A geotechnical-ecological disaster-resistant slow-flow-resilient prevention and control synergy method for a watershed debris flow

Abstract

This invention provides a synergistic method for soil-rock and ecological disaster mitigation and flow control resilience in debris flows, comprising the following steps: Step 1: Conducting on-site surveys and parameter collection in the watershed to obtain the topographic features, sediment source distribution, and hydrological information of the debris flow watershed; Step 2: Designing the geometric dimensions of the main structure based on particle size distribution and topographic features; Step 3: Designing the main structure for graded flow mitigation and drainage; Step 4: Identifying the ecological species in the watershed and surrounding environment, and conducting ecological design in conjunction with the main structure configuration; Step 5: Conducting flume physical model tests to calculate the energy dissipation rate and flow control capacity of the main structure configuration method and technology for debris flow disaster mitigation and flow control; Step 6: Based on the test results, constructing a three-dimensional fish-scale flume model, and conducting numerical simulations on debris flow scenarios of different scales, particle sizes, and rainfall conditions to correct and optimize the soil-rock and ecological synergistic configuration mode. This application proposes a synergistic method for rock-soil-ecological disaster mitigation and flow control resilience for debris flows in watersheds. This method can disperse the mainstream impact energy of debris flows to form local backflow, thereby controlling the flow direction of debris flows to avoid buildings and people. It organically combines graded flow mitigation and drainage of rock and soil structures with ecological materials and vegetation measures, thereby improving the adaptive recovery capacity of the resilience control system and the ecological diversity of the watershed, and realizing the sustainable and comprehensive management of debris flows.

Description

Technical Field

[0001] This invention belongs to the field of geological disaster reduction technology, and in particular, it is a collaborative method for rock and soil-ecological disaster resistance, flow mitigation and resilience control of debris flows in watersheds. Background Technology

[0002] Debris flows are a common high-sediment-content disaster in mountainous areas of my country. As a crucial link in sediment transport between small watersheds and rivers, they occur suddenly, in multiple locations, and involve repeated sediment transport. The scale of sediment transport varies significantly under different scenarios (different scales, particle sizes, and rainfall conditions). Compared to low-sediment-content floods, high-sediment-content floods continuously erode channels and banks, increasing their flow rate, velocity, and impact force. This leads to localized siltation and blockage at bends and confluence points in watershed channels, easily forming secondary disaster chains such as landslide dams and amplifying the overall disaster scale. Therefore, resilient mitigation measures not only require disaster mitigation and energy dissipation, and flow slowing and diversion, but also necessitate the safe diversion of high-sediment-content water flows along planned paths, controlling their direction to avoid buildings and residential areas.

[0003] Current geotechnical engineering measures focused on "stabilization, interception, drainage, and siltation control" can achieve rapid interception, disaster mitigation, and flow control through engineering structures such as dams, retaining walls, and drainage channels. However, these methods also have limitations, including limited lifespan, high construction and maintenance costs, and significant disruption to the original topography and ecological environment. While purely biological or ecological measures offer advantages such as good long-term stability, relatively low cost, and environmental friendliness, the long growth cycle of vegetation and root-based soil stabilization makes them unsuitable for the urgent need to control hazards in a short period after a disaster. For this reason, a collaborative prevention and control system that integrates the "rapid stabilization" advantages of geotechnical engineering with the "long-term restoration" function of biological measures has become a widely recognized technical direction. This collaborative model is particularly suitable for debris flow basins with high sediment content. It can quickly stabilize slopes and sources at key locations through geotechnical structures, inhibiting the initiation of debris flows. At the same time, it can gradually improve soil structure and enhance infiltration and water retention capacity by relying on the subsequently restored vegetation system, thereby fundamentally improving the disaster-causing environment. This reflects the organic combination of "short-term emergency response" and "long-term ecological restoration". Against the backdrop of the national strategy of "systematic governance of mountains, rivers, forests, fields, lakes, grasslands, and deserts" and "enhancing the diversity, stability, and sustainability of ecosystems," this invention proposes a synergistic method for rock and soil-ecological disaster mitigation and flow control resilience in debris flow basins. Targeting debris flow basins with high sediment content, the aim is to promote a shift in debris flow prevention and control measures from a single rapid drainage model to an orderly flow mitigation, tiered drainage, ecological integration, and dynamic adaptation model. This also represents a beneficial exploration in implementing the national disaster prevention and mitigation strategy and the concept of ecological civilization construction into specific engineering technologies. Summary of the Invention

[0004] The purpose of this invention is to provide a synergistic method for soil-rock and ecological disaster mitigation and flow control of debris flows in watersheds. This method utilizes a specially designed fish-scale-shaped flow-damping channel to achieve graded flow mitigation and drainage of debris flows within the channel. Combining the stability of soil-rock engineering with the resilience of bioengineering, this method effectively reduces debris flow velocity and weakens the energy of impact, thereby enhancing the adaptability and long-term resilience of the control system, reducing the disaster risk of debris flows to downstream areas, and promoting the gradual restoration and sustainable development of the ecological environment within the watershed.

[0005] To achieve the above-mentioned technical features, the objective of this invention is as follows: a synergistic method for soil-rock ecological disaster mitigation and flow control of debris flows in watersheds, comprising the following steps: Step 1: Conduct on-site surveys and parameter collection in the watershed to obtain information on the topographic features, source distribution, and hydrological information of the debris flow watershed; Step 2: Based on particle size distribution and terrain features, design the geometric dimensions of the main structure; Step 3: Configure the main structure for the graded flow control and drainage system; Step 4: Identify the ecological species in the watershed and surrounding environment, and conduct ecological design in conjunction with the main configuration; Step 5: Conduct a physical model test of the water tank to calculate the impact of the main configuration method and technology on the debris flow disaster resistance, flow mitigation, energy dissipation rate, and flow control capability. Step 6: Based on the experimental results, construct a three-dimensional model of the fish-scale trough, conduct numerical simulations of debris flow scenarios with different scales, particle sizes, and rainfall conditions, and correct and optimize the soil-rock-ecology collaborative configuration mode.

[0006] Preferably, the main structure adopts a slow-flow drainage system, which is deployed in the debris flow connectivity zone of the watershed. The slow-flow drainage system is a multi-dimensional resilient prevention and control system composed of fish-scale channels, retaining walls and vegetation fences. The fish-scale grooves are arranged symmetrically in pairs on the left and right sides of the central divider of the slow-flow drainage system. The retaining wall is symmetrically arranged on the outer side of the fish-scale grooves; The vegetation fences are symmetrically arranged on the outside of the retaining wall.

[0007] Preferably, the inner side of the fish scale groove is connected to the central dividing strip of the slow flow drainage system, and the outer side is connected to the retaining wall. The interior is a groove similar to a fish scale, which is a closed ring formed by an arc made by two vertices of an equilateral triangle with the side length as the radius and the upper vertex as the center. The groove is scaled down by one time. The retaining wall is constructed from locally sourced crushed stone within the watershed. It is designed as a right-angled trapezoid with the inner side connected to the outer side of the fish-scale groove and the outer side connected to the inner side of the vegetation fence. The angle between the hypotenuse and the horizontal is 75°~80°.

[0008] Preferably, the vegetation fence is symmetrically distributed and connected to the retaining wall on the inner side. It consists of thin soil flower beds planted with shrubs every 1-2 meters on the top of the retaining wall and thick soil flower beds planted with pine trees every 3-4 meters.

[0009] Preferably, the watershed field investigation and parameter collection in step 1 includes soil samples from the upper and lower layers of the source area, flow area, and deposition area within the watershed; The source region provides the material conditions for the formation of debris flows; The flow zone is used to alter the movement characteristics of debris flows; The deposition area is used to provide a place for debris flows to stop and accumulate; The basic information on the topographic features and hydrological information of the basin's debris flow includes: hydrological conditions, climatic conditions, topography, geological environment, human conditions, and disaster status; The hydrological conditions include river length, river flow direction, tributary morphology, number of tributaries, river network density, river drop, and canyon distribution. The topography includes topography type, terrain undulation, terrain slope direction, terrain extremes, and altitude.

[0010] Preferably, in step 2, during the design of the dimensions of the slow-flow drainage system: the characteristics of the particle size distribution of the debris flow source include the maximum particle size, the minimum particle size, and the average particle size; the average particle size P of the debris flow source particles is taken as: P=( + ) / 2; In the formula, The maximum particle size within the watershed. This represents the minimum particle size within the watershed. The depth and width of the fish-scale grooves are directly related to the peak value of the debris flow. Determined by the storm flood flow corresponding to frequency P1; debris flow peak flow. The calculation formula is: ; in, The peak flow rate of debris flow at frequency P1 is expressed in m³ / s. The design flow rate for a rainstorm flood with frequency P1 is expressed in m³ / s. Here is the debris flow sediment correction factor, where ; This refers to the unit weight of debris flow, expressed in t / m³. This is the specific gravity of clean water, expressed in t / m³, with a value of 1.0. The specific gravity of solid matter in a debris flow is expressed in t / m³. The blockage coefficient of debris flow; The formula for calculating the velocity of viscous debris flows is as follows: ; The average velocity of the debris flow cross section is expressed in m / s. The average mud depth of the debris flow is expressed in meters. For viscous debris flows, the riverbed roughness is denoted as . The hydraulic gradient of the debris flow is expressed as %, replaced by the longitudinal slope of the gully. The height of the retaining wall, wherein the maximum debris flow lift-up height ΔH is calculated using the following formula: ; In the formula: The average velocity of the debris flow cross section is expressed in m / s. This is the acceleration due to gravity.

[0011] Preferably, in step 3, the impact force of the debris flow on the main structure is calculated using the following formula: ; In the formula, δ represents the debris flow impingement force acting on a unit area perpendicular to the flow velocity direction, with units of... ; The average velocity of the debris flow cross section is given in units of 1000 m / s. λ is the building shape factor; This refers to the unit weight of the debris flow fluid, in units of... ; The angle between the stress-bearing surface of the building and the direction of the debris flow's impact force; This is the acceleration due to gravity.

[0012] Preferably, in step 4, the ecological species of the watershed and surrounding environment are determined, and ecological design is carried out in combination with the main configuration. Shrubs are planted at 1-meter intervals on the top of the retaining wall, and dense pine trees with many branches are planted at 3-meter intervals on the outside. New ecological materials composed of polymer composite materials, nano-montmorillonite modified fly ash, and vegetation concrete are used to fill the gaps between the stones.

[0013] Preferably, the debris flow mitigation and energy dissipation conductivity in step 5 is: ; Where W is the energy reduction rate of debris flow within the watershed; C is the experimental coefficient of debris flow energy. This represents the volume fraction of solid particles. The average particle size of the solid particles is expressed in meters (m). The unit is the bulk density of solid particles, expressed in kN / m³. The solid particle flow velocity is expressed in m / s. The liquid phase density is expressed in kN / m³. The liquid flow rate is expressed in m / s. The angle between the flow direction and the flow velocity.

[0014] Preferably, the three-dimensional model of the fish-scale channel in step 6 involves numerical simulations of the scale of different types of debris flows, the distribution of sediment particle size distribution, and rainfall conditions within the watershed. It quantitatively reveals the mechanisms of the fish-scale channel's blocking, disaster mitigation, energy dissipation, and slow-flow drainage from the process of sediment generation in the source area, movement in the flow area, and deposition in the accumulation area. The model's geometric morphology, spatial layout, and ecosystem coordination parameters are iteratively optimized. The continuity equation in the model is: ; In the formula, Q represents the debris flow rate, in units of... A represents the cross-sectional area, in units of... t represents time, in seconds; x represents flow length, in meters. This indicates the net recharge of a debris flow per unit width; The equation of motion is: ; In the formula: h is the mud depth, in meters; v is the flow velocity, in meters. ; Slope; For resistance slope; The net recharge rate of a debris flow per unit width; g is the acceleration due to gravity; The friction coefficient in the rheological model depends on the dimensionless inertia number I, expressed as: ; In the formula, The coefficient of friction is the steady-state friction coefficient. The peak friction coefficient; I is a material constant; I is a dimensionless inertia number. This invention has the following beneficial effects: This invention provides a synergistic method for soil-rock and ecological disaster mitigation and flow control resilience against debris flows in watersheds. Based on the watershed's hydrological, climatic, topographical, geological, human, and disaster conditions, the method plans and designs the planar layout and cross-sectional morphology of a fish-scale channel flow mitigation system, forming a staggered, stepped sequence of channels to achieve multi-level energy attenuation during debris flow. Specifically, considering the peak flow rate and particle size distribution of the debris flow, the method determines the dimensional parameters of the fish-scale channels, including channel width, depth, and spacing between channels, to guide, decelerate, and regulate the deposition of debris flows within the channel structure. This prevention and control system also takes into account the goal of ecological restoration. Vegetation restoration is arranged on the sides of the fish-scale channel to enhance the ecological integration capacity and landscape harmony of the entire system. This invention achieves efficient diversion and kinetic energy consumption of debris flows by using the fish-scale channel slow-flow system. It focuses on improving the structural adaptability of the system when subjected to debris flow impact and its functional recovery after disaster, significantly improving the long-term adaptability and service life of the protective engineering. This method couples geotechnical engineering with bioengineering, which not only effectively prevents and controls disasters, but also helps the watershed vegetation reconstruction and ecosystem stability, achieving the expected synergistic governance effect of disaster prevention, ecological restoration and landscape optimization. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a flowchart illustrating a collaborative method for soil-rock and ecological disaster mitigation and flow control of debris flows in a watershed, as implemented in this invention.

[0017] Figure 2 This is a three-dimensional diagram of the system of the present invention.

[0018] Figure 3 This is a top view of the system of the present invention.

[0019] Figure 4 This is a front view of the system of the present invention.

[0020] Figure 5 This is a three-dimensional diagram of the test conducted on the physical model of the water tank of the present invention.

[0021] Figure 6 This is a front view of the test conducted in the physical model test example of the water tank of the present invention.

[0022] In the diagram: 1. Fish scale trough; 2. Retaining wall; 3. Shrub; 4. Pine; 5. Thin soil flower bed; 6. Thick soil flower bed; 7. Base; 8. Water trough physical model test support; 9. Material source area; 10. Flow area; 11. Accumulation area; 12. Impact force sensor; 13. Pore water pressure sensor; 14. Slow flow drainage system; 15. Vegetation fence; 16. Central divider. Detailed Implementation

[0023] The present invention will be further described in detail below through specific embodiments. These embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way.

[0024] Example 1: Reference Figure 1-6 A collaborative method for soil-rock and ecological disaster mitigation and flow control resilience of debris flows in a watershed is proposed. The flow mitigation and drainage system 14 is deployed in the debris flow-connecting zone of the watershed. This system is a multi-dimensional, resilient control system composed of fish-scale channels 1, retaining walls 2, and vegetation fences 15. The fish-scale channels 1 are arranged symmetrically in pairs on both sides of the central dividing zone 16 of the flow mitigation and drainage system 14. The retaining walls 2 are symmetrically arranged outside the fish-scale channels 1, and the vegetation fences 15 are symmetrically arranged outside the retaining walls 2. By employing the aforementioned flow mitigation and drainage system 14, the continuous friction and multiple collisions of solid particles in the debris flow are fully utilized to achieve gradual energy dissipation, forming a natural flow mitigation zone that effectively reduces the impact and damage of debris flows. The flow mitigation and drainage system 14 uses ecological materials and a shrub-tree hierarchical plant barrier structure, which improves the resilience of the control system and enhances the ecological diversity within the watershed, achieving comprehensive ecological management of debris flows.

[0025] Furthermore, the fish-scale groove 1 is configured as a double-groove symmetrical distribution. The inner side connects to the central dividing strip 16 of the flow mitigation system 14, and the outer side connects to the retaining wall 2. The interior is a closed loop groove resembling fish scales, formed by an arc drawn from two vertices of an equilateral triangle with the side length as the radius and the upper vertex as the center, scaled down by a factor of 1. Through the aforementioned fish-scale groove 1, the debris flow can be effectively diverted and mitigated, thereby achieving the effects of tiered disaster mitigation, energy dissipation, and flow mitigation.

[0026] Furthermore, the retaining wall 2 is constructed from locally sourced crushed stone within the watershed, and is arranged in a symmetrical right-angled trapezoidal shape, with its inner side connected to the outer side of the fish-scale channel 1 and its outer side connected to the inner side of the vegetation fence 15, with the hypotenuse forming an angle of 75° with the horizontal. The retaining wall 2 described above can resist the impact of large boulders, thereby extending the service life of the slow-flow drainage system 14.

[0027] Furthermore, the vegetation fence 15 is symmetrically distributed and connected to the retaining wall 2 on its inner side. It consists of thin soil flower beds 5 planted with shrubs 3 every 1 meter on the top of the retaining wall 2 and thick soil flower beds 6 planted with pine trees 4 every 3 meters. The vegetation fence 15 can effectively resist the impact and damage of boulders on the main structure. The shrub-tree hierarchical planting structure weakens the initial impact force of the debris flow.

[0028] Furthermore, the retaining wall 2 uses a novel ecological material composed of polymer composite materials, nano-montmorillonite modified fly ash, and vegetation concrete to fill the gaps between the stones. This ecological design increases the internal additional resistance of the slow-flow drainage system 14, thereby assisting the fish-scale channel 1 in its graded disaster resistance, energy dissipation, and slow-flow drainage, and improving the system's resilience.

[0029] Example 2: Mountain debris flows often carry large amounts of mud, sand, and rocks under heavy rainfall conditions, resulting in tremendous impact and destructive power. While existing rigid control structures can mitigate the damage, they frequently disrupt ecological connectivity and hinder resource utilization. Based on the concept of multi-dimensional collaborative governance, this invention innovatively constructs a collaborative method for rock-soil-ecological disaster-resistance and flow-damping resilience control of debris flows in watersheds, such as... Figure 1 The diagram shown is a flowchart of a collaborative method for soil-rock and ecological disaster mitigation and flow control based on the resilience of debris flows in a watershed, according to an embodiment of the present invention.

[0030] A collaborative method for rock-soil-ecological disaster mitigation and flow control of debris flows in watersheds includes the following steps: P101. Conduct on-site investigations and parameter collection in the watershed to obtain information on the topographic features, source distribution, and hydrological information of the debris flow watershed; In this example, the watershed is rationally divided into source area, flow area and deposition area based on on-site survey and parameter collection. The basic information on topographic features and hydrological information within the watershed includes: hydrological conditions, climatic conditions, topography, geological environment, human conditions and disaster situation. The hydrological conditions within the region include river length, river flow direction, tributary morphology, number of tributaries, river network density, river drop, and canyon distribution. The topography and landforms within the region include topographic type, terrain undulation, terrain slope direction, terrain extremes, and altitude.

[0031] P102. Based on particle size distribution and terrain features, design the geometric dimensions of the main configuration body; In this example, the characteristics of the particle size distribution of debris flow source particles in the three regions divided within the watershed are determined, including the maximum particle size, minimum particle size, and average particle size; the average particle size P of the debris flow source particles is taken as: P=( + ) / 2; In the formula, The maximum particle size within the watershed. This represents the minimum particle size within the watershed. The hierarchical design of the plant fence is as follows: Its purpose is to block and slow down large solid particles, and to filter out small-diameter slurry with an average particle size of 0 or less, thereby achieving the functions of primary disaster prevention and energy dissipation and slow flow drainage.

[0032] During the design of the 14-dimensional slow-flow drainage system: the depth and width of the fish-scale groove 1 are directly related to the peak value of the debris flow. Determined by the storm flood flow corresponding to frequency P1; debris flow peak flow. The calculation formula is: ; in, For frequency The peak flow rate of debris flow, in m³ / s; For frequency The design flow rate for rainstorm floods is expressed in m³ / s. Here is the debris flow sediment correction factor, where ; This refers to the unit weight of debris flow, expressed in t / m³. This is the specific gravity of clean water, expressed in t / m³, with a value of 1.0. The specific gravity of solid matter in a debris flow is expressed in t / m³. The blockage coefficient of debris flow; In this example, the velocity of a debris flow is selected using the following formula for calculating the velocity of a viscous debris flow: ; The average velocity (m / s) of the debris flow cross section; The average mud depth of the debris flow is (m). For viscous debris flows, the riverbed roughness is denoted as . Hydraulic gradient of debris flow (%); In this example, the height of retaining wall 2 is calculated using the following formula, taking the maximum debris flow lift height ΔH as an example: ; In the formula: The average velocity (m / s) of the debris flow cross section; This is the acceleration due to gravity.

[0033] P103. Configure the main structure for graded flow control and drainage; In this example, the slow-flow drainage system 14 is deployed in the watershed debris flow connection zone. The slow-flow drainage system 14 is a multi-dimensional resilient prevention and control system composed of fish-scale channels 1, retaining walls 2, and vegetation fences 15. The fish-scale channels 1 are arranged symmetrically in pairs on the left and right sides of the central divider 16 of the slow-flow drainage system 14. The retaining walls 2 are symmetrically arranged on the outside of the fish-scale channels 1. The vegetation fences 15 are symmetrically arranged on the outside of the retaining walls 2.

[0034] In the example, the fish scale groove 1 is set as a double groove symmetrically distributed. The inner side is connected to the central dividing strip 16 of the slow flow drainage system 14, and the outer side is connected to the retaining wall 2. The interior is a groove similar to a fish scale, which is a closed ring groove made by an arc formed by two vertices of an equilateral triangle with the side length as the radius and the upper vertex as the center.

[0035] In the example, retaining wall 2 is constructed from locally sourced crushed stone within the watershed. It is designed as a right-angled trapezoid with its inner side connected to the outer side of fish-scale groove 1 and its outer side connected to the inner side of vegetation fence 15. The angle between the hypotenuse and the horizontal is 75°.

[0036] In the example, the vegetation fence 15 is set to be symmetrically distributed and connected to the retaining wall 2 on the inner side. It is composed of thin soil flower beds 5 on the top of the retaining wall 2, with shrubs 3 planted every 1 meter and thick soil flower beds 6, with pine trees 4 planted every 3 meters.

[0037] In this example, the impact force of the debris flow on the main structure is expressed by the following formula: ; In the formula, δ is the mudflow impact force (Pa) acting on a unit area perpendicular to the direction of flow velocity; λ represents the average velocity (m / s) across the debris flow cross section; λ is the building shape factor. The bulk density of debris flow (kN / ) ); θ is the angle between the stress surface of the building and the direction of the debris flow impact force; g is the acceleration due to gravity.

[0038] P104. Identify the ecological species in the watershed and surrounding environment, and conduct ecological design in conjunction with the main configuration; In this example, based on the ecological species of the watershed and surrounding environment, combined with the main design of the retaining wall 2, shrubs 3 are planted at 1-meter intervals on the top, and dense pine trees 6 with many branches are planted at 3-meter intervals on the outside to form a vegetation fence 15. In this example, a novel ecological material composed of polymer composite materials, nano-montmorillonite modified fly ash, and vegetation concrete is used to fill the gaps in the retaining wall 2.

[0039] P105. Conduct a physical model test of the flume to calculate the impact of the main configuration method and technology on the debris flow disaster resistance, flow mitigation, energy dissipation rate, and flow control capability. In this example, the energy dissipation rate of the 14 pairs of debris flow mitigation and drainage systems configured in the main body was calculated: ; Where W is the energy reduction rate of debris flow within the watershed; C is the experimental coefficient of debris flow energy. R represents the volume fraction of solid particles; R is the average particle size of the solid particles, in meters. The unit is the bulk density of solid particles, expressed in kN / m³. The solid particle flow velocity is expressed in m / s. The liquid phase density is expressed in kN / m³. The liquid flow rate is expressed in m / s. The angle between the flow direction and the flow velocity.

[0040] like Figure 5-6 As shown, in this example, the flume physical model test rationally divides the watershed into source area 9 (providing material conditions for debris flow formation), flow area 10 (changing the movement characteristics of debris flow), and deposition area 11 (providing a place for debris flow to stop and deposit) based on the hydrological conditions, climate conditions, topography, geological environment, human conditions and disaster conditions in the watershed; all designs are scaled down proportionally for the experiment.

[0041] For sediment source area 9, a 0.8-meter-long, 0.8-meter-wide, and 0.8-meter-high acrylic model box with a gate was used. The debris flow sources were sampled from 10 debris flow channels along the Minjiang River, including Qipangou and Cutougou. Based on the characteristics of each channel, five different sorting methods were combined to simulate viscosity and particle size distribution. Control experiments were then conducted with and without fish-scale channels for disaster mitigation and energy dissipation, as well as slow-flow drainage. A total of 122 sets of experiments were carried out. In each set of experiments, a rainfall device was used above sediment source area 9 to simulate rainfall at 50 mm per hour.

[0042] The circulation zone 10 uses a 2-meter-long and 30-centimeter-wide water trough, with an angle of 30°. The upper part is connected to the gate of the material source zone 9, and the lower part is connected to the water trough of the accumulation zone 11. The configuration of the present invention is installed at the center of the circulation zone 10, and a pore water pressure sensor 13 and an impact force sensor 12 are respectively installed 20 and 30 centimeters in front of and behind the configuration.

[0043] Stacking area 11 uses a water tank that is 2 meters long and 1 meter wide, and is built at an angle of 5°.

[0044] According to the experimental results, the synergistic method of rock-soil-ecological disaster mitigation and flow control for debris flow in the watershed has a disaster mitigation and flow energy dissipation rate of 45.7%.

[0045] P106. Based on the experimental results, a three-dimensional model of fish-scale grooves was constructed, and numerical simulations were carried out on debris flow scenarios of different scales, particle sizes, and rainfall conditions to correct and optimize the soil-ecology collaborative configuration mode. Numerical simulations were conducted on the scale of different types of debris flows, the distribution of sediment particle size distribution, and rainfall conditions within the watershed. The process from the occurrence in the source area to the movement in the flow zone to the deposition in the accumulation zone was quantitatively revealed, demonstrating the mechanisms of fish-scale channels in terms of interception, disaster mitigation, energy dissipation, and slow-flow drainage. The geometric morphology, spatial layout, and ecosystem coordination parameters of the fish-scale channels were iteratively optimized. The continuity equation in the model is: ; In the formula, Q represents the debris flow rate, in units of... A represents the cross-sectional area, in units of... t represents time, in seconds; x represents flow length, in meters. This indicates the net recharge of a debris flow per unit width; The equation of motion is: ; In the formula: h is the mud depth, in meters; v is the flow velocity, in meters. ; Slope; For resistance slope; The net recharge rate of a debris flow per unit width; g is the acceleration due to gravity; The friction coefficient in the rheological model depends on the dimensionless inertia number I, expressed as: ; In the formula, The coefficient of friction is the steady-state friction coefficient. The peak friction coefficient; is a material constant; I is a dimensionless inertial number.

[0046] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many specific modifications under the guidance of the present invention without departing from the spirit of the invention and the scope of protection of the claims, and these modifications all fall within the scope of protection of the present invention.

Claims

1. A synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in watersheds, characterized in that, Includes the following steps: Step 1: Conduct on-site surveys and parameter collection in the watershed to obtain information on the topographic features, source distribution, and hydrological data of the debris flow watershed; Step 2: Based on particle size distribution and terrain features, design the geometric dimensions of the main structure; Step 3: Configure the main structure for the graded flow control and drainage system; Step 4: Identify the ecological species in the watershed and surrounding environment, and conduct ecological design in conjunction with the main configuration; Step 5: Conduct a physical model test of the water tank to calculate the impact of the main configuration method and technology on the debris flow disaster resistance, flow mitigation, energy dissipation rate, and flow control capability. Step 6: Based on the experimental results, construct a three-dimensional model of the fish-scale trough, conduct numerical simulations of debris flow scenarios with different scales, particle sizes, and rainfall conditions, and correct and optimize the soil-rock-ecology collaborative configuration mode.

2. The method for coordinated prevention and control of debris flows in watersheds using a soil-rock ecological disaster mitigation and flow-resilience approach, as described in claim 1, is characterized in that... The main structure adopts a slow-flow drainage system (14), which is deployed in the debris flow connection area of ​​the watershed. The slow-flow drainage system (14) is a multi-dimensional resilient prevention and control system composed of fish scale trough (1), retaining wall (2) and vegetation fence (15). The fish scale groove (1) is a double groove symmetrically arranged on the left and right sides of the central dividing strip (16) of the slow flow drainage system (14); The retaining wall (2) is symmetrically arranged on the outside of the fish scale groove (1); The vegetation fence (15) is symmetrically arranged on the outside of the retaining wall (2).

3. The method for coordinated prevention and control of debris flows in watersheds using a soil-rock ecological disaster mitigation and flow-resilience approach, as described in claim 2, is characterized in that... The inner side of the fish scale groove (1) is connected to the central dividing strip (16) of the slow flow drainage system (14), and the outer side is connected to the retaining wall (2). The inner side is a groove similar to a fish scale, which is formed by an arc made by an equilateral triangle with the side length as the radius and the upper vertex as the center of the circle, and the two vertices of the bottom side. The groove is reduced by 1 times proportionally. The retaining wall (2) is constructed from locally sourced crushed stone within the watershed. It is designed as a right-angled trapezoid with the inner side connected to the outer side of the fish-scale trough (1) and the outer side connected to the inner side of the vegetation fence (15). The angle between the hypotenuse and the horizontal is 75°~80°.

4. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 2, is characterized in that... The vegetation fence (15) is symmetrically distributed and connected to the retaining wall (2) on the inner side. It consists of a thin soil flower bed (5) on the top of the retaining wall (2) with shrubs (3) planted every 1-2 meters and a thick soil flower bed (6) with pine trees (4) planted every 3-4 meters.

5. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 2, is characterized in that... The watershed field investigation and parameter collection in step 1 includes soil samples from the upper and lower layers of the source area (9), flow area (10) and deposition area (11) within the watershed; The source region provides the material conditions for the formation of debris flows; The flow zone is used to alter the movement characteristics of debris flows; The deposition area is used to provide a place for debris flows to stop and accumulate; The basic information on the topographic features and hydrological information of the basin's debris flow includes: hydrological conditions, climatic conditions, topography, geological environment, human conditions, and disaster status; The hydrological conditions include river length, river flow direction, tributary morphology, number of tributaries, river network density, river drop, and canyon distribution. The topography includes topography type, terrain undulation, terrain slope direction, terrain extremes, and altitude.

6. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 5, is characterized in that... In step 2, during the design of the dimensions of the slow-flow drainage system (14): the characteristics of the particle size distribution of the debris flow source include the maximum particle size, the minimum particle size, and the average particle size; the average particle size P of the debris flow source particles is taken as: P=（ + ） / 2； In the formula, The maximum particle size within the watershed. This represents the minimum particle size within the watershed. The depth and width of the fish-scale groove (1) are directly related to the peak value of the debris flow. Determined by the storm flood flow corresponding to frequency P1; debris flow peak flow. The calculation formula is: ； in, The peak flow rate of debris flow at frequency P1 is expressed in m³ / s. The design flow rate for a rainstorm flood with frequency P1 is expressed in m³ / s. Here is the debris flow sediment correction factor, where ; This refers to the unit weight of debris flow, expressed in t / m³. This is the specific gravity of clean water, expressed in t / m³, with a value of 1.

0. The specific gravity of solid matter in a debris flow is expressed in t / m³. The blockage coefficient of debris flow; The formula for calculating the velocity of viscous debris flows is as follows: The average velocity of the debris flow cross section is expressed in m / s. The average mud depth of the debris flow is expressed in meters. For viscous debris flows, the riverbed roughness is denoted as . The hydraulic gradient of the debris flow is expressed as %, replaced by the longitudinal slope of the gully. The height of the retaining wall (2), wherein the maximum debris flow lift height ΔH is calculated using the following formula: ； In the formula: The average velocity of the debris flow cross section is expressed in m / s. This is the acceleration due to gravity.

7. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 6, is characterized in that... In step 3, the impact force of the debris flow on the main structure is expressed by the following formula: ； In the formula, δ represents the debris flow impingement force acting on a unit area perpendicular to the flow velocity direction, with units of... ; The average velocity of the debris flow cross section is given in units of 1000 m / s. λ is the building shape factor; This refers to the unit weight of the debris flow fluid, in units of... ; The angle between the stress-bearing surface of the building and the direction of the debris flow's impact force; This is the acceleration due to gravity.

8. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 7, is characterized in that... In step 4, the ecological species of the watershed and surrounding environment are determined, and ecological design is carried out in combination with the main configuration. Shrubs are planted at 1 meter intervals on the top of the retaining wall (2), and dense pine trees with many branches are planted at 3 meters intervals on the outside. New ecological materials composed of polymer composite materials, nano-montmorillonite modified fly ash and vegetation concrete are used to fill the gaps between the stones.

9. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 7, is characterized in that... The debris flow mitigation and energy dissipation rate in step 5 is as follows: ； Where W is the energy reduction rate of debris flow within the watershed; C is the experimental coefficient of debris flow energy. This represents the volume fraction of solid particles. The average particle size of the solid particles is expressed in meters (m). The unit is the bulk density of solid particles, expressed in kN / m³. The solid particle flow velocity is expressed in m / s. The liquid phase density is expressed in kN / m³. The value represents the liquid flow rate, expressed in m / s. The angle between the flow direction and the flow velocity.

10. The synergistic method for rock-soil-ecological disaster mitigation and flow-resilience control of debris flows in a watershed, as described in claim 9, is characterized in that: The three-dimensional model of the fish-scale channel in step 6 involves numerical simulations of the scale of different types of debris flows, the distribution of sediment particle size distribution, and rainfall conditions within the watershed. It quantitatively reveals the mechanisms of the fish-scale channel's blocking, disaster mitigation, energy dissipation, and slow-flow drainage, from the occurrence of the sediment source area to the movement in the flow zone and the deposition in the accumulation zone. The model's geometric morphology, spatial layout, and ecosystem coordination parameters are iteratively optimized. The continuity equation in the model is: ； In the formula, Q represents the debris flow rate, in units of... ; A represents the cross-sectional area, in units of... ; t represents time, in seconds; x represents flow length, in meters. This indicates the net recharge of a debris flow per unit width; The equation of motion is: ； In the formula: h is the mud depth, in meters; v is the flow velocity, in meters. ; Slope; For resistance slope; The net recharge rate of a debris flow per unit width; g is the acceleration due to gravity; The friction coefficient in the rheological model depends on the dimensionless inertia number I, expressed as: ； In the formula, The coefficient of friction is the steady-state friction coefficient. The peak friction coefficient; is a material constant; I is a dimensionless inertial number.

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