Slope infiltration boundary reconstruction method based on atmosphere-plant-soil collaborative monitoring

Abstract

The application discloses a kind of slope infiltration boundary reconstruction methods based on atmosphere-plant-soil collaborative monitoring, comprising: the test area of slope to be monitored is divided into the root zone close to trunk and the crown projection area away from trunk, and in two area open space, soil layer monitoring unit is arranged in pairs;Atmosphere layer and plant layer monitoring unit are arranged in test area;With single rainfall event as basic analysis unit, the data collected by each monitoring unit is time-synchronized, quality-controlled and event-processed, and the monitoring results are integrated as atmospheric input index, plant regulation index and soil hydraulic response index;Based on plant regulation index, determine the water distribution relationship after rainfall through vegetation canopy and trunk influence, and correspond the root zone throughfall and the trunk runoff converted by area to the root zone infiltration boundary, correspond the throughfall of the crown projection area to the infiltration boundary of the area, to reconstruct the partition infiltration boundary of two areas under single rainfall event.The result obtained by the present application is closer to the real situation.

Description

Technical Field

[0001] This invention relates to the field of geological disaster monitoring and prevention, specifically to a method for reconstructing slope infiltration boundaries based on coordinated atmospheric-vegetation-soil monitoring. Background Technology

[0002] Shallow landslides are characterized by their high degree of concealment, suddenness, and difficulty in early warning. These disasters are typically triggered by extreme rainfall. Rainfall infiltration alters the shallow water state of the slope, affecting the slope's sliding force and soil shear strength, thus reducing slope stability. Vegetation, as a key medium connecting the atmosphere and soil, directly influences rainfall infiltration, surface runoff formation, and slope stability: canopy interception and penetrating rain alter the spatiotemporal distribution of rainfall reaching the slope; trunk runoff and root channels create significant spatial concentration of local infiltration and water migration; and transpiration water loss affects the initial water field within the slope over a longer timescale. Therefore, the incubation and triggering of shallow geological disasters under extreme rainfall conditions are essentially the result of the interaction between the atmosphere, vegetation, and soil.

[0003] In recent years, scholars both domestically and internationally have conducted extensive research on the interaction between the atmosphere, plant, and soil (SAP) and its impact on slope stability. Related studies have established comprehensive monitoring systems by deploying meteorological stations, soil temperature and humidity sensors, and matrix suction sensors. These studies have analyzed the influence of vegetation roots on soil water-holding capacity, permeability, and suction changes, providing crucial theoretical support for understanding the mechanism of vegetation-based slope protection. Furthermore, with the development of monitoring technology, multi-scale, three-dimensional collaborative monitoring across air, space, and ground, as well as multi-source data fusion methods, have been increasingly applied to geological disaster monitoring and early warning, becoming an important technical means and development trend in the industry.

[0004] However, existing research still has the following shortcomings: First, the considerations for slope infiltration boundaries in various models are inconsistent with actual inputs, neglecting a refined assessment of the redistribution effect of vegetation on rainfall. Current landslide stability assessments often directly use external rainfall as the slope infiltration boundary, relying on meteorological data (such as rainfall thresholds) or local soil monitoring data (such as pore water pressure and displacement). They often focus only on the empirical relationship between rainfall and slope response, ignoring the dynamic regulatory role of vegetation on rainfall input, such as canopy interception, trunk runoff, and transpiration. These processes directly affect the spatial distribution and temporal evolution of the slope infiltration boundary. If the regulatory role of vegetation is ignored and rainfall is used as the direct input boundary, it is impossible to accurately characterize the actual amount of water entering the soil and its non-uniform spatiotemporal distribution characteristics, thus affecting the basic judgment of landslide stability.

[0005] Second, existing landslide monitoring systems do not pay enough attention to the moderating role of vegetation. Many monitoring methods simplify vegetation to land use type, vegetation cover, NDVI, root reinforcement parameters, or empirical correction coefficients, rarely incorporating the vegetation layer as an independent dynamic monitoring layer into the field monitoring system. This results in the failure to establish a correlation between key hydrological processes affecting the non-uniform hydraulic response within the soil, such as canopy interception, redistribution of throughfall, concentrated input of trunk runoff, and recovery of transpiration, and landslide disaster occurrence.

[0006] Third, existing slope risk assessment and early warning systems often rely on fixed rainfall thresholds, failing to adequately consider the anti-slide mechanisms dominated by evapotranspiration from slope vegetation and the pro-slide mechanisms dominated by infiltration accumulation. The hydro-mechanical response of vegetated slopes exhibits significant spatial heterogeneity, hysteresis, and resilience. Relying solely on rainfall thresholds or single soil response indicators makes it difficult to distinguish between transient wetting fluctuations and dynamic changes such as continuous instability evolution of slopes. Summary of the Invention

[0007] To address the shortcomings of existing physical processes, on-site monitoring and early warning systems, and risk identification, this invention proposes a slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring. This method, grounded in an atmospheric-vegetation-soil collaborative monitoring system, no longer simply equates rainfall outside the forest with the slope infiltration boundary. Instead, it conducts collaborative process analysis of the atmospheric, vegetation, and soil layers. On one hand, it transforms the rainfall redistribution process in the vegetation layer into infiltration boundaries for different zones: the root zone near the trunk and the canopy projection zone away from the trunk, thus improving the accuracy of infiltration boundary representation on vegetation-covered slopes. On the other hand, based on the same monitoring system, it incorporates the transpiration-dominated anti-slide mechanism and the infiltration-dominated promoting-slide mechanism of vegetation into the dynamic early warning and discrimination of shallow landslides.

[0008] The objective of this invention is achieved through the following technical solution: A method for reconstructing slope infiltration boundaries based on coordinated atmospheric-vegetation-soil monitoring includes: S1: Divide the test area of ​​the slope to be monitored into the root zone near the trunk and the canopy projection zone away from the trunk, and set up soil layer monitoring units in pairs in the open space of the two zones; set up atmospheric layer monitoring units and vegetation layer monitoring units in the test area of ​​the slope to be monitored. S2: Using a single rainfall event as the basic analysis unit, the data collected by each monitoring unit are synchronized in time, quality controlled, and processed as events. The monitoring results are then integrated into atmospheric input indicators, vegetation regulation indicators, and hydraulic response indicators within the soil. S3: Based on the plant regulation index, determine the water distribution relationship after rainfall passes through the vegetation canopy and tree trunk, and use the through rainfall of the root zone and the trunk runoff converted by area as the root zone infiltration boundary, and the through rainfall of the tree canopy projection area as the tree canopy projection area infiltration boundary, thereby reconstructing the partition infiltration boundary of the root zone and the tree canopy projection area under a single rainfall event.

[0009] A slope infiltration boundary reconstruction system based on atmospheric-vegetation-soil collaborative monitoring includes: Atmospheric layer monitoring units and vegetation layer monitoring units were set up in the test area of ​​the slope to be monitored, as well as soil layer monitoring units that were set up in pairs in the open space of the root zone near the tree trunk and the canopy projection zone away from the tree trunk in the test area of ​​the slope to be monitored. The root zone is the soil area affected by root channels, concentrated trunk runoff input, and through rain input; the canopy projection zone is the area not affected by trunk runoff and concentrated root system, but only receives through rain input from the forest floor. The vegetation layer monitoring unit is used to acquire data on penetration rainfall, trunk runoff, trunk sap flow, and vegetation structure in the open areas of the root zone and canopy projection zone. The soil layer monitoring unit is used to obtain the displacement of the soil surface and the soil moisture content, matrix suction and pore water pressure at multiple depths.

[0010] An application of a slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring for graded early warning of shallow landslides, specifically including: Step 1: After completing the reconstruction of the zonal infiltration boundary, and combining the spatial correspondence between the reconstructed infiltration boundary under vegetation influence and the soil response in the root zone and canopy projection zone, comprehensively determine the type of vegetation action on the monitored slope under the current rainfall event. The judgment rule is as follows: If sap flow in the trunk recovers after a rainfall event, and all soils in the root zone and canopy projection zone show a recovery trend over time, then the plant action type is determined to be an anti-slip mechanism dominated by evapotranspiration regulation. If the reconstruction results of the zonal infiltration boundary show that there is concentrated input or continuous infiltration after rain in the root zone or canopy projection zone, and the soil response of any of the corresponding areas shows an unfavorable trend over time, then the vegetation action type is determined to be the infiltration accumulation-dominated pro-sliding mechanism. Step 2: Based on the baseline state of the slope test area to be monitored, consider the deviation, persistence and recovery of the soil response in the root zone and the canopy projection zone from the baseline state of the corresponding area, analyze the displacement changes, and in combination with the plant action type, output low, medium or high warnings in real time according to the entire process of the rainfall event.

[0011] The beneficial effects of this invention are as follows: 1. This invention uses an atmosphere-plant-soil collaborative monitoring system as its core technology. It establishes a spatial correspondence between atmospheric input, vegetation layer rainfall redistribution, and soil hydraulic response. This transforms vegetation hydrological processes such as canopy interception, spatial differentiation of throughfall, and concentrated trunk runoff recharge into a direct basis for infiltration boundary reconstruction, thereby obtaining effective water input in the root zone near the trunk and the canopy projection zone away from the trunk. Compared to traditional methods that directly use rainfall as infiltration input, this invention can more realistically characterize the actual infiltration boundary of vegetated slopes, providing a unified data foundation for subsequent determination of vegetation activity types and early warning of shallow landslide classification.

[0012] This invention avoids the problem of traditional single-point soil moisture monitoring failing to reflect the spatial differences in hydraulic response within vegetated slopes by deploying soil layer monitoring units in pairs in the root zone and canopy projection zone, and using these two units as collaborative discrimination units for zoned comparison. This setup can simultaneously identify preferential infiltration in the root zone, concentrated trunk runoff recharge, concentrated wetting in the canopy projection zone, and the resulting differential soil response, which is beneficial for improving the ability of infiltration boundary reconstruction to characterize local water input and spatial non-uniform response.

[0013] 3. This invention incorporates the transpiration-dominated anti-slide mechanism and infiltration-dominated facilitating mechanism of vegetation into the shallow landslide early warning and discrimination process. Based on the reconstruction results of the zonal infiltration boundary, it combines the spatial correspondence between the reconstructed infiltration boundary under the influence of vegetation and the soil response in the root zone and canopy projection zone to comprehensively determine the actual role of vegetation. Furthermore, it combines the deviation, persistence, and recovery of the soil response relative to the baseline state and the displacement change to output dynamic graded early warning results, which can distinguish between recoverable hydraulic disturbances and continuous instability evolution, reducing the risk of misjudgment and omission caused by relying solely on rainfall or local soil response indicators. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a slope infiltration boundary reconstruction system based on atmospheric-vegetation-soil collaborative monitoring, according to an embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram showing the division of the root zone near the trunk and the canopy projection zone away from the trunk according to an embodiment of the present invention.

[0016] Figure 3 This is a flowchart of the slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to the present invention.

[0017] Figure 4 This is a schematic diagram illustrating the reconstruction of the infiltration boundary between the root zone near the trunk and the canopy projection zone far from the trunk in an embodiment of the present invention.

[0018] Figure 5 This is a flowchart of the shallow landslide classification and early warning method of the present invention.

[0019] In the diagram, 1. Trees; 2. Shrubs; 3. Herbaceous layer; 4. Multi-element weather station; 5. Forest rain collector; 6. Throughfall collector; 7. Trunk runoff collector; 8. Infrared temperature sensor; 9. Automated runoff and sediment collector; 10. Trunk sap flow sensor; 11. Soil evapotranspiration meter; 12. Matrix suction sensor; 13. Tensiometer; 14. Soil temperature and humidity sensor; 15. Pore water pressure sensor; 16. Displacement monitoring device. Detailed Implementation

[0020] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0021] In this embodiment, a test vegetation slope was selected on a soil and water conservation test slope with vegetation cover. The soil layer thickness was within the common range of shallow landslides, which provided conditions for rainfall infiltration to induce changes in the hydraulic state of the slope.

[0022] Runoff plots with a vegetation configuration of trees, shrubs, and grasses were selected at the existing runoff plot test sites. The plots had a planar dimension of 20m × 5m, and the plot boundaries were constructed using concrete retaining walls deeply embedded in bedrock or an impermeable layer to prevent lateral runoff and water exchange. Tree locations, canopy projections, root distribution, and forest gap distribution were investigated to determine monitoring areas in the root zone near the trunk and in the canopy projection zone away from the trunk. The root zone is the soil area affected by root channels, concentrated trunk runoff input, and throughfall input; the canopy projection zone is the area unaffected by trunk runoff and concentrated root system input, receiving only throughfall input.

[0023] During the zoning process, the slope coordinates, relative elevation, slope, aspect, and distance from the tree trunk of each monitoring point are recorded. This information is used to map the vegetation layer monitoring data to the slope infiltration boundary reconstruction later.

[0024] like Figure 1 and Figure 2 As shown, the slope infiltration boundary reconstruction system based on atmospheric-vegetation-soil collaborative monitoring includes atmospheric layer monitoring units and vegetation layer monitoring units set up in the test area of ​​the slope to be monitored, as well as soil layer monitoring units arranged in pairs on the open space in the root zone near the tree trunk and the canopy projection zone away from the tree trunk in the test area of ​​the slope to be monitored.

[0025] (1) Atmospheric monitoring unit In this embodiment, the atmospheric monitoring unit consists of a multi-element meteorological station 4 deployed in an open area near the test plot to continuously monitor meteorological elements such as rainfall, rainfall intensity, temperature, relative humidity, wind speed and direction, and solar radiation. The meteorological data sampling interval is set to 1 minute, which meets the requirements for characterizing short-duration heavy rainfall events. Simultaneously, an extra-forest rainfall collector 5 is deployed outside the forest to serve as the baseline data for extra-forest rainfall input.

[0026] (2) Plant layer monitoring unit The vegetation layer monitoring unit is used to acquire data on throughfall, trunk runoff, sap flow, and vegetation structure in the root zone near the trunk and the canopy projection area away from the trunk. In this embodiment, the vegetation layer monitoring unit includes a throughfall collector 6, a spiral trunk runoff collector 7, and a trunk sap flow sensor 10.

[0027] In this embodiment, three representative Masson pine trees were selected as monitoring objects in the community. A penetrating rain collector 6 was installed under the canopy to collect the effective rainfall and its spatial differences under the canopy covering the root zone and the canopy projection area.

[0028] At a height of approximately 1.0-1.2 m above the ground, a spiral-type trunk runoff collector 7 is used to wrap the trunk, and the runoff is continuously collected via a hose into a measuring cylinder, a tipping bucket meter, or a flow meter. The trunk runoff data is used to characterize the local water input along the trunk to the root zone and is analyzed in correspondence with soil responses, including root zone soil moisture content, matrix suction, and pore water pressure response.

[0029] Simultaneously, sap flow sensors 10 were installed on selected representative trees to continuously monitor the sap flow rate using heat dissipation or other equivalent methods. The sap flow data, combined with synchronously collected meteorological data such as solar radiation, air temperature, relative humidity, and saturated vapor pressure difference, were used to characterize the plant transpiration water consumption process and to interpret the initial soil moisture content before rainfall, water consumption during rainfall intervals, and the matrix suction recovery process after the event.

[0030] To further characterize the controlling role of vegetation structure in rainfall redistribution and soil response, vegetation structure surveys were conducted regularly during the monitoring period, including tree diameter at breast height (DBH), tree height, crown width, crown projection range, canopy closure, leaf area index, trunk location, and shrub and grass cover. These surveys could be conducted through manual measurements, UAV imagery, handheld lidar, or ground-based laser scanning, and together with data from throughfall, trunk runoff, and trunk sap flow monitoring, constituted a vegetation layer monitoring dataset.

[0031] (3) Soil layer monitoring unit The soil layer monitoring unit is used to acquire soil surface displacement and soil moisture content, matrix suction, and pore water pressure at multiple depths. In this embodiment, the soil layer monitoring unit includes a surface monitoring subunit, a runoff monitoring subunit, an evapotranspiration monitoring subunit, a profile monitoring subunit, and a deformation monitoring subunit.

[0032] (3.1) Surface monitoring subunit Representative measuring points were selected in the central part of the community, and infrared temperature sensor 8 was installed on a bracket at a height of about 0.25m above the ground surface. The field of view was adjusted to cover the surface of the soil under the forest. Infrared temperature sensor 8 was connected to the data acquisition system, and the sampling interval was set to 1 minute to obtain the daily variation of surface temperature and the rapid response during rainstorms, so as to assist in the analysis of the comprehensive impact of plant shading, rainwater cooling and evapotranspiration on the surface thermal state.

[0033] (3.2) Runoff Monitoring Subunit An automated runoff and sediment collector 9 was installed at the community exit and connected to the data acquisition system, with a sampling interval set to 1 minute. This device continuously records runoff flow and automatically collects runoff samples for sediment content analysis, thereby calculating indicators such as event runoff initiation time, peak flow, total runoff, and sediment loss. Runoff data, combined with throughfall and trunk runoff data, is used to estimate the effective recharge into the soil.

[0034] (3.3) Evapotranspiration monitoring subunit To quantitatively characterize evapotranspiration loss in the shallow water balance of slopes, soil lysimeters 11 were deployed within the plot. The soil lysimeter 11 is a cylindrical container filled with undisturbed soil, maintaining its original stratification, while the upper part remains naturally exposed and configured with the original vegetation. By monitoring changes in mass over time, mass loss is converted into water loss per unit time, thereby obtaining a representative evapotranspiration flux, which is then cross-checked with sap flow data.

[0035] (3.4) Profile monitoring subunit Hydrological profiles were monitored in the root zone near the tree trunk and the canopy projection zone away from the tree trunk in the test area of ​​the slope to be monitored. Soil temperature and humidity sensors 14 and tensiometers 13 were buried at depths of 20cm, 40cm, 70cm, and 100cm in each profile to monitor volumetric water content and soil temperature. A matrix suction sensor 12 was installed at the surface layer (20cm) of the slope to verify the soil matrix suction data measured by the tensiometer 13 at a depth of 20cm. A pore water pressure sensor 15 was buried at a depth of 100cm or at the potential temporary saturation zone. Each sensor maintained a spatial correspondence with the monitoring points in the vegetation layer to identify the response differences between the root zone and the canopy projection zone.

[0036] (3.5) Deformation monitoring subunit To obtain early signs of shallow instability, displacement monitoring devices 16 are deployed on the surface of the slope, in the root zone near the tree trunk and in the canopy projection zone away from the tree trunk. In this embodiment, array-type or wire-type displacement gauges are used to continuously acquire shallow displacement data. Displacement data, along with vegetation layer monitoring data, moisture content, matrix suction, and pore water pressure data, are collected synchronously using a unified time reference. Displacement rate and acceleration are calculated to identify deformation acceleration characteristics and the approach process to a critical state.

[0037] On the other hand, such as Figure 3 As shown, this embodiment of the invention also provides a method for reconstructing slope infiltration boundaries based on atmospheric-vegetation-soil collaborative monitoring, including the following steps one through three.

[0038] Step 1: Divide the test area of ​​the slope to be monitored into the root zone near the tree trunk and the canopy projection zone away from the tree trunk, and set up soil layer monitoring units in pairs in the open space of the two zones; set up atmospheric layer monitoring units and vegetation layer monitoring units in the test area of ​​the slope to be monitored.

[0039] Step 2: Using a single rainfall event as the basic analysis unit, the data collected from each monitoring unit are synchronized in time, quality controlled, and processed as events. The monitoring results are then integrated into atmospheric input indicators, vegetation regulation indicators, and hydraulic response indicators within the soil.

[0040] Based on the continuous monitoring sequence of rainfall outside the forest, the start and end of a rainfall event are determined by a joint standard of "duration of continuous rainless period + minimum event rainfall + minimum rainfall duration + peak rainfall intensity".

[0041] In this embodiment, the continuous rainless time of ≥6h is used as the segmentation condition for adjacent rainfall events; when the cumulative rainfall of an event is less than 1-2mm, the rainfall duration is less than 10-30min, or the peak rainfall intensity is less than 0.5mm / h, it can be determined as an invalid light rain event and merged into adjacent events or removed.

[0042] Each rainfall event will be divided into a pre-rainfall baseline phase, a rainfall input phase, an infiltration response phase, and a post-event recovery phase. Among these: The pre-rainfall baseline phase refers to the period when all monitoring indicators are relatively stable before the start of a rainfall event, and is used to determine the initial state of soil hydraulic-deformation. The rainfall input phase refers to the period during which rainfall occurs and is redistributed through the vegetation canopy and tree trunks to form slope input. It is used to calculate the rainfall redistribution in the vegetation layer and to form the zonal infiltration boundary. The infiltration response stage refers to the period during which slope input enters the soil and causes changes in soil moisture content, matrix suction, or pore water pressure. It is used to calculate the difference in hydraulic-deformation response of the soil in the root zone and the canopy projection zone. The post-event recovery phase refers to the period after rainfall ends when vegetation evapotranspiration, soil hydraulic state, and displacement state recover or continue to evolve. It is used to evaluate the ability of evapotranspiration to recover and soil hydraulic state to return to baseline.

[0043] Canopy interception can be estimated at the rainfall event scale by the difference between external rainfall and throughfall, and by converting area to trunk runoff. Trunk sap flow data is not directly used as infiltration input, but is used to assess transpiration loss and post-event recovery.

[0044] For the soil response in the root zone and canopy projection zone, the following parameters were extracted: soil moisture content response start time, peak time, peak increment, infiltration response depth, matrix suction attenuation amplitude, suction recovery time, pore water pressure rise amplitude, duration, cumulative displacement, displacement rate, and displacement acceleration. The soil water storage increment can be obtained by weighting the volumetric moisture content changes at different depths according to soil layer thickness.

[0045] Step 3: Based on plant regulation indicators, determine the water distribution relationship after rainfall passes through the vegetation canopy and tree trunk, and use the through rainfall in the root zone and the trunk runoff converted by area as the root zone infiltration boundary, and use the through rainfall in the canopy projection area as the canopy projection area infiltration boundary, thereby reconstructing the zonal infiltration boundaries of the root zone and the canopy projection area under a single rainfall event.

[0046] like Figure 4 As shown, rainfall outside the forest P As an atmospheric input baseline, combined with throughfall obtained from vegetation layer monitoring T f Tree trunk runoff S f and slope surface runoff R s The actual infiltration input of different spatial partitions is reconstructed.

[0047] When reconstructing the zonal infiltration boundary, first determine the effective water-receiving area coefficient of the root zone. A r Tree trunk runoff S f Converted to equivalent trunk runoff S fe ,Right now

[0048] For the root zone near the trunk, its actual infiltration boundary is determined by both the root zone penetration rainfall and the trunk runoff converted from area; when considering the deduction of surface runoff, the effective water input to the root zone... I r It can be represented as

[0049] For the canopy projection area far from the tree trunk, its infiltration boundary is mainly determined by the throughfall rainfall in that area; when considering the deduction of surface runoff, the effective water input of the canopy projection area... I c It can be represented as

[0050] in, T f,r and T f,c These represent the penetration rainfall in the root zone and the canopy projection zone, respectively. R s This indicates the surface runoff of the slope.

[0051] For bare areas outside the canopy projection range or unaffected by the canopy, the following can be adopted: P - R s This indicates the effective water input.

[0052] The role of zonal infiltration boundary reconstruction is to transform the redistribution process of extraforest rainfall and vegetation layer rainfall at the atmospheric end into comparable zonal water input conditions at the soil end.

[0053] Furthermore, this invention also provides an application of a slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring, used for graded early warning of shallow landslides, such as... Figure 5 As shown, the specific steps include the following: S1: After completing the reconstruction of the zonal infiltration boundary, the spatial correspondence between the reconstructed infiltration boundary under vegetation influence and the soil response in the root zone and canopy projection zone is combined to comprehensively determine the type of vegetation action on the monitored slope under the current rainfall event. The judgment rule is as follows: If sap flow in the trunk recovers after a rainfall event, and all soils in the root zone and canopy projection zone show a recovery trend over time, then the plant action type is determined to be an anti-slip mechanism dominated by evapotranspiration regulation. If the reconstruction results of the zonal infiltration boundary show that there is concentrated input or continuous infiltration after rain in the root zone or canopy projection zone, and the soil response of any of the corresponding areas shows an unfavorable trend over time, then the vegetation action type is determined to be the infiltration accumulation-dominated pro-sliding mechanism. Step 2: Based on the baseline state of the slope test area to be monitored, consider the deviation, persistence and recovery of the soil response in the root zone and the canopy projection zone from the baseline state of the corresponding area, analyze the displacement changes, and in combination with the plant action type, output low, medium or high warnings in real time according to the entire process of the rainfall event.

[0054] The baseline condition can be determined by the soil moisture content, matrix suction, pore water pressure, trunk sap flow, and normal fluctuation range of displacement during the baseline stage before rainfall.

[0055] The specific rules for determining the warning level are as follows: During the infiltration response phase, the soil response and displacement changes in the root zone and canopy projection zone are updated in real time, and the warning level is output or updated according to the following rules: A low warning is output when the following conditions are met simultaneously: (1) the duration of all soil responses in the root zone and the canopy projection zone deviating from the baseline state of the corresponding area is within the preset range and the degree of deviation from the baseline state does not continue to increase; (2) the displacement of the root zone and the canopy projection zone does not show continuous growth. The warning is output when the following conditions are met simultaneously: (1) it is identified as a sliding mechanism dominated by infiltration accumulation; (2) all soil responses in the root zone or canopy projection zone continuously deviate from the baseline state of the corresponding area; (3) the displacement in the root zone and canopy projection zone does not show continuous growth. A high warning is issued when the following conditions are met simultaneously: (1) the sliding mechanism is identified as dominated by infiltration accumulation; (2) the response of all soils in the root zone or canopy projection zone deviates from the baseline state of the corresponding area, and the response of any soil reaches the preset saturation state; (3) the displacement of the root zone or canopy projection zone shows a continuous increase. Among the above conditions, when the displacement of the root zone or canopy projection zone changes from continuous growth to accelerated growth, a high warning will be directly output.

[0056] During the post-incident recovery phase, the warning level output during the infiltration response phase shall be adjusted according to the following rules: If the plant action type is identified as an anti-slip mechanism dominated by evapotranspiration regulation, and all soil responses in the root zone and canopy projection zone return to the baseline state of the corresponding area, while the displacement does not show continuous increase, then the warning level is reduced or the warning is lifted. If the plant action type is identified as an anti-slip mechanism dominated by evapotranspiration regulation, but the soil response in the root zone or canopy projection zone has not recovered to the baseline state of the corresponding area, and the displacement in the corresponding area has not shown a continuous increase, then it is judged as an insufficient recovery state, and the warning level already output in the infiltration response stage is maintained. If the soil response in the root zone or canopy projection zone continues to deviate from the baseline state of the corresponding area, and the displacement of the corresponding area continues to increase, a high warning will be issued or maintained.

[0057] The soil response includes the soil moisture content response, matrix suction response, and pore water pressure response.

[0058] The preset saturation state of the soil response is when the soil moisture content reaches saturation, the matrix suction becomes zero, or the pore water pressure becomes positive.

[0059] The recovery trend of soil response is specifically manifested in the decrease of moisture content over time, the increase of matrix suction over time, and the decrease of pore water pressure over time.

[0060] The unfavorable trends in soil response are specifically manifested as increased moisture content, decreased matrix suction, or increased pore water pressure.

[0061] This invention uses an atmosphere-plant-soil collaborative monitoring system as its core, adding an observable, calculable, and comparable vegetation layer rainfall redistribution process between traditional atmospheric and soil monitoring. On one hand, this method can correct extra-forest rainfall into partitioned infiltration boundaries between the root zone near the tree trunk and the canopy projection zone away from the tree trunk, improving the accuracy of the partitioned expression of infiltration input boundaries on vegetated slopes. On the other hand, based on the partitioned infiltration boundary reconstruction results, this method can comprehensively determine the type of vegetation action on the monitored slope by combining the spatial correspondence between the reconstructed infiltration boundary under vegetation influence and the soil response in the root zone and canopy projection zone. Furthermore, it can output shallow landslide graded early warning by combining the deviation, persistence, and recovery of soil response relative to the baseline state and displacement changes, thus improving the accuracy of early warning.

[0062] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A method for reconstructing slope infiltration boundaries based on atmospheric-vegetation-soil collaborative monitoring, characterized in that, include: S1: Divide the test area of ​​the slope to be monitored into the root zone near the trunk and the canopy projection zone away from the trunk, and set up soil layer monitoring units in pairs in the open space of the two zones; set up atmospheric layer monitoring units and vegetation layer monitoring units in the test area of ​​the slope to be monitored. S2: Using a single rainfall event as the basic analysis unit, the data collected by each monitoring unit are synchronized in time, quality controlled, and processed as events. The monitoring results are then integrated into atmospheric input indicators, vegetation regulation indicators, and hydraulic response indicators within the soil. S3: Based on the plant regulation index, determine the water distribution relationship after rainfall passes through the vegetation canopy and tree trunk, and use the through rainfall of the root zone and the trunk runoff converted by area as the root zone infiltration boundary, and the through rainfall of the tree canopy projection area as the tree canopy projection area infiltration boundary, thereby reconstructing the partition infiltration boundary of the root zone and the tree canopy projection area under a single rainfall event.

2. The slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 1, characterized in that, The root zone is the soil area affected by root channels, concentrated trunk runoff input, and through rain input; the canopy projection zone is the area not affected by trunk runoff and concentrated root system, but only receives through rain input from the forest.

3. The slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 1, characterized in that, The event-based organization specifically refers to: (1) A single rainfall event is divided into the pre-rainfall baseline stage, the rainfall input stage, the infiltration response stage, and the post-event recovery stage; (2) Use the monitoring data of the pre-rainfall baseline stage to determine the initial state of soil hydraulic-deformation, use the monitoring data of the rainfall input stage to calculate the redistribution of rainfall in the vegetation layer and form the zonal infiltration boundary, use the monitoring data of the infiltration response stage to calculate the difference in soil hydraulic-deformation response between the root zone and the canopy projection zone, and use the monitoring data of the post-event recovery stage to evaluate the ability of evapotranspiration water consumption recovery and soil hydraulic state to return to the baseline.

4. The slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 3, characterized in that, Based on the continuous monitoring sequence of rainfall outside the forest, the start and end of a single rainfall event are determined by a joint standard of "continuous rainless duration + minimum event rainfall + minimum rainfall duration + peak rainfall intensity".

5. The slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 1, characterized in that, In step three, when reconstructing the zonal infiltration boundary, the effective water input of the root zone and the canopy projection zone must be reduced by surface runoff.

6. A slope infiltration boundary reconstruction system based on atmospheric-vegetation-soil collaborative monitoring, characterized in that, include: Atmospheric layer monitoring units and vegetation layer monitoring units were set up in the test area of ​​the slope to be monitored, as well as soil layer monitoring units that were set up in pairs in the open space of the root zone near the tree trunk and the canopy projection zone away from the tree trunk in the test area of ​​the slope to be monitored. The root zone is the soil area affected by root channels, concentrated trunk runoff input, and through rain input; the canopy projection zone is the area not affected by trunk runoff and concentrated root system, but only receives through rain input from the forest floor. The vegetation layer monitoring unit is used to acquire data on penetration rainfall, trunk runoff, trunk sap flow, and vegetation structure in the root zone and canopy projection zone. The soil layer monitoring unit is used to obtain the displacement of the soil surface and the soil moisture content, matrix suction and pore water pressure at multiple depths.

7. An application of a slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring, characterized in that, Used for graded early warning of shallow landslides, specifically including: Step 1: After completing the reconstruction of the zonal infiltration boundary, and combining the spatial correspondence between the reconstructed infiltration boundary under vegetation influence and the soil response in the root zone and canopy projection zone, comprehensively determine the type of vegetation action on the monitored slope under the current rainfall event. The judgment rule is as follows: If sap flow in the trunk recovers after a rainfall event, and all soils in the root zone and canopy projection zone show a recovery trend over time, then the plant action type is determined to be an anti-slip mechanism dominated by evapotranspiration regulation. If the reconstruction results of the zonal infiltration boundary show that there is concentrated input or continuous infiltration after rain in the root zone or canopy projection zone, and the soil response of any of the corresponding areas shows an unfavorable trend over time, then the vegetation action type is determined to be the infiltration accumulation-dominated pro-sliding mechanism. Step 2: Based on the baseline state of the slope test area to be monitored, consider the deviation, persistence and recovery of the soil response in the root zone and the canopy projection zone from the baseline state of the corresponding area, analyze the displacement changes, and in combination with the plant action type, output low, medium or high warnings in real time according to the entire process of the rainfall event.

8. The application of the slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 7, characterized in that, During the infiltration response phase, the soil response and displacement changes in the root zone and canopy projection zone are updated in real time, and low, medium, or high warning levels are output or updated according to the following rules: A low warning is output when the following conditions are met simultaneously: (1) the duration of all soil responses in the root zone and the canopy projection zone deviating from the baseline state of the corresponding area is within the preset range and the degree of deviation from the baseline state does not continue to increase. (2) The displacement of both the root zone and the canopy projection zone did not show a continuous increase; The warning is output when the following conditions are met simultaneously: (1) it is identified as a sliding mechanism dominated by infiltration accumulation; (2) all soil responses in the root zone or canopy projection zone continuously deviate from the baseline state of the corresponding area; (3) the displacement in the root zone and canopy projection zone does not show continuous growth. A high warning is issued when the following conditions are met simultaneously: (1) the sliding mechanism is identified as dominated by infiltration accumulation; (2) the response of all soils in the root zone or canopy projection zone deviates from the baseline state of the corresponding area, and the response of any soil reaches the preset saturation state; (3) the displacement of the root zone or canopy projection zone shows a continuous increase. Among the above conditions, when the displacement of the root zone or canopy projection zone changes from continuous growth to accelerated growth, a high warning will be directly output.

9. The application of the slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 7, characterized in that, During the post-incident recovery phase, the warning level output during the infiltration response phase shall be adjusted according to the following rules: If the plant action type is identified as an anti-slip mechanism dominated by evapotranspiration regulation, and all soil responses in the root zone and canopy projection zone return to the baseline state of the corresponding area, while the displacement does not show continuous increase, then the warning level is reduced or the warning is lifted. If the plant action type is identified as an anti-slip mechanism dominated by evapotranspiration regulation, but the soil response in the root zone or canopy projection zone has not recovered to the baseline state of the corresponding area, and the displacement in the corresponding area has not shown a continuous increase, then it is judged as an insufficient recovery state, and the warning level already output in the infiltration response stage is maintained. If the soil response in the root zone or canopy projection zone continues to deviate from the baseline state of the corresponding area, and the displacement of the corresponding area continues to increase, a high warning will be issued or maintained.

10. The application of the slope infiltration boundary reconstruction method based on atmospheric-vegetation-soil collaborative monitoring according to claim 7, characterized in that, The soil response includes soil moisture content response, matrix suction response, and pore water pressure response; the preset saturation state of the soil response is when the soil moisture content reaches saturation, the matrix suction becomes zero, or the pore water pressure becomes positive. The recovery trend of soil response is specifically manifested as a decrease in moisture content over time, an increase in matrix suction over time, and a decrease in pore water pressure over time. The unfavorable trends in soil response are specifically manifested as increased moisture content, decreased matrix suction, or increased pore water pressure.

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