A reservoir area geological disaster analysis method based on reservoir water-bank slope coupling

Abstract

The present application relates to the technical field of geological disaster prevention, and discloses a reservoir area geological disaster analysis method based on reservoir water-shore slope coupling, which can realize efficient and accurate disaster prevention by the following steps: firstly, screening key geological disasters through reservoir water-shore slope coupling analysis, the front elevation of which is lower than the normal water level, or higher than the normal water level but with characteristics such as near dam, large volume, surge, and threat to facilities; secondly, evaluating stability; thirdly, evaluating harmfulness according to the instability mode and object; and finally, superimposing stability and harmfulness to generate a risk zoning map for engineering prevention and control and operation management, thus establishing a complete technical system for screening, evaluation and prediction, solving the problems of strong subjectivity of evaluation factors, unreasonable weight determination, and insufficient coupling degree of model and reservoir water, and accurately reflecting the actual impact of reservoir operation on the stability of the shore slope.

Description

Technical Field

[0001] This invention belongs to the field of geological disaster prevention and control technology, specifically relating to a reservoir area geological disaster analysis method based on reservoir water-bank slope coupling. Background Technology

[0002] Water conservancy and hydropower projects are important infrastructure supporting national economic and social development. While conventional hydropower stations provide comprehensive benefits such as flood control, power generation, water supply, and ecological regulation, geological safety issues, especially slope-related geological hazards, within their reservoir areas and basins have always been core risks that need to be focused on during project construction and long-term operation.

[0003] The development and evolution of geological hazards in reservoir areas are the result of the coupled effects of multiple factors, including topography, lithology, geological structure, rainfall, reservoir water action, and human engineering activities. These influencing factors are complex and exhibit significant spatial variability. After a hydropower station begins operation, the repeated rise and fall of reservoir water, softening through infiltration, wave erosion, and changes in hydrostatic and seepage pressures significantly alter the physical and mechanical properties and stress state of the riverbank soil and rock. This can lead to increased deformation and strength deterioration of previously stable or relatively stable natural slopes, and even overall instability.

[0004] Currently, the evaluation methods for geological hazards in reservoir areas mainly include: qualitative evaluation based on engineering geological analogy, susceptibility evaluation based on the analytic hierarchy process (AHP) or information model, and stability calculation based on numerical simulation. However, existing technologies still have the following shortcomings when applied to reservoir areas in deep river valleys: (1) The selection of evaluation factors and the determination of their weights are highly subjective. In existing susceptibility assessment methods, the selection of assessment factors often relies on expert experience, and different researchers select factors with significant differences. The determination of factor weights often adopts subjective weighting methods such as the analytic hierarchy process, which lacks an objective coupling mechanism with the core inducing conditions of the reservoir area (such as the effect of reservoir water), resulting in assessment results that vary from person to person and have poor repeatability.

[0005] (2) Insufficient coupling between the model and the reservoir water interaction Existing evaluation models often treat the effects of reservoir water as a static factor or a simple buffer factor, failing to fully consider dynamic mechanical mechanisms such as reservoir water soaking and softening, changes in hydrodynamic pressure caused by water level rises and falls, and wave erosion. As a result, they are difficult to accurately reflect the actual impact of reservoir water storage and operation on bank slope stability.

[0006] (3) Lack of a systematic technical process that connects the whole area with key areas Hydropower project reservoir areas have numerous geological hazard points. Conducting detailed on-site investigations and analyses of all hazard points would be an enormous undertaking and extremely difficult to implement. On the other hand, relying solely on experience to select key hazards could easily lead to omissions or misallocation of resources. Currently, there is a lack of a complete technical process that starts with a systematic interpretation of the entire reservoir area, uses refined identification to screen out key hazards that are significantly affected by water storage or pose a threat to project safety, and then conducts targeted evaluations.

[0007] To address the aforementioned issues, this invention provides a reservoir area geological hazard analysis method based on reservoir-slope coupling. By establishing key geological hazard screening criteria, a systematic stability evaluation standard, and a hazard prediction method, a complete technical chain is formed from "overall identification—key screening—stability analysis—hazard assessment—engineering application," providing reliable technical support for the scientific prevention and control of geological hazards in hydropower station reservoir areas and the safe operation of engineering projects. Summary of the Invention

[0008] To address the aforementioned problems in the existing technology, this invention provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, comprising the following steps: Step S1: Screening of key geological hazards; Based on the interaction between the reservoir and the bank slope, establish screening criteria for key geological hazards, and screen out key geological hazards that are significantly affected by water storage or pose a threat to the safety of the project from the geological hazards in the entire reservoir area; The screening criteria include: Guideline 1: The elevation of the geological disaster front is lower than the normal water level of the reservoir; Guideline 2: The elevation of the geological hazard front edge is not lower than the normal water level of the reservoir, and the geological hazard has one of the following characteristics: located near the dam bank, with a scale of more than one million cubic meters, which may lead to surge or blockage of the river after instability, or directly threatens the infrastructure and safety of residents in the reservoir area; Geological hazards that meet either Criterion 1 or Criterion 2 will be designated as key geological hazards. Step S2, Stability Evaluation: For the key geological hazards selected, the engineering geological qualitative evaluation method is adopted, and the stability status level of the geological hazards is classified by combining deformation signs, topography, stratigraphy, geological structure, hydrogeological conditions, reservoir water action and human engineering activities. Step S3, Hazard Assessment: Based on the stability assessment results described in Step S2, and combined with the potential instability modes and hazardous objects of geological disasters, the hazard level is classified, and the assessment results are output for engineering prevention and control and operation management. Step S4, Risk Zoning: The stability evaluation results of step S2 and the hazard evaluation results of step S3 are spatially overlaid to generate a geological disaster risk zoning map of the reservoir area. The risk zoning map divides the prevention and control areas according to the risk level.

[0009] In a further preferred technical solution, the geological hazards in the entire reservoir area mentioned in step S1 are obtained through the following methods: preliminary identification of the entire area is carried out using remote sensing interpretation; key areas are captured by drone aerial photography based on the remote sensing interpretation results; the identified geological hazard points are verified and supplemented through on-site inspection to form a geological hazard spatial distribution database. In the second criterion, "located near the dam / reservoir bank" refers to geological hazards within 5 kilometers of the dam; "amounting to one million cubic meters" refers to geological hazards with a volume of not less than 100 × 100 cubic meters. The risk of instability leading to surges or river blockage refers to the situation where a geological disaster occurs near the reservoir or in a narrow river valley, and instability results in surges or blockage of the river channel; the infrastructure includes key buildings, reservoir area roads, power transmission lines, residential areas, or production facilities.

[0010] In a further preferred technical solution, the deformation signs mentioned in step S2 include one or more of the following: trailing edge cracks, troughs, reverse faulting, local collapses, slope erosion, gully erosion, and secondary landslides; wherein, the trailing edge cracks include tensile cracks and shear cracks, and the secondary landslides include local collapses within the landslide body and secondary landslides at the front of the deposit; the reservoir water effect includes the softening and reduction of the mechanical parameters of the soil and rock by reservoir water soaking, the change in dynamic water pressure inside the bank slope caused by the rise and fall of the reservoir water level, the change in the morphology of the bank slope front edge by reservoir water wave erosion, and the influence of hydrostatic pressure changes on the stress state of the bank slope.

[0011] In a further preferred embodiment, the stability state levels in step S2 include stable, basically stable, poorly stable, and unstable, and the classification of the stability state levels adopts the following criteria: When the reservoir water-bank slope does not have a unified or regular interface for damage control, there are no signs of recent activity, no obvious triggering factors, or a stable slope shape has been formed at the leading edge, it is classified as a stable state. When the reservoir water and bank slope have a generally uniform failure surface and the leading edge is not exposed, the overall stability is maintained or there are signs of local deformation but it does not affect the overall stability. When the reservoir water and bank slope have a uniform failure surface, the critical value of the inducing factors is low, there are multiple deformation instability or local collapses and landslides, or human engineering activities and reservoir water action can trigger instability, it is classified as a state of poor stability. When the reservoir water-bank slope exhibits significant recent deformation or disintegration instability, the deformation shows an increasing trend, the critical value of the inducing factors is small, or the overall stability is in a critical state, it is classified as an unstable state. Furthermore, the stability level will be downgraded by one level if any of the following adverse conditions exist: There are active and adverse geological phenomena in the nearby area; The deposits exhibit significant differences in permeability and contain accumulated groundwater. The seepage of groundwater or the rapid rise and fall of river water levels can cause dynamic water pressure. Signs of recent and ongoing deformation; The loading at the rear edge or the excavation at the front edge exceeds the slope's bearing capacity; The region experiences frequent rainfall or is prone to earthquakes; The rock and soil mass consists of loose deposits, weak interlayers, or fault fracture zones.

[0012] In a further preferred embodiment of the technical solution, the stability evaluation in step S2 further includes: distinguishing between recent deformation signs and historical deformation traces based on the temporal characteristics of deformation activities of geological disasters, and determining the correlation between deformation activities and reservoir water storage operation by combining the time series of reservoir water action.

[0013] In a further preferred embodiment of the technical solution, the method for determining the potential instability mode in step S3 includes: comprehensively determining the instability type based on the topographic conditions of the geological disaster, the occurrence and combination relationship of structural surfaces, the morphology of the failure control interface, and the induction mode of reservoir water action.

[0014] In a further preferred embodiment, the potential instability modes include one or more of creep deformation, successive disintegration, overall sliding, collapse, and bank collapse; wherein, creep deformation is a continuous and slow displacement deformation, successive disintegration is a gradual instability that expands from a local area to the whole, and overall sliding is an overall sliding along a uniform failure surface.

[0015] In a further preferred technical solution, the hazard level in step S3 is divided into four levels: large, medium, small, and none. The classification criteria include the probability of geological disaster instability, scale of instability, speed of instability, height of surge waves, possibility of blocking the river, and the importance and distance of the hazard objects. The hazard objects include key structures, reservoir banks near the dam, navigation structures, reservoir roads, power transmission lines, residential areas around the reservoir, production facilities, and grazing areas.

[0016] Further, the preferred technical solution also includes step S5: for the key geological hazards selected in step S1, establish development characteristic ledgers for landslide bodies, collapse deposits, and deformable bodies according to the geological hazard type. The ledgers include information on distance from the dam, volume scale, elevation of the front and rear edges, lithology of the strata, signs of deformation activity, current stability, and evolution trend after water impoundment.

[0017] A further preferred technical solution includes step S6: outputting the evaluation results formed in steps S1 to S5 as a thematic map of geological disaster prevention and control in the reservoir area, wherein the thematic map includes a geological disaster distribution map, a stability zoning map, a hazard zoning map, a risk zoning map, and an engineering treatment suggestion map.

[0018] In a further preferred embodiment of the technical solution, the spatial overlay analysis in step S4 adopts the following risk level classification rules: When the stability of a geological disaster after water storage is unstable and the hazard is high or medium, the risk level is high. When the stability of a geological disaster is unstable and the hazard is low after water storage, the risk level is medium; when the stability of a geological disaster is unstable and the hazard is zero after water storage, the risk level is low. When the stability of a geological disaster after water storage is poor and the hazard is high, the risk level is high; when the stability of a geological disaster after water storage is poor and the hazard is medium, the risk level is medium; when the stability of a geological disaster after water storage is poor and the hazard is low, the risk level is low; when the stability of a geological disaster after water storage is poor and the hazard is nonexistent, the risk level is extremely low. When the stability of a geological disaster after water storage is basically stable and the hazard is high, the risk level is medium; when the stability of a geological disaster after water storage is basically stable and the hazard is medium or low, the risk level is low; when the stability of a geological disaster after water storage is basically stable and the hazard is zero, the risk level is extremely low. When the stability of a geological disaster is stable and its hazard level is high or medium after water storage, the risk level is low; when the stability of a geological disaster is stable and its hazard level is low or nonexistent after water storage, the risk level is extremely low.

[0019] A further preferred technical solution also includes step S7, hierarchical prevention and control: based on the risk zoning map generated in step S4, a hierarchical prevention and control system is constructed according to risk level; For high-risk areas, automated professional monitoring, engineering remediation, and personnel evacuation plans are configured; the automated professional monitoring includes GNSS monitoring, deep displacement monitoring, and pore water pressure monitoring; the engineering remediation includes anti-slide piles, anchor cables, and drainage measures. For medium-risk areas, simple monitoring and auxiliary drainage protection measures are implemented; the simple monitoring includes InSAR observation, drone patrols, and regular on-site inspections. For low-risk areas, routine monitoring is adopted, combining community-based monitoring and prevention with annual professional inspections. For areas with extremely low risk levels, they are only included in the hazard log and reviewed once a year.

[0020] In a further preferred technical solution, the automated professional monitoring includes deploying 3 to 5 GNSS monitoring stations, deep-layer wire displacement gauges, and pore water pressure gauges at each geological disaster site; the engineering treatment includes anti-slide piles combined with prestressed anchor cables and slope toe filter layer reinforced with grouted masonry.

[0021] Compared with existing technologies, the present invention provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, which has the following advantages: 1. This invention addresses the issues of subjective evaluation factors and unreasonable weighting, thereby improving the objectivity and repeatability of evaluation results. It establishes a systematic set of screening criteria and stability evaluation standards for key geological hazards, using "reservoir-slope coupling" as the core screening basis. Through objective indicators such as the relationship between the leading edge elevation and reservoir water level, the scale, location characteristics, and affected objects of the geological hazard, quantitative screening of key hazards is achieved. The stability evaluation employs a multi-indicator comprehensive qualitative method, clarifying the types of deformation signs, the reservoir-slope interaction mechanism, and the standards for classifying stability levels. This reduces human interference in the evaluation process, resulting in stronger objectivity and repeatability of the evaluation results.

[0022] 2. This invention addresses the issue of insufficient coupling between the model and reservoir water action, accurately reflecting the actual impact of water storage operation on bank slope stability. It uses reservoir water action as a core evaluation element, systematically analyzing the influence of four mechanical mechanisms on bank slope stability: reservoir water soaking and softening, dynamic water pressure changes caused by water level fluctuations, reservoir water wave erosion, and hydrostatic pressure changes. Furthermore, the stability evaluation incorporates the relationship between the geological hazard front elevation and the reservoir water level, and the correlation between the temporal characteristics of deformation activity and the reservoir water action sequence. This ensures a high degree of coupling between the evaluation model and the core inducing conditions of the reservoir area, enabling more accurate prediction of the stability evolution trend of geological hazards under water storage operation conditions.

[0023] 3. This invention addresses the lack of a systematic technical process connecting the entire region with key areas, enabling efficient and precise disaster prevention and control. It constructs a complete technical chain from "regional identification—key area screening—stability analysis—hazard assessment—risk zoning—engineering application." First, a region-wide geological hazard database is established through a combination of remote sensing interpretation, UAV aerial photography, and on-site verification. Then, based on a dual-criteria screening method of "reservoir-slope coupling," key hazards significantly affected by water storage or posing a threat to engineering safety are quickly identified from the region-wide hazards. Next, systematic stability assessments and hazard predictions are conducted for these key hazards. Finally, spatial overlay analysis generates a risk zoning map to guide the prioritization of engineering remediation and the deployment of monitoring systems during operation.

[0024] 4. The evaluation results have a clear engineering orientation and can directly serve operational risk management. The hazard assessment of this invention focuses on the safety of key structures, near-dam reservoir banks, reservoir capacity, important infrastructure, and surrounding residents, classifying hazards into four levels: large, medium, small, and none. These hazard levels are then spatially overlaid with the stability assessment results to generate a risk zoning map. The evaluation results can be directly used to guide operational risk management work, such as prioritizing engineering remediation, deploying monitoring points, and determining inspection frequency, thus highly matching the safety management needs of hydropower projects.

[0025] 5. Furthermore, this invention constructs a hierarchical prevention and control system linked to risk levels, and formulates differentiated monitoring, governance and control strategies for high, medium, low and extremely low risk levels, realizing the direct transformation from risk assessment to engineering application, and significantly improving the accuracy and operability of risk control during the operation period of geological disasters in reservoir areas. Attached Figure Description

[0026] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a map showing the distribution of key geological hazards in an embodiment of the present invention. Detailed Implementation

[0027] The following will provide a clear and complete description of the concept, specific steps, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be particularly noted that the described embodiments are merely some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without making creative contributions are all within the protection scope of the present invention.

[0028] Example 1 This implementation provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, combined with... Figure 1 The flowchart of the method of the present invention includes the following steps: Step S1: Screening of Key Geological Hazards; Based on the interaction between the reservoir and the riverbank, a screening criterion for key geological hazards is established. Key geological hazards significantly affected by water storage or posing a threat to engineering safety are selected from the geological hazards across the entire reservoir area. Geological hazards across the entire reservoir area are obtained through the following methods: preliminary identification of the entire area is performed using remote sensing interpretation; the remote sensing interpretation results are then used for aerial photography of key areas using drones; and the identified geological hazard points are verified and supplemented through on-site inspections, forming a spatial distribution database of geological hazards.

[0029] In this embodiment, the key geological hazard screening criteria include: Criterion 1: The elevation of the geological hazard front is lower than the normal water level of the reservoir.

[0030] Criterion 2: The elevation of the leading edge of a geological hazard is not lower than the normal water level of the reservoir, and the geological hazard possesses one of the following characteristics: located near the dam bank, with a volume exceeding one million cubic meters, risking surges or river blockage after instability, or directly threatening the infrastructure and safety of residents in the reservoir area. Geological hazards that meet either Criterion 1 or Criterion 2 will be designated as key geological hazards.

[0031] In Guideline Two, geological hazards located near the dam or reservoir bank are defined as those within 5 kilometers of the dam; a scale of over one million cubic meters refers to a geological hazard with a volume of not less than 100 × The risk of instability leading to surging waves or river blockage refers to the geological disaster occurring near the reservoir or in a narrow river valley, which, after instability, could lead to surging waves or blockage of the river channel; infrastructure includes key structures, reservoir area roads, power transmission lines, residential areas, or production facilities.

[0032] Step S2, Stability Evaluation: For the key geological hazards selected, the engineering geological qualitative evaluation method is adopted, and the stability status level of the geological hazards is classified by combining deformation signs, topography, stratigraphy, geological structure, hydrogeological conditions, reservoir water action and human engineering activities.

[0033] The deformation signs include one or more of the following: trailing edge cracks, troughs, reverse faulting, local collapses, slope erosion, gully erosion, and secondary landslides; the trailing edge cracks include tension cracks and shear cracks, and the secondary landslides include local collapses within the landslide body and secondary landslides at the front of the deposit; the reservoir water effects include the softening and reduction of the mechanical parameters of the soil and rock by reservoir water soaking, the changes in dynamic water pressure inside the bank slope caused by the rise and fall of the reservoir water level, the alteration of the bank slope front morphology by reservoir water wave erosion, and the influence of hydrostatic pressure changes on the stress state of the bank slope.

[0034] The stability state levels include stable, basically stable, poorly stable, and unstable. The classification of the stability state levels is based on the following criteria: When the reservoir water-bank slope does not have a unified or regular interface for controlling damage, there are no signs of recent activity, no obvious triggering factors, or a stable slope shape has already formed at the leading edge, it is classified as a stable state.

[0035] When the reservoir water and bank slope have a generally uniform failure surface and the leading edge is not exposed, the overall situation is stable, or there are signs of local deformation but it does not affect the overall stability, it is classified as basically stable.

[0036] When the reservoir water and bank slope have a uniform failure surface, the critical value of the inducing factors is low, and there are multiple deformation instability or local collapses and landslides, or human engineering activities and reservoir water action can trigger instability, it is classified as a state of poor stability.

[0037] When the reservoir water-bank slope exhibits significant recent deformation or disintegration instability, the deformation shows an increasing trend, the inducing factor has a small critical value, or the overall stability is in a critical state, it is classified as an unstable state.

[0038] Furthermore, the stability level will be downgraded by one level when any of the following unfavorable conditions exist: ① Active adverse geological phenomena exist in the adjacent area; ② The permeability of the deposits varies greatly and groundwater accumulates; ③ There is groundwater seepage or rapid rise and fall of river water levels causing dynamic water pressure; ④ New and continuously developing deformation signs have emerged; ⑤ Loading at the rear edge or excavation at the front edge exceeds the slope's bearing capacity; ⑥ Frequent regional rainfall or high earthquake incidence; ⑦ The rock and soil mass is a loose deposit, a weak interlayer, or a fault fracture zone.

[0039] In this embodiment of the invention, the stability evaluation in step S2 further includes: distinguishing between recent deformation signs and historical deformation traces based on the temporal characteristics of geological disaster deformation activities, and determining the correlation between deformation activities and reservoir water storage operation by combining the time series of reservoir water action.

[0040] Step S3, Hazard Assessment: Based on the stability assessment results described in Step S2, and combined with the potential instability modes and hazardous objects of geological disasters, the hazard level is classified, and the assessment results are output for engineering prevention and control and operation management.

[0041] The method for determining the potential instability mode in step S3 includes: comprehensively judging the instability type based on the topographic conditions of the geological disaster, the occurrence and combination relationship of structural planes, the morphology of the failure control interface, and the induction mode of reservoir water action.

[0042] Among them, potential instability modes include one or more of creep deformation, successive disintegration, overall sliding, collapse, and bank collapse; further, creep deformation is continuous and slow displacement deformation, successive disintegration is a gradual instability that expands from local to overall, and overall sliding is an overall sliding along a unified failure surface.

[0043] In this embodiment of the invention, the hazard level in step S3 is divided into four levels: large, medium, small, and none. The classification is based on factors such as the probability of geological disaster instability, scale of instability, speed of instability, height of surge waves, possibility of blocking the river, and the importance and distance of the hazard objects. Hazard objects include key structures, reservoir banks near the dam, navigation structures, reservoir roads, power transmission lines, residential areas around the reservoir, production facilities, and grazing areas.

[0044] Step S4, Risk Zoning: The stability evaluation results of step S2 and the hazard evaluation results of step S3 are spatially overlaid to generate a geological disaster risk zoning map of the reservoir area. The risk zoning map divides the prevention and control areas according to the risk level.

[0045] An embodiment of the present invention provides a reservoir geological hazard analysis method based on reservoir water-bank slope coupling, which further includes step S5: for the key geological hazards screened in step S1, establish development characteristic ledgers for landslide bodies, collapse deposits, and deformable bodies according to the geological hazard type. The ledgers include distance from the dam, volume scale, elevation of the front and rear edges, lithology of the strata, signs of deformation activity, current stability, and evolution trend after water impoundment.

[0046] In step S4, the spatial overlay analysis adopts the following risk level classification rules: When the stability of a geological disaster after water storage is unstable and the hazard is high or medium, the risk level is high; when the stability of a geological disaster after water storage is unstable and the hazard is low, the risk level is medium; when the stability of a geological disaster after water storage is unstable and the hazard is zero, the risk level is low; when the stability of a geological disaster after water storage is poor and the hazard is high, the risk level is high; when the stability of a geological disaster after water storage is poor and the hazard is medium, the risk level is medium; when the stability of a geological disaster after water storage is poor and the hazard is low... When the geological disaster is stable after water storage and poses no threat, the risk level is low; when the geological disaster is basically stable after water storage and poses a significant threat, the risk level is medium; when the geological disaster is basically stable after water storage and poses a moderate or minor threat, the risk level is low; when the geological disaster is basically stable after water storage and poses no threat, the risk level is extremely low; when the geological disaster is stable after water storage and poses a significant or moderate threat, the risk level is low; when the geological disaster is stable after water storage and poses a minor or no threat, the risk level is extremely low.

[0047] An embodiment of the present invention provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, which further includes step S6: outputting the evaluation results formed in steps S1 to S5 as a thematic map of reservoir area geological hazard prevention and control, wherein the thematic map includes a geological hazard distribution map, a stability zoning map, a hazard zoning map, a risk zoning map, and an engineering treatment suggestion map.

[0048] An embodiment of the invention provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, which further includes step S7: graded prevention and control. Based on the risk zoning map generated in step S4, a graded prevention and control system is constructed according to risk level. For high-risk areas, automated professional monitoring, engineering remediation, and personnel evacuation plans are configured. Automated professional monitoring includes GNSS monitoring, deep displacement monitoring, and pore water pressure monitoring, including the deployment of 3 to 5 GNSS monitoring stations, deep-line displacement gauges, and pore water pressure gauges at each geological hazard site. Engineering remediation includes anti-slide piles, anchor cables, and drainage measures, including anti-slide piles combined with prestressed anchor cables and a slope toe filter layer reinforced with mortar and masonry. For medium-risk areas, simple monitoring and auxiliary drainage protection measures are configured. Simple monitoring includes InSAR observation, drone patrols, and regular on-site inspections. For low-risk areas, routine monitoring combining mass monitoring and annual professional inspections is adopted. For extremely low-risk areas, they are only included in the hazard log and reviewed annually.

[0049] Example 2 This embodiment uses a reservoir area of ​​a hydropower station in a deep river valley in western my country as the application object. This reservoir area has steep terrain, complex geological conditions, and is prone to geological hazards. The geological hazard analysis method for the reservoir area based on reservoir-water-bank slope coupling provided in this embodiment includes the following steps: Step S1: Screening of key geological hazards.

[0050] First, remote sensing interpretation was used to preliminarily identify geological hazards across the entire reservoir area. Aerial photography using drones was then employed to collect images of key areas based on the interpretation results. On-site verification and supplementation were conducted on the identified geological hazard sites, and a spatial distribution database of geological hazards was established. Through comprehensive interpretation, a total of 1128 geological hazards were identified in the study area, of which 220 were slope-related hazards distributed within the reservoir area, including 147 landslides, 35 deformed bodies, and 38 collapsed accumulation bodies.

[0051] Then, based on the key geological hazard screening criteria established according to this invention, key geological hazards were selected from 220 geological hazards. The core of this screening criterion is to use the interaction between reservoir water and bank slope as the judgment basis, achieving coupled screening from two dimensions: Criterion 1 (Water Storage Impact Criterion - Reflecting the Direct Effect of Reservoir Water on Bank Slopes): Nine geological hazard sites were selected where the elevation of the geological hazard front was 2535m lower than the normal water storage level of the reservoir, including one landslide and eight collapse accumulation sites. Criterion Two (Engineering Impact Criterion—Reflecting the Potential Impact of Bank Slopes on Reservoir Safety): The elevation of the geological hazard front is higher than the normal water level of the reservoir, but the geological hazard has one of the following high-risk characteristics: located near the dam bank (≤5km from the dam), or with a scale of over one million cubic meters (volume ≥100×10⁻⁶). 4 The criteria emphasize that even if the reservoir water does not directly affect the bank slope, once the bank slope becomes unstable, its secondary disasters such as surges and river blockages will have a reverse effect on the safety of the reservoir project, forming a coupled impact between the bank slope and the reservoir. A total of 31 sites were selected, including 13 landslides, 11 deformed bodies, and 7 collapsed accumulation bodies. These sites pose a risk of swells or river blockages after instability (if the bank slope is adjacent to the reservoir or located in a narrow valley section), or directly threaten important infrastructure and the safety of residents within the reservoir area (if there are key structures, reservoir roads, power transmission lines, residential areas, or production facilities within the affected area).

[0052] Geological hazards meeting either Criterion 1 or Criterion 2 were identified as key geological hazards, totaling 40 sites, including 14 landslides, 15 collapse deposits, and 11 deformed bodies. This selection result fully reflects the selection logic of the reservoir-slope two-way coupling. The distribution of key geological hazards is as follows: Figure 2 As shown in the figure, from bottom to top, R01-R15 are collapsed deposits, D01-D11 are deformed bodies, and L01-L14 are landslide bodies.

[0053] Furthermore, the stability level will be downgraded by one level when any of the following adverse conditions exist: active and unfavorable geological phenomena in the adjacent area; large differences in the permeability of the deposits and accumulation of groundwater; groundwater seepage or rapid rise and fall of river water levels causing dynamic water pressure; recent and continuously developing signs of deformation; loading at the rear edge or excavation at the front edge exceeding the slope's bearing capacity; frequent regional rainfall or high earthquake incidence; the rock and soil mass is a loose deposit, a weak interlayer, or a fault fracture zone.

[0054] Step S2: Stability evaluation.

[0055] For the 40 key geological hazards selected, an engineering geological qualitative evaluation method was adopted to classify the stability level of the geological hazards by comprehensively considering deformation signs, topography, stratigraphy, geological structure, hydrogeological conditions, reservoir water action and reservoir water-slope coupling mechanism, and human engineering activities.

[0056] (1) Identification of deformation signs Through on-site investigation and drone aerial photography, deformation and damage signs of key geological hazards were identified. Of the 14 landslides, 8 showed varying degrees of deformation and damage, mainly manifested as: slope erosion, gully erosion or localized landslides, rear-edge collapse loading, and instability at the front leading to secondary landslides. Of the 15 collapsed deposits, all but one showed signs of deformation and damage, mainly manifested as: new collapse loading at the rear edge, large-scale secondary landslides or collapses, localized collapses, and slope erosion. Of the 11 deformed bodies, 9 showed varying degrees of deformation, such as rear-edge sinkholes, deformation cracks, reverse faulting, and localized collapses.

[0057] (2) Analysis of reservoir water-bank slope coupling mechanism The core of this invention lies in using the interaction between reservoir water and bank slope as a key basis for stability evaluation. In this embodiment, the reservoir water-bank slope coupling mainly manifests as four mechanical mechanisms: Mechanism 1 (Soaking and Softening Coupling): Reservoir water soaks the soil and rock mass of the bank slope, reducing the mechanical parameters of the soil and rock mass (such as cohesion and internal friction angle), weakening the shear strength of the bank slope, and forming a "softening coupling" of reservoir water on the bank slope; Mechanism 2 (hydrodynamic pressure coupling): The rise and fall of reservoir water level causes changes in groundwater level inside the bank slope, generating hydrodynamic pressure, which changes the seepage force field and stress field of the bank slope, forming "water level fluctuation coupling". Mechanism 3 (wave erosion coupling): Reservoir water waves erode the leading edge of the bank slope, changing the bank slope geometry, reducing the anti-sliding force, and forming a "morphological change coupling". Mechanism 4 (Hydrostatic Pressure Coupling): The reservoir water exerts hydrostatic pressure on the bank slope, changing the stress state of the bank slope and affecting the overall stability, thus forming "stress field coupling".

[0058] In this embodiment, the nine geological hazards with leading-edge elevations lower than the normal water level are all affected by the combined effects of the above four coupling mechanisms; geological hazards with leading-edge elevations higher than the normal water level but located near the dam bank or at risk of swell are mainly affected indirectly by Mechanism 1 and Mechanism 2.

[0059] (3) Classification of stable state levels Based on the stability level classification standard established according to this invention, the stability state of geological hazards is divided into four levels: stable, basically stable, poorly stable, and unstable. The evaluation results are as follows: Landslides: Of the 14 landslides, 10 are stable, 3 are basically stable, and 1 is poorly stable.

[0060] Collapsed deposits: Of the 15 collapsed deposits, 13 were basically stable and 2 were less stable.

[0061] Deformation: Of the 11 deformed bodies, 7 are basically stable and 4 are poorly stable.

[0062] The stability assessment results for some geological hazards are detailed in Table 1 below.

[0063] Table 1. Overview of the current stability of geological hazards and the characteristics of water storage evolution.

[0064] Furthermore, the stability level will be downgraded by one level when any of the following adverse conditions exist: active and unfavorable geological phenomena in the adjacent area; large differences in the permeability of the deposits and accumulation of groundwater; groundwater seepage or rapid rise and fall of river water levels causing dynamic water pressure; recent and continuously developing signs of deformation; loading at the rear edge or excavation at the front edge exceeding the slope's bearing capacity; frequent regional rainfall or high earthquake incidence; the rock and soil mass is a loose deposit, a weak interlayer, or a fault fracture zone.

[0065] During the stability assessment, recent deformation signs were distinguished from historical deformation traces based on the temporal characteristics of the deformation activities of geological hazards. In this embodiment, 33 geological hazards showed signs of deformation and damage to varying degrees, accounting for 82.5% of the total number of key hazards. Some of these deformation signs were recent activities, indicating that the deformation activity is still developing.

[0066] Step S3: Hazard assessment.

[0067] Based on the stability assessment results, and combined with the potential instability modes and targets of geological disasters, the severity level is classified.

[0068] (1) Analysis of potential instability modes Based on topographic conditions, structural features, and reservoir water action, the potential instability modes of key geological hazards are determined. The main instability modes include: creep deformation, successive disintegration, overall sliding, collapse, and bank collapse. For example, the L05 landslide exhibits a successive disintegration mode; the R02 collapsed deposit may undergo overall sliding; and the D03 deformed body may experience a collapse and slide.

[0069] (2) Identification of hazardous objects Identify engineering objects and safety targets that may be affected by geological disasters. In this embodiment, the main hazardous objects include: key structures, reservoir banks near the dam, navigation structures, reservoir roads, power transmission lines, residential areas around the reservoir, and grazing areas. Among them, the reservoir banks near the dam have a large number of residents, who were relocated before the impoundment of water; the hazardous objects directly related to key geological disasters include four residential areas or cattle farms.

[0070] (3) Hazard level classification Based on the probability of instability, scale of instability, speed of instability, height of surge waves, possibility of blocking the river, and the importance and distance of the affected objects, the severity of geological disasters is divided into four levels: large, medium, small, and none.

[0071] The evaluation results are as follows: Highly hazardous: L08, L10, R02, R03, R07, D01, D02, D03, a total of 8 locations; Among the hazards: R12, D04, D06, D09, D10, and D11, a total of 6 locations; Low risk: L05, L07, R04, R05, R06, R08, R11, D05, D07, D08, a total of 10 locations; No harm: the remaining 16 locations.

[0072] The potential instability modes and hazard assessment results of some geological hazards are detailed in Table 2 below.

[0073] Table 2. Overview of Potential Instability Modes and Hazard Assessments for Geological Hazards

[0074] Step S4: Risk Zoning and Engineering Application.

[0075] The stability evaluation results from step S2 and the hazard evaluation results from step S3 are spatially overlaid to generate a geological hazard risk zoning map of the reservoir area. Prevention and control areas are divided according to risk level, classifying the reservoir area into high-risk, medium-risk, low-risk, and no-risk zones.

[0076] Risk zoning results are used to guide the prioritization of engineering remediation and the deployment of monitoring systems during operation. High-risk areas (highly hazardous and unstable): prioritize engineering remediation and increase the density of monitoring points; Medium-risk areas (medium hazard or poor stability): key areas for inspection and regular monitoring; Low-risk areas (low risk and basically stable): routine patrols.

[0077] In step S4, the spatial overlay analysis adopts the following risk level classification rules: When the stability of a geological disaster after water storage is unstable and the hazard is high or medium, the risk level is high; when the stability of a geological disaster after water storage is unstable and the hazard is low, the risk level is medium; when the stability of a geological disaster after water storage is unstable and the hazard is zero, the risk level is low; when the stability of a geological disaster after water storage is poor and the hazard is high, the risk level is high; when the stability of a geological disaster after water storage is poor and the hazard is medium, the risk level is medium; when the stability of a geological disaster after water storage is poor and the hazard is low... When the geological disaster is stable after water storage and poses no threat, the risk level is low; when the geological disaster is basically stable after water storage and poses a significant threat, the risk level is medium; when the geological disaster is basically stable after water storage and poses a moderate or minor threat, the risk level is low; when the geological disaster is basically stable after water storage and poses no threat, the risk level is extremely low; when the geological disaster is stable after water storage and poses a significant or moderate threat, the risk level is low; when the geological disaster is stable after water storage and poses a minor or no threat, the risk level is extremely low.

[0078] Step S5: Categorized ledger management.

[0079] For the 40 key geological hazards selected, development characteristic ledgers were established for landslides, collapse deposits, and deformable bodies, categorized by hazard type. The ledgers included information such as distance from the dam, volume and scale, elevation of the front and rear edges, lithology of the strata, signs of deformation activity, current stability, and evolutionary trends after impoundment.

[0080] An embodiment of the present invention provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, which further includes step S6: outputting the evaluation results formed in steps S1 to S5 as a thematic map of reservoir area geological hazard prevention and control, wherein the thematic map includes a geological hazard distribution map, a stability zoning map, a hazard zoning map, a risk zoning map, and an engineering treatment suggestion map.

[0081] An embodiment of the invention provides a reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, which further includes step S7: graded prevention and control. Based on the risk zoning map generated in step S4, a graded prevention and control system is constructed according to risk level. For high-risk areas, automated professional monitoring, engineering remediation, and personnel evacuation plans are configured. Automated professional monitoring includes GNSS monitoring, deep displacement monitoring, and pore water pressure monitoring, including the deployment of 3 to 5 GNSS monitoring stations, deep-line displacement gauges, and pore water pressure gauges at each geological hazard site. Engineering remediation includes anti-slide piles, anchor cables, and drainage measures, including anti-slide piles combined with prestressed anchor cables and a slope toe filter layer reinforced with mortar and masonry. For medium-risk areas, simple monitoring and auxiliary drainage protection measures are configured. Simple monitoring includes InSAR observation, drone patrols, and regular on-site inspections. For low-risk areas, routine monitoring combining mass monitoring and annual professional inspections is adopted. For extremely low-risk areas, they are only included in the hazard log and reviewed annually.

[0082] Example 3 This embodiment takes the reservoir area of ​​a deep valley hydropower station (hereinafter referred to as GX Hydropower Station) in Southwest my country as the application object to further illustrate the implementation process of the present invention.

[0083] Step S1: Screening of Key Geological Hazards Using the same screening method as in Example 1, and based on the dual criteria of reservoir water-slope coupling, key geological hazards significantly affected by water storage or posing a threat to engineering safety were selected from the geological hazards across the entire reservoir area. Through remote sensing interpretation, UAV aerial photography, and on-site verification, a total of 40 key geological hazards were identified, including 14 landslides, 15 collapse deposits, and 11 deformed bodies. The numbers and basic information of some of the hazard bodies are as follows: landslides L01 to L14, collapse deposits R01 to R15, and deformed bodies D01 to D11.

[0084] Step S2, Stability Evaluation For the aforementioned 40 key geological hazards, the engineering geological qualitative evaluation method described in step S2 of this invention is adopted, and the stability status level of each hazard body is classified by combining the refined standards and the unfavorable downgrade rules.

[0085] Taking the collapsed accumulation body R02 as an example: the front edge of this disaster body is adjacent to the reservoir, and the rear edge has recently developed tensile cracks. Groundwater is seeping out in sheets on the slope, and it is located near the dam reservoir bank (approximately 2.5 km from the dam). According to the assessment criteria, it has a uniform potential failure surface, multiple signs of deformation, and significant softening effect from reservoir water soaking, initially classified as poorly stable. Furthermore, the disaster body exhibits two unfavorable conditions: groundwater seepage causing dynamic water pressure and newly developed and continuously evolving deformation. Therefore, the stability level is downgraded by one level, and it is ultimately classified as unstable.

[0086] Taking landslide L05 as an example: the rear edge of this landslide has tensile cracks, and the front edge is eroded by reservoir water, resulting in localized collapses and slides, but no signs of overall deformation. The preliminary assessment is that it has poor stability, with no adverse conditions, and its stability is unlikely to be maintained.

[0087] The stability evaluation results for other hazardous bodies are shown in Table 3 below.

[0088] Step S3, Hazard Assessment The assessment is conducted based on the instability pattern and the affected objects, according to the hazard level classification standard. The affected objects include key structures, reservoir banks near the dam, residential areas around the reservoir, and important infrastructure.

[0089] Taking the collapsed accumulation body R02 as an example: its potential instability mode is a complete landslide. After instability, it may generate large-scale surge waves, directly threatening the safety of the reservoir bank and key structures near the dam. At the same time, the surge waves may also affect residential areas around the reservoir. According to the hazard assessment criteria, it meets the criteria of being prone to generating large-scale surge waves after instability, posing a great threat to key structures, and posing a great threat to the safety of residents around the reservoir. Therefore, its hazard level is classified as high.

[0090] Taking landslide L05 as an example: its potential instability mode is successive disintegration, the scale of instability is small, the surge height is low, there is no risk of blocking the river, and the target of the hazard is an uninhabited area, so the hazard level is small.

[0091] The potential instability modes and hazard assessment results of some geological hazards are shown in Table 3 below.

[0092] Table 3. Potential instability modes and hazard assessment results of some geological hazards

[0093] Step S4, Risk Zoning The stability evaluation results from step S2 and the hazard evaluation results from step S3 are spatially superimposed according to the risk level classification matrix described in step S4 of this invention, as shown in Table 4 below, to generate a geological hazard risk zoning map of the reservoir area.

[0094] Table 4 Geological Hazard Risk Level Classification Matrix

[0095] Based on the above matrix, the risk level of each hazard is determined. For example: R02 (unstable stability, high hazard) corresponds to high risk; L05 (poor stability, low hazard) corresponds to low risk; L08 (stable stability, high hazard) corresponds to low risk; R12 (basically stable stability, medium hazard) corresponds to low risk; and D09 (poor stability, medium hazard) corresponds to medium risk. The risk zoning results are used to guide subsequent tiered prevention and control measures.

[0096] Step S5: Classification Ledger Management For the 40 key geological hazards selected, development characteristic ledgers were established for landslide bodies, collapse deposits, and deformed bodies, respectively. The ledgers included information on distance from the dam, volume and scale, elevation of the front and rear edges, lithology of the strata, signs of deformation activity, current stability, and evolution trend after impoundment. The ledger format is the same as in Example 2, and will not be repeated here.

[0097] Step S6: Output thematic map The evaluation results generated in steps S1 to S5 are output as a thematic map of geological disaster prevention and control in the reservoir area, including a geological disaster distribution map, a stability zoning map, a hazard zoning map, a risk zoning map, and an engineering treatment suggestion map.

[0098] Step S7: Tiered prevention and control Based on the risk zoning map generated in step S4, a hierarchical prevention and control system is constructed according to risk levels: High-risk areas (such as R02, R03, D01, D02, D03, etc.): Configure automated professional monitoring, engineering remediation, and personnel evacuation plans. Automated professional monitoring includes deploying 3-5 GNSS monitoring stations (accuracy ±1mm), deep-line displacement gauges (monitoring depth 20-50m), and pore water pressure gauges (burial depth 5-20m) at each geological hazard site; engineering remediation includes anti-slide piles (pile length 20-40m, pile diameter 2-3m, spacing 5-8m) in conjunction with prestressed anchor cables (tension 1000-2000kN), and slope toe filter layer with mortared masonry protection; at the same time, delineate warning zones, prepare special emergency response plans, and implement relocation and evacuation when necessary.

[0099] Medium-risk areas (such as D09, D10, D11, etc.): Implement simple monitoring and auxiliary drainage protection measures. Simple monitoring includes quarterly InSAR observations, monthly drone patrols, and quarterly on-site inspections by professionals; auxiliary drainage measures include deploying intercepting ditches at the rear edge of the disaster body.

[0100] Low-risk areas (such as L05, L07, R04, R05, etc.): Routine monitoring is adopted, combining community-based monitoring and prevention with annual professional inspections. Local monitors are trained to conduct inspections monthly, and professional technicians conduct a review annually.

[0101] Extremely low-risk areas (such as stable and harmless disaster bodies like L01 and L02): are only included in the hazard log and reviewed once a year, without the need for professional monitoring and engineering remediation.

[0102] Through the aforementioned tiered prevention and control system, the evaluation results have been directly transformed into engineering applications, significantly improving the accuracy and operability of risk management during the operation period of geological disasters in the reservoir area.

[0103] Compared with existing technologies, the beneficial effects of this invention's reservoir area geological hazard analysis method based on reservoir water-bank slope coupling are: 1. This invention addresses the issues of subjective evaluation factors and unreasonable weighting, thereby improving the objectivity and repeatability of evaluation results. It establishes a systematic set of screening criteria and stability evaluation standards for key geological hazards, using "reservoir-slope coupling" as the core screening basis. Through objective indicators such as the relationship between the leading edge elevation and reservoir water level, the scale, location characteristics, and affected objects of the geological hazard, quantitative screening of key hazards is achieved. The stability evaluation employs a multi-indicator comprehensive qualitative method, clarifying the types of deformation signs, the reservoir-slope interaction mechanism, and the standards for classifying stability levels. This reduces human interference in the evaluation process, resulting in stronger objectivity and repeatability of the evaluation results.

[0104] 2. This invention addresses the issue of insufficient coupling between the model and reservoir water action, accurately reflecting the actual impact of water storage operation on bank slope stability. It uses reservoir water action as a core evaluation element, systematically analyzing the influence of four mechanical mechanisms on bank slope stability: reservoir water soaking and softening, dynamic water pressure changes caused by water level fluctuations, reservoir water wave erosion, and hydrostatic pressure changes. Furthermore, the stability evaluation incorporates the relationship between the geological hazard front elevation and the reservoir water level, and the correlation between the temporal characteristics of deformation activity and the reservoir water action sequence. This ensures a high degree of coupling between the evaluation model and the core inducing conditions of the reservoir area, enabling more accurate prediction of the stability evolution trend of geological hazards under water storage operation conditions.

[0105] 3. This invention addresses the lack of a systematic technical process connecting the entire region with key areas, enabling efficient and precise disaster prevention and control. It constructs a complete technical chain from "regional identification—key area screening—stability analysis—hazard assessment—risk zoning—engineering application." First, a region-wide geological hazard database is established through a combination of remote sensing interpretation, UAV aerial photography, and on-site verification. Then, based on a dual-criteria screening method of "reservoir-slope coupling," key hazards significantly affected by water storage or posing a threat to engineering safety are quickly identified from the region-wide hazards. Next, systematic stability assessments and hazard predictions are conducted for these key hazards. Finally, spatial overlay analysis generates a risk zoning map to guide the prioritization of engineering remediation and the deployment of monitoring systems during operation.

[0106] 4. The evaluation results have a clear engineering orientation and can directly serve operational risk management. The hazard assessment of this invention focuses on the safety of key structures, near-dam reservoir banks, reservoir capacity, important infrastructure, and surrounding residents, classifying hazards into four levels: large, medium, small, and none. These hazard levels are then spatially overlaid with the stability assessment results to generate a risk zoning map. The evaluation results can be directly used to guide operational risk management work, such as prioritizing engineering remediation, deploying monitoring points, and determining inspection frequency, thus highly matching the safety management needs of hydropower projects.

[0107] 5. Furthermore, this invention constructs a hierarchical prevention and control system linked to risk levels, and formulates differentiated monitoring, governance and control strategies for high, medium, low and extremely low risk levels, realizing the direct transformation from risk assessment to engineering application, and significantly improving the accuracy and operability of risk control during the operation period of geological disasters in reservoir areas.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A reservoir area geological hazard analysis method based on reservoir water-bank slope coupling, characterized in that, Includes the following steps: Step S1: Screening of key geological hazards; Based on the interaction between the reservoir and the bank slope, establish screening criteria for key geological hazards, and screen out key geological hazards that are significantly affected by water storage or pose a threat to the safety of the project from the geological hazards in the entire reservoir area; The screening criteria include: Guideline 1: The elevation of the geological disaster front is lower than the normal water level of the reservoir; Guideline 2: The elevation of the geological hazard front edge is not lower than the normal water level of the reservoir, and the geological hazard has one of the following characteristics: located near the dam bank, with a scale of more than one million cubic meters, which may lead to surge or blockage of the river after instability, or directly threatens the infrastructure and safety of residents in the reservoir area; Geological hazards that meet either Criterion 1 or Criterion 2 will be designated as key geological hazards. Step S2, Stability Evaluation: For the key geological hazards selected, the engineering geological qualitative evaluation method is adopted, and the stability status level of the geological hazards is classified by combining deformation signs, topography, stratigraphy, geological structure, hydrogeological conditions, reservoir water action and human engineering activities. Step S3, Hazard Assessment: Based on the stability assessment results described in Step S2, and combined with the potential instability modes and hazardous objects of geological disasters, the hazard level is classified, and the assessment results are output for engineering prevention and control and operation management. Step S4, Risk Zoning: The stability evaluation results of step S2 and the hazard evaluation results of step S3 are spatially overlaid to generate a geological disaster risk zoning map of the reservoir area. The risk zoning map divides the prevention and control areas according to the risk level.

2. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The geological hazards in the entire reservoir area mentioned in step S1 are obtained through the following methods: preliminary identification of the entire area is carried out using remote sensing interpretation; key areas are captured by drone aerial photography based on the remote sensing interpretation results; the identified geological hazard points are verified and supplemented through on-site inspection to form a geological hazard spatial distribution database. In the second criterion, "located near the dam / reservoir bank" refers to geological hazards within 5 kilometers of the dam; "amounting to one million cubic meters" refers to geological hazards with a volume of not less than 100 × 100 cubic meters. The risk of instability leading to surges or river blockage refers to the situation where a geological disaster occurs near the reservoir or in a narrow river valley, and instability results in surges or blockage of the river channel; the infrastructure includes key buildings, reservoir area roads, power transmission lines, residential areas, or production facilities.

3. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The deformation signs mentioned in step S2 include one or more of the following: trailing edge cracks, troughs, reverse faulting, local collapses, slope erosion, gully erosion, and secondary landslides; wherein, the trailing edge cracks include tensile cracks and shear cracks, and the secondary landslides include local collapses within the landslide body and secondary landslides at the front of the deposit; the reservoir water effect includes the softening and reduction of the mechanical parameters of the soil and rock by reservoir water soaking, the change in dynamic water pressure inside the bank slope caused by the rise and fall of the reservoir water level, the change in the bank slope front morphology by reservoir water wave erosion, and the influence of hydrostatic pressure changes on the stress state of the bank slope.

4. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The stability state levels mentioned in step S2 include stable, basically stable, poorly stable, and unstable. The classification of stability state levels adopts the following criteria: When the reservoir water-bank slope does not have a unified or regular interface for damage control, there are no signs of recent activity, no obvious triggering factors, or a stable slope shape has been formed at the leading edge, it is classified as a stable state. When the reservoir water and bank slope have a generally uniform failure surface and the leading edge is not exposed, the overall stability is maintained or there are signs of local deformation but it does not affect the overall stability. When the reservoir water and bank slope have a uniform failure surface, the critical value of the inducing factors is low, there are multiple deformation instability or local collapses and landslides, or human engineering activities and reservoir water action can trigger instability, it is classified as a state of poor stability. When the reservoir water-bank slope exhibits significant recent deformation or disintegration instability, the deformation shows an increasing trend, the critical value of the inducing factors is small, or the overall stability is in a critical state, it is classified as an unstable state. Furthermore, the stability level will be downgraded by one level if any of the following adverse conditions exist: There are active and adverse geological phenomena in the nearby area; The deposits exhibit significant differences in permeability and contain accumulated groundwater. The seepage of groundwater or the rapid rise and fall of river water levels can cause dynamic water pressure. Signs of recent and ongoing deformation; The loading at the rear edge or the excavation at the front edge exceeds the slope's bearing capacity; The region experiences frequent rainfall or is prone to earthquakes; The rock and soil mass consists of loose deposits, weak interlayers, or fault fracture zones.

5. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The stability evaluation in step S2 also includes: distinguishing between recent deformation signs and historical deformation traces based on the temporal characteristics of geological disaster deformation activities, and judging the correlation between deformation activities and reservoir water storage operation by combining the time series of reservoir water action.

6. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The method for determining the potential instability mode in step S3 includes: comprehensively judging the instability type based on the topographic conditions of the geological disaster, the occurrence and combination relationship of structural planes, the morphology of the failure control interface, and the induction mode of reservoir water action.

7. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 6, characterized in that, The potential instability modes include one or more of creep deformation, successive disintegration, overall sliding, collapse, and bank collapse; wherein, creep deformation is continuous and slow displacement deformation, successive disintegration is a gradual instability that expands from local to overall, and overall sliding is an overall sliding along a uniform failure surface.

8. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The hazard level described in step S3 is divided into four levels: large, medium, small, and none. The classification is based on factors such as the probability of geological disaster instability, scale of instability, speed of instability, height of surge waves, possibility of blocking the river, and the importance and distance of the hazardous objects. The hazardous objects include key structures, reservoir banks near the dam, navigation structures, reservoir roads, power transmission lines, residential areas around the reservoir, production facilities, and grazing areas.

9. A reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, It also includes step S5: For the key geological hazards selected in step S1, establish development characteristic ledgers for landslide bodies, collapse deposits, and deformable bodies according to the geological hazard type. The ledgers include information on distance from the dam, volume scale, elevation of the front and rear edges, lithology of strata, signs of deformation activity, current stability, and evolution trend after water impoundment.

10. A reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, It also includes step S6: outputting the evaluation results formed in steps S1 to S5 as a thematic map of geological disaster prevention and control in the reservoir area. The thematic map includes a geological disaster distribution map, a stability zoning map, a hazard zoning map, a risk zoning map, and an engineering treatment suggestion map.

11. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 1, characterized in that, The spatial overlay analysis described in step S4 adopts the following risk level classification rules: When the stability of a geological disaster after water storage is unstable and the hazard is high or medium, the risk level is high. When the stability of a geological disaster is unstable and the hazard is low after water storage, the risk level is medium; when the stability of a geological disaster is unstable and the hazard is zero after water storage, the risk level is low. When the stability of a geological disaster after water storage is poor and the hazard is high, the risk level is high; when the stability of a geological disaster after water storage is poor and the hazard is medium, the risk level is medium; when the stability of a geological disaster after water storage is poor and the hazard is low, the risk level is low; when the stability of a geological disaster after water storage is poor and the hazard is nonexistent, the risk level is extremely low. When the stability of a geological disaster after water storage is basically stable and the hazard is high, the risk level is medium; when the stability of a geological disaster after water storage is basically stable and the hazard is medium or low, the risk level is low; when the stability of a geological disaster after water storage is basically stable and the hazard is zero, the risk level is extremely low. When the stability of a geological disaster is stable and its hazard level is high or medium after water storage, the risk level is low; when the stability of a geological disaster is stable and its hazard level is low or nonexistent after water storage, the risk level is extremely low.

12. The reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 10, characterized in that, It also includes step S7, hierarchical prevention and control: based on the risk zoning map generated in step S4, a hierarchical prevention and control system is constructed according to the risk level; For high-risk areas, automated professional monitoring, engineering remediation, and personnel evacuation plans are configured; among which, automated professional monitoring includes GNSS monitoring, deep displacement monitoring, and pore water pressure monitoring; Engineering treatment includes anti-slide piles, anchor cables, and drainage measures; For medium-risk areas, simple monitoring and auxiliary drainage protection measures are implemented; the simple monitoring includes InSAR observation, drone patrols, and regular on-site inspections. For low-risk areas, routine monitoring is adopted, combining community-based monitoring and prevention with annual professional inspections. For areas with extremely low risk levels, they are only included in the hazard log and reviewed once a year.

13. A reservoir area geological hazard analysis method based on reservoir water-bank slope coupling according to claim 12, characterized in that, The automated professional monitoring includes deploying 3 to 5 GNSS monitoring stations, deep-layer wire displacement gauges, and pore water pressure gauges at each geological hazard site; the engineering treatment includes anti-slide piles combined with prestressed anchor cables and slope toe filter layer with grouted masonry protection.

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