A waterlogging risk zoning updating method and system based on rainfall comparability

Abstract

The application relates to the technical field of risk management, and discloses a waterlogging risk zoning updating method and system based on rainfall comparability, which comprises the following steps: collecting waterlogging event account, hourly precipitation data and risk zoning standard parameters of a target waterlogging-prone point, obtaining historical rain intensity characteristics of a historical waterlogging-causing process and exposure rain intensity characteristics of a subsequent non-waterlogging process through space-time matching; when the maximum one-hour rain intensity of the subsequent non-waterlogging process is higher than that of the historical waterlogging-causing process, a response reversal event group is established, and rainfall comparability conditions are judged according to the maximum one-hour rain intensity, continuous period rainfall and peak concentration degree. When the conditions are met and the comparable exceeding times reach a preset number, the historical waterlogging-causing process is marked as a dormant waterlogging-causing process, and the risk zoning standard parameters are updated. When the subsequent low-intensity rain causes waterlogging again, the dormant waterlogging-causing process and the risk zoning standard parameters are restored. The application improves the stability and applicability of dynamic revision of the annual standard of urban rainstorm waterlogging meteorological risk grade.

Description

Technical Field

[0001] This invention relates to the field of risk management technology, and more specifically, to a method and system for updating waterlogging risk zones based on rainfall comparability. Background Technology

[0002] With the expansion of urban built-up areas and the increase in short-duration heavy rainfall events, the impact of urban rainstorm flooding on road traffic, underground space safety, and urban flood control scheduling is becoming increasingly prominent. Urban rainstorm flooding meteorological risk early warning requires the correlation and processing of hourly precipitation data, historical flooding records, and risk zoning of flood-prone areas. This allows meteorological departments to generate zoning and standardized risk parameters based on historical flooding responses of flood-prone areas without relying on complete underground pipe network data and hydrodynamic models. This provides data support for short-term precipitation forecasting, urban flood control duty, and inter-departmental coordinated response. Therefore, how to continuously update the standard parameters for flood-prone area risk zoning is a crucial technical aspect of the practical application of urban rainstorm flooding meteorological risk level standards.

[0003] In the prior art, Chinese invention patent application CN119398487A discloses a method and system for calculating urban flood risk warning thresholds based on multi-source data analysis. This method acquires information on building heights, drainage facilities, elevation model data, and satellite imagery around the target flood-prone area, analyzes runoff paths and catchment areas, and calculates the rainfall-water accumulation relationship of the target flood-prone area to obtain personalized rainfall warning thresholds. While this approach can improve the precision of initial warning thresholds, it still faces challenges in maintaining a stable connection between newly added flood-prone records and existing risk zoning results when updating annual risk zoning standards for meteorological departments. Furthermore, when subsequent observations of the same flood-prone point differ from early flood-causing records, maintaining early records for an extended period can lead to overly conservative risk zoning, while directly adopting subsequent non-flood-prone results may prematurely broaden risk zoning, thus affecting the accuracy of dynamic revisions to urban rainstorm and flood meteorological risk level standards.

[0004] Therefore, it is necessary to design a waterlogging risk zoning update method and system based on rainfall comparability to solve the problems existing in the current technology. Summary of the Invention

[0005] In view of this, the present invention proposes a method and system for updating waterlogging risk zones based on rainfall comparability, aiming to solve the problem that it is difficult to accurately update the standard parameters of risk zones when there is an inconsistency between the historical waterlogging records and subsequent non-waterlogging records of waterlogged areas.

[0006] This invention proposes a method for updating waterlogging risk zoning based on rainfall comparability, comprising: Collect records of waterlogging events, hourly precipitation data, and risk zoning standard parameters for target flood-prone areas; Spatiotemporal matching is performed on the flood event ledger and the hourly precipitation data to obtain the historical rainfall intensity characteristics of historical flood-causing processes and the exposure rainfall intensity characteristics of subsequent non-flooding processes. The subsequent non-flooding processes are the rainfall processes that complete the regional flood summary and do not record flooding at the target flood-prone points. When the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics, a response reversal event group is established; The response reversal event group is judged to meet the rainfall comparability condition based on the maximum hourly rainfall intensity, continuous period rainfall, and peak concentration. When the rainfall comparability conditions are met and the number of comparable exceedances reaches a preset number, the historical flood-causing process is marked as a dormant flood-causing process, and the risk zoning standard parameters are updated according to the remaining effective flood-causing processes. When a flood-prone area experiences another flood-causing process with a maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary, the dormant flood-causing process will be restored as an effective flood-causing process, and the risk zone standard parameters will be restored.

[0007] Furthermore, the determination of the subsequent non-flooding process includes: Obtain a summary of regional waterlogging results after the rainfall event ends; When the regional waterlogging summary results cover the area where the target waterlogging point is located, and the regional waterlogging summary results do not record waterlogging at the target waterlogging point, the rainfall process is determined as a subsequent non-waterlogging process; When the aggregated results of regional waterlogging do not cover the area where the target flood-prone point is located, the rainfall process shall not be identified as a subsequent non-flooding process.

[0008] Furthermore, the formation of the historical rainfall intensity characteristics and the exposed rainfall intensity characteristics includes: The maximum hourly rainfall intensity was extracted from both the historical flood-causing process and the subsequent non-flooding process. Extract the rainfall data for consecutive time periods that contain the period with the maximum hourly rainfall intensity; The peak concentration is determined by the proportion of the maximum hourly rainfall intensity in the total rainfall over a continuous period.

[0009] Furthermore, the comparable rainfall conditions include: The maximum hourly rainfall intensity in the exposed rainfall intensity characteristics exceeds the maximum hourly rainfall intensity in the historical rainfall intensity characteristics by a preset exceedance amount; The continuous period rainfall in the exposed rainfall intensity characteristics is not less than the continuous period rainfall in the historical rainfall intensity characteristics; The absolute value of the difference between the peak concentration in the exposed rainfall intensity characteristics and the peak concentration in the historical rainfall intensity characteristics does not exceed the concentration threshold.

[0010] Furthermore, when the response reversal event group does not meet the rainfall comparability condition, the response reversal event group is identified as the surface reversal event group, the risk zoning standard parameters are maintained, and the cumulative number of comparable exceedances is prohibited.

[0011] Furthermore, the cumulative number of comparable surpassing times includes: The number of comparable exceedances is increased by one only if the response reversal event group satisfies the rainfall comparability condition; When a new flood-causing process occurs at the target flood-prone point between two adjacent response reversal event groups that meet the rainfall comparability conditions, the accumulated comparability exceedance counts are cleared.

[0012] Furthermore, updating the risk zoning standard parameters includes: When the number of comparable exceedances reaches a preset number, a point flooding rainfall intensity threshold is formed based on the remaining effective flooding process. When the flood-causing rainfall intensity threshold of the location falls within the range of an adjacent lower-risk zone, the risk level of the target flood-prone location is reduced by one level; when the flood-causing rainfall intensity threshold of the location does not fall within the range of an adjacent lower-risk zone, the current risk zone of the target flood-prone location is maintained.

[0013] Furthermore, the formation of the dormant flooding process includes: Historical flood-causing processes that maintain the target flood-prone area's risk zone before it is reduced are selected from the effective flood-causing processes as dormant processes; The process to be dormant is labeled as a dormant flood-inducing process; When the threshold for rainfall intensity causing flooding at a given location is established, the dormant flooding process is excluded, while the event record of the dormant flooding process is retained.

[0014] Furthermore, the recovery of the risk zoning standard parameters includes: When a flood-prone area experiences another flood-causing process with a maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary, the dormant flood-causing process will be restored as an effective flood-causing process. The flood-causing rainfall intensity thresholds at specific locations were re-established based on the effective flood-causing process after recovery. The risk zoning standard parameters are restored based on the newly formed point-induced flooding rainfall intensity threshold, and the comparable exceedance times of the target flood-prone points are removed.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: When a response reversal occurs between a historical flood-causing process and a subsequent non-flooding process, characterized by "flooding due to lower rainfall intensity and non-flooding due to higher rainfall intensity," the comparability of the two rainfall processes is determined by jointly considering the maximum hourly rainfall intensity, continuous rainfall, and peak concentration. This avoids mistaking short-term high-peak but insufficiently sustained non-flooding rainfall as a sign that the risk has been reduced. After the rainfall comparability conditions are met and the number of comparable exceedances reaches a preset number, the historical flood-causing process is marked as a dormant flood-causing process, and the risk zoning standard parameters are updated based on the remaining effective flood-causing processes. This ensures that early sporadic flood-causing records or those no longer reflecting the current location status do not control the risk zoning for a long time. At the same time, when the target flood-prone point subsequently experiences flooding again under rainfall intensity conditions lower than the updated risk zoning lower limit boundary, the dormant flood-causing process can be restored as an effective flood-causing process, and the risk zoning standard parameters can be restored. This forms a two-way update mechanism of "release after comparability and restoration after flooding." Compared to the method of using historical low rainfall and heavy flooding records in the long term, it can reduce the overly conservative risk zoning; compared to the method of directly adopting subsequent non-flooding results to reduce risk zoning, it can reduce the probability of misjudgment due to premature relaxation of risk zoning. Thus, without relying on complete underground pipe network data, hydrodynamic models and complex terrain simulation, it can improve the stability and applicability of the annual dynamic revision of the urban rainstorm and waterlogging meteorological risk level standard.

[0016] On the other hand, this application also provides a waterlogging risk zoning update system based on rainfall comparability, used to apply the above-mentioned waterlogging risk zoning update method based on rainfall comparability, including: The data acquisition module is used to collect records of waterlogging events, hourly precipitation data, and risk zoning standard parameters for target flood-prone areas; The spatiotemporal matching module is used to perform spatiotemporal matching between the flooding event ledger and the hourly precipitation data to obtain the historical rainfall intensity characteristics of historical flooding events and the exposure rainfall intensity characteristics of subsequent non-flooding events; The event group establishment module is used to establish a response reversal event group when the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics. The comparability judgment module is used to determine whether the response reversal event group meets the rainfall comparability conditions based on the maximum hourly rainfall intensity, continuous period rainfall, and peak concentration. The zoning update module is used to mark the historical flooding process as a dormant flooding process when the rainfall comparability conditions are met and the number of comparable exceedances reaches a preset number, and to update the risk zoning standard parameters according to the remaining effective flooding processes. The zone recovery module is used to restore the dormant flooding process into an effective flooding process and restore the standard parameters of the risk zone when a flooding process occurs again at the target flood-prone point with the maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary.

[0017] It is understandable that the above-mentioned waterlogging risk zoning update method and system based on rainfall comparability have the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0018] The accompanying drawings are used to illustrate the technical solutions of the present invention and do not constitute a limitation on the scope of protection of the present invention. The process nodes, regional relationships, and functional block diagrams in the drawings are used to illustrate the implementation methods of the embodiments of the present invention. In the drawings: Figure 1 A flowchart illustrating the waterlogging risk zoning update method based on rainfall comparability provided in this embodiment of the invention; Figure 2 This is a flowchart for determining the comparability of rainfall in response reversal event groups provided in an embodiment of the present invention; Figure 3 A flowchart for screening subsequent non-flooding processes and forming rainfall intensity characteristics provided in this embodiment of the invention; Figure 4 This is a schematic diagram of the risk partitioning standard parameter version record provided in an embodiment of the present invention; Figure 5 A functional block diagram of a waterlogging risk zoning update system based on rainfall comparability provided in an embodiment of the present invention. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described with reference to the accompanying drawings. These embodiments are used to illustrate the technical solutions of the present invention and do not limit the scope of protection of the present invention. Unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] In some embodiments of this application, see Figure 1-3 As shown, this application proposes a method for updating waterlogging risk zoning based on rainfall comparability, including: S100: Collect the waterlogging event log, hourly precipitation data, and risk zoning standard parameters for the target flood-prone areas.

[0021] S200: Spatiotemporal matching of waterlogging event ledgers and hourly precipitation data to obtain historical rainfall intensity characteristics of historical waterlogging events and exposure rainfall intensity characteristics of subsequent non-waterlogging events. Subsequent non-waterlogging events are rainfall events that complete the regional waterlogging summary but do not record waterlogging at target waterlogging-prone points.

[0022] S300: When the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics, establish a response reversal event group.

[0023] S400: Determine whether the response reversal event group meets the rainfall comparability condition based on the maximum hourly rainfall intensity, continuous period rainfall, and peak concentration.

[0024] S500: When the rainfall comparability conditions are met and the number of comparable exceedances reaches the preset number, the historical flood-causing process is marked as a dormant flood-causing process, and the risk zoning standard parameters are updated according to the remaining effective flood-causing processes.

[0025] S600: When a flood-prone area experiences another flood-causing process with a maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary, the dormant flood-causing process will be restored as an effective flood-causing process, and the risk zone standard parameters will be restored.

[0026] In some embodiments of this application, a waterlogging risk zoning update method based on rainfall comparability is used for the annual assessment, dynamic revision, and short-term warning operational parameter update of urban rainstorm waterlogging meteorological risk level standards. Target waterlogging-prone points are fixed waterlogging points included in the urban rainstorm waterlogging meteorological risk level standards management. The waterlogging event ledger includes the target waterlogging-prone point name, target waterlogging-prone point location, waterlogging start time, water receding time, waterlogging depth, waterlogging duration, and waterlogging level. Hourly precipitation data includes hourly precipitation associated with the target waterlogging-prone point location; preferably, the hourly precipitation data is urban-scale hourly precipitation fusion data, but it can also be hourly precipitation data from nearby rain gauges. Risk zoning standard parameters include the current risk zoning of the target waterlogging-prone point, risk zoning boundary, zoning rainfall intensity threshold, effective waterlogging processes, dormant waterlogging processes, and comparable exceedance counts. Effective waterlogging processes are used to participate in the formation of the current location's waterlogging rainfall intensity threshold. Dormant waterlogging processes retain event records but do not participate in the formation of the current location's waterlogging rainfall intensity threshold.

[0027] During implementation, flood event logs, hourly precipitation data, and risk zoning standard parameters are collected for target flood-prone areas. When performing spatiotemporal matching of the flood event logs and hourly precipitation data, associated precipitation grid points or associated rain gauges are selected based on the location of the target flood-prone area, and rainfall intensity features are extracted based on the flood start time, receding time, and rainfall duration. For historical flooding events, the retrieval range is the rainfall sequence from a preset duration before the flood start time to the receding time. The preset duration is preferably 1 to 3 hours to cover situations where flood records lag behind the rainfall peak. For subsequent rainfall events, the retrieval range is the rainfall sequence from the rainfall start time to the rainfall end time, and the results of regional flooding aggregation are combined to determine whether the target flood-prone area has a flood record.

[0028] In some embodiments of this application, the rainfall start time and rainfall end time are determined based on hourly precipitation data. The first time period in which the hourly precipitation reaches the process-based starting rainfall is designated as the rainfall start candidate period. After the rainfall start candidate period, if the hourly precipitation is consistently lower than the process-separated rainfall for a consecutive preset interval, the last effective precipitation period before falling below the process-separated rainfall is designated as the rainfall end period. The process-based starting rainfall and the process-separated rainfall are preferably both between 0.5 mm / h and 2 mm / h, and the preset interval is preferably between 1 hour and 3 hours. Within the same annual evaluation version, the process-based starting rainfall, the process-separated rainfall, and the preset interval remain consistent.

[0029] In some embodiments of this application, the subsequent non-flooding process is not determined solely by the absence of the target flood-prone point in the logbook. Instead, the regional waterlogging summary results are obtained after the rainfall event. When the regional waterlogging summary results cover the area where the target flood-prone point is located, and the regional waterlogging summary results do not record waterlogging at the target flood-prone point, the rainfall event is determined as the subsequent non-flooding process. When the regional waterlogging summary results do not cover the area where the target flood-prone point is located, the rainfall event is prohibited from being determined as the subsequent non-flooding process. Through the above processing, the two situations of "the target flood-prone point did not experience waterlogging" and "the target flood-prone point was not reported or was not summarized" can be distinguished, avoiding the misjudgment of missing information as a non-flooding fact.

[0030] In some embodiments of this application, the regional waterlogging summary result covering the area where the target waterlogging-prone point is located refers to the summary of waterlogging information after the administrative district, street management area, drainage responsibility area, or preset business grid where the target waterlogging-prone point is located has completed the rainfall process. The regional waterlogging summary result can be a summary ledger containing a list of waterlogging points, or it can be an inspection record containing both waterlogging points and non-waterlogging verification points. When the regional waterlogging summary result only covers areas other than the area where the target waterlogging-prone point is located, or when it cannot be confirmed whether the waterlogging information summary has been completed in the area where the target waterlogging-prone point is located, the rainfall process is not considered as a subsequent non-waterlogging process in the risk zoning reduction judgment.

[0031] In some embodiments of this application, both historical rainfall intensity characteristics and exposed rainfall intensity characteristics include maximum hourly rainfall intensity, continuous period rainfall, and peak concentration. Maximum hourly rainfall intensity is used to characterize the peak rainfall intensity. Continuous period rainfall is used to characterize the duration of the rainfall event, preferably using the cumulative rainfall over three consecutive hours that includes the period containing the maximum hourly rainfall intensity. Peak concentration is formed by the proportion of the maximum hourly rainfall intensity in the continuous period rainfall, and is used to characterize whether the rainfall peak is excessively concentrated in a single hour. If the rainfall event is shorter than three consecutive hours, the continuous period rainfall with valid records within the complete rainfall event is used, and the adopted period length is recorded in the risk zoning standard parameter version.

[0032] In some embodiments of this application, a response reversal event group is established when the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics. The response reversal event group indicates that the same target flood-prone point exhibits opposite response results: "historically lower rainfall intensity caused flooding, subsequent higher rainfall intensity did not cause flooding." After establishing the response reversal event group, the risk zoning of the target flood-prone point is not directly reduced; instead, it is further determined whether the historical flooding process and the subsequent non-flooding process meet the rainfall comparability conditions. The rainfall comparability conditions include: the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics by a preset exceedance amount; the continuous period rainfall in the exposed rainfall intensity characteristics is not lower than the continuous period rainfall in the historical rainfall intensity characteristics; and the absolute value of the difference between the peak concentration degree in the exposed rainfall intensity characteristics and the peak concentration degree in the historical rainfall intensity characteristics does not exceed the concentration threshold.

[0033] In some embodiments of this application, a preset exceedance is used to exclude misjudgments caused by minor differences in rainfall, preferably 5 mm / h to 10 mm / h, but can also be determined based on the distance between adjacent risk zone boundaries, for example, 10% to 20% of the distance between adjacent risk zone boundaries. A concentration threshold is used to determine whether the peak distributions of two rainfall events are similar, preferably 0.10 to 0.15, but can also be determined based on back-calculation of local historical flooding events. During back-calculation, the difference in peak concentration between similar flooding events within the same risk zone is statistically analyzed, and the quantile value that can cover the main similar events is selected as the concentration threshold, which remains unchanged within the same annual assessment version.

[0034] In some embodiments of this application, the updated risk zone lower limit boundary refers to the lower boundary value of the updated risk zone in terms of the point-induced flooding rainfall intensity threshold. For example, when risk zones are divided into high-risk, medium-risk, and low-risk zones according to the point-induced flooding rainfall intensity threshold from low to high, the lower limit boundary of the medium-risk zone is the boundary value of the medium-risk zone closer to the high-risk zone. If, after the risk zone of a target flood-prone point is reduced, a flooding process occurs again with a maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary, it indicates that the target flood-prone point still experiences waterlogging under rainfall intensity lower than the updated risk zone admission criteria, thus triggering the recovery of the dormant flooding process.

[0035] See Figure 4As shown in some embodiments of this application, the risk zoning standard parameter version record table is used to record the risk zoning changes of target flood-prone points in different updated versions, response reversal judgment results, dormant flood-causing process status, and recovery triggering status. The risk zoning standard parameter version record table includes version number, target flood-prone point number, target flood-prone point name, current risk zoning, risk zoning before update, risk zoning after update, historical flood-causing process number, subsequent non-flooding process number, response reversal event group number, rainfall comparability judgment result, comparability exceedance count, dormant flood-causing process number, dormant flood-causing process status, recovery triggering event number, version update time, and remarks. Figure 4 The example expression for the name of the target flood-prone point is "XX Road Elevated East Section". It is used to illustrate that the target flood-prone point can be named using roads, underpasses, culverts, subway entrances or other fixed water accumulation locations. The example expression does not limit the actual location type of the target flood-prone point.

[0036] Specifically, the historical flood-causing process number in the risk zoning standard parameter version record table is used to identify flood-causing processes that have already caused flooding and participated in the risk zoning calculation. The subsequent non-flooding process number is used to identify rainfall processes that have completed the regional flooding summary but have not recorded flooding at the target flood-prone point. The response reversal event group number is used to identify event groups established by historical flood-causing processes and subsequent non-flooding processes. The rainfall comparability judgment result is used to distinguish between surface reversal and comparable exceedance. When the rainfall comparability judgment result is surface reversal, the risk zoning standard parameters are maintained, and the number of comparable exceedances is not accumulated. When the rainfall comparability judgment result is comparable exceedance, the number of comparable exceedances is accumulated. After the number of comparable exceedances reaches a preset number, the corresponding historical flood-causing process is marked as a dormant flood-causing process, and the risk zoning standard parameters are updated according to the remaining effective flood-causing processes. When a flood-causing process with a maximum hourly rainfall intensity lower than the updated risk zoning lower limit occurs again at the target flood-prone point, the dormant flood-causing process is restored as an effective flood-causing process, and the risk zoning standard parameters are restored.

[0037] pass Figure 4 The risk zoning standard parameter version record table shown can link each process of risk zoning reduction, maintenance, and recovery with specific historical flood-causing processes, subsequent flood-free processes, and response reversal event groups. This ensures that the dynamic updating process of risk zoning standard parameters has a clear data source and a record of status changes. This recording method avoids the problem of only providing the final risk zoning without being able to trace the basis for updates, and facilitates the identification of the reasons for changes in the risk zoning of target flood-prone areas during annual assessments, reviews, and short-term early warning operations.

[0038] In one specific embodiment, the historical flooding event at the target flood-prone area was a single, continuous rainfall event. The maximum hourly rainfall intensity of the historical flooding event was 36 mm / h, the cumulative rainfall over three hours was 82 mm, and the peak concentration was 0.44. The subsequent first rainfall event completed the regional waterlogging summary but did not record waterlogging at the target flood-prone area. The maximum hourly rainfall intensity of the subsequent first rainfall event was 48 mm / h, the cumulative rainfall over three hours was 61 mm, and the peak concentration was 0.79. Although the maximum hourly rainfall intensity of the subsequent first rainfall event was higher than that of the historical flooding event, the cumulative rainfall over three hours of the subsequent first rainfall event was lower than that of the historical flooding event, and the difference in peak concentration exceeded the concentration threshold. Therefore, the response reversal event group was identified as the surface reversal event group, the risk zoning standard parameters were maintained, and the cumulative comparable exceedance was prohibited. Through this processing, the result of no waterlogging under short-term isolated heavy rainfall can be avoided from mistakenly believing that the risk of the target flood-prone area has decreased.

[0039] In another specific embodiment, the subsequent second rainfall process completes the regional waterlogging summary but does not record waterlogging at the target waterlogged point. The maximum hourly rainfall intensity of the subsequent second rainfall process is 51 mm / h, the cumulative rainfall over three consecutive hours is 88 mm, and the peak concentration is 0.58. If the preset exceedance is 5 mm / h and the concentration threshold is 0.15, then the subsequent second rainfall process meets the maximum hourly rainfall intensity exceedance condition relative to the historical waterlogging process, the cumulative rainfall over three consecutive hours is not lower than the historical waterlogging process, and the difference in peak concentration does not exceed the concentration threshold. Therefore, the subsequent second rainfall process is determined as a comparable exceedance exposure process, and the comparable exceedance number of the target waterlogged point is increased by one. If the target waterlogged point experiences a preset number of comparable exceedance exposure processes consecutively, and no new waterlogging process occurs between adjacent comparable exceedance exposure processes, then it is determined that the control effect of the early historical waterlogging process on the current risk zone needs to be released. The preset number is preferably 2 or 3 times. An effective subsequent rainfall process is a subsequent rainfall process that completes the regional waterlogging summary result and can extract the exposure rainfall intensity characteristics. When the number of effective subsequent rainfall events in the target flood-prone area within an annual assessment period is less than 30, 3 events are preferred. When the number of effective subsequent rainfall events in the target flood-prone area within an annual assessment period is not less than 30, and the coverage rate of the regional waterlogging summary results is not less than 90%, 2 events are preferred. The coverage rate of the regional waterlogging summary results is the proportion of subsequent rainfall events for which regional waterlogging summaries have been completed to the total number of subsequent rainfall events.

[0040] In some embodiments of this application, when the number of comparable exceedances reaches a preset number, historical flooding processes that keep the target flood-prone point in the pre-reduction risk zone are selected from the effective flooding processes as dormant processes, and these dormant processes are marked as dormant flooding processes. The selection criteria for dormant processes are: if the historical flooding process continues to be an effective flooding process, the target flood-prone point will still fall within the pre-reduction risk zone. If the historical flooding process is excluded, the point flooding rainfall intensity threshold formed based on the remaining effective flooding processes can fall within the range of the adjacent lower risk zone. Dormant flooding processes do not participate in the formation of point flooding rainfall intensity thresholds, but retain the event number, occurrence time, rainfall intensity characteristics, water depth, water accumulation duration, dormancy time, and the number of the comparable exceedance exposure process that triggered the dormancy.

[0041] In some embodiments of this application, when forming the point-based flood-inducing rainfall intensity threshold based on the remaining effective flood-inducing processes, the minimum and maximum one-hour rainfall intensity within the remaining effective flood-inducing processes are preferentially adopted. When there are no remaining effective flood-inducing processes, the target flood-prone point is not allowed to cross more than two risk levels. The target flood-prone point is reduced to at most the adjacent lower risk zone, and the lower limit boundary of the adjacent lower risk zone is used as the temporary point-based flood-inducing rainfall intensity threshold until a new effective flood-inducing process or a new comparable surpassing exposure process occurs. Through the above restrictions, the risk zone of the target flood-prone point can be excessively reduced due to a small number of non-flooding processes.

[0042] In some embodiments of this application, after the risk zoning standard parameters are updated, if a flood-causing process occurs again at the target flood-prone point with a maximum hourly rainfall intensity lower than the updated risk zoning lower limit boundary, it indicates that the parameters after risk reduction are inconsistent with the new flood-causing facts. In this case, the dormant flood-causing process is restored as an effective flood-causing process. The point-causing rainfall intensity threshold is reconstructed based on the restored effective flood-causing process, and the risk zoning standard parameters are restored based on the reconstructed point-causing rainfall intensity threshold. Simultaneously, the comparable exceedance counts of the target flood-prone point are cleared. If multiple dormant flood-causing processes exist, the dormant flood-causing process that is closer to the new flood-causing process in terms of rainfall intensity range and peak concentration is prioritized for restoration. If multiple dormant flood-causing processes meet the restoration conditions, all are restored as effective flood-causing processes.

[0043] In some embodiments of this application, a risk zoning standard parameter version record table can be set. The risk zoning standard parameter version record table includes at least the target flood-prone point number, the risk zoning before the update, the risk zoning after the update, the historical flood-causing process number, the subsequent non-flood-causing process number, the response reversal event group number, the rainfall comparability judgment result, the number of comparable exceedances, the dormant flood-causing process status, the recovery trigger event, and the version update time. The risk zoning standard parameter version record table is used to record the basis for each risk zoning standard parameter update, ensuring that the reduction, maintenance, and recovery of risk zoning all have traceable event evidence.

[0044] This embodiment does not simply reduce the risk zoning of target flood-prone areas based on subsequent non-flooding events. Instead, it places subsequent non-flooding events and historical flood-causing events into the same response reversal event group for rainfall comparability assessment. By combining constraints of maximum hourly rainfall intensity, continuous rainfall, and peak concentration, this embodiment can distinguish between "stronger rainfall of the same type without flooding" and "surface non-flooding caused by short-term high peaks but insufficient persistence," thus preventing the risk zoning from being prematurely broadened due to a single non-flooding event. Simultaneously, through dormant flood-causing processes and recovery mechanisms, this embodiment avoids early low-intensity flood-causing events permanently controlling the risk zoning of target flood-prone areas. Compared to risk zoning methods that rely solely on historical minimum flood-causing rainfall intensity, this embodiment can enable controlled bidirectional adjustment of risk zoning standard parameters without increasing underground pipe network models and hydrodynamic simulation data, improving the stability of annual dynamic revisions.

[0045] Based on another preferred embodiment described above, see [link to preferred embodiment]. Figure 5 As shown, this embodiment provides a waterlogging risk zoning update system based on rainfall comparability, used to apply the above-described waterlogging risk zoning update method based on rainfall comparability, including: The data acquisition module is used to collect records of waterlogging events, hourly precipitation data, and risk zoning standard parameters for target flood-prone areas.

[0046] The spatiotemporal matching module is used to perform spatiotemporal matching on the flood event ledger and hourly precipitation data to obtain the historical rainfall intensity characteristics of historical flood-causing processes and the exposure rainfall intensity characteristics of subsequent non-flood-causing processes.

[0047] The event group creation module is used to create a response reversal event group when the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics.

[0048] The comparability judgment module is used to determine whether the response reversal event group meets the rainfall comparability conditions based on the maximum hourly rainfall intensity, continuous period rainfall, and peak concentration.

[0049] The zoning update module is used to mark historical flooding processes as dormant flooding processes when the rainfall comparability conditions are met and the number of comparable exceedances reaches a preset number, and to update the risk zoning standard parameters based on the remaining effective flooding processes.

[0050] The zone recovery module is used to restore a dormant flooding process into an effective flooding process and restore the standard parameters of the risk zone when a flooding process occurs again at a target flood-prone point with a maximum hourly rainfall intensity lower than the updated lower limit boundary of the risk zone.

[0051] When the above system executes the aforementioned method, it can achieve the same technical effect as the aforementioned method.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for updating waterlogging risk zones based on rainfall comparability, characterized in that, include: Collect flood event logs, hourly precipitation data, and risk zoning standard parameters for target flood-prone areas; Spatiotemporal matching is performed on the flood event ledger and the hourly precipitation data to obtain the historical rainfall intensity characteristics of historical flood-causing processes and the exposure rainfall intensity characteristics of subsequent non-flooding processes. The subsequent non-flooding processes are the rainfall processes that complete the regional flood summary and do not record flooding at the target flood-prone points. When the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics, a response reversal event group is established; The response reversal event group is judged to meet the rainfall comparability condition based on the maximum hourly rainfall intensity, continuous period rainfall, and peak concentration. When the rainfall comparability conditions are met and the number of comparable exceedances reaches a preset number, the historical flood-causing process is marked as a dormant flood-causing process, and the risk zoning standard parameters are updated according to the remaining effective flood-causing processes. When a flood-prone area experiences another flood-causing process with a maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary, the dormant flood-causing process will be restored as an effective flood-causing process, and the risk zone standard parameters will be restored.

2. The waterlogging risk zoning update method based on rainfall comparability according to claim 1, characterized in that, The determination of the subsequent non-flooding process includes: Obtain a summary of regional waterlogging results after the rainfall event ends; When the regional waterlogging summary results cover the area where the target waterlogging point is located, and the regional waterlogging summary results do not record waterlogging at the target waterlogging point, the rainfall process is determined as a subsequent non-waterlogging process; When the aggregated results of regional waterlogging do not cover the area where the target flood-prone point is located, the rainfall process shall not be identified as a subsequent non-flooding process.

3. The waterlogging risk zoning update method based on rainfall comparability according to claim 1, characterized in that, The formation of the historical rainfall intensity characteristics and the exposed rainfall intensity characteristics includes: The maximum hourly rainfall intensity was extracted from both the historical flood-causing process and the subsequent non-flooding process. Extract the rainfall data for consecutive time periods that contain the period with the maximum hourly rainfall intensity; The peak concentration is determined by the proportion of the maximum hourly rainfall intensity in the total rainfall over a continuous period.

4. The waterlogging risk zoning update method based on rainfall comparability according to claim 1, characterized in that, The comparable rainfall conditions include: The maximum hourly rainfall intensity in the exposed rainfall intensity characteristics exceeds the maximum hourly rainfall intensity in the historical rainfall intensity characteristics by a preset exceedance amount; The continuous period rainfall in the exposed rainfall intensity characteristics is not less than the continuous period rainfall in the historical rainfall intensity characteristics; The absolute value of the difference between the peak concentration in the exposed rainfall intensity characteristics and the peak concentration in the historical rainfall intensity characteristics does not exceed the concentration threshold.

5. The waterlogging risk zoning update method based on rainfall comparability according to claim 4, characterized in that, When the response reversal event group does not meet the rainfall comparability condition, the response reversal event group is identified as the surface reversal event group, the risk zoning standard parameters are maintained, and the cumulative number of comparability exceedances is prohibited.

6. The waterlogging risk zoning update method based on rainfall comparability according to claim 4, characterized in that, The cumulative number of comparable surpassing times includes: The number of comparable exceedances is increased by one only when the response reversal event group satisfies the rainfall comparability condition; When a new flood-causing process occurs at the target flood-prone point between two adjacent response reversal event groups that meet the rainfall comparability conditions, the accumulated comparability exceedance counts are cleared.

7. The waterlogging risk zoning update method based on rainfall comparability according to claim 1, characterized in that, Updating the risk zoning standard parameters includes: When the number of comparable exceedances reaches a preset number, a point flooding rainfall intensity threshold is formed based on the remaining effective flooding process. When the flood-causing rainfall intensity threshold of the specified location falls within the range of an adjacent lower-risk zone, the risk level of the target flood-prone location is reduced by one level; when the flood-causing rainfall intensity threshold of the specified location does not fall within the range of an adjacent lower-risk zone, the current risk zone of the target flood-prone location is maintained.

8. The waterlogging risk zoning update method based on rainfall comparability according to claim 1, characterized in that, The formation of the dormant flooding process includes: Historical flood-causing processes that maintain the reduced risk zone of the target flood-prone area during effective flood-causing processes are selected as dormant processes; The process to be dormant is labeled as a dormant flood-inducing process; When the threshold for rainfall intensity causing flooding at a given location is established, the dormant flooding process is excluded, while the event record of the dormant flooding process is retained.

9. The waterlogging risk zoning update method based on rainfall comparability according to claim 8, characterized in that, The recovery of the risk zoning standard parameters includes: When a flood-prone area experiences another flood-causing process with a maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary, the dormant flood-causing process will be restored as an effective flood-causing process. The flood-causing rainfall intensity thresholds at specific locations were re-established based on the effective flood-causing process after recovery. The risk zoning standard parameters are restored based on the newly formed point-induced flooding rainfall intensity threshold, and the comparable exceedance times of the target flood-prone points are removed.

10. A waterlogging risk zoning update system based on rainfall comparability, used to apply the waterlogging risk zoning update method based on rainfall comparability as described in any one of claims 1-9, characterized in that, include: The data acquisition module is used to collect records of waterlogging events, hourly precipitation data, and risk zoning standard parameters for target flood-prone areas; The spatiotemporal matching module is used to perform spatiotemporal matching between the flooding event ledger and the hourly precipitation data to obtain the historical rainfall intensity characteristics of historical flooding events and the exposure rainfall intensity characteristics of subsequent non-flooding events; The event group establishment module is used to establish a response reversal event group when the maximum hourly rainfall intensity in the exposed rainfall intensity characteristics is higher than the maximum hourly rainfall intensity in the historical rainfall intensity characteristics. The comparability judgment module is used to determine whether the response reversal event group meets the rainfall comparability conditions based on the maximum hourly rainfall intensity, continuous period rainfall, and peak concentration. The zoning update module is used to mark the historical flooding process as a dormant flooding process when the rainfall comparability conditions are met and the number of comparable exceedances reaches a preset number, and to update the risk zoning standard parameters according to the remaining effective flooding processes. The zone recovery module is used to restore the dormant flooding process into an effective flooding process and restore the standard parameters of the risk zone when a flooding process occurs again at the target flood-prone point with the maximum hourly rainfall intensity lower than the updated risk zone lower limit boundary.

Images