A real-time quantitative assessment method for flood risk

Abstract

The present invention discloses a method for quantitatively evaluating real-time flood risk. The method establishes the relationship between flood frequency (P), corresponding loss (L), and flood control risk rate (P f ), and constructs a flood risk control standard diagram, thereby quantitatively evaluating the risk level of real-time flood, that is, determining whether it belongs to the acceptable risk area, the tolerable risk area, or the unacceptable risk area. The solution provided by the present invention for quantitatively evaluating real-time flood risk overcomes the deficiency in the current hydrological field that the risk control standard for real-time flood risk assessment only considers the flood control risk rate or flood occurrence frequency without considering flood losses. By combining the flood control risk rate and flood losses, the risk control standard can be tailored to specific situations and adapt to different flood control protection objects, providing a technical basis for basin flood control, disaster reduction, and emergency management.

Description

Technical Field

[0001] The present invention belongs to the technical field of water conservancy engineering, and particularly relates to a method for quantitatively evaluating real-time flood risk. Background Art

[0002] Risk can usually be expressed as the product of the probability of an adverse event occurring and the consequences it may cause. Flood risk assessment mainly analyzes the probability of flood occurrence and the possible economic, life losses, environmental and social impacts, and judges whether it can be tolerated or accepted by the public according to the risk criteria. Therefore, a reasonable risk criterion is the basis and key for accurate risk assessment. Flood risk assessment is also called flood risk analysis, which mainly consists of three parts: flood risk identification, flood risk estimation and flood risk evaluation.

[0003] Currently, the commonly used form of flood risk control criteria is to classify the protected objects according to the flood control risk rate or flood occurrence frequency. This method isolates the risk rate and losses, and cannot reflect the actual needs of each basin for flood control safety, nor can it reflect the differences between different protected objects of the same scale. In addition, the current flood risk assessment work mainly focuses on "qualitative assessment during the event and quantitative assessment after the event", and how to quantitatively evaluate flood risk in real time is a difficult problem. Summary of the Invention

[0004] In order to solve the technical problems in the prior art that the risk control criteria for real-time flood risk assessment cannot consider both the flood control risk rate and flood disaster losses at the same time, and the difficulty of real-time quantitative assessment is relatively large, the present invention proposes a method for quantitatively evaluating real-time flood risk.

[0005] The object of the present invention is achieved as follows:

[0006] The present invention provides a method for quantitatively evaluating real-time flood risk, and the method includes the following steps:

[0007] Step 1, establish the relationship between flood occurrence frequency and corresponding losses

[0008] S101, select several representative basins or regions, and calculate the flood processes with different flood occurrence frequencies and their corresponding loss data;

[0009] S102, integrate the data of the above-mentioned several basins or regions, establish a quantitative statistical relationship between the frequency P of flood events and the corresponding loss L, and draw a P~L flood loss curve.

[0010] Step 2, establish a flood risk control standard map

[0011] Adopt the risk rate calculation method to obtain the flood control risk rate P corresponding to the flood event with a frequency of P f , and establish the flood control risk rate Pf The corresponding relationship with the loss L forms a flood risk control standard map, which includes an acceptable risk area, a tolerable risk area, and an unacceptable risk area.

[0012] Step 3, Quantitative assessment of real-time flood risk

[0013] S301, When a flood actually occurs, determine the recurrence period T of this flood according to the peak flood or flood volume * or frequency P * ;

[0014] S302, Adopt the risk rate calculation method to obtain the flood control risk rate corresponding to the flood event with a frequency of P * Query the P~L flood loss curve graph described in Step 1 to obtain the loss L corresponding to the flood event with a frequency of P * ; * * ;

[0015] S303, According to the value obtained in S302 Query the flood risk control standard map established in Step 2 to obtain the risk level of the real-time flood event, that is, judge whether it belongs to the acceptable risk area (low risk), the tolerable risk area (medium risk) or the unacceptable risk area (high risk).

[0016] Furthermore, in S101 of Step 1, the loss L is expressed as the proportion of the economic loss caused by the flood in the regional GDP, and the flood occurrence frequency P is replaced by the recurrence period T. Specifically:

[0017] P = 1 / T.

[0018] It is also possible to collect existing flood risk map results, which generally include the above data.

[0019] Furthermore, the specific method for establishing the flood risk control standard map in Step 2 is as follows:

[0020] S201: For a flood with a certain frequency P in the representative basin or region described in Step 1, adopt the risk rate calculation method to obtain the corresponding flood control risk rate P f ;

[0021] S202: Repeat S201 to obtain several groups of (P, P f ) data; According to the P~L flood loss curve graph drawn in Step 1, obtain (P f , L) data;

[0022] S203: Synthesize the (P f , L) data to form a regional flood risk control standard map.

[0023] Further, in step 2, the different regions shown in the flood risk control standard map respectively represent:

[0024] The acceptable risk area refers to the area where the probability of adverse consequences of a flood event is small and the resulting losses are small, which can be accepted. In principle, no risk control and reduction measures are required.

[0025] The tolerable risk area refers to the area where the probability of adverse consequences of a flood event is relatively large and the resulting losses are relatively large, but can be tolerated.

[0026] The unacceptable risk area refers to the area where the probability of adverse consequences of a flood event is very large and the losses are also very large and unacceptable, and measures need to be taken to reduce the risk.

[0027] Further, in step 2, by calculating the probability that the flood load is greater than the resistance, the flood control risk rate P corresponding to the flood event with a frequency of P is obtained f ;

[0028] Among them, the flood load is expressed as peak flood flow, flood volume or flood level, and the resistance is expressed as flood discharge capacity, flood control capacity or flood control level.

[0029] Further, in step 3, S301, the specific method for obtaining the flood frequency P * of this flood is as follows:

[0030] According to the position of the peak flood or flood volume corresponding to the peak flood experience frequency curve or flood volume experience frequency curve in this basin, its frequency P * (P * = 1 / T * )

[0031] The advantages and beneficial effects of the present invention are:

[0032] The real-time flood risk quantitative assessment method described in the present invention overcomes the deficiency that the risk control standard for real-time flood risk assessment in the current hydrological field only considers the flood control risk rate or flood occurrence frequency, without considering the flood disaster losses. It can only evaluate the flood disaster losses after the flood occurs, and is applicable to the real-time flood risk assessment of different protection objects of the same scale, providing a technical basis for basin flood control and disaster reduction and emergency management. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the drawings and embodiments.

[0034] Figure 1 It is a schematic diagram of the P~L flood loss curve drawn by selecting some representative basins (or regions);

[0035] Figure 2It is a schematic diagram of flood risk control standards drawn for some representative river basins (or regions). Specific implementation manners

[0036] Example:

[0037] In this example, a flood event N occurred in an existing river basin A. According to the method described in the present invention, the process of real-time risk quantitative assessment of this flood is as follows:

[0038] Step 1: Establish the relationship between flood occurrence frequency and corresponding losses

[0039] S101: Select several representative river basins or regions within the area where river basin A is located or a larger river basin range, collect the corresponding historical flood events and their corresponding economic loss data and information (it is possible to collect existing flood risk map results, and such data is generally included in the flood risk map results). According to flood frequency analysis, calculate the frequencies corresponding to the historical flood events as P = (P1, P2, P3,...), and their corresponding losses as L = (L1, L2, L3,...).

[0040] S102: Integrate the (P, L) data of the above several river basins, establish a quantitative statistical relationship between the flood event frequency P and the corresponding loss L, and draw a P~L flood loss curve as shown in Figure 1 Figure

[0041] Step 2: Establish a flood risk control standard map

[0042] S201: For the frequencies P = (P1, P2, P3,...) corresponding to the historical flood events in Step 1, use a risk rate calculation method (such as calculating the probability that the flood load is greater than the resistance) to obtain the corresponding flood control risk rate P f =(P f,1 ,P f,2 ,P f,3 ,...).

[0043] Among them, the flood load is expressed as peak flood discharge, flood volume or flood level, and the resistance is expressed as flood discharge capacity, flood control capacity or flood control level.

[0044] S202: Integrate the (P f 、L) data and draw a regional flood risk control standard map as shown in Figure 2 Figure. It includes three regions: acceptable, tolerable, and unacceptable, corresponding to high, medium, and low levels of risk respectively.

[0045] Acceptable risk means that the probability of adverse consequences of a flood event occurring in this area is small, the resulting losses are small, and it is acceptable. In principle, no risk control and reduction measures need to be taken; Tolerable risk means that the probability of adverse consequences of a flood event occurring in this area is relatively large, and the resulting losses are relatively large, but it can be tolerated (measures can be taken to reduce the risk, but the benefit of reducing the risk should be higher than the cost of reducing the risk); Unacceptable risk means that the probability of adverse consequences of a flood event occurring in this area is very large, the losses are also very large and unacceptable, and measures need to be taken to reduce the risk.

[0046] Step 3, Quantitative assessment of real-time flood risk

[0047] S301, For the current flood event N, query the peak flood frequency curve or flood volume frequency curve of basin A to determine the frequency P of this flood. * 。

[0048] S302, Using the risk rate calculation method, obtain the flood control risk rate corresponding to the flood event with a frequency of P * of Query the frequency P of flood event N * At the data point position on the P~L flood loss curve as shown in Figure 1 , obtain the loss L corresponding to flood event N * 。

[0049] S303, According to the value obtained in S302, query the regional flood risk control standard map as shown in Figure 2 to obtain the risk level of the real-time flood event N, that is, judge whether it belongs to the acceptable risk area (low risk), tolerable risk area (medium risk) or unacceptable risk area (high risk), so as to complete the quantitative assessment of the risk of this real-time flood.

[0050]

[0050] In summary, the real-time flood risk quantitative assessment method disclosed in the present invention, by establishing the relationship between flood frequency (P), corresponding loss (L) and flood control risk rate (P f ), drawing the flood risk control standard map, and then quantitatively assessing the risk level of real-time flood events.

[0051] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred arrangement, those of ordinary skill in the art should understand that the technical solution of the present invention (such as the application of various formulas, the sequence of steps, etc.) can be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A real-time flood risk quantitative assessment method, characterized in that, The method includes the following steps: Step 1, establish the relationship between flood occurrence frequency and corresponding losses S101, select several representative basins or regions, and calculate the flood processes with different flood occurrence frequencies and their corresponding loss data; the loss L is represented by the proportion of the economic loss caused by the flood in the regional GDP, and the flood occurrence frequency P is replaced by the recurrence period T. Specifically: P = 1 / T S102, synthesize the data of the above-mentioned several basins or regions, establish the quantitative statistical relationship between the frequency P of flood events and the corresponding loss L, and draw the P~L flood loss curve; Step 2, establish the flood risk control standard map Using the risk rate calculation method, the flood control risk rate P corresponding to the flood event with a frequency of P is obtained f , and the corresponding relationship between the flood control risk rate P f and the loss L is established to form a flood risk control standard diagram, which includes an acceptable risk area, a tolerable risk area, and an unacceptable risk area. Specifically: S201: For a flood with a certain recurrence interval P in the representative basin or region described in Step 1, use the risk rate calculation method to obtain the corresponding flood control risk rate P f ; S202: Repeat S201 to obtain several groups of (P, P f ) data; According to the P~L flood loss curve diagram drawn in step 1, obtain (P f , L) data; S203: Synthesize (P f , L) data to form a regional flood risk control standard map; Step 3, quantitative assessment of real-time flood risk S301. When a flood actually occurs, determine the recurrence interval T or frequency P of this flood according to the peak flood or flood volume. * or frequency P * ; S302. Using the risk rate calculation method, obtain the flood control risk rate corresponding to the flood event with a frequency of P * Query the P-L flood loss curve described in Step 1 to obtain the loss L corresponding to the flood event with a frequency of P Query the P-L flood loss curve described in Step 1 to obtain the loss L corresponding to the flood event with a frequency of P * of the flood event * ; S303, based on the value obtained in S302 query the flood risk control standard map established in step 2 to obtain the risk level of the real-time flood event, that is, determine whether it belongs to the acceptable risk area, the tolerable risk area or the unacceptable risk area.

2. The real-time flood risk quantitative assessment method according to claim 1, wherein In Step 2, the different regions shown in the flood risk control standard map respectively represent: The acceptable risk area means that the probability of adverse consequences of flood events occurring in this area is small, the resulting losses are small, and it is acceptable. In principle, no risk control and reduction measures need to be taken; The tolerable risk area means that the probability of adverse consequences of flood events occurring in this area is relatively large, the resulting losses are relatively large, but it can be tolerated; The unacceptable risk area means that the probability of adverse consequences of flood events occurring in this area is very large, the losses are also very large and unacceptable, and measures need to be taken to reduce the risk.

3. The real-time flood risk quantitative assessment method according to claim 1, wherein, In Step 2, by calculating the probability that the flood load is greater than the resistance, the flood control risk rate P corresponding to the flood event with a frequency of P is obtained. f ; Among them, the flood load is expressed as peak flood flow, flood volume or flood level, and the resistance is expressed as flood discharge capacity, flood control capacity or flood control level.

4. The real-time flood risk quantitative assessment method according to claim 1, characterized in that In step 3, in S301, obtain the flood frequency P of this flood event * The specific method is as follows: Determine its frequency P according to the position corresponding to the peak flow or flood volume on the peak flow empirical frequency curve or flood volume empirical frequency curve of the basin * .

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