A method for calculating flood resilience of housing in a flood detention area

Abstract

The application discloses a kind of flood storage area housing flood prevention resilience calculation method, the method comprises the following steps: step 1, collect flood storage area basic information;Step 2, calculate the housing damage index caused by flood;Step 3, calculate the recovery capacity index of flood storage area;Step 4, calculate the housing flood prevention resilience index of flood storage area.The method considers the harm caused by different flood storage area submerged flood to housing and the recovery capacity of housing in the area to recover to pre-disaster level, is suitable for all flood storage areas, fast in calculation speed, result is real and reliable, strong practicality, can be used to quickly assess the flood prevention resilience of housing in flood storage area, provides technical support for formulating flood prevention resilience improvement measures of flood storage area.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flood control and disaster reduction, and particularly relates to a calculation method for housing flood resilience in a flood storage area. BACKGROUND

[0002] The flood storage area is an important part of the flood control engineering system in China and is a place for flood storage. When the starting standard is reached, the flood storage area is started to store a certain amount of flood, and then the water is discharged from the flood storage area after the flood peak of the large river is passed. Therefore, the water storage time of the flood storage area is generally long. In addition, there are millions of people living in the flood storage area. Due to actual problems such as land and compensation, these people living in the flood storage area cannot be completely relocated. Therefore, once the flood storage is used, it will cause great damage to the housing of the people originally living in the flood storage area.

[0003] As an important part of the flood control and disaster reduction system of a river basin, the flood storage area plays an irreplaceable important role in defending the large floods of the river basin in the past and basically guarantees the safety of important cities and important flood control areas in the middle and lower reaches. At the same time, the flood storage area is also an important space for the production and life of the people in the area. Under the guidance of new concepts such as "two insistences and three changes" for disaster prevention, reduction and relief, the construction and development mode of the flood storage area cannot fully adapt to the changes in the current situation and requirements. In recent years, with the continuous improvement of the flood control and disaster reduction system of the river basin, the functions and starting conditions of some flood storage areas have changed greatly, and at the same time, the social and economic conditions in the area have also changed significantly. A part of the flood storage area is used frequently, and the living conditions of the residents are difficult to improve, while a part of the reserved flood storage area has high starting standards, but the economic development is greatly restricted, and the conflict between people and water for land is more prominent. In view of the reality of long-term coexistence of people and water in the flood storage area, how to improve the flood resilience of the housing in the flood storage area is a problem to be solved, but there is no calculation method for the flood resilience of the flood storage area at present. SUMMARY

[0004] The purpose of the present application is to provide a calculation method for the flood resilience of housing in a flood storage area to solve the above technical problems.

[0005] To achieve the above purpose, the present application provides the following technical scheme:

[0006] The present application discloses a calculation method for the flood resilience of housing in a flood storage area, which comprises the following steps:

[0007] Step 1, collecting the basic data of the flood storage area: collecting the basic data of the research flood storage area, including the total area of the flood storage area, the flood submergence water depth data under the design working condition, the housing space distribution layer in the flood storage area, the housing loss rate corresponding to different submergence water depths in the flood storage area, and the water recession time after the flood storage and flood storage operation of the flood storage area;

[0008] Step 2, calculate the housing damage index caused by flood: analyze the damage of flood to housing from three aspects of flood risk, housing exposure and housing vulnerability, and calculate the housing damage index I caused by flood Risk ; in the calculation process, first, the inundation water depth data is divided into different inundation water depth grades, the inundation area corresponding to different inundation water depth grades is counted, and then the housing area in the inundation area corresponding to different inundation water depth grades is counted, the housing area is obtained by superimposing the inundation water depth data and the housing space distribution layer in the detention basin; the calculation formula of the housing damage index I Risk

[0009]

[0010] In the formula, I H is the risk of the detention basin, which is characterized by the ratio of the inundation area under different grades of inundation water depth to the total area of the detention basin, and is dimensionless; I E is the housing exposure in the detention basin, which is characterized by the ratio of the housing area in the inundation area under different grades of inundation water depth to the inundation area, and is dimensionless; I V is the housing vulnerability in the detention basin, which is characterized by the housing loss rate corresponding to different grades of inundation water depth, and is dimensionless; i is the grade variable of inundation water depth; l is the grade of inundation water depth; I Ai is the inundation area corresponding to the i-th grade of inundation water depth, km 2 ; A is the total area of the detention basin, km 2 ; I Ei is the housing area in the inundation area corresponding to the i-th grade of inundation water depth, km 2 ; I Vi is the housing loss rate corresponding to the i-th grade of inundation water depth, dimensionless;

[0011] Step 3, calculate the recovery ability index of the detention basin: the recovery ability index I Rec of the detention basin is calculated by formula (2) considering the recovery time of the detention basin and the housing compensation and compensation ratio of the detention basin

[0012] I Rec = m1·I T + m2·I M (2)

[0013] In the formula, I T is the recovery time of the detention basin; I M is the housing compensation and compensation ratio of the detention basin; m1 and m2 are weights, which are determined by expert scoring method or analytic hierarchy process;

[0014] ​Step 4: Calculate the housing flood resilience index of the flood storage and detention area: give the flood-caused housing damage degree index and the flood storage and detention area recovery capacity index corresponding weights respectively, and calculate the housing flood resilience index R of the flood storage and detention area by using formula (6) D :

[0015] R D =n1·(1-I Risk )+n2·I Rec (6)

[0016] In the formula: n1, n2 are weights, which are determined by expert scoring method or analytic hierarchy process.

[0017] Further, the total area of the flood storage and detention area in step 1 is obtained from the flood storage and detention area operation plan; the flood inundation water depth data is obtained by simulating the flood inundation process using a flood numerical simulation model; the housing space distribution layer in the flood storage and detention area is obtained by querying the third national land survey data to select residential land in the land use status classification, or extracting residential land based on the latest land use remote sensing monitoring data; the housing loss rate corresponding to different inundation water depths in the flood storage and detention area is obtained by conducting field investigation on the flood storage and detention area, combined with the disaster season, range, flood prediction period, rescue time, and rescue measures; the water recession time is the flood emptying time under the design working condition of the flood storage and detention area, which is calculated using a flood numerical simulation model.

[0018] Further, the recovery time I T of the flood storage and detention area in step 3 is calculated by formula (3):

[0019]

[0020] In the formula: the start of the water recession time is considered according to the time when the flood storage water level starts to drop or the outflow is greater than the inflow; the housing damage critical time is the critical value at which the housing may be soaked to destruction; when the water recession time is greater than the critical time, the critical time is assigned;

[0021] The housing compensation and compensation ratio I M of the flood storage and detention area is calculated by formula (4):

[0022]

[0023] In the formula, the government compensation housing amount is determined according to the "Interim Measures for Compensation of Flood Storage and Detention Area Operation"; the insurance compensation housing amount is obtained by field investigation; and the housing loss in the flood storage and detention area is calculated by formula (5):

[0024]

[0025] In the formula, W is the pre-disaster value of the housing in the flood detention area, yuan, which is obtained by pre-disaster field investigation and evaluation;

[0026] If the flood detention area has been used historically, the government compensation for housing, the insurance compensation for housing, and the housing loss in the flood detention area are determined based on post-disaster investigation.

[0027] The method has the advantages that the method considers the damage caused by the flood in the different flood detention areas to the housing and the recovery ability of the housing in the flood detention area to recover to the pre-disaster level, is suitable for all flood detention areas, has fast calculation speed, real and reliable results, strong practicability, and can be used for quickly evaluating the flood resistance of the housing in the flood detention area, and provides technical support for formulating the flood resistance improvement measures of the flood detention area.

[0028] The application will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The method flowchart is shown. DETAILED DESCRIPTION

[0030] The application discloses a flood detention area housing flood resistance calculation method, as shown in the formula, the method comprises the following steps: Figure 1

[0031] Step 1, collecting the basic data of the flood detention area: collecting the basic data of the studied flood detention area, including the total area of the flood detention area, the flood inundation water depth data under the design working condition, the housing space distribution layer in the flood detention area, the housing loss rate corresponding to different inundation water depths in the flood detention area, the water recession time after the flood detention and flood diversion of the flood detention area, and the like.

[0032] The total area of the flood detention area is obtained from the flood detention area operation plan; the flood inundation water depth data can generally be obtained by simulating the flood inundation process by using a flood numerical simulation model; the housing space distribution layer in the flood detention area can generally be obtained by selecting the residential land in the land use status classification by querying the third national land survey data, or by extracting the residential land based on the latest period of land use remote sensing monitoring data; the housing loss rate corresponding to different inundation water depths in the flood detention area is generally obtained by conducting field investigation in the studied flood detention area, and on this basis, the correlation between the housing loss rate and the inundation water depth is obtained by combining the disaster season, range, flood prediction period, rescue time, and rescue measures; and the water recession time is the flood emptying time under the design working condition of the flood detention area, which can be calculated by using the flood numerical simulation model.

[0033] ​Step 2: Calculate the housing damage index caused by flood: analyze the possible damage to housing from flood from three aspects of flood risk, housing exposure and housing vulnerability, and calculate the housing damage index I caused by flood using formula (1) Risk . Wherein, it is necessary to first divide the submerged water depth data into different submerged water depth grades, count the submerged area corresponding to different submerged water depth grades, and then count the housing area in the submerged area corresponding to different submerged water depth grades, which is obtained by superimposing the submerged water depth and the housing space distribution layer in the flood storage and detention area.

[0034]

[0035] wherein: I H is the risk of the flood storage and detention area, which is represented by the ratio of the submerged area under different submerged water depth grades to the total area of the flood storage and detention area, dimensionless; I E is the exposure of housing in the flood storage and detention area, which is represented by the ratio of the housing area in the submerged area under different submerged water depth grades to the submerged area, dimensionless; I V is the vulnerability of housing in the flood storage and detention area, which is represented by the housing loss rate corresponding to different submerged water depth grades, dimensionless; i is the submerged water depth grade variable; l is the submerged water depth grade series; I Ai is the submerged area corresponding to the i-th submerged water depth grade, km 2 ; A is the total area of the flood storage and detention area, km 2 ; I Ei is the housing area in the submerged area corresponding to the i-th submerged water depth grade, km 2 ; I Vi is the housing loss rate corresponding to the i-th submerged water depth grade, dimensionless, which can be found by looking up the housing loss rate corresponding to different submerged water depths collected in step 1.

[0036] Step 3: Calculate the recovery capacity index of the flood storage and detention area: the recovery capacity index I Rec of the flood storage and detention area is calculated by considering the recovery time of the flood storage and detention area and the housing compensation and compensation ratio of the flood storage and detention area, and using formula (2):

[0037] I Rec = m1·I T +m2·I M (2)

[0038] wherein: I T is the recovery time of the flood storage and detention area; I M is the housing compensation and compensation ratio of the flood storage and detention area; m1 and m2 are weights, which are determined by expert scoring method or analytic hierarchy process.

[0039] wherein, the recovery time I TThe formula (3) is used to calculate:

[0040]

[0041] In the formula, the beginning of the flood recession time is considered according to the time when the flood storage water level begins to drop or the outflow is greater than the inflow; the critical time of the house damage is a critical value at which the house can be soaked to be damaged, and when the flood recession time exceeds the critical value, the house will be damaged due to long-term soaking; and the critical time is assigned when the flood recession time is greater than the critical time.

[0042] The housing compensation and indemnity ratio I of the flood storage and detention area M The formula (4) is used to calculate:

[0043]

[0044] In the formula, the government compensation housing amount can be determined according to the Temporary Measures for Compensation of Flood Storage and Detention Areas; the insurance compensation housing amount can be determined according to the local specific policy, and for the studied flood storage and detention area, the insurance compensation housing amount can be determined through field investigation; and if the flood storage and detention area has been used historically, the government compensation and insurance compensation housing amounts of the flood storage and detention area can be determined through post-disaster investigation.

[0045] The housing loss in the flood storage and detention area is calculated by the formula (5):

[0046]

[0047] In the formula, W is the pre-disaster value (yuan) of the housing in the flood storage and detention area, which is generally obtained through pre-disaster field investigation and evaluation; and if the flood storage and detention area has been used historically, the housing loss in the flood storage and detention area can be determined according to the post-disaster investigation.

[0048] Step 4: Calculate the housing flood resilience index of the flood storage and detention area: give the housing damage degree index caused by the flood and the recovery ability index of the flood storage and detention area corresponding weights respectively, and calculate the housing flood resilience index R of the flood storage and detention area by the formula (6): D :

[0049] R D =n1·(1-I Risk )+n2·I Rec (6)

[0050] In the formula, n1 and n2 are weights, which are determined by expert scoring method or analytic hierarchy process.

[0051] Example 1

[0052] This example is an application example of the above method.

[0053] This embodiment discloses a method for calculating the flood resilience of housing in flood storage and detention areas, including the following steps:

[0054] Step 1: Collect basic data on flood storage and detention areas: Collect basic data on the flood storage and detention areas to be studied, including the total area of ​​the flood storage and detention areas, flood inundation depth data under design conditions, spatial distribution map of housing within the flood storage and detention areas, housing loss rates corresponding to different inundation depths within the flood storage and detention areas, and the receding time after the flood storage and detention areas are used for flood storage and detention; in this embodiment, the total area of ​​the flood storage and detention areas is 253 km². 2 .

[0055] Step 2: Calculate housing damage index caused by flood: In this embodiment, the flood depth data is divided into 7 levels. The housing area and housing loss rate within the flood range corresponding to different flood depth levels are shown in Table 1.

[0056] Table 1

[0057] Submergence depth class (m) Housing area (km 2 )]]> Rate of housing loss (%) 0.05～0.5 3.2129251 8 0.5～1.0 4.811825 14 1.0～1.5 4.928101 25 1.5～2.0 4.1240047 34 2.0～2.5 2.724999 43 2.5～3.0 1.7790947 50 ＞3.0 0.380297 67

[0058] The housing damage index I caused by floods is calculated using formula (1). Risk :

[0059]

[0060] Based on the data in Table 1, this embodiment calculates the housing damage index I. Risk It is 0.0232.

[0061] Step 3: Calculate the recovery capacity index of the flood storage and detention area: Flood storage and detention area recovery capacity index I Rec Calculate according to formula (2):

[0062] I Rec =m1·I T +m2·I M (2)

[0063] In the formula: I T The recovery time for flood storage and detention areas; I M The values ​​for housing compensation and damages in flood storage and detention areas are: m1 and m2 are weights; in this embodiment, the values ​​of m1 and m2 are both 0.5.

[0064] Among them, the recovery time of flood storage and detention areas I T Calculated using formula (3), in this embodiment, the critical time for housing damage due to flooding in the flood storage and detention area is set to 10 days, and the water receding time of the flood storage and detention area is 23 days. Since the water receding time is longer than the critical time for housing damage due to flooding, the water receding time is set to 10 days based on the critical time for housing damage due to flooding. Therefore, the recovery time index I of the flood storage and detention area in this embodiment is... T for:

[0065]

[0066] The housing compensation ratio I of the flood storage area M The housing compensation ratio I of the flood storage area in the embodiment is calculated by formula (4) M :

[0067]

[0068] The government compensation, the insurance compensation housing amount and the housing loss in the flood storage area in the embodiment are all from the post-disaster investigation statistics.

[0069] Therefore, the recovery capacity index I of the flood storage area in the embodiment is finally calculated as Rec 0.35.

[0070] Step 4: Calculate the housing flood prevention resilience index of the flood storage area: the housing flood prevention resilience index R of the flood storage area is calculated by formula (6) D The values of n1 and n2 in the embodiment are both 0.5, so the housing flood prevention resilience index of the flood storage area in the embodiment is calculated as

[0071] R D = n1·(1-I Risk ) + n2·I Rec = 0.6634 (6)

[0072] Finally, it should be noted that the above description is only used to illustrate the technical solutions of the present application and is not limited. Although the present application has been described in detail with reference to the preferred arrangement, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for calculating flood resilience of a flood storage area housing, characterized in that, The method comprises the following steps: Step 1, collecting the basic information of the flood storage area: collecting the basic information of the research flood storage area, including the total area of the flood storage area, the flood submerged water depth data under the design working condition, the housing space distribution layer in the flood storage area, the housing loss rate corresponding to different submerged water depths in the flood storage area, the water recession time after the flood storage and drainage operation of the flood storage area; Step 2, calculating the housing damage index caused by flood: analyzing the damage of flood to housing from three aspects of flood danger, housing exposure and housing vulnerability, and calculating the housing damage index I caused by flood Risk ; in the calculation process, first, the submerged water depth data is divided into different submerged water depth grades, the submerged area corresponding to different submerged water depth grades is counted, and then the housing area in the submerged area corresponding to different submerged water depth grades is counted, the housing area being obtained by superimposing the submerged water depth data and the housing space distribution layer in the detention basin; the calculation formula of the housing damage index I Risk is: In the formula: I H is the risk of the flood detention basin, which is represented by the proportion of the area of the flooded area under different levels of flooded water depth to the total area of the flood detention basin, dimensionless; I E is the exposure of housing in the flood detention basin, which is represented by the proportion of the housing area in the flooded area under different levels of flooded water depth to the area of the flooded area, dimensionless; I V is the vulnerability of housing in the flood detention basin, which is represented by the housing loss rate corresponding to different levels of flooded water depth, dimensionless; i is the variable of the flooded water depth level; l is the level number of the flooded water depth; I Ai is the area of the flooded area corresponding to the i-th level of flooded water depth, km 2 ; A is the total area of the flood detention basin, km 2 ; I Ei is the housing area in the flooded area corresponding to the i-th level of flooded water depth, km 2 ; I Vi is the housing loss rate corresponding to the i-th level of flooded water depth, dimensionless; Step 3, calculate the flood storage and detention basin recovery capacity index: the flood storage and detention basin recovery capacity index I Rec Considering the recovery time of the flood storage and detention basin and the flood storage and detention basin housing compensation and compensation ratio, formula (2) is used for calculation: I Rec = m1 · I T + m2 · I M (2) In the formula: I T is the recovery time of the flood detention area; I M is the housing compensation and compensation ratio of the flood detention area; m1 and m2 are weights, which are determined by expert scoring method or analytic hierarchy process. Step 4: Calculate the housing flood resilience index of the flood detention basin: give the flood damage degree index of the housing and the recovery ability index of the flood detention basin corresponding weights respectively, and calculate the housing flood resilience index R of the flood detention basin by using formula (6) D : R D = n1 · (1 - i Risk )+ n2 · I Rec (6) In the formula, n1 and n2 are weights, which are determined by expert scoring method or analytic hierarchy process.

2. The method of claim 1, wherein, The total area of the flood storage area in step 1 is obtained from the flood storage operation plan; the flood submerged water depth data is obtained by simulating the flood submerged process by using a flood numerical simulation model; the housing space distribution layer in the flood storage area is obtained by selecting residential land in the land use status classification by querying the third national land survey data, or extracting residential land based on the latest period of land use remote sensing monitoring data; the housing loss rate corresponding to different submerged water depths in the flood storage area is obtained by field investigation of the flood storage area, combined with disaster season, range, flood prediction period, rescue time, rescue measures; the water recession time is the flood emptying time under the design working condition of the flood storage area, which is calculated by using a flood numerical simulation model.

3. The method of claim 1, wherein, Retention basin recovery time I in step 3 T From equation (3) In the formula, the starting flood recession moment of the water recession time is considered according to the moment when the flood storage water level starts to drop or the outflow is greater than the inflow; the critical time of housing damage due to flooding is the critical value of housing being soaked to damage; when the water recession time is greater than the critical time, the critical time is valued; Compensation and indemnification ratio of housing in flood detention area I M From formula (4), we get: In the formula, the government compensation housing amount is determined with reference to the Interim Measures for Compensation of Flood Storage Area Operation; the insurance compensation housing amount is obtained by field investigation; the housing loss in the flood storage area is calculated by using formula (5): In the formula, W is the pre-disaster value of the housing in the flood storage area, yuan, which is obtained by pre-disaster field investigation and evaluation; If the flood storage area has been used in history, the government compensation housing amount, the insurance compensation housing amount and the housing loss in the flood storage area are determined with reference to post-disaster investigation.

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