A dam-break prevention method for barrier lake based on erosion reference point protection
By protecting against erosion benchmarks and scientifically deploying temporary spillways, the systemic deficiencies in the control and mitigation technologies for landslide-dammed lakes have been addressed, enabling safe and efficient discharge of the landslide-dammed lakes, ensuring the safety of downstream river channels, and reducing the impact of disasters.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHANGJIANG RIVER SCI RES INST CHANGJIANG WATER RESOURCES COMMISSION
- Filing Date
- 2026-03-26
- Publication Date
- 2026-06-09
AI Technical Summary
The existing landslide dam control and hazard mitigation technologies lack systematic design and cannot accurately control the flow, resulting in devastating impacts on downstream areas from breached floods. The safety and efficiency of emergency hazard mitigation are also insufficient.
By calculating the breach parameters, a temporary spillway was scientifically deployed, erosion benchmark point protection was adopted, the discharge was precisely controlled, and high-strength PVC materials and umbrella-shaped anchors were used to fix the spillway to ensure that the flow velocity and flow rate were within a safe range.
This achieved safe and controllable release of water from the landslide dammed lake, avoiding downstream flooding, improving the safety and efficiency of emergency response, and reducing casualties and property losses.
Smart Images
Figure CN122169457A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of emergency hazard mitigation technology for water conservancy projects, and in particular to a method for controlling and mitigating hazards in landslide-dammed lakes based on erosion benchmark protection. Background Technology
[0002] Landslide-dammed lakes are formed when landslides caused by geological disasters block river channels and store water. These dams are susceptible to natural breaches due to factors such as water level rise and erosion. Sudden, large-volume breaches can cause devastating damage to downstream villages, infrastructure, and the river's ecosystem. Therefore, the core of emergency response to landslide-dammed lakes lies in achieving safe and controllable water release through artificial intervention, ensuring that the peak flow of the breach does not exceed the safe carrying capacity of the downstream river channel.
[0003] The existing technologies for controlling and mitigating risks associated with landslide dams have significant limitations. The protection and treatment approaches are mostly focused on passive protection of local areas such as the upstream slope, both sides of the diversion channel, and the dam crest, lacking a systematic design for the entire flood discharge process. Furthermore, the existing technologies cannot accurately control the discharge according to the target flow rate, making it difficult to achieve the core requirement that the breach flood does not exceed the downstream guaranteed water level. The safety and efficiency of emergency risk mitigation urgently need to be improved.
[0004] To address the aforementioned technical problems, this invention proposes a method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark protection. By accurately calculating the breach parameters and scientifically deploying temporary spillways, the method enables controllable discharge of water from the landslide-dammed lake, effectively avoiding the risk of downstream flood disasters. Summary of the Invention
[0005] The purpose of this invention is to provide a method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark protection, which solves the problems of low flood discharge control accuracy, imperfect protection system, and poor emergency risk mitigation safety in the existing technology, and realizes rapid, efficient, and safe control and mitigation of risks of landslide-dammed lakes.
[0006] To achieve the above objectives, the present invention provides the following solution: A method for controlling and mitigating the risks of landslide-dammed lakes based on erosion benchmark protection includes: The maximum peak outburst flow of the landslide dammed lake was determined using the guaranteed water level downstream of the river as a constraint. The allowable breach height of the landslide dam is calculated based on the dam length corresponding to the protection elevation, the dam volume above the protection height, and the reservoir capacity above the protection height. The protection elevation of the erosion benchmark point is determined based on the allowable breach height. Calculate the cross-sectional dimensions of the spillway based on the determined maximum outburst flood peak flow. A temporary flood discharge channel was laid based on the protection elevation of the erosion benchmark point and the cross-sectional dimensions of the discharge channel.
[0007] Furthermore, the determination of the maximum peak outburst flow of the landslide dammed lake specifically refers to: The water level-discharge curve formula for a typical cross-section in the downstream of the river was obtained by fitting measured hydrological data. The maximum allowable peak outburst discharge of the landslide dammed lake was obtained based on the water level-discharge curve formula and the downstream guaranteed water level calculation.
[0008] Furthermore, the formula for calculating the allowable breach height of the landslide dammed lake is as follows: in, It is the acceleration due to gravity; The height of the collapse; Unit length; The length of the dam body corresponding to the protection elevation; To protect the dam volume above the height; To protect the storage capacity above the specified height, the above formula is used for iterative calculation to obtain... .
[0009] Furthermore, the cross-sectional dimensions of the flood discharge channel are specifically calculated as follows: The Manning roughness coefficient is selected based on the material properties of the spillway, and the Chezy coefficient is obtained. The cross-sectional area of the spillway corresponding to the maximum outburst flow is calculated based on the Chezy formula for uniform flow in open channels. The cross-sectional dimensions of the flood discharge channel are obtained based on the cross-sectional area of the discharge channel.
[0010] Furthermore, the formula for calculating the cross-sectional area of the spillway based on the uniform flow formula for open channels is as follows: in, For the Xie Cai coefficient, The cross-sectional area of the flood discharge channel; For hydraulic radius, It is the bottom slope of the flood discharge channel; The formula for obtaining the cross-sectional dimensions of the flood discharge channel based on its cross-sectional area is as follows: in, The bottom width of the flood discharge channel, This refers to the height of the flood discharge channel.
[0011] Furthermore, the sidewalls of the temporary flood discharge channel are made of inflated cylindrical PVC material.
[0012] Furthermore, after obtaining the cross-sectional dimensions of the flood discharge channel, the process also includes: calculating the average flow velocity of the cross-section using the formula for the average flow velocity of the open channel cross-section; if the flow velocity exceeds 15 m / s, widening the bottom width of the flood discharge channel and recalculating the cross-sectional area and dimensions, iterating until the average flow velocity of the cross-section is ≤15 m / s and there is no risk of flood overflow in the flood discharge channel during the flood peak.
[0013] Furthermore, before laying the temporary spillway, the embankment and horizontal section were excavated at the erosion benchmark elevation to form the basic structure for the spillway.
[0014] The present invention discloses the following technical effects: This invention determines the maximum peak outburst flow rate by using the downstream guaranteed water level as a constraint, calculates the allowable outburst height and determines the protection elevation of the erosion benchmark, and then calculates the cross-sectional dimensions of the spillway and lays a temporary spillway made of high-strength PVC material. This forms a systematic and precise technical solution for controlling and mitigating risks in landslide-dammed lakes. It effectively achieves safe and controllable discharge of water from landslide-dammed lakes, ensuring that the peak flow rate does not exceed the downstream river's carrying capacity, the spillway velocity meets the erosion resistance requirements, and there is no risk of overflow and erosion. It also improves the safety, efficiency, and operability of emergency mitigation for landslide-dammed lakes, effectively avoiding downstream flood disasters caused by landslide dam failure, minimizing casualties and property losses, and is applicable to emergency response scenarios for landslide-dammed lakes formed by various geological disasters. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a top view of the temporary flood discharge channel of the present invention; Figure 3 This is a schematic diagram illustrating the implementation of the landslide dam control and hazard mitigation method of the present invention; Among them, 1. Umbrella-shaped anchor; 2. Flood discharge channel; 3. Cylindrical PVC sidewall. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.
[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0019] like Figure 1 As shown, this invention provides a method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection, comprising: Step 1: Using the downstream river channel's guaranteed water level as a constraint, determine the maximum allowable peak outburst flood discharge for the project. , which serves as the core control indicator for subsequent design; Step 2: Determine the dam length corresponding to the protection elevation. Dam volume above the protection height and above the protection height of the reservoir The height of the breach was calculated using the Qi Zijie and Huang Wei breach parameter model, which takes three parameters. ; Step 3: Determine the protective elevation based on the calculated breach height, and excavate a drop sill (height is...) at this elevation. ) and horizontal segment (length) Temporary flood discharge channels were laid in the horizontal section and downstream.
[0020] The temporary spillway is made of high-strength PVC material, and the horizontal section of the spillway is fixed with umbrella-shaped anchors to ensure that the water flow will not destroy it. Step 4: Based on the determined peak flow rate, calculate the cross-sectional dimensions of the flood discharge channel using the Chezy formula (uniform flow formula for open channels) to ensure that there is no overflow during the peak flow and that the average flow velocity of the cross-section is ≤15m / s.
[0021] Step 5: Complete the overall layout of the temporary flood discharge channel and enter the safe discharge control stage to achieve the safe elimination of the landslide dam.
[0022] Step 1 specifically includes the following steps: Step 1.1: Obtain the water level-discharge curve of a typical cross-section in the downstream section of the river by fitting or calibrating measured hydrological data. ; Step 1.2: Based on the downstream typical section water level-discharge curve obtained in Step 1.1, calculate the breach flood peak discharge according to the downstream channel guarantee water level using the downstream typical section water level-discharge curve formula. The downstream typical section water level-discharge curve formula is as follows: (1) In equation (1), Q is the peak flow of the breach flood. This is a typical cross-sectional water level-discharge curve for the downstream section of the river.
[0023] Step 2 specifically includes the following steps: Based on the peak flow rate of the breach dam calculated in step 1.2, the breach height is calculated using the landslide dam breach parameter model and the Qi Zijie and Huang Wei formulas. The Qi Zijie and Huang Wei formulas are as follows: (2) in, The acceleration due to gravity is 9.81 m / s². 2 ; The collapse height is in meters (m). Unit length; The length of the dam body corresponding to the protected elevation, that is, the length from the steep slope to the same elevation upstream, in meters; The volume of the dam above the protection height is expressed in meters (m). 3 ; For storage capacity above the protected height, the unit is m. 3 .
[0024] Step 3 specifically includes the following steps: Step 3.1, according to Figure 2 The breach height calculated using the formulas of Qi Zijie and Huang Wei was used to determine the protective elevation. At the corresponding protective elevation position of the landslide dam, a drop sill was excavated according to the design requirements. and horizontal segment The drop-slope is excavated to a depth of 2-3m, and the horizontal section is 3-5m deep. This ultimately forms the flood discharge foundation structure of the drop-slope and horizontal section. Step 3.2, according to Figure 3 High-strength PVC temporary spillway was laid in the horizontal section and downstream along the water flow direction. The sidewalls of the spillway were made of inflated cylindrical PVC material. Umbrella anchors were used to reinforce the spillway at the beginning of the spillway and the connection with the drop sill. Umbrella anchors were inserted at fixed intervals in the horizontal section to fix the PVC material. The joints were sealed and waterproofed to ensure that the construction quality met the erosion resistance requirements of a flow velocity of 15m / s.
[0025] Step 4 specifically includes the following steps: The Manning roughness coefficient was selected based on the characteristics of high-strength PVC material. (Values range from 0.010 to 0.013), determine the Chezy coefficient. Design peak flow determined by downstream channel guaranteed water level constraints The bottom slope of the spillway is pre-designed according to the topography of the landslide dam. Based on the formula for uniform flow in open channels, the known... , , Substituting the Cheze formula, the bottom width of the rectangular cross-section spillway is solved using a trial-and-error method. and the height of the spillway After the calculation is completed, the average flow velocity of the check section is calculated using the formula for calculating the average flow velocity of the open channel cross-section. If the flow velocity exceeds 15 m / s, the width should be increased. The cross-sectional area of the spillway is increased, and the formula is iteratively applied again until the spillway's capacity meets the requirements under peak flood flow, there is no risk of overflow, and the flow velocity is ≤15m / s. Finally, the core cross-sectional dimensions of the spillway, such as the bottom width and water depth, are determined. The formula for calculating the cross-sectional area of the spillway is: (3) in, The bottom width of the flood discharge channel, This refers to the height of the flood discharge channel; The formula for uniform flow in the open channel is: (4) in, The Chezy coefficient is given by Manning's formula. Derivation; The cross-sectional area of the flood discharge channel; Where is the hydraulic radius, due to >>10 Therefore, the hydraulic radius Available Approximate representation, i.e. ≈ ; The bottom slope of the flood discharge channel (slope) >0); The formula for calculating the average flow velocity of the open channel cross-section is as follows: (5) in, The average flow velocity is the cross-sectional velocity of the open channel; the other variables are the same as described above.
[0026] Step 5 specifically includes the following steps: After completing the full-process quality acceptance, including verifying the cross-sectional dimensions of the spillway, testing the anchor fixing strength, verifying the waterproof sealing of the splice joints, and checking the flow velocity, a final inspection was carried out on the temporary spillway as a whole. This confirmed that the spillway was undamaged, smoothly connected to the drop slopes and horizontal sections, and that the anchors were not loose. It also ensured that the flood peak flow during the flood discharge process did not exceed the allowable value corresponding to the guaranteed water level of the downstream river, the flow velocity of the spillway was ≤15m / s, and there was no risk of overflow or erosion. Ultimately, this achieved the safe removal of the landslide dam.
[0027] This invention effectively combines protective elevation positioning technology, flood discharge foundation excavation technology, flood discharge channel cross-sectional dimension calculation method, and erosion-resistant fixing and protection measures. The protective elevation is determined by calculating the breach height using the Qi Zijie and Huang Wei formulas. The flood discharge foundation is formed by excavating the drop slope and horizontal section. The cross-sectional dimensions of the rectangular flood discharge channel are designed based on the Xie Cai formula and related hydraulic parameter formulas, and the flow velocity is checked. Temporary flood discharge channels are laid using erosion-resistant measures such as PVC and umbrella-shaped anchors. This ensures that the peak flood flow does not exceed the bearing capacity corresponding to the downstream river's guaranteed water level during flood discharge, the average flow velocity of the flood discharge channel cross-section does not exceed the allowable erosion velocity, and there is no risk of overflow or erosion. This allows for the rapid deployment and safe control of temporary flood discharge facilities in various landslide dam emergency responses, providing safe and reliable technical support for landslide dam emergency mitigation operations, improving the efficiency and safety of emergency response, effectively avoiding the downstream disaster chain effect caused by landslide dam failure, providing strong evidence for landslide dam emergency management and decision-making, and minimizing casualties and property losses.
[0028] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0029] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection, characterized in that, include: The maximum peak outburst flow of the landslide dammed lake was determined using the guaranteed water level downstream of the river as a constraint. The allowable breach height of the landslide dam lake is calculated based on the dam length, dam volume, and reservoir capacity corresponding to the protection elevation. The protection elevation of the erosion benchmark point is determined based on the allowable breach height. Calculate the cross-sectional dimensions of the spillway based on the determined maximum outburst flood peak flow. A temporary flood discharge channel was laid based on the protection elevation of the erosion benchmark point and the cross-sectional dimensions of the discharge channel.
2. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 1, characterized in that, The specific details for determining the maximum peak outburst flow of the landslide dammed lake are as follows: The water level-discharge curve formula for a typical cross-section in the downstream of the river was obtained by fitting measured hydrological data. The maximum allowable peak outburst discharge of the landslide dammed lake was obtained based on the water level-discharge curve formula and the downstream guaranteed water level calculation.
3. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 1, characterized in that, The formula for calculating the allowable breach height of the landslide dammed lake is as follows: in, It is the acceleration due to gravity; The height of the collapse; Unit length; The length of the dam body corresponding to the protection elevation; To protect the dam volume above the height; To protect the storage capacity above the specified height, the above formula is used for iterative calculation to obtain... .
4. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 1, characterized in that, The specific cross-sectional dimensions of the flood discharge channel are as follows: The Manning roughness coefficient is selected based on the material properties of the spillway, and the Chezy coefficient is obtained. The cross-sectional area of the spillway corresponding to the maximum outburst flow is calculated based on the Chezy formula for uniform flow in open channels. The cross-sectional dimensions of the flood discharge channel are obtained based on the cross-sectional area of the discharge channel.
5. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 4, characterized in that, The formula for calculating the cross-sectional area of a spillway based on the Chezy formula for uniform flow in open channels is as follows: in, For the Xie Cai coefficient, The cross-sectional area of the flood discharge channel; For hydraulic radius, It is the bottom slope of the flood discharge channel; The formula for obtaining the cross-sectional dimensions of the flood discharge channel based on its cross-sectional area is as follows: in, The bottom width of the flood discharge channel, This refers to the height of the flood discharge channel.
6. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 1, characterized in that, The sidewalls of the temporary flood discharge channel are made of inflated cylindrical PVC material.
7. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 4, characterized in that, After obtaining the cross-sectional dimensions of the flood discharge channel, the process also includes: calculating the average flow velocity of the cross-section using the formula for the average flow velocity of the open channel cross-section; if the flow velocity exceeds 15 m / s, widening the bottom width of the flood discharge channel and recalculating the cross-sectional area and dimensions, iterating until the average flow velocity of the cross-section is ≤15 m / s and there is no risk of the flood discharge channel overflowing during the flood peak.
8. The method for controlling and mitigating risks of landslide-dammed lakes based on erosion benchmark point protection according to claim 1, characterized in that, Before laying the temporary flood discharge channel, the embankment and horizontal section were excavated at the erosion benchmark elevation to form the basic structure for flood discharge.