Flood damage model construction method and risk avoiding transfer method for flood protection area

Abstract

The invention relates to the technical field of regional flood control protection, in particular to a flood control protection area flood damage model construction method and a risk avoiding transfer method, and aims to solve the problems that currently used flood control measures are not constructed in combination with a global flood damage model, the used historical method is too single, and factors of climate, geography and space changes are not combined. Therefore, the reliability of flood control measures is low. According to the method, the long-duration dynamic flood damage model of the flood control protection area is analyzed by combining the construction of the global disaster damage model, aiming at the disaster damage model of the flood control protection area and combining the future disaster damage condition under the global climate change, the future risk avoiding transfer analysis of the flood control protection area is carried out, and the flood control non-engineering measures are established corresponding to the flood control protection area. And the reliability of flood control measures can be effectively improved, so that the problems of future change degree and regional pertinence of flood control non-engineering measures are solved. The technical problems that existing flood control measures are low in reliability, and danger avoiding transfer cannot be effectively carried out can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of regional flood protection, and in particular to a method for constructing a flood disaster damage model in a flood protection zone and a risk avoidance and transfer method. Background Art

[0002] Against the backdrop of urbanization and global warming, extreme precipitation disasters occur frequently, leading to an urgent need to improve the effectiveness of existing flood control measures in urban and rural areas.

[0003] Existing flood control measures are based on historical regional river conditions. Given global climate change and urbanization, the practicality of these measures in regional flood protection zones remains to be verified. Therefore, it is crucial to develop a disaster loss model for flood protection zones, analyze future risk avoidance and relocation within these zones, and analyze future damage scenarios under global climate change.

[0004] Because the current flood control measures and risk avoidance transfer analysis methods are not constructed in conjunction with the global flood damage model, the historical methods used are too single and do not take into account factors such as climate, geography and spatial changes. As a result, the reliability of flood control measures is low and risk avoidance transfer cannot be effectively carried out. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for constructing a flood damage model in a flood protection zone and a risk avoidance transfer method, which can solve the technical problems that existing flood control measures have low reliability and cannot effectively carry out risk avoidance transfer.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention designs a method for constructing a flood damage model for a flood protection zone, comprising the following steps:

[0008] Select several climate models and historical reference data, and perform downscaling analysis and bias correction on the climate variables output by each climate model;

[0009] The downscaled and bias-corrected climate model is input into the global hydrological model to simulate runoff at global grid points;

[0010] Select runoff observation data for each grid point and conduct verification and comparison of runoff data to screen or combine global hydrological models;

[0011] Construct a global hydrodynamic model, input the optimized climate model and hydrological model results into the hydrodynamic model, conduct global hydrodynamic flood risk simulation, and use historical flood level statistics to calibrate the global hydrodynamic model;

[0012] Combined with measured disaster loss indicator data, a global flood loss model was constructed;

[0013] Calibrate and verify the global flood loss model by combining global historical loss indicator data;

[0014] For a fixed future period, we selected the optimal climate model, downscaling and bias correction methods, hydrological model, calibrated global hydrodynamic model, and calibrated and validated global flood damage model to construct a long-duration dynamic flood damage model.

[0015] According to the estimation results of the long-duration dynamic flood damage model, the calculation scope of the flood protection zone is determined, and a long-duration dynamic flood damage model for the flood protection zone is constructed.

[0016] As a preferred solution, the method for constructing the global hydrodynamic model is as follows:

[0017] Parameters involved in the global hydrodynamic model: river water storage is S r , river depth D r , D r Determined by sea level elevation; the water storage in the floodplain is S f , floodplain water depth D f , flooded area in the floodplain A f ; Grid water storage S at the initial stage of flood ini ;

[0018] S ini The calculation formula is as follows:

[0019] S ini =B ini W ini L ini ;

[0020] B ini 、W ini 、L ini Corresponding to the river depth B at the initial stage of flood ini , river width W ini , River Chief L ini ;

[0021] The water storage of the next time step of the total water storage S is less than or equal to the grid water storage S at the initial flood period. ini The calculation formula of the global hydrodynamic model for the initial flood process is as follows:

[0022]

[0023] The water storage of the next time step of the total water storage S is greater than the grid water storage S at the initial flood period. ini The calculation formula of the global hydrodynamic model for the late flood retreat process is as follows:

[0024]

[0025] Where A f is the flooded area of the floodplain, which is determined by the topography, water depth of the floodplain, and water storage in the floodplain; A1 is the floodplain drainage area; D(A1) is the floodplain drainage depth; D f is the water depth in the floodplain; D(A f ) is the floodplain area in the flood submerged area A f Elevation profile function at D -1 (D f ) is the floodplain elevation contour function D(A f ) is the inverse function of .

[0026] Furthermore, the calibration method of the global hydrodynamic model is as follows:

[0027] The flood evolution process is calculated by calculating the grid water storage of each grid, which is calculated from the grid runoff and time-shifted according to the terrain data. The global hydrodynamic model is calibrated based on the flood evolution process as follows:

[0028] Calculate the water storage S at grid point i based on the river flow i The amount of change:

[0029] Water storage S at grid point i i The change from time t to time t+Δt is expressed by the following formula:

[0030]

[0031] in, and represent the water storage of grid point i at time t and time t+Δt, respectively;

[0032] Upstream represents the total number of grid points of upstream inflow, Q k t is the inflow flow of the river (plus floodplain + bifurcation channel) from the upstream grid point k, is the sum of the inflow flows of all upstream grid points within the time Δt;

[0033] Q i t is the outflow of the river (plus floodplain + bifurcation channel) at grid point i, is the outflow rate at grid point i in time Δt;

[0034] Ac i is the unit watershed area within grid point i, R i t is the input runoff at grid point i, is the inflow rate at grid point i in time Δt;

[0035] B, W, and L correspond to the river depth B, river width W, and river length L at time t, respectively;

[0036] if Then use formula (1) to calibrate the global hydrodynamic model;

[0037]

[0038] if Then use formula (2) to calibrate the global hydrodynamic model;

[0039]

[0040] The global hydrodynamic model is corrected using formulas (3) and (4).

[0041] Furthermore, the river flow is calculated based on the Saint-Venant equation:

[0042]

[0043] Where, Q is the river flow (m3 / s), A is the cross-sectional area (m2), h is the fluid depth (m), z is the riverbed elevation (m), R is the hydraulic radius (m), g is the gravitational acceleration (ms -2 ), n is the Manning friction coefficient (m -1 / 3 s -1 ), the value of the Manning friction coefficient n is determined by the grid topography; x and t represent the distance and time of river flow, respectively.

[0044] As a preferred option, the global flood damage model is as follows:

[0045] Risk = F (hazard, exposure, vulnerability);

[0046] Risk: refers to the possibility of human or economic loss;

[0047] Hazard: refers to the intensity, frequency and scope of the occurrence of disaster-causing factors;

[0048] Exposure: refers to the intersection of the impact range of the disaster and the spatial distribution of the disaster-bearing bodies;

[0049] Vulnerability: refers to the size of the population or economic losses in the affected area.

[0050] As a preferred solution, a long-duration dynamic flood damage model is constructed and represented by an X matrix. The calculation formula is as follows:

[0051] X=(X ijt ) N×M×T ;

[0052] Among them, X ijt is the disaster occurrence matrix, when X ijt =1, it is determined that the affected area needs to conduct regional flood impact analysis and loss assessment calculation at time t;

[0053] i is the number of areas experiencing disasters;

[0054] j is the disaster loss indicator data of the disaster, including population or economic losses;

[0055] t is the time when the disaster occurs, 0≤t≤T;

[0056] N is the number of samples in the disaster-affected area (determined by the grid size corresponding to the area of interest), 0≤i≤N;

[0057] M is the disaster loss indicator data of the affected area, that is, the population or economic loss data caused by the flooding; if the population loss or economic loss is greater than the threshold, it is recorded as 1, otherwise it is recorded as 0;

[0058] T is the estimated maximum duration of the disaster in the affected area.

[0059] The present invention also designs a risk avoidance and transfer method based on a flood damage model of a flood protection zone, comprising the following steps:

[0060] Basic data collection and on-site investigation, data compilation and evaluation, and checking the completeness, accuracy, consistency and timeliness of data;

[0061] Hydrological analysis and calculation: Combined with the inflow characteristics of the flood protection area, conduct flood composition analysis, determine the hydrological combination for calculating inflow, combine climate models and hydrological models for the basin where the flood protection area is located, and make long-term inflow forecasts;

[0062] Flood analysis and calculation: Calibrate the parameters of the hydrodynamic model of the river channel and protected area corresponding to the river channel and protected area where the flood protection area is located, and analyze the inundation range, water depth, duration and flood arrival time under different working conditions in the flood protection area;

[0063] Conduct regional flood impact analysis and loss assessment based on the flood damage model of the flood protection zone. Analyze the corresponding socio-economic and demographic conditions based on the inundation situation within the calculation range to conduct flood loss assessment.

[0064] Analyze the risk transfer, determine the scope of risk transfer, personnel transfer methods, resettlement area demarcation principles, and draw a risk transfer map to form a risk transfer path.

[0065] Beneficial effects of the present invention:

[0066] This invention provides a method for constructing a flood damage model and a risk avoidance and migration method for flood protection zones. By combining the construction of a global damage model with analysis of a long-duration dynamic flood damage model for flood protection zones, this method conducts an analysis of future risk avoidance and migration within the flood protection zones. Furthermore, non-engineering flood control measures are established in response to these measures. This method effectively improves the reliability of these measures, thereby addressing the future variability and regional specificity of these non-engineering flood control measures. This invention addresses the technical issues of existing flood control measures, which suffer from low reliability and ineffective risk avoidance and migration. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is the overall flow chart of the present invention.

[0068] Figure 2 Flowchart of the risk avoidance transfer process of the present invention. DETAILED DESCRIPTION

[0069] In order to make the technical solutions and advantages of the present invention more clearly understood, the present invention is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present invention and are not intended to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0070] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0071] Because current flood control measures are not built in conjunction with global flood damage models and the historical methods used are overly simplistic, without incorporating factors such as climate, geography, and spatial variation, the reliability of these measures is low. With the development of computer technology, methods for constructing non-engineering flood control measures based on mathematical and physical analysis have become an important tool for flood control. Non-engineering flood control measures involve analyzing the damage models of flood protection zones and analyzing future damage under global climate change. This analysis, combined with the development of a risk-avoidance map, is based on future risk-avoidance transfers within these zones. These measures, designed to protect people's lives and property before floods occur, are based on non-physical water conservancy project construction.

[0072] The present invention relates to a method for constructing a flood damage model and a risk avoidance and transfer method for flood protection zones. By combining the construction of a global damage model with analysis of a long-duration dynamic flood damage model for flood protection zones, future risk avoidance and transfer analysis for flood protection zones is conducted, and corresponding non-engineering flood control measures are established for flood protection zones. This method can effectively improve the reliability of flood control measures, thereby addressing the future variability and regional specificity of non-engineering flood control measures. The present invention can address the technical issues of low reliability and ineffective risk avoidance and transfer in existing flood control measures.

[0073] like Figure 1 As shown, the present invention discloses a method for constructing a flood damage model in a flood protection zone and a risk avoidance and transfer method, comprising the following steps:

[0074] Step 1: Select several climate models in CMIP6 and historical reference data, such as the historical statistical data of climate variables in ECWMF, and perform downscaling analysis and bias correction on the climate variables output by each climate model.

[0075] Step 2: Input the downscaled climate model into a global hydrological model, such as SWAT and H08, to perform global grid point runoff simulation analysis. The grid scale used here is 0.25°×0.25°.

[0076] Step three: Select runoff observation data for each grid point, such as earth2observe, to verify and compare the runoff data, so as to screen or combine the global hydrological models.

[0077] Step 4: Build a global hydrodynamic model, input the optimal climate model and hydrological model results into the global hydrodynamic model, conduct a global hydrodynamic flood risk simulation, and use historical statistical flood level data to calibrate the global hydrodynamic model.

[0078] The global hydrodynamic model is constructed as follows:

[0079] Parameters involved in the global hydrodynamic model: river water storage is S r , river depth D r , D r Determined by sea level elevation; the water storage in the floodplain is S f , floodplain water depth D f , flooded area in the floodplain A f ; Grid water storage S at the initial stage of flood ini ;

[0080] S ini The calculation formula is as follows:

[0081] S ini =B ini W ini Lini ;

[0082] B ini 、W ini , L ini Corresponding to the river depth B at the initial stage of flood ini , river width W ini , River Chief L ini ;

[0083] The water storage of the next time step of the total water storage S is less than or equal to the grid water storage S at the initial flood period. ini The calculation formula of the global hydrodynamic model for the initial flood process is as follows:

[0084]

[0085] The water storage of the next time step of the total water storage S is greater than the grid water storage S at the initial flood period. ini The calculation formula of the global hydrodynamic model for the late flood retreat process is as follows:

[0086]

[0087] Where A f is the flooded area of the floodplain, which is determined by the topography, water depth of the floodplain, and water storage in the floodplain; A1 is the floodplain drainage area; D(A1) is the floodplain drainage depth; D f is the water depth in the floodplain; D(A f ) is the floodplain area in the flood submerged area A f Elevation profile function at D -1 (D f ) is the floodplain elevation contour function D(A f ) is the inverse function of .

[0088] The calibration method of the global hydrodynamic model is as follows:

[0089] The flood evolution process is calculated by calculating the grid water storage of each grid, which is calculated from the grid runoff and time-shifted according to the terrain data. The global hydrodynamic model is calibrated based on the flood evolution process as follows:

[0090] River discharge is calculated based on the Saint-Venant equation:

[0091]

[0092] Where Q is the river flow (m 3 / s), A is the cross-sectional area (m 2 ), h is the fluid water depth (m), z is the riverbed bottom elevation (m), R is the hydraulic radius (m), g is the gravitational acceleration (ms -2), n is the Manning friction coefficient (m -1 / 3 S -1 ), the value of the Manning friction coefficient n is determined by the grid topography; x and t represent the distance and time of river flow, respectively.

[0093] Calculate the water storage S at grid point i based on the river flow i The amount of change:

[0094] Water storage S at grid point i i The change from time t to time t+Δt is expressed by the following formula:

[0095]

[0096] in, and represent the water storage of grid point i at time t and time t+Δt, respectively;

[0097] Upstream represents the total number of grid points of upstream inflow, Q k t is the inflow flow of the river (plus floodplain + bifurcation channel) from the upstream grid point k, is the sum of the inflow flows of all upstream grid points within the time Δt;

[0098] Q i t is the outflow of the river (plus floodplain + bifurcation channel) at grid point i, is the outflow rate at grid point i in time Δt;

[0099] Ac i is the unit watershed area within grid point i, R i t is the input runoff at grid point i, is the inflow rate at grid point i in time Δt;

[0100] B, W, and L correspond to the river depth B, river width W, and river length L at time t, respectively;

[0101] if Then use formula (1) to calibrate the global hydrodynamic model;

[0102]

[0103] if Then use formula (2) to calibrate the global hydrodynamic model;

[0104]

[0105] The global hydrodynamic model is corrected using formulas (3) and (4).

[0106] The river cross-sectional parameters, river depth B and river width W, are estimated by an empirical formula related to river flow, and other terrain parameters are determined by high-precision terrain and river network flow direction maps;

[0107]

[0108] Among them, R up Refers to the annual maximum value of the 30-day rolling average of upstream runoff.

[0109] Step five: Combined with measured disaster loss indicator data, including population and economic losses, a global flood loss model is constructed, using indicators including population exposure and socioeconomic exposure.

[0110] The global flood damage model is as follows:

[0111] Risk = F (hazard, exposure, vulnerability);

[0112] Risk: refers to the possibility of human or economic loss;

[0113] Hazard: refers to the intensity, frequency and scope of the occurrence of disaster-causing factors;

[0114] Exposure: refers to the intersection of the impact range of the disaster and the spatial distribution of the disaster-bearing bodies;

[0115] Vulnerability: refers to the size of the population or economic losses in the affected area.

[0116] Population and economic data are counted according to the grid area. For example, the grid size used here is 0.25°×0.25°.

[0117] Step six: Combine historical disaster loss indicator data (including population and economy) from seven continents around the world to calibrate and verify the disaster loss model.

[0118] Step seven: For a fixed period in the future, select the optimal climate model, downscaling and bias correction method, hydrological model, and the calibrated global hydrodynamic model and the calibrated and verified global flood damage model to construct a long-duration dynamic flood damage model.

[0119] A long-duration dynamic flood damage model is constructed and represented by an X matrix. The calculation formula is as follows:

[0120] X=(X ijt ) N×M×T ;

[0121] Among them, X ijt is the disaster occurrence matrix, when X ijt =1, it is determined that the affected area needs to conduct regional flood impact analysis and loss assessment calculation at time t;

[0122] i is the number of areas experiencing disasters;

[0123] j is the disaster loss indicator data of the disaster, including population or economic losses;

[0124] t is the time when the disaster occurs, 0≤t≤T;

[0125] N is the number of samples in the disaster-affected area (determined by the grid size corresponding to the area of interest), 0≤i≤N;

[0126] M is the disaster loss indicator data of the affected area, that is, the population or economic loss data caused by the flooding; if the population loss or economic loss is greater than the threshold, it is recorded as 1, otherwise it is recorded as 0;

[0127] T is the estimated maximum duration of the disaster in the affected area.

[0128] Step 8: Determine the calculation scope of the flood protection zone based on the estimated results of the global flood damage model;

[0129] Step nine: basic data collection and on-site investigation, collect basic data such as natural geography and hydrological data of the basin where the flood protection zone is located, river flood data, flood control project data of the protection zone, data on structures that affect the hydraulic characteristics of floods, socio-economic data, historical floods and flood disasters.

[0130] Step 10: Data compilation and evaluation: Check the data for completeness, accuracy, consistency, and timeliness. If data is insufficient, it needs to be supplemented through on-site surveys.

[0131] Step 11: Hydrological analysis and calculation. Combined with the inflow characteristics of the flood protection zone, flood composition analysis is performed to determine the hydrological combination for calculating inflow. A combination of climate and hydrological models is optimized for the flood protection zone's basin, and long-term inflow forecasts are performed.

[0132] Step 12: Flood analysis and calculation. For the river channel and protected area where the flood protection zone is located, the hydrodynamic model calculation parameters of the river channel and protected area are calibrated, such as roughness and other parameters, to analyze the inundation range, water depth, duration and flood arrival time under different working conditions in the flood protection zone.

[0133] Step 13: Conduct a regional flood impact analysis and loss assessment based on the flood damage model for the flood protection zone. Leveraging GIS technology, the flood loss assessment is conducted based on the inundation situation within the calculation area and the corresponding socioeconomic and demographic conditions.

[0134] Step 14: Risk evacuation analysis: determine the scope of risk evacuation, personnel transfer methods, resettlement area demarcation principles, and draw a risk evacuation map to form a risk evacuation route.

[0135] It should be understood that the specific order or hierarchy of steps in the processes disclosed herein are examples of exemplary methods. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the processes may be rearranged without departing from the scope of the present disclosure. The accompanying method claims present elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0136] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for constructing a flood damage model in a flood protection zone, characterized by: The following steps are included: Select several climate models and historical reference data, and perform downscaling analysis and bias correction on the climate variables output by each climate model; The downscaled and bias-corrected climate model is input into the global hydrological model to simulate runoff at global grid points; Select runoff observation data for each grid point and conduct verification and comparison of runoff data to screen or combine global hydrological models; Construct a global hydrodynamic model, input the optimized climate model and hydrological model results into the hydrodynamic model, conduct global hydrodynamic flood risk simulation, and use historical flood level statistics to calibrate the global hydrodynamic model; Combined with measured disaster loss indicator data, a global flood loss model was constructed; Calibrate and verify the global flood loss model by combining global historical loss indicator data; For a fixed future period, we selected the optimal climate model, downscaling and bias correction methods, hydrological model, calibrated global hydrodynamic model, and calibrated and validated global flood damage model to construct a long-duration dynamic flood damage model. According to the estimation results of the long-duration dynamic flood damage model, the calculation scope of the flood protection zone is determined, and a long-duration dynamic flood damage model for the flood protection zone is constructed.

2. The method for constructing a flood damage model for a flood protection zone according to claim 1, characterized in that: The global hydrodynamic model is constructed as follows: Parameters involved in the global hydrodynamic model: river water storage is S r , river depth D r , D r Determined by sea level elevation; the water storage in the floodplain is S f , floodplain water depth D f , flooded area in the floodplain A f ; Grid water storage S at the initial stage of flood ini ; S ini The calculation formula is as follows: S ini =B ini W ini L ini ; B ini 、W ini 、L ini Corresponding to the river depth B at the initial stage of flood ini , river width W ini , River Chief L ini ; The water storage of the next time step of the total water storage S is less than or equal to the grid water storage S at the initial flood period. ini The calculation formula of the global hydrodynamic model for the initial flood process is as follows: The water storage of the next time step of the total water storage S is greater than the grid water storage S at the initial flood period. ini The calculation formula of the global hydrodynamic model for the late flood retreat process is as follows: Where A f is the flooded area of the floodplain, which is determined by the topography, water depth of the floodplain, and water storage in the floodplain; A1 is the floodplain drainage area; D(A1) is the floodplain drainage depth; D f is the water depth in the floodplain; D(A f ) is the floodplain area in the flood submerged area A f Elevation profile function at D -1 (D f ) is the floodplain elevation contour function D(A f ) is the inverse function of .

3. The method for constructing a flood damage model for a flood protection zone according to claim 2, characterized in that: The calibration method of the global hydrodynamic model is as follows: The flood evolution process is calculated by calculating the grid water storage of each grid, which is calculated from the grid runoff and time-shifted according to the terrain data. The global hydrodynamic model is calibrated based on the flood evolution process as follows: Calculate the water storage S at grid point i based on the river flow i The amount of change: Water storage S at grid point i i The change from time t to time t+Δt is expressed by the following formula: in, and represent the water storage of grid point i at time t and time t+Δt, respectively; Upstream represents the total number of grid points of upstream inflow, Q k t is the inflow flow of the river (plus floodplain + bifurcation channel) from the upstream grid point k, is the sum of the inflow flows of all upstream grid points within the time Δt; Q i t is the outflow of the river (plus floodplain + bifurcation channel) at grid point i, is the outflow rate at grid point i in time Δt; Ac i is the unit watershed area within grid point i, R i t is the input runoff at grid point i, is the inflow rate at grid point i in time Δt; B, W, and L correspond to the river depth B, river width W, and river length L at time t, respectively; if Then use formula (1) to calibrate the global hydrodynamic model; if Then use formula (2) to calibrate the global hydrodynamic model; The global hydrodynamic model is corrected using formulas (3) and (4).

4. The method for constructing a flood damage model for a flood protection zone according to claim 3, characterized in that: The river flow is calculated based on the Saint-Venant equation: Where Q is the river flow (m 3 / s), A is the cross-sectional area (m 2 ), h is the fluid water depth (m), z is the riverbed bottom elevation (m), R is the hydraulic radius (m), g is the gravitational acceleration (ms- 2 ), n is the Manning friction coefficient (m -1 / 3 s -1 ), the value of the Manning friction coefficient n is determined by the grid topography; x and t represent the distance and time of river flow, respectively.

5. The method for constructing a flood damage model for a flood protection zone according to claim 4, characterized in that: The global flood damage model is as follows: Risk = F (hazard, exposure, vulnerability); Risk: refers to the possibility of human or economic loss; Hazard: refers to the intensity, frequency and scope of the occurrence of disaster-causing factors; Exposure: refers to the intersection of the impact range of the disaster and the spatial distribution of the disaster-bearing bodies; Vulnerability: refers to the size of the population or economic losses in the affected area.

6. The method for constructing a flood damage model for a flood protection zone according to claim 5, characterized in that: A long-duration dynamic flood damage model is constructed and represented by an X matrix. The calculation formula is as follows: X=(X ijt ) N×M×T ; Among them, X ijt is the disaster occurrence matrix, when X ijt =1, it is determined that the affected area needs to conduct regional flood impact analysis and loss assessment calculation at time t; i is the number of areas experiencing disasters; j is the disaster loss indicator data of the disaster, including population or economic losses; t is the time when the disaster occurs, 0≤t≤T; N is the number of samples in the disaster-affected area (determined by the grid size corresponding to the area of interest), 0≤i≤N; M is the disaster loss indicator data of the affected area, that is, the population or economic loss data caused by the flooding; if the population loss or economic loss is greater than the threshold, it is recorded as 1, otherwise it is recorded as 0; T is the estimated maximum duration of the disaster in the affected area.

7. A risk avoidance and transfer method based on a flood damage model in a flood protection zone, characterized by: The following steps are involved: Basic data collection and on-site investigation, data compilation and evaluation, and checking the completeness, accuracy, consistency and timeliness of data; Hydrological analysis and calculation: Combined with the inflow characteristics of the flood protection area, conduct flood composition analysis, determine the hydrological combination for calculating inflow, combine climate models and hydrological models for the basin where the flood protection area is located, and make long-term inflow forecasts; Flood analysis and calculation: Calibrate the parameters of the hydrodynamic model of the river channel and protected area corresponding to the river channel and protected area where the flood protection area is located, and analyze the inundation range, water depth, duration and flood arrival time under different working conditions in the flood protection area; Conduct regional flood impact analysis and loss assessment based on the flood damage model of the flood protection zone. Analyze the corresponding socio-economic and demographic conditions based on the inundation situation within the calculation range to conduct flood loss assessment. Analyze the risk transfer, determine the scope of risk transfer, personnel transfer methods, resettlement area demarcation principles, and draw a risk transfer map to form a risk transfer path.

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