattern can provide clear guidance for predicting and formulating prevention and control measures for landslide-blocked river risks (such as prioritizing monitoring areas with steep mountain slopes and narrow river valleys).

[0052] Assume a landslide in a high mountain canyon has a total volume of 1 million m³, and the longitudinal section of the landslide along the valley is 400 m long. What is the volume of the landslide per meter of the cross section? The valley width is 2500 m³. m, original slope gradient for Surface slope of the landslide dam for The width of the river valley The values ​​of the variation are 0, 25, 50, 100, and 150 m; The change value , , as well as , The change value , , , The height of the dammed water is calculated, and the three parameters mentioned above are discussed. , and The effect of changes on the height of the dammed water is shown in the following results. Figure 4 .

[0053] S4. Determine the river blockage status based on the water level rise value. If the water level rise value is greater than zero, output the predicted water level rise. If the water level rise value is less than or equal to zero, output a determination that the river will not be blocked. The determination of river blockage based on the stated backwater height aims to clarify the blocking effect of a landslide on the river's flood discharge capacity through quantitative indicators. This step, based on the calculation results of physical geometric relationships, uses the desired backwater height as a critical criterion for determining whether a landslide has blocked the river. Its core logic lies in verifying whether the volume of the landslide accumulation within the river valley cross-section is sufficient to exceed the original river channel's flow cross-section and generate a positive water level rise. Specifically, by comparing the relative magnitudes of the calculated backwater height with zero, two distinct disaster evolution scenarios are defined: When the backwater height is positive, it indicates that the minimum height of the landslide dam formed by the effective volume of the landslide body under gravity is higher than the original river level, and the river is substantially blocked. In this case, the positive value is output as the predicted backwater height for subsequent inundation range assessment. When the backwater height is less than or equal to zero, it indicates that the effective volume of the landslide body entering the river is insufficient to fill the cross-section of the valley or can only partially fill it without causing a rise in water level, and the flood discharge function of the river is not blocked. In this case, the judgment result that the river will not be blocked is output.

[0054] Specifically, the calculated water dam height value is compared with a zero value. If the water dam height value is greater than zero, it is determined that the landslide body can block the river channel and the water dam height value is output as the predicted water dam height. If the water level is less than or equal to zero, the landslide is determined to be insufficient to block the river channel and a text judgment result stating that it will not block the river is output.

[0055] This step, by introducing a zero value as the physical threshold for river closure, establishes a direct mapping mechanism from theoretical calculations to actual disaster status assessment. This not only eliminates errors from vague empirical judgments but also enables rapid, binary identification of river closure risks. This assessment method can instantly distinguish between potential disaster scenarios and safe operating conditions, avoiding over-warning of situations without river closure risk. It significantly improves the targeting and timeliness of emergency decision-making, providing clear quantitative evidence for whether to initiate personnel evacuation or engineering rescue plans.

[0056] This invention constructs a calculation model based on the principle of equivalent two-dimensional cross-sectional area and the law of volume conservation, overcoming the limitation of traditional empirical formula methods that lack physical mechanism support. Through verification through two typical landslide blocking river cases, Tangjiashan and Baige (see Table 1 for details), the calculation results deviate from the actual height of the landslide dam by less than 10%, indicating that the model has extremely high reliability and accuracy.

[0057] The advantages of this technical solution can be demonstrated by calculating the 2018 Baige landslide dam blockage incident and the 2008 Tangjiashan landslide dam blockage incident using this invention. The Baige landslide is located in Baige Village, on the right bank of the Jinsha River, bordering Sichuan Province and the Tibet Autonomous Region. The landslide body is approximately 1413 m long, 560 m wide on average, and 40 m thick on average. After two landslides, it entered the Jinsha River channel through collision and leaping, depositing and forming a landslide dam. The dam body is characterized by a lower right bank and a higher left bank. The total height of the landslide dam formed by the combined action of the two landslides is 96 m. The Tangjiashan landslide is located upstream of the Tongkou River in Beichuan County, Mianyang City, Sichuan Province. Under the action of an earthquake, it formed a high-speed rock landslide, which rapidly slid down and blocked the river, forming a landslide dam. It is 803.4 m long along the river, with a maximum lateral width of 611.8 m, and a dam height of 82-124 m.

[0058] The calculation results are summarized in Table 1. The final calculated dam heights H of the Baige and Tangjiashan landslide dams are 104.02 m and 95.67 m, respectively, while the actual heights are 96 m and 82~124 m, respectively. The calculations are basically consistent with the actual situation, indicating that this method can quickly and effectively determine the equivalent landslide dam height.

[0059] Table 1. Calculation results for two typical cases.

[0060] Example 2 To make the technical solution of this invention clearer and easier to understand, the implementation process of this invention is explained in detail below with reference to specific engineering cases and calculation conditions: (1) Project Background The upper reaches of the Lancang River in Yunnan Province are a typical high-mountain, deeply incised canyon area with a fragile hydrogeological environment. Due to the impact of hydropower project construction, multiple landslides are distributed along the reservoir banks. Among them, the Atadeng landslide on the right bank of the tail of the Dahuaqiao Hydropower Station reservoir has recently shown significant deformation. This landslide is about 5km away from the Dahuaqiao dam site. If a landslide were to block the river, it could cause the water from the landslide dammed lake to backflow into the underground powerhouse, threatening the safe operation of the hydropower station.

[0061] (2) Basic parameters Based on on-site investigation, topographic survey, and soil and rock mass test data, the core parameters are determined as follows: Valley cross-sectional type: T-shaped valley (trapezoidal valley); The width of the valley floor is B = 60m; The average natural slope angle of the mountain is φ0 = 45°; The slope angle of the landslide dam surface is φ1=10°; Total volume of landslide: 7 million m³ The proportion of landslides entering the river: 1 / 10 (determined based on similar cases in the region); The longitudinal section length of the landslide along the valley is L=420m.

[0062] (3) Parameter calculation Typical instability conditions: The effective volume of the landslide entering the river is V = 7 million m³ × 1 / 10 = 700,000 m³. The volume of the cross-section flowing into the river per meter is V' = 700,000 m³ / 420 m ≈ 1667 m³ / m.

[0063] Extreme instability conditions: The effective volume of the landslide entering the river is V = 7 million m³ × 3 / 10 = 2.1 million m³. The volume of the cross-section flowing into the river per meter is V' = 2.1 million m³ / 420m = 5000 m³ / m.

[0064] (4) Calculation of backwater height 1. Conventional instability conditions Input parameters: B=60m, φ0=45°, φ1=10°, V'=1667m³ / m, cross-section type = T-shaped valley; The system calls the T-shaped valley calculation model, and substitutes it into equation (2): to solve for H≈12.67m (positive root). Result determination: H>0, river blockage will occur, with a predicted water level of 12.67m.

[0065] 2. Extreme instability conditions Input parameters: B=60m, φ0=45°, φ1=10°, V'=5000m³ / m, cross-section type = T-shaped valley; Substituting into equation (2), we get: H≈38.67m (positive root); Result determination: H>0, river blockage will occur, with a predicted water level of 38.67m.

[0066] 3. Verification under non-blocked river conditions Assuming the effective volume of the landslide entering the river is V = 84,000 m³, then V' = 84,000 m³ / 420 m = 200 m³ / m; Input parameters: B=60m, φ0=45°, φ1=10°, V'=200m³ / m; Substituting into equation (2), we get: H≈-12.3m (negative root); Result determination: No river blockage will occur; system output: "No river blockage will occur".

[0067] (5) Application of results Based on the calculation results, the Dahuaqiao Hydropower Station has formulated an emergency prevention and control plan for the Atadeng landslide: Normal instability condition (water backlog 12.67m): Strengthen the waterproofing and sealing of the underground powerhouse entrance, and set a water level monitoring and early warning threshold of 12m; Extreme instability conditions (water level 38.67m): Activate the personnel evacuation plan and plan the excavation route for the flood discharge channel; Establish a routine monitoring mechanism, focusing on monitoring the deformation rate of the landslide body and the changes in its volume entering the river, and update the predicted water level in real time using this system.

[0068] Besides the Lancang River, the method proposed in this invention is also applicable to areas such as the Jinsha River, Tangjiashan, and Atadeng. Figure 6 The diagram shown is a schematic representation of the Baige landslide blocking the Jinsha River. Figure 7 The diagram shown is a schematic representation of the Tangjiashan landslide blocking the river. Figure 8 The diagram shown is of the Atadden landslide.

[0069] Example 3 like Figure 9 As shown, this invention proposes a system 10 for calculating the water damming height in high mountain canyon reservoir areas where landslides block rivers, comprising: The basic data acquisition and cross-section type determination module 100 is used to acquire the topographic feature parameters of the target reservoir area valley cross section and the effective volume data of the landslide body entering the river, and to determine the type of the valley cross section. The module 200 for constructing the geometric model and parameter equivalence relationship of the landslide dam is used to construct a geometric model of the landslide dam that reflects the deposition morphology of the landslide body in the valley based on the principle of equivalence of two-dimensional cross-sectional area and the law of volume conservation, and to establish the equivalence relationship between the effective volume data and the topographic feature parameters and the water impoundment height to be determined. The categorized logic solution module 300 is used to call the corresponding calculation logic according to the determined river valley cross section type to solve the equivalent relationship and obtain the water dam height value. The river blockage status determination and result output module 400 is used to determine the river blockage status based on the water level height value. If the water level height value is greater than zero, the predicted water level height is output. If the water level height value is less than or equal to zero, the determination result that the river will not be blocked is output.

[0070] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-mentioned method for calculating the water damming height for landslides blocking rivers in high mountain canyon reservoir areas.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "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.

[0072] Furthermore, 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A method for calculating the impoundment height of a landslide blocking a river in a high mountain canyon reservoir area, characterized in that, Includes the following steps: S1, Obtain the topographic feature parameters of the target reservoir area valley cross section and the effective volume data of the landslide body entering the river, and determine the type of the valley cross section; S2. Based on the principle of equivalent two-dimensional cross-sectional area and the law of volume conservation, a geometric model of a landslide dam reflecting the depositional morphology of the landslide body in the valley is constructed, and the equivalent relationship between the effective volume data, the topographic feature parameters, and the water impoundment height to be determined is established. S3, based on the determined valley cross-section type, call the corresponding calculation logic to solve the equivalent relationship to obtain the backwater height value; S4. Determine the river blockage status based on the water level value. If the water level value is greater than zero, output the predicted water level. If the water level value is less than or equal to zero, output the determination result that the river will not be blocked.

2. The method as described in claim 1, characterized in that, S1 includes: S11, the width of the valley bottom and the average natural slope angle of the mountains on both sides are obtained through on-site topographic survey or high-precision topographic data extraction, and the slope angle of the landslide dam surface is determined based on colluvial rock and soil mechanics test or engineering experience. S12, the effective volume of the landslide entering the river is calculated based on the total volume of the landslide and the preset proportion of the landslide entering the river, and the volume of the landslide entering the river per meter of the cross section is calculated by combining the distribution length of the landslide along the longitudinal section of the river valley. S13, Based on the extracted topographic contour features, the type of the valley cross section is determined to be one of V-shaped valley, U-shaped valley or T-shaped valley.

3. The method as described in claim 2, characterized in that, S13 includes: When the width B at the bottom of the valley is identified as zero or close to zero, the type of the valley cross section is determined to be a V-shaped valley. When a valley bottom is identified as having a significant width and both sides of the slope extend in a straight line, the valley cross section is classified as a T-shaped valley. When a valley bottom is identified as having a significant width and a relatively open valley shape, the valley cross-section is determined to be a U-shaped valley.

4. The method as described in claim 1, characterized in that, S3 includes: When the determined valley cross-section type is a T-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface, and the water backfill height is calculated. When the valley cross-section type is determined to be a V-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface. The valley bottom width is set to zero, and the water backing height is calculated. When the valley cross-section is determined to be a U-shaped valley, a calculation model is constructed that includes the valley bottom width, the effective volume of the landslide entering the river, the average natural slope angle of the mountains on both sides, and the slope angle of the dam surface. The valley bottom width is set to zero, and an area correction coefficient is introduced to calculate the backwater height.

5. The method as described in claim 4, characterized in that, The calculation model for T-shaped valleys is as follows: ； The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. Using the quadratic formula: The water level was calculated.

6. The method as described in claim 4, characterized in that, The calculation model for V-shaped valleys is as follows: ； The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. By setting the width of the valley floor to zero and substituting it into the coefficient calculation formula of the calculation model, we obtain: ； The backwater height is then calculated by reverse calculation based on the simplified volume equivalence relation.

7. The method as described in claim 4, characterized in that, The calculation model for the U-shaped valley is as follows: ； The coefficients a, b, and c are respectively derived from the formula , and Calculated; Where B is the width of the valley floor. φ0 represents the effective volume of the landslide entering the river, φ1 represents the average natural slope angle of the mountains on both sides, and φ1 represents the slope angle of the surface of the landslide dam. By setting the width of the valley floor to zero and substituting the area correction factor into the coefficient calculation formula of the calculation model, the corrected volume equivalence relationship is constructed: ； Where k is the area correction factor; The water level rise is obtained by using the corrected volume equivalence formula, combined with the known volume and area correction coefficient of the landslide body entering the river per meter of cross section.

8. The method as described in claim 1, characterized in that, The method for determining the river blockage status based on the water level height in step S4 is as follows: The calculated water dam height is compared with the zero value. If the water dam height is greater than zero, it is determined that the landslide can block the river channel and the water dam height is output as the predicted water dam height. If the water level is less than or equal to zero, the landslide is determined to be insufficient to block the river channel and a text judgment result stating that it will not block the river is output.

9. A system for calculating the water impoundment height in the event of a landslide blocking a river in a high mountain canyon reservoir area, characterized in that, include: The basic data acquisition and cross-section type determination module is used to acquire the topographic feature parameters of the river valley cross section of the target reservoir area and the effective volume data of the landslide body entering the river, and to determine the type of the river valley cross section. The module for constructing geometric models and parameter equivalence relationships of landslide dams is used to construct geometric models of landslide dams that reflect the depositional morphology of landslide bodies in river valleys based on the principle of equivalence of two-dimensional cross-sectional area and the law of volume conservation, and to establish the equivalence relationship between the effective volume data, the topographic feature parameters, and the water impoundment height to be determined. The categorized logic module for solving the backwater height is used to call the corresponding calculation logic based on the determined river valley cross-section type to solve the equivalent relationship and obtain the backwater height value. The river blockage status determination and result output module is used to determine the river blockage status based on the water level height value. If the water level height value is greater than zero, the predicted water level height is output; if the water level height value is less than or equal to zero, the determination result that the river will not be blocked is output.

10. A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method as claimed in any one of claims 1-8.

Images