A method and system for determining flood control standards for earth-rock dams based on dam break risk.

Abstract

This invention relates to a method and system for determining flood control standards for earth-rock dams based on dam break risk, belonging to the field of hydraulic engineering technology. The method mainly includes: calculating the total failure probability of the earth-rock dam corresponding to different flood return periods based on the annual exceedance probability of floods, the failure probability of the earth-rock dam, and the independent probability of seepage failure; calculating the first and second predicted total costs corresponding to different flood return periods using the total failure probability of the earth-rock dam, engineering costs, direct losses, indirect losses, and environmental losses; and selecting the target flood return period as the flood control standard for the earth-rock dam from multiple flood return periods based on the first and second predicted total costs corresponding to different flood return periods.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to a method and system for determining flood control standards for earth-rock dams based on dam break risk. Background Technology

[0002] Floods are water inundations caused by factors such as heavy rainfall, snowmelt, and dam failures, resulting in enormous economic losses and casualties. To effectively address flood disasters, scientific flood risk assessment and optimization of flood control engineering design are crucial. Flood risk assessment aims to predict the likelihood and extent of floods by analyzing historical and real-time monitoring data, providing a scientific basis for flood control engineering design.

[0003] In recent years, China has carried out nationwide flood risk zoning, proposing the use of comprehensive flood risk levels to characterize flood risk, and has produced nationwide flood risk zoning results. However, current technologies suffer from wide ranges in flood control standards and a lack of unified standards for upper and lower limits. The selection of indicators is highly subjective, and different values ​​will affect flood control safety capabilities, the level and scale of dike design projects, and the amount of funding required. Furthermore, they do not fully consider flood risk factors, thus hindering the construction of urban flood control projects. Summary of the Invention

[0004] The present invention aims to provide a method and system for determining flood control standards for earth-rock dams based on dam break risk, in order to overcome the shortcomings of the existing technology. The technical problem to be solved by the present invention is achieved through the following technical solution.

[0005] This invention provides a method for determining flood control standards for earth-rock dams based on dam break risk, the method comprising:

[0006] Obtain the annual flood exceedance probability corresponding to different flood return periods, and obtain the failure probability and independent probability of seepage failure of earth-rock dams;

[0007] The total probability of failure of earth-rock dams corresponding to different flood return periods is calculated based on the annual flood exceedance probability, the failure probability of earth-rock dams, and the independent probability of seepage failure.

[0008] The first and second predicted total costs corresponding to different flood return periods are calculated based on the total failure probability of earth-rock dams, engineering costs, direct losses, indirect losses, and environmental losses.

[0009] Based on the first and second total predicted costs corresponding to the different flood return periods, the target flood return period is selected from multiple flood return periods as the flood control standard for earth-rock dams.

[0010] In an optional embodiment, the calculation of the second predicted total cost corresponding to different flood return periods, based on the total failure probability of the earth-rock dam, engineering cost, direct losses, indirect losses, and environmental losses corresponding to the different flood return periods, includes:

[0011] Based on historical data of the target area and historical data with the same attributes as the target area, the direct loss factor, indirect loss factor and environmental loss factor are predicted.

[0012] The direct loss, indirect loss, and environmental loss are corrected by direct loss factor, indirect loss factor, and environmental loss factor;

[0013] The second predicted total cost is calculated based on the corrected direct losses, indirect losses, environmental losses, and total earth-rock dam failure probability for different flood return periods.

[0014] In an optional embodiment, selecting the target flood return period as the flood control standard for the earth-rock dam based on the first predicted total cost and the second predicted total cost corresponding to the different flood return periods includes:

[0015] The first predicted total cost and the second predicted total cost are weighted and calculated to obtain the final predicted total cost corresponding to different flood return periods.

[0016] Based on the final predicted total cost, the target flood recurrence period is selected from multiple flood recurrence periods as the flood control standard for earth-rock dams.

[0017] In an optional embodiment, selecting the target flood return period from multiple flood return periods as the flood control standard for the earth-rock dam based on the final predicted total cost includes:

[0018] For each flood recurrence period, data standardization is performed to calculate the flood recurrence period for its final predicted total cost, total probability of earth-rock dam failure, number of people affected by earth-rock dam area, and environmental losses.

[0019] The final predicted total cost, total probability of earth-rock dam failure, number of people affected by earth-rock dam area, and environmental loss are weighted and calculated to obtain a comprehensive score for each flood return period.

[0020] The flood recurrence period with the highest comprehensive score is taken as the target flood recurrence period, and the target flood recurrence period is determined as the flood control standard for earth-rock dams.

[0021] This invention provides a system for determining flood control standards for earth-rock dams based on dam break risk. The system includes:

[0022] The acquisition module is used to obtain the annual exceedance probability of floods corresponding to different flood return periods, as well as the independent probability of failure of earth-rock dams and seepage failure.

[0023] The calculation module is used to calculate the total failure probability of the earth-rock dam corresponding to different flood return periods based on the annual flood exceedance probability, the failure probability of the earth-rock dam, and the independent probability of seepage failure.

[0024] The calculation module is also used to calculate the first predicted total cost and the second predicted total cost corresponding to different flood return periods based on the total failure probability of earth-rock dams, engineering costs, direct losses, indirect losses and environmental losses corresponding to the different flood return periods.

[0025] The selection module is used to select a target flood return period as the flood control standard for earth-rock dams from multiple flood return periods based on the first predicted total cost and the second predicted total cost corresponding to the different flood return periods.

[0026] The embodiments of the present invention have the following advantages:

[0027] This invention provides a method and system for determining flood control standards for earth-rock dams based on dam break risk. First, it obtains the annual flood exceedance probability corresponding to different flood return periods, as well as the dam failure probability and the independent probability of seepage failure. Then, it calculates the total dam failure probability corresponding to different flood return periods based on the annual flood exceedance probability, the dam failure probability, and the independent probability of seepage failure. Next, it calculates the first and second predicted total costs corresponding to different flood return periods using the total dam failure probability, engineering costs, direct losses, indirect losses, and environmental losses. Finally, it selects the target flood return period as the flood control standard for the earth-rock dam based on the first and second predicted total costs. Compared to existing technologies with large ranges in flood standard intervals and no unified standard for upper and lower limits, this application calculates the total failure probability of earth-rock dams for different flood return periods based on the annual exceedance probability, failure probability of earth-rock dams, and independent probability of seepage failure corresponding to different flood return periods. This allows for the calculation of the first and second predicted total costs for different flood return periods. By using the first and second predicted total costs, the target flood return period can be selected from multiple flood return periods as the flood control standard for earth-rock dams. Therefore, this application can improve the accuracy of determining the flood control standard for earth-rock dams, thereby benefiting urban flood control engineering construction. Attached Figure Description

[0028] Figure 1This is a flowchart of a method for determining flood control standards for earth-rock dams based on dam break risk, provided by an embodiment of the present invention;

[0029] Figure 2 This is a flowchart of the process for determining flood control standards for earth-rock dams provided in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of a system for determining flood control standards for earth-rock dams based on dam break risk, provided in an embodiment of the present invention. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] Please see Figure 1 This invention provides a method for determining flood control standards for earth-rock dams based on dam break risk, specifically comprising steps S101-S104:

[0033] S101, obtain the flood year exceedance probability corresponding to different flood return periods, and obtain the failure probability and seepage failure independent probability of earth-rock dam.

[0034] Among them, the flood recurrence period refers to the dam structure corresponding to different design standards (such as once-in-a-century floods and once-in-a-millennium floods). The failure probability of the rockfill dam refers to the annual dam failure probability under different flood control standards.

[0035] In one optional embodiment provided in the application, obtaining the flood year exceedance probability corresponding to different flood return periods includes

[0036] The annual flood exceedance probability corresponding to different flood return periods is calculated using the following formula:

[0037]

[0038] Where AEP(T) is the flood year exceedance probability with flood return period T, and Q T Let ξ be the flood discharge at the flood return period T, ξ be the shape parameter, μ be the location parameter, and σ be the scale parameter.

[0039] For example, parameter μ = 2500m 3 σ=400m 3 / s, ξ=0.2, T=100.

[0040] That is, calculate AEP(100) = 3000m 3 Probability of flood year exceeding / s:

[0041]

[0042] In one optional embodiment provided in the application, obtaining the independent probability of seepage failure includes: calculating the gradient difference between the actual hydraulic gradient and the critical hydraulic gradient; if the gradient difference is greater than or equal to 0, it is determined that seepage failure has occurred, and N sets of parameter samples are randomly generated by Monte Carlo simulation, and the gradient difference of each set of parameter samples is calculated, and the independent probability of seepage failure is determined according to the proportion of the gradient difference of the parameter samples that is greater than or equal to 0.

[0043] In this embodiment, the formula for calculating the actual hydraulic gradient is:

[0044]

[0045] The critical hydraulic gradient is:

[0046]

[0047] Where Δh is the head difference, representing extreme water level fluctuations, L is the seepage path length, and G... s denoted as ρ, where ρ is the specific gravity of soil particles and e is the void ratio, which represents the variability of soil density.

[0048] Specifically, in this embodiment, N sets of parameter samples (permeability coefficient k, void ratio e, head difference Δh) are randomly generated through Monte Carlo simulation, and then the gradient difference of each set of parameter samples is calculated; the failure probability P is obtained by counting the number of gradient differences of the parameter samples that are less than or equal to 0. f Then the failure probability P f Dividing N yields the independent probability of penetration and destruction.

[0049] In this embodiment, the core of the failure sub-probability of earth-rock dams is to quantify the joint occurrence probability of multiple independent or related failure paths. The main failure modes in this embodiment (which need to be based on the characteristic analysis of earth-rock dams) may include: overtopping failure: floods exceeding the dam crest elevation cause overflow erosion; seepage failure: seepage leads to piping or internal erosion; slope instability: floods or earthquakes trigger dam slope sliding; earthquake liquefaction: seismic ground motion causes liquefaction of dam foundation or dam body materials.

[0050] For multiple failure modes, the acquisition of the failure probability of the earth-rock dam in this implementation can include: calculating the failure sub-probabilities of the earth-rock dam using series models, parallel models, and hybrid models respectively; and calculating the failure probability of the earth-rock dam using the following formula:

[0051]

[0052] Among them, P failure|flood(T) represents the failure probability of an earth-rock dam corresponding to the flood recurrence period T. P1 is the failure probability of an earth-rock dam in the series model, P2 is the failure probability of an earth-rock dam in the parallel model, and P3 is the failure probability of an earth-rock dam in the hybrid model. The series model requires multiple events to occur simultaneously for dam failure, for example: P_dam_break = P(flood exceeding standard) × P(structural failure | flood occurrence), which is applicable to overtopping failure (flood exceeding standard is a necessary condition). The parallel model (logical "OR" relationship) allows any independent event to cause dam failure. The hybrid model is for complex scenarios that require a combination of series and parallel models.

[0053] For example, floods exceeding the standard (P A =0.01) → Overlapping failure (P B|A =0.3) → P1 = 0.01 × 0.3 = 0.003. Parallel model: seepage failure (P C =0.001) or earthquake landslide (P D =0.0005) → P2 = 1 - (1 - 0.001)(1 - 0.0005) = 0.0015. Hybrid model: Construction defects (P E =0.005) → triggers seepage (P) F|E =0.4) or crack propagation (P G|E =0.2)→P3=0.005×(0.4+0.2-0.08)=0.0026.

[0054] If each path is independent, the total failure probability is:

[0055]

[0056] S102, calculate the total probability of failure of the earth-rock dam corresponding to different flood return periods based on the annual exceedance probability of floods corresponding to different flood return periods, the failure probability of the earth-rock dam, and the independent probability of seepage failure.

[0057] In one optional embodiment provided in the application, the step of calculating the total earth-rock dam failure probability corresponding to different flood return periods based on the flood annual exceedance probability, the earth-rock dam failure probability, and the independent probability of seepage failure includes:

[0058] The total failure probability of earth-rock dams for different flood return periods is calculated using the following formula:

[0059] Ptotal(T) = AEP(T) × P failure|flood (T)+P seepage -AEP(T)×P failure|flood (T)×P seepage

[0060] Where Ptotal(T) is the total probability of failure of the earth-rock dam corresponding to the flood return period T, AEP(T) is the flood year exceedance probability of the flood return period T, and P failure|tlood (T) represents the probability of earth-rock dam failure corresponding to the flood return period T, which is a conditional probability related to the flood size, P seepage Let T be the independent probability of seepage failure corresponding to the flood recurrence period T, which is a fixed probability independent of the flood.

[0061] S103, calculate the first and second predicted total costs corresponding to different flood return periods based on the total failure probability of the earth-rock dam, engineering cost, direct loss, indirect loss and environmental loss.

[0062] In one optional embodiment provided in the application, the calculation of the first predicted total cost corresponding to different flood return periods, based on the total failure probability of the earth-rock dam, engineering cost, direct losses, indirect losses, and environmental losses corresponding to the different flood return periods, includes:

[0063] The first total forecast cost corresponding to different flood return periods is calculated using the following formula:

[0064]

[0065] Among them, C T1 Let C be the first predicted total cost corresponding to the flood return period T, which is the initial investment in flood control projects (such as raising the dam body and reinforcing the spillway). 工程 For project costs, L 直接 For direct losses, L 间接 As an indirect loss, L 环境 Let Ptotal(T) represent environmental loss, r be the discount rate (reflecting the time value of money, typically 5%–8%), and t represent year t. t Let T be the total probability of failure of the earth-rock dam in year t, corresponding to the flood recurrence period T (considering the effects of engineering aging or climate change).

[0066] Direct losses include casualties and property damage. Casualties are calculated using the Statistical Value of Life (VSL), for example, approximately 3 million yuan per person in China. Property damage is estimated based on the inundation depth-loss rate curve, determining the value of damaged houses, farmland, and infrastructure. Indirect losses include economic disruption and transportation paralysis. Economic disruption uses input-output models (such as IMPLAN) to calculate the regional GDP loss due to work stoppages. Transportation paralysis represents the supply chain delay costs caused by transportation disruptions. For example, a one-month work stoppage might result in a GDP loss of 200 million yuan, while transportation disruptions would result in a loss of 50 million yuan, totaling 250 million yuan in indirect losses. Environmental losses include pollution remediation and ecological restoration. Pollution remediation includes the costs of cleaning up polluted water bodies and remediating soil; ecological restoration includes the costs of rebuilding wetlands and fish habitats.

[0067] In one optional embodiment provided in the application, the step of calculating the second predicted total cost corresponding to different flood return periods based on the total failure probability of the earth-rock dam, engineering cost, direct loss, indirect loss, and environmental loss corresponding to the different flood return periods includes: predicting direct loss factors, indirect loss factors, and environmental loss factors based on historical data of the target area and historical data with the same attributes as the target area; correcting the direct loss, indirect loss, and environmental loss using the direct loss factors, indirect loss, and environmental loss factors; and calculating the second predicted total cost corresponding to different flood return periods based on the corrected direct loss, indirect loss, environmental loss, and total failure probability of the earth-rock dam.

[0068] S104. Based on the first and second predicted total costs corresponding to different flood return periods, the target flood return period is selected from multiple flood return periods as the flood control standard for earth-rock dams.

[0069] like Figure 2 As shown, in one optional embodiment provided in the application, the step of selecting the target flood return period as the flood control standard for the earth-rock dam from multiple flood return periods based on the first predicted total cost and the second predicted total cost corresponding to the different flood return periods includes:

[0070] S1041, the first predicted total cost and the second predicted total cost are weighted and calculated to obtain the final predicted total cost corresponding to different flood return periods.

[0071] The weight values ​​corresponding to the first predicted total cost and the second predicted total cost can be set according to actual needs, or determined according to the accuracy rates corresponding to the first predicted total cost and the second predicted total cost obtained from historical data statistics. The higher the accuracy rate, the greater the corresponding weight value.

[0072] S1042, Based on the final predicted total cost, select the target flood return period from multiple flood return periods as the flood control standard for earth-rock dams.

[0073] Specifically, the step of selecting a target flood return period from multiple flood return periods based on the final predicted total cost as the flood control standard for earth-rock dams includes: for each flood return period, standardizing the data for calculating the flood return period based on its final predicted total cost, total earth-rock dam failure probability, number of people affected in the earth-rock dam area, and environmental losses; weighting the standardized final predicted total cost, total earth-rock dam failure probability, number of people affected in the earth-rock dam area, and environmental losses to obtain a comprehensive score for each flood return period; and selecting the flood return period with the highest comprehensive score as the target flood return period, and determining the target flood return period as the flood control standard for earth-rock dams.

[0074] This embodiment provides a method for determining the flood control standard of earth-rock dams based on dam break risk. First, it obtains the annual flood exceedance probability corresponding to different flood return periods, as well as the dam failure probability and the independent probability of seepage failure. Then, it calculates the total dam failure probability corresponding to different flood return periods based on the annual flood exceedance probability, the dam failure probability, and the independent probability of seepage failure. Next, it calculates the first and second predicted total costs corresponding to different flood return periods using the total dam failure probability, engineering costs, direct losses, indirect losses, and environmental losses. Finally, it selects the target flood return period as the flood control standard for the earth-rock dam based on the first and second predicted total costs corresponding to different flood return periods. Compared to existing technologies with large ranges in flood standard intervals and no unified standard for upper and lower limits, this application calculates the total failure probability of earth-rock dams for different flood return periods based on the annual exceedance probability, failure probability of earth-rock dams, and independent probability of seepage failure corresponding to different flood return periods. This allows for the calculation of the first and second predicted total costs for different flood return periods. By using the first and second predicted total costs, the target flood return period can be selected from multiple flood return periods as the flood control standard for earth-rock dams. Therefore, this application can improve the accuracy of determining the flood control standard for earth-rock dams, thereby benefiting urban flood control engineering construction.

[0075] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0076] In one embodiment, a system for determining flood control standards for earth-rock dams based on dam break risk is provided. For example... Figure 3 As shown, the functional modules of this system for determining flood control standards for earth-rock dams based on dam break risk are described in detail below:

[0077] The acquisition module 31 is used to acquire the annual exceedance probability of floods corresponding to different flood return periods, as well as the failure probability and the independent probability of seepage failure of earth-rock dams.

[0078] Calculation module 32 is used to calculate the total failure probability of earth-rock dam corresponding to different flood return periods based on the annual flood exceedance probability, the failure probability of earth-rock dam, and the independent probability of seepage failure.

[0079] The calculation module 32 is also used to calculate the first predicted total cost and the second predicted total cost corresponding to different flood return periods based on the total failure probability of the earth-rock dam, engineering cost, direct loss, indirect loss and environmental loss corresponding to the different flood return periods.

[0080] Selection module 33 is used to select a target flood return period as the flood control standard for earth-rock dams from multiple flood return periods based on the first predicted total cost and the second predicted total cost corresponding to the different flood return periods.

[0081] In an optional embodiment, the acquisition module 31 is specifically used for:

[0082] The annual flood exceedance probability corresponding to different flood return periods is calculated using the following formula:

[0083]

[0084] Where AEP(T) is the flood year exceedance probability with flood return period T, and Q T Let ξ be the flood discharge at the flood return period T, ξ be the shape parameter, μ be the location parameter, and σ be the scale parameter.

[0085] In an optional embodiment, the acquisition module 31 is specifically used for:

[0086] Calculate the gradient difference between the actual hydraulic gradient and the critical hydraulic gradient;

[0087] If the gradient difference is greater than or equal to 0, then a penetration failure is determined. N sets of parameter samples are randomly generated through Monte Carlo simulation, and the gradient difference of each set of parameter samples is calculated. The independent probability of penetration failure is determined based on the proportion of parameter samples whose gradient difference is greater than or equal to 0.

[0088] In an optional embodiment, the acquisition module 31 is specifically used for:

[0089] The failure sub-probabilities of earth-rock dams were calculated using series, parallel, and hybrid models, respectively.

[0090] The failure probability of an earth-rock dam can be calculated using the following formula:

[0091]

[0092] Among them, P failure|flood (T) The failure probability of earth-rock dams corresponding to the flood recurrence period T, P1 is the failure sub-probability of earth-rock dams in the series model, P2 is the failure sub-probability of earth-rock dams in the parallel model, and P3 is the failure sub-probability of earth-rock dams in the hybrid model.

[0093] In an optional embodiment, the calculation module 32 is specifically used for:

[0094] The total failure probability of earth-rock dams for different flood return periods is calculated using the following formula:

[0095] Ptotal(T) = AEP(T) × P failure|flood (T)+P seepage -AEP(T)×P failure|flood (T)×P seepage

[0096] Where Ptotal(T) is the total probability of failure of the earth-rock dam corresponding to the flood return period T, AEP(T) is the flood year exceedance probability of the flood return period T, and P failure|flood (T) represents the failure probability of the earth-rock dam corresponding to the flood return period T, P seepage Let T be the independent probability of seepage failure corresponding to the flood recurrence period T.

[0097] In an optional embodiment, the calculation module 32 is specifically used for:

[0098] The first total forecast cost corresponding to different flood return periods is calculated using the following formula:

[0099]

[0100] Among them, C T1 C represents the first predicted total cost corresponding to the flood recurrence interval T. 工程 For project costs, L 直接 For direct losses, L 间接 As an indirect loss, L 环境 Let Ptotal(T) represent environmental loss, r be the discount rate, and t represent year t. t Let T be the total probability of failure of the earth-rock dam in year t, corresponding to the flood recurrence period T.

[0101] In an optional embodiment, the calculation module 32 is specifically used for:

[0102] Based on historical data of the target area and historical data with the same attributes as the target area, the direct loss factor, indirect loss factor and environmental loss factor are predicted.

[0103] The direct loss, indirect loss, and environmental loss are corrected by direct loss factor, indirect loss factor, and environmental loss factor;

[0104] The second predicted total cost is calculated based on the corrected direct losses, indirect losses, environmental losses, and total earth-rock dam failure probability for different flood return periods.

[0105] In an optional embodiment, module 33 is selected, specifically for:

[0106] The first predicted total cost and the second predicted total cost are weighted and calculated to obtain the final predicted total cost corresponding to different flood return periods.

[0107] Based on the final predicted total cost, the target flood recurrence period is selected from multiple flood recurrence periods as the flood control standard for earth-rock dams.

[0108] In an optional embodiment, module 33 is selected, specifically for:

[0109] For each flood recurrence period, data standardization is performed to calculate the flood recurrence period for its final predicted total cost, total probability of earth-rock dam failure, number of people affected by earth-rock dam area, and environmental losses.

[0110] The final predicted total cost, total probability of earth-rock dam failure, number of people affected by earth-rock dam area, and environmental loss are weighted and calculated to obtain a comprehensive score for each flood return period.

[0111] The flood recurrence period with the highest comprehensive score is taken as the target flood recurrence period, and the target flood recurrence period is determined as the flood control standard for earth-rock dams.

[0112] It should be noted that the above detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0113] Specific limitations regarding the system for determining flood control standards for earth-rock dams based on dam break risk can be found in the limitations of the method for determining flood control standards for earth-rock dams based on dam break risk described above, and will not be repeated here. Each module in the aforementioned equipment can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in the computer device in hardware form, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0114] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above.

[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for determining flood control standards for earth-rock dams based on dam break risk, characterized in that, The method includes: Obtain the annual flood exceedance probability corresponding to different flood return periods, and obtain the failure probability and independent probability of seepage failure of earth-rock dams; The total probability of failure of earth-rock dams corresponding to different flood return periods is calculated based on the annual flood exceedance probability, the failure probability of earth-rock dams, and the independent probability of seepage failure. The first and second predicted total costs corresponding to different flood return periods are calculated based on the total failure probability of earth-rock dams, engineering costs, direct losses, indirect losses, and environmental losses. The first total forecast cost corresponding to different flood return periods is calculated using the following formula: ； in, Let T be the first predicted total cost corresponding to the flood recurrence period T, which represents the initial investment in the flood control project. For project costs, For direct losses, As an indirect loss, For environmental damage, The discount rate is given, and t represents year t. Let T be the total probability of failure of the earth-rock dam in year t, corresponding to the flood recurrence period T. Calculating the second predicted total cost includes: The direct loss factor, indirect loss factor, and environmental loss factor are predicted based on historical data of the target area and historical data with the same attributes as the target area. The direct loss, indirect loss, and environmental loss are corrected by direct loss factor, indirect loss factor, and environmental loss factor; The second predicted total cost corresponding to different flood return periods is calculated based on the corrected direct losses, indirect losses, environmental losses, and total probability of failure of the earth-rock dam. Based on the first predicted total cost and the second predicted total cost corresponding to different flood return periods, the target flood return period is selected from multiple flood return periods as the flood control standard for the earth-rock dam. The annual flood exceedance probability corresponding to different flood return periods is calculated using the following formula: ； in, Let T be the flood year exceedance probability. Let T be the flood discharge during the flood recurrence interval. For shape parameters, For position parameters, For scale parameters; The process of obtaining the independent probability of penetration and destruction includes: Calculate the gradient difference between the actual hydraulic gradient and the critical hydraulic gradient; If the gradient difference is greater than or equal to 0, then a penetration failure is determined. N sets of parameter samples are randomly generated through Monte Carlo simulation, and the gradient difference of each set of parameter samples is calculated. The independent probability of penetration failure is determined based on the proportion of parameter samples whose gradient difference is greater than or equal to 0.

2. The method according to claim 1, characterized in that, The acquisition of the failure probability of the earth-rock dam includes: The failure sub-probabilities of earth-rock dams were calculated using series, parallel, and hybrid models, respectively. Calculate the failure probability of an earth-rock dam using the following formula: ； in, The probability of failure of an earth-rock dam corresponding to the flood recurrence period T. This represents the failure subprobability of an earth-rock dam in a series model. For the failure subprobability of earth-rock dam in the parallel model, The failure subprobabilities of earth-rock dams are given by the hybrid model; the cascade model is as follows: Dam collapse = (Flood exceeding standard) × (Structural failure | Flood occurrence) is applicable to overtopping failure; the parallel model is for dam failure caused by any independent event; the hybrid model is for complex scenarios that require a combination of series and parallel connections.

3. The method according to claim 2, characterized in that, The calculation of the total earth-rock dam failure probability corresponding to different flood return periods, based on the annual flood exceedance probability, the earth-rock dam failure probability, and the independent probability of seepage failure, includes: The total failure probability of earth-rock dams for different flood return periods is calculated using the following formula: 。 4. The method according to claim 3, characterized in that, The step of selecting the target flood return period as the flood control standard for earth-rock dams from multiple flood return periods based on the first predicted total cost and the second predicted total cost corresponding to the different flood return periods includes: The first predicted total cost and the second predicted total cost are weighted and calculated to obtain the final predicted total cost corresponding to different flood return periods. Based on the final predicted total cost, the target flood recurrence period is selected from multiple flood recurrence periods as the flood control standard for earth-rock dams.

5. The method according to claim 4, characterized in that, The step of selecting the target flood return period as the flood control standard for earth-rock dams from multiple flood return periods based on the final predicted total cost includes: For each flood recurrence period, the data for calculating the flood recurrence period are standardized to include the final predicted total cost, the total probability of earth-rock dam failure, the number of people affected by the earth-rock dam area, and environmental losses. The final predicted total cost, total probability of earth-rock dam failure, number of people affected by earth-rock dam area, and environmental loss are weighted and calculated to obtain a comprehensive score for each flood return period. The flood recurrence period with the highest comprehensive score is taken as the target flood recurrence period, and the target flood recurrence period is determined as the flood control standard for earth-rock dams.

6. A system for determining flood control standards for earth-rock dams based on dam break risk, characterized in that, The system, employing the method as described in any one of claims 1-5, comprises: The acquisition module is used to obtain the annual exceedance probability of floods corresponding to different flood return periods, as well as the independent probability of failure of earth-rock dams and seepage failure. The calculation module is used to calculate the total failure probability of the earth-rock dam corresponding to different flood return periods based on the annual flood exceedance probability, the failure probability of the earth-rock dam, and the independent probability of seepage failure. The calculation module is also used to calculate the first predicted total cost and the second predicted total cost corresponding to different flood return periods based on the total failure probability of earth-rock dams, engineering costs, direct losses, indirect losses and environmental losses corresponding to the different flood return periods. The selection module is used to select a target flood return period as the flood control standard for earth-rock dams from multiple flood return periods based on the first predicted total cost and the second predicted total cost corresponding to the different flood return periods.

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