Hierarchical population exposure evaluation method oriented to urban rain flood and tide composite disasters

Abstract

The invention provides a hierarchical population exposure evaluation method for urban rainfall flood and tide composite disasters, and relates to the technical field of hydrological event and disaster risk evaluation. According to the method, a plurality of flood driving factors of rainfall, flood and sea tide are designed for a specific scene of urban rainfall flood tide complex disasters, urban area composite flood coupling modeling is carried out, a risk-vulnerability risk assessment framework is combined, a risk and vulnerability index assessment system is constructed, and multi-scene composite disaster population exposure calculation is realized. According to the method, constraint influences of three complex factors of buildings, roads and population on the geographical environment are considered, constraint analysis and feature recognition are carried out on urban buildings, and population redistribution of a spatial scale is carried out. And on the basis, population thermodynamic correlation coefficient calculation and population redistribution on a time scale are carried out, so that accurate calculation of urban rainfall flood and tide composite disaster hierarchical population exposure is carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrological events and disaster risk assessment, and in particular to a hierarchical population exposure assessment method for urban rain-flood-tide compound disasters. Background Art

[0002] Faced with complex and severe flood disasters, conducting research on urban flood simulation and comprehensive disaster risk assessment is of great practical significance. The mainstream approach to urban flood risk assessment is generally based on physical-driven methods based on urban flood models. Currently, many studies utilize various hydrological and hydrodynamic models to simulate flood risk, assess flood disaster risk, and provide reference for urban disaster prevention and mitigation efforts. However, current simulation research still has the following shortcomings: Existing urban flood simulation research often focuses on process simulation and modeling methods under specific scenarios, with little consideration of the impact of complex geographical and hydrological driving factors in the simulation. Furthermore, climate change and the complexity of urban natural-social systems lead to significant uncertainty in simulation results, making it difficult to meet the increasingly complex requirements of urban disaster prevention and mitigation. Summary of the Invention

[0003] The present invention provides a hierarchical population exposure assessment method for urban rain-flood-tide combined disasters, which solves the problem of risk recognition and assessment of urban rain-flood-tide combined disasters in complex geographical environments and realizes population exposure assessment under combined disasters.

[0004] A first aspect of the present invention provides a hierarchical population exposure assessment method for urban rain-flood-tidal combined disasters, the method comprising: Based on the intensity of rainfall hazard factors, flood hazard factors, and sea tide hazard factors in each time period, the distribution data of urban rain, flood, and tide composite disasters in each time period are simulated. The intensity of rainfall hazard factors is determined based on the rainstorm intensity formula, the Chicago rain pattern design method, and rainfall design data; the intensity of flood hazard factors is calculated based on the comprehensive unit line method and the time period deduction loss method; and the intensity of sea tide hazard factors is calculated based on the design tide level method. Based on the spatial active population redistribution data of grid cells at the building scale, a multi-agent model for urban rain-flood-tide combined disasters is constructed; based on the multi-agent model for urban rain-flood-tide combined disasters, urban population activity distribution data for each time period is determined; Construct a hierarchical population exposure assessment system for combined urban rain, flood, and tide disasters, incorporating temporal attributes to characterize dynamic changes. In this assessment system, dynamic flooding depth and flow velocity are used to characterize hazard indicators, while population density, affected building area, affected road length, proportion of vulnerable population, GDP distribution, and emergency rescue distance data for each time period are used to characterize vulnerability indicators. These dynamic flooding depth, flow velocity, population density, affected building area, affected road length, proportion of vulnerable population, GDP distribution, and emergency rescue distance data for each time period are derived from public urban information, urban rain, flood, and tide combined disaster distribution data for each time period, and simulations using the multi-agent model for urban rain, flood, and tide combined disasters. The quantitative results of hierarchical population exposure to urban rain-flood-tide combined disasters in each time period are determined based on the hazard index factors, vulnerability index factors and weights of each index in each time period.

[0005] The second aspect of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When executed, the processor implements the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters as described in the first aspect of the present invention.

[0006] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters as described in the first aspect of the present invention.

[0007] The fourth aspect of the present invention provides a computer program product, including a computer program / instruction, which is used by a processor to implement the steps of the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters as described in the first aspect of the present invention.

[0008] In this invention, aiming at the specific scenario of complex disasters such as urban rainstorms and floods, multiple flood driving factors such as rainfall, floods and sea tides are designed to carry out complex flood coupling modeling in urban areas. Combined with the "hazard-vulnerability" risk assessment framework, a hazard and vulnerability indicator assessment system is constructed to realize the calculation of population exposure to multi-scenario complex disasters.

[0009] In this paper, in addition to considering the constraints imposed by three complex factors—buildings, roads, and population—on the geographic environment, we conduct constraint analysis and feature identification on urban buildings, and perform population redistribution on a spatial scale. Furthermore, we calculate population thermal correlation coefficients and redistribute population on a temporal scale, thereby accurately calculating the hierarchical population exposure to combined urban rain, flood, and tide disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] Figure 1 This is a flowchart of the steps of a hierarchical population exposure assessment method for urban rain, flood and tide combined disasters provided by an embodiment of the present invention; Figure 2 This is a result diagram of identifying building functional characteristics in a research area of ​​an exemplary embodiment of a hierarchical population exposure assessment method for urban rain-flood-tide combined disasters provided by an embodiment of the present invention; Figure 3 It is a population distribution map at a building scale of an exemplary embodiment of a hierarchical population exposure assessment method for urban rain, flood and tide combined disasters provided by an embodiment of the present invention; Figure 4 This is an exposure assessment result diagram of an exemplary embodiment of the hierarchical population exposure assessment method for urban rain, flood and tide combined disasters provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0012] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] The dynamic distribution of urban systems makes it difficult to accurately assess disaster impacts. Urban systems are not completely independent and static. For example, urban residents, as the primary disaster risk factor, exhibit significant temporal and spatial variability in their daily activities. A detailed description of urban impacts in flood-prone environments depends on the spatial and temporal accuracy of the distribution and dynamic changes of urban impacts during a disaster.

[0014] Based on this, the embodiment of the present invention provides a hierarchical population exposure assessment method for urban rain, flood and tide combined disasters, such as Figure 1 As shown, it shows a flowchart of the steps of a hierarchical population exposure assessment method for urban rain, flood and tide combined disasters provided by an embodiment of the present invention. Specifically, the method includes the following steps: S101, based on the intensity of rainfall disaster factors, flood disaster factors, and tide disaster factors in each time period, simulate and obtain urban rain-flood-tide composite disaster distribution data in each time period.

[0015] Among them, the intensity of the rainfall disaster factor is determined based on the rainstorm intensity formula, the Chicago rain type design method and the rainfall design data; the intensity of the flood disaster factor is calculated based on the comprehensive unit line method and the time period deduction method; the intensity of the tidal disaster factor is calculated based on the design tide level method.

[0016] S102, constructing a multi-agent model for urban rain-flood-tide combined disasters based on the spatial active population redistribution data of the grid unit at the building scale; and determining the urban population activity distribution data for each time period based on the multi-agent model for urban rain-flood-tide combined disasters.

[0017] S103, construct a hierarchical population exposure assessment system for urban rain, flood and tide combined disasters, and add time attributes to represent dynamic changes.

[0018] Among them, in the evaluation system, dynamic flooding water depth and flow velocity are used to represent the hazard index factor, and population density, affected building area, affected road length, proportion of vulnerable population, GDP distribution and emergency rescue distance data in each time period are used to represent the vulnerability index factor. The dynamic flooding water depth, flow velocity, population density, affected building area, affected road length, proportion of vulnerable population, GDP distribution and emergency rescue distance data in each time period are obtained based on urban public information, urban rain-flood-tide complex disaster distribution data in each time period and the urban rain-flood-tide complex disaster multi-agent model simulation.

[0019] S104, determining the quantitative results of the hierarchical population exposure to the urban rain-flood-tide combined disaster in each time period based on the hazard index factor, vulnerability index factor and weights of each index in each time period.

[0020] In this embodiment of the present invention, considering that rainfall, floods, and ocean tides are the three most important and direct hazard factors, it is proposed to consider urban flooding disasters as a combined rain-flood-tide event. The risk and probability of a combined rain-flood-tide event are closely related to the relevant driving factors of the city. Therefore, this embodiment of the present invention proposes to comprehensively consider these three hazard factors and their interactions in the assessment of population exposure to combined urban rain-flood-tide disasters.

[0021] Specifically, in the embodiment of the present invention, the entire rainfall process is divided into multiple time periods. The specific division rules can be determined according to actual needs, for example: each hour is regarded as a time period.

[0022] In an embodiment of the present invention, the intensity of rainfall disaster factors, flood disaster factors and tidal disaster factors in each time period can be taken into account, and the influence of hydrological and geographical factors can be taken into account to simulate the reproduction of composite disaster scenarios of various urban rain-flood-tide composite disaster scenarios (rainfall-flood two-dimensional scenario, rainfall-tide two-dimensional scenario, flood-tide two-dimensional scenario and rainfall-flood-tide three-dimensional composite flood), thereby obtaining the distribution data of urban rain-flood-tide composite disasters in each time period.

[0023] In an embodiment of the present invention, in a complex disaster scenario, if all relevant disaster factors in the scenario exceed corresponding specific thresholds, a warning of the occurrence of a complex disaster is issued. For example, in a two-dimensional rainfall-flood scenario, if the intensity of the rainfall hazard factor exceeds the corresponding rainfall threshold, and the intensity of the flood hazard factor exceeds the corresponding flood threshold, a warning of the occurrence of a complex disaster is issued.

[0024] In an embodiment of the present invention, the intensity of disaster factors, flood disaster factors and tidal disaster factors in each time period corresponding to each of the multiple recurrence periods can be determined based on the design data of multiple recurrence periods, and then the urban rain-flood-tide composite disaster distribution data in each time period corresponding to each of the multiple recurrence periods can be determined.

[0025] In the embodiment of the present invention, before step S101, the intensity of rainfall hazard factors, flood hazard factors, and tidal hazard factors in each time period may be determined to simulate the distribution data of urban rain-flood-tidal composite disasters in each time period. Specifically, the hierarchical population exposure assessment method for urban rain-flood-tidal composite disasters provided by the embodiment of the present invention may further include the following steps: S11, determining the design rainfall intensity value based on the design rainfall data combined with the rainstorm intensity formula and the Chicago rain pattern design method; determining the rainfall disaster factor intensity of each time period according to the design rainfall intensity value, the historical measured rainfall data of each time period and the cumulative value of the historical measured rainfall data of each time period.

[0026] S12, based on the design rainfall data, the net rainfall in each period is calculated using the integrated unit line method and the time period deduction method to determine the design flood flow; based on the design flood flow, the historical measured flood data of each time period and the cumulative value of the historical measured flood data of each time period, the intensity of the flood disaster factor in each time period is determined.

[0027] S13, based on the historical measured process data of historical tide levels and the extreme values ​​of designed coastal tide levels, combined with the variable proportional amplification method, determines the intensity of tide disaster factors in each time period.

[0028] In the embodiment of the present invention, the design rainfall for each time period is determined based on the design rainstorms with different recurrence periods in each region, for example, a rainstorm with a return period of 10 years.

[0029] Specifically, in the embodiment of the present invention, the design rainfall time series data under different return periods can be constructed based on the design rainfall data, using the Chicago rain pattern generator and combining the rainstorm intensity formula. The calculation formula is as follows: (1) In formula (1), is the design rainfall, in mm; is the rainfall variation parameter; is the return period in years; is the rainfall duration, unit is min; and is a constant that reflects the change of rainfall intensity over time; It is the rainfall intensity, unit is mm / min.

[0030] The peak ratio parameter of the Chicago rain pattern calculation method is used to divide the rainfall process into two parts: the pre-peak part and the post-peak part, and the rainfall intensity values ​​are calculated separately (as shown in Formula (2) and Formula (3)).

[0031] (2) (3) In formula (2) and formula (3), the peak ratio (0< r <1) is a design parameter used in the Chicago rain pattern design method to describe the peak moment of a rainstorm. This parameter divides the rainfall process into two parts: the pre-peak part and the post-peak part. 、 、 are the constants derived from the rainfall intensity formula; and represent the rainfall moments before and after the peak, respectively; and represent the rainfall intensity before and after the peak, respectively.

[0032] Combine formula (1), formula (2) and formula (3) to determine the design rainfall intensity value.

[0033] In the embodiment of the present invention, the design flood flow is indirectly designed using the design rainstorm, and the period-by-period loss method is used to calculate the period-by-period net rainfall. That is, the period-by-period rainfall in the maximum 24-hour design rainfall process is deducted from the period-by-period loss, and the period-by-period net rainfall is obtained to calculate the design flood flow (as shown in formula (4)).

[0034] (4) In formula (4), It means pure rain, Indicates the rainfall during the rainfall process. is the period loss rate, Indicates the time interval.

[0035] In the embodiment of the present invention, the following formula is used to calculate the intensity of rainfall hazard factors, flood hazard factors or tide hazard factors (as shown in formula (5)).

[0036] (5) In formula (5), For the i Historical rainfall data, historical flood data or historical coastal tide data for a certain period of time, The cumulative value of historical measured rainfall data, historical measured flood data or historical measured coastal tide data for a period of time, For each return period, the design rainfall, design flood flow or design coastal tide level, The historical measured data refers to the data that has been observed.

[0037] For example, with respect to the intensity of tidal disaster factors, in an embodiment of the present invention, the tide type during a typical typhoon is selected as the typical tide type. According to the variable proportional amplification method (the main tide peak is amplified at the same ratio, and the low tide level remains unchanged), the measured process data of historical tide levels is used as a reference. According to the extreme value of the designed coastal tide level, the hourly tide level process data is scaled at the same ratio to determine the intensity of the tidal disaster factors in each time period.

[0038] In an embodiment of the present invention, the rainfall hazard factor intensity, flood hazard factor intensity or tidal hazard factor intensity corresponding to different recurrence periods can be calculated based on the design rainfall, design flood flow and design coastal tide level of different recurrence periods.

[0039] In this embodiment of the present invention, under the influence of multiple driving factors such as rain, floods, and tides, different combinations of driving factors are considered, and based on the probability of co-occurrence recurrence periods (indicating the recurrence period when all disaster factors exceed a certain threshold), a composite flood disaster scenario is reproduced (as shown in Formula (6)). In this embodiment of the present invention, four composite flood disaster scenarios are designed: a two-dimensional rainfall-flood scenario, a two-dimensional rainfall-tide scenario, a two-dimensional flood-tide scenario, and a three-dimensional rainfall-flood-tide composite flood scenario.

[0040] (6) In formula (6), ， Represent any two disasters among rainfall, flood and tide, It represents the probability of disaster occurrence. The probability of rainfall disaster, flood disaster and tidal disaster is represented by the intensity of rainfall disaster factor, flood disaster factor and tidal disaster factor respectively. represents the two-dimensional co-occurrence recurrence period.

[0041] In the embodiment of the present invention, the spatially active population redistribution data of the grid unit based on the building scale is determined by performing constraint analysis and feature identification on urban buildings, taking into account the constraints of three complex factors, namely buildings, roads, and population, on the geographical environment. Specifically, before step S102, the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters provided by the embodiment of the present invention may further include the following steps: S21, functional building types are divided based on the dominant POI types of the buildings.

[0042] S22, based on dynamic population thermal distribution data, unified coordinate correction is performed and a grid is established.

[0043] S23, determining the importance of each functional building type based on the frequency of occurrence of each functional building type in the grid.

[0044] S24, based on the importance of each functional building type and the population thermal value in each grid, determining the population thermal value correlation coefficient of each grid.

[0045] S25, redistribute the population of grid cells based on functional building types and population thermal correlation coefficients.

[0046] In the embodiment of the present invention, in step S21 , the density distribution of different types of urban buildings may be determined based on the urban building POI information, and then the dominant POI of each building may be determined.

[0047] Specifically, the following steps can be used to determine the dominant POI type of a building: S31, classify urban building types according to urban POI data, assign different POI categories and search radius setting values ​​to different types of buildings, perform kernel density analysis on each building type, and determine the weight value of each building type based on the kernel density analysis results.

[0048] S32. For a certain building, within its specified frequency radius, determine the frequency density of each building type based on the weight value of each building type and the number of buildings of that type, as well as the weights of all building types and the number of buildings of the corresponding type, and determine the dominant POI type of the building based on the frequency density of each building type.

[0049] In this embodiment of the present invention, urban building types can be divided based on urban building POI data. Buildings of known building types are assigned their own POI categories and search radius settings. Kernel density analysis is then used to calculate the density contribution of sample points (locations of buildings of known building types) to the unit center within a specified area (as shown in Formula (7)). The kernel density analysis results are combined with the number and type of POIs, and different weight scores are assigned to determine the functional type of the building.

[0050] (7) In formula (7), Represents any point in space The kernel density value of Representative Points To POI the distance between them; is the specified neighborhood radius, and To be greater than ; The number of all POI points contained in the specified neighborhood radius.

[0051] In this embodiment of the present invention, the weight value of each building type can be determined by combining the kernel density analysis results of each building type, and the frequency radius and type ratio of the building can be calculated (as shown in formula (8)) to determine the dominant functional type of the building. Within the same building unit, the building type with the largest type ratio is used as the functional type of the building unit.

[0052]

[0053] (8) In formula (8), Indicates POI category; Indicates the building Number of POI types; Indicates the POI-like weight score; Indicates the building Frequency density of POI types in the total number of POIs; Indicates the The frequency density of a type of POI accounts for the proportion of the frequency density of all types of POIs.

[0054] In this embodiment of the present invention, high-precision dynamic population thermal distribution data can be used in steps S22 to S24 to perform unified coordinate correction and establish a grid. The importance of each functional building type is quantified by calculating its frequency of occurrence in the grid (as shown in formula (9)). On this basis, the correlation coefficient of the population thermal value of each grid is calculated (as shown in formula (10)).

[0055] (9) In formula (9), Indicates the In the grid The area of ​​similar functional buildings; Indicates the The area of ​​all functional buildings in a grid; Indicates the total number of grids; Indicates that it contains The number of grids for this type of functional building. The smaller the value, the denser the spatial distribution of this type of functional building.

[0056]

[0057]

[0058]

[0059] (10) In formula (10), Characterization In the grid The importance of the functional building; Indicates the The population heat value of each grid, Indicates the i The correlation coefficient of population thermal value of each grid.

[0060] In this embodiment of the present invention, step S25 includes the following sub-steps: S251, based on the relationship between population size and population thermal value in the same period, the grid population thermal value is converted into the grid active population to obtain the spatiotemporal distribution of population size at the grid level; S252, based on the distribution of functional buildings in a single grid, using the functional building type and population thermal correlation coefficient, calculate the number of active population of different functional building types in a single grid, and allocate the active population; S253, counting the total number of active population in buildings with the same function, and obtaining the data on the redistribution of active population in grid unit space based on the building scale.

[0061] In the embodiment of the present invention, based on the relationship between the population size and the population thermal value in the same period, the grid population thermal value can be converted into the grid active population to obtain the spatiotemporal distribution of the population size at the grid level (as shown in formula (11)). (11) In formula (11), express Moment The population heat value of each grid; express Thermal values ​​of all grids at the moment; represents the total population of the region; express Moment The population of each grid.

[0062] In the embodiment of the present invention, the number of active population of different functional building types in a single grid can be calculated based on the distribution of functional buildings in a single grid and the thermal correlation coefficient of functional building types and population, and the active population can be allocated (as shown in formula (12)). (12) In formula (12), Indicates the In the grid Functional building area; Indicates the All functional building areas in a grid; Indicates the The correlation coefficient between the type of functional building and population heat; Indicates the In the grid Number of active people at a given moment; Indicates Moment In the grid The population of a functional building.

[0063] In the embodiment of the present invention, the total number of active people in a building with the same function can be counted based on the following formula (as shown in formula (13)).

[0064] (13) In formula (13), Indicates t The total number of active people in the same functional building at any given time, Indicates Moment In the grid The population of each functional building, n Indicates the k Functional buildings corresponding to n A grid.

[0065] In this embodiment of the present invention, in step S103, a hierarchical population exposure assessment system for urban rain, flood, and tide combined disasters is constructed. Urban flood risk is quantified based on the flood criterion-level indicator factors (hazard factor hazard and hazard-bearing body vulnerability indicators). In conjunction with urban risk assessment theory, the maximum water depth and maximum flow velocity obtained during the urban rain, flood, and tide combined disaster distribution simulation in step S101 are selected as hazard indicator layer factors. Urban population activity distribution data obtained from the multi-agent model simulation of urban rain, flood, and tide combined disasters in step S102, as well as relevant urban data obtained from public databases (e.g., urban GDP data, urban building area data, road length data, etc.), are selected to determine population density, exposed building area, exposed road length, vulnerable population ratio, GDP, and emergency rescue density as carrier vulnerability indicator layer factors.

[0066] In the embodiment of the present invention, the entropy weight method and the analytic hierarchy process can be used to calculate the index weights of the hazard index factor and the carrier vulnerability index factor in the population exposure assessment of urban rain, flood and tide combined disasters. The combined weight value is calculated according to formula (14).

[0067] (14) In formula (14), The entropy weight method The weight of the indicator, The analytic hierarchy process The weight of the indicator, is the result weight value of the combination method.

[0068] In the embodiment of the present invention, a hierarchical population exposure assessment is implemented based on the simulation of urban rain, flood and tide compound disasters. Specifically, the simulation of urban rain, flood and tide compound disasters includes two parts: compound disaster simulation and disaster-bearing body simulation.

[0069] Among them, the complex disaster simulation includes extracting the distribution data of urban rain, flood and tide complex disasters. Specifically, based on the intensity of rainfall disaster factors, flood disaster factors and tidal disaster factors, and considering the influence of hydrological and geographical factors, four different scenarios of complex disaster scenarios are reproduced to simulate the dynamic process of multi-scenario complex flood disasters, and the distribution data of urban rain, flood and tide complex disasters at different times under four different scenarios are extracted respectively.

[0070] Among them, the disaster-prone body simulation includes the three important components of the urban system based on buildings, population, and roads. The population of grid units of building scales at different times is simulated on the Gama platform to ensure the reasonable distribution of the population of each grid unit and build a multi-agent model of urban rain, flood and tide complex disasters.

[0071] In this embodiment of the present invention, during the hierarchical population exposure assessment process for urban rain, flood, and tide combined disasters, a constructed urban rain, flood, and tide combined hierarchical population exposure assessment system is constructed, incorporating a time attribute to characterize dynamic changes. The dynamic inundation depth and flow velocity obtained during the combined disaster simulation are used to characterize the hazard. Population density, affected building area, affected road length, vulnerable population ratio, GDP distribution, and emergency rescue distance data at each time point are selected to characterize vulnerability. The vulnerability index factor is derived from public urban information, urban rain, flood, and tide combined disaster distribution data for each time period, and the multi-agent model simulation of the urban rain, flood, and tide combined disaster. Specifically, the multi-agent model is used to obtain the model state at time t, query population type and spatial coordinates, perform coordinate conversion and processing, and then obtain urban population activity distribution data for each time period. The hierarchical population exposure calculation for urban rain, flood, and tide combined disasters is then performed (as shown in Formula (15)).

[0072]

[0073]

[0074] (15) In formula (15), Indicates dynamic danger, Indicates dynamic vulnerability, represents the multi-agent simulation time, Represents the position, Represents the number of indicators, Representative The weight of the risk indicator, Representative The weight of each vulnerability indicator, represent Quantitative results of hierarchical population exposure to urban rain, flood and tide combined disasters at all times.

[0075] In the embodiment of the present invention, the hierarchical population exposure assessment result of the urban rain-flood-tide composite disaster can be output based on the calculation result of formula (15). Furthermore, in the embodiment of the present invention, the hierarchical population exposure assessment result of the urban rain-flood-tide composite disaster can be expressed in the form of a graph based on the rainfall hazard factor intensity, flood hazard factor intensity, or tidal hazard factor intensity corresponding to different recurrence periods and the calculation result of the hierarchical population exposure assessment result of the urban rain-flood-tide composite disaster. Specifically, a graph of the hierarchical population exposure assessment result of the urban rain-flood-tide composite disaster driven by different hazard factors with different recurrence periods can be output.

[0076] For ease of understanding, an exemplary embodiment is also provided in the embodiments of the present invention. This exemplary embodiment is applied to the main urban area of ​​a certain city. The hierarchical population exposure evaluation method for urban rain, flood and tide complex disasters proposed in the embodiments of the present invention is used to realize the risk estimation of rain, flood and tide flood disasters in the main urban area of ​​a certain city.

[0077] Specifically, in this embodiment, rainfall data from 1961 to 2014, covering a total of 54 years, was used to calculate rainfall intensity for different return periods (5, 10, 50, and 100 years). Flood discharge for different return periods was calculated using rainfall data and average loss rates for these periods. Tidal levels for different return periods were calculated using tidal monitoring data from Chiwan Station during Typhoon Tali in 2023. Referring to step S101, a three-dimensional composite flood scenario design for "rainfall-flood-tide" was performed to simulate and obtain urban rainfall, flood, and tide composite disaster distribution data for each time period.

[0078] In this embodiment, the dominant functional characteristics of urban buildings are first identified and classified, and then the number of buildings in each building is calculated based on the frequency density and type ratio algorithm. and Distribution, according to the proportion of each type of distribution to determine the dominant functional type of each building. The results of the identification of building functional characteristics in the study area are as follows: Figure 2 As shown, the large picture on the left is an overall schematic diagram of the functional division of buildings in the exemplary study area, the four small pictures ①②③④ arranged vertically in the middle are the enlarged functional schematic diagrams of buildings corresponding to the four areas ①②③④ marked in the large picture on the left, and the four small pictures arranged vertically on the right are the satellite images corresponding to the four areas ①②③④ marked in the large picture on the left.

[0079] In this embodiment, the thermal data of the suitable travel population is used to calculate the The correlation coefficient between each functional building and the population heat value and the number of active population of different functional building types in a single grid are calculated, and the grid population is allocated to each functional building to obtain the number of active population of functional buildings at different times. The population distribution diagram at the building scale is shown in Figure 2. Figure 3As shown, the large picture on the left is an overall schematic diagram of the population size of the exemplary study area, and the four small pictures on the right (a), (b), (c), and (d) are respectively schematic diagrams of the enlarged population size corresponding to the four areas marked (a), (b), (c), and (d) in the large picture on the left.

[0080] In this embodiment, each indicator layer factor is normalized, and the indicator weight is calculated based on the entropy weight method and the hierarchical analysis method. The final weight distribution is shown in the following table:

[0081] In this embodiment, based on steps S104-S105, a hierarchical population exposure calculation is performed for the main urban area of ​​a city, and the calculation results are divided into four levels: low risk, medium risk, medium-high risk, and high risk according to a unified grading standard. The hierarchical population exposure evaluation result diagram of the urban rain-flood-tide composite disaster with four recurrence periods is output (as shown in FIG. Figure 4 shown), Figure 4 The rainfall disaster factor intensity, flood disaster factor intensity, and tide disaster factor intensity used in the calculation are based on a 5-year recurrence period.

[0082] Based on the same inventive concept, an embodiment of the present invention further provides a hierarchical population exposure assessment device for urban rain, flood and tide combined disasters, the device comprising: The first simulation module is used to simulate the intensity of rainfall hazard factors, flood hazard factors, and tidal hazard factors in each time period to obtain urban rain-flood-tidal composite disaster distribution data for each time period. The rainfall hazard factor intensity is determined based on the rainstorm intensity formula, the Chicago rain pattern design method, and rainfall design data; the flood hazard factor intensity is calculated based on the comprehensive unit line method and the time period loss deduction method; and the tidal hazard factor intensity is calculated based on the design tide level method. The second simulation module is used to construct a multi-agent model of urban rain-flood-tide combined disasters based on the spatial active population redistribution data of grid cells at the building scale; and determine the urban population activity distribution data for each time period based on the multi-agent model of urban rain-flood-tide combined disasters; A construction module is used to construct a hierarchical population exposure assessment system for urban rain-flood-tidal combined disasters, incorporating temporal attributes to characterize dynamic changes. In this assessment system, dynamic flooding depth and flow velocity are used to characterize hazard index factors, and population density, affected building area, affected road length, proportion of vulnerable population, GDP distribution, and emergency rescue distance data for each time period are used to characterize vulnerability index factors. The dynamic flooding depth, flow velocity, population density, affected building area, affected road length, proportion of vulnerable population, GDP distribution, and emergency rescue distance data for each time period are obtained based on public urban information, urban rain-flood-tidal combined disaster distribution data for each time period, and simulation of the multi-agent model for urban rain-flood-tidal combined disasters. The calculation module is used to determine the quantitative results of the hierarchical population exposure to urban rain-flood-tide compound disasters in each time period based on the risk index factor, vulnerability index factor and the weight of each index.

[0083] Based on the same inventive concept, an embodiment of the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When executed, the processor implements the steps in the hierarchical population exposure assessment method for urban rain, flood and tide combined disasters as described in any of the above embodiments.

[0084] Based on the same inventive concept, an embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters described in any of the above embodiments are implemented.

[0085] Based on the same inventive concept, an embodiment of the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters described in any of the above embodiments.

[0086] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0087] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, apparatus, or computer program products. Thus, embodiments of the present invention may take the form of a fully hardware embodiment, a fully software embodiment, or an embodiment combining software and hardware. Furthermore, embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0088] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (apparatuses), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable terminal device generate instructions for implementing the process in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0089] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable terminal device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0090] These computer program instructions can also be loaded onto a computer or other programmable terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0091] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0092] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0093] The above is a detailed introduction to the hierarchical population exposure assessment method for urban rain, flood and tide combined disasters provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for general technical personnel in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A hierarchical population exposure assessment method for urban rain, flood and tide combined disasters, characterized by: The method comprises: Based on the intensity of rainfall disaster factors, flood disaster factors and sea tide disaster factors in each time period, the distribution data of urban rain, flood and tide composite disasters in each time period are simulated. The intensity of rainfall disaster factors is determined based on the rainstorm intensity formula, Chicago rain type design method and rainfall design data; the intensity of flood disaster factors is calculated based on the comprehensive unit line method and the time period deduction loss method; the intensity of sea tide disaster factors is calculated based on the design tide level method; Constructing a multi-agent model of urban rain-flood-tide compound disaster based on the spatial active population redistribution data of grid units at the building scale; determining the distribution data of urban population activities in each time period based on the multi-agent model of urban rain-flood-tide compound disaster; Construct a hierarchical population exposure evaluation system for urban rain-flood-tide composite disasters, and add time attributes to characterize dynamic changes. In the evaluation system, dynamic flooding depth and flow velocity are used to characterize the hazard index factor, and population density, disaster-affected building area, disaster-affected road length, vulnerable population ratio, GDP distribution, and emergency rescue distance data in each time period are used to characterize the vulnerability index factor. The dynamic flooding depth, flow velocity, population density, disaster-affected building area, disaster-affected road length, vulnerable population ratio, GDP distribution, and emergency rescue distance data in each time period are obtained based on urban public information, urban rain-flood-tide composite disaster distribution data in each time period, and the urban rain-flood-tide composite disaster multi-agent model simulation; The quantitative results of hierarchical population exposure to urban rain-flood-tide combined disasters in each time period are determined based on the hazard index factors, vulnerability index factors and weights of each index in each time period.

2. The hierarchical population exposure assessment method for urban rain-flood-tide combined disasters according to claim 1 is characterized in that: The method further comprises: Determine the design rainfall intensity value based on the design rainfall data combined with the rainstorm intensity formula and the Chicago rain type design method; The intensity of rainfall disaster factors in each time period is determined based on the designed rainfall intensity value, the historical measured rainfall data in each time period and the cumulative value of the historical measured rainfall data in each time period.

3. The hierarchical population exposure assessment method for urban rain-flood-tide combined disasters according to claim 2 is characterized in that: The method further comprises: Based on the design rainfall data, the comprehensive unit line method and the loss deduction method for each period are used to calculate the net rainfall in each period and determine the design flood flow; The intensity of flood disaster factors in each time period is determined based on the designed flood flow, the historical measured flood data in each time period and the cumulative value of the historical measured flood data in each time period.

4. The hierarchical population exposure assessment method for urban rain-flood-tide combined disasters according to claim 1 is characterized in that: The method further comprises: Based on the historical measured process data of historical tide levels and the extreme values ​​of designed coastal tide levels, combined with the variable proportional amplification method, the intensity of tidal disaster factors in each time period is determined.

5. The hierarchical population exposure assessment method for urban rain-flood-tide combined disasters according to claim 1 is characterized in that: The method further comprises: Functional building types are divided based on the dominant POI types of buildings; Based on dynamic population thermal distribution data, unified coordinate correction is performed and grid is established; Determine the importance of each functional building type based on its frequency of occurrence in the grid; Based on the importance of each functional building type and the population thermal value in each grid, the correlation coefficient of the population thermal value of each grid is determined; Population redistribution of grid cells is carried out based on functional building types and population thermal correlation coefficients.

6. The hierarchical population exposure assessment method for urban rain-flood-tide combined disasters according to claim 5 is characterized in that: Redistribute the population of grid cells based on functional building types and population thermal correlation coefficients, including: Based on the relationship between population size and population thermal value in the same period, the grid population thermal value is converted into the grid active population to obtain the spatiotemporal distribution of population size at the grid level. According to the distribution of functional buildings in a single grid, the number of active populations of different functional building types in a single grid is calculated using the thermal correlation coefficient of functional building types and population, and the active population is allocated; The total number of active population in buildings with the same function is counted to obtain the data on the redistribution of active population in grid unit space based on the building scale.

7. The hierarchical population exposure assessment method for urban rain-flood-tide combined disasters according to claim 5 is characterized in that: The method further comprises: According to the city POI data, the city building types are divided, different POI categories and search radius setting values ​​are assigned to different types of buildings, kernel density analysis is performed on each building type, and the weight value of each building type is determined based on the kernel density analysis results of each building type; For a certain building, within its specified frequency radius, the frequency density of each building type is determined based on the weight value of each building type and the number of buildings of this type as well as the weights of all building types and the number of buildings of the corresponding type, and the dominant POI type of the building is determined based on the frequency density of each building type.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters described in any one of claims 1-7 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters described in any one of claims 1 to 7 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps in the hierarchical population exposure assessment method for urban rain-flood-tide combined disasters described in any one of claims 1-7 are implemented.

Images