KR20220080463A - Urban flash flood forecast/warning system and method - Google Patents

Abstract

A method for predicting and warning an urban flash flood is disclosed. The urban flash flood prediction and warning method collects rainfall data through radar and rainfall gauge data of the relevant watershed, generates synthetic rainfall through conditional synthesis, and extracts rainfall data for the length of the arrival time of the watershed to determine the amount of rainfall. estimating; setting a predictive warning standard through an allowable flood area ratio and a coefficient of variation; and a flood warning warning step of comparing the rainfall intensity and/or runoff with the preliminary warning standard to implement a flood warning warning.

Description

Urban flash flood warning system and method {URBAN FLASH FLOOD FORECAST/WARNING SYSTEM AND METHOD}

The present invention relates to an urban flash flood forecasting system and a method therefor, and more particularly, by establishing a forecasting process using a flood-induced rainfall threshold and a flood-induced runoff threshold to ensure the accuracy and reliability of the flood forecasting and warning system, rainfall It relates to an urban flash flood forecasting system and method that can derive an accurate threshold value of a flood warning based on information on and flooded areas.

The occurrence of extreme weather due to climate change is increasing worldwide, and the frequency of natural disasters is increasing every year due to industrialization and urbanization.

Early flood warning systems are widely applied to mitigate damage caused by floods. One of the most important components of early flood warning systems is Flood-inducing Rainfall (FIR), which is used as the basis for flood warnings.

Determination of flood-induced rainfall (FIR) can be classified as either a simulation-based approach or a data-driven approach, which is prone to errors in unmeasured watersheds because model parameters cannot be calibrated.

To this end, we use a data-driven approach to determine flood-induced rainfall (FIR) based on field data from flooded areas and empirical analysis of those rainfall, which requires large amounts of accurate rainfall, runoff, and flooded area data.

To date, only flood-induced rainfall (FIR) corresponding to river floods and landslides has been covered, and there has been no study explicitly discussing flood-induced rainfall (FIR) in urban environments. Accurately estimate FIR in urban environments because flooding in urban environments responds faster to rainfall compared to river floods and landslides, and artificial changes in underground drainage networks and local topography and surface play important roles in flood mechanisms in urban areas. It was difficult.

On the other hand, watershed flooding is greatly affected by the temporal variability of rainfall and the impermeability of the watershed. Therefore, in order to increase the accuracy of the flood warning, it is necessary to consider not only the flood-induced rainfall (FIR), but also the flood-inducing runoff (FIRO, Flood-inducing Runoff) considering the effects of watershed imperviousness and antecedent function (moisture) conditions. the current situation.

The present invention is to solve the limitations of the conventional urban watershed flood prediction and warning system as described above. An example of an urban flash flood that can accurately predict and alert the flash flood in an urban watershed through the flood-induced rainfall threshold and the flood-induced runoff threshold. To provide an alarm system and method therefor.

The urban flash flood prediction and warning method according to an embodiment of the present invention for solving the above technical problem collects rainfall data through radar and rainfall gauge data of the watershed, and generates synthetic rainfall through a conditional synthesis technique. estimating rainfall by extracting rainfall data corresponding to the length of the arrival time of the watershed; setting a predictive warning standard through an allowable flood area ratio and a coefficient of variation; and a flood warning warning step of comparing the rainfall intensity and/or runoff with the preliminary warning standard to implement a flood warning warning.

The concentration time (TOC), which is the arrival time of the corresponding watershed, is the sum of the surface flow time and the channel flow time, and the concentration time (TOC) is estimated through the pipe network GIS database of the corresponding area.

The conditional synthesis technique is characterized in that the gauge-based rainfall field is adjusted using information about the rainfall spatial structure obtained from radar data.

The step of setting the preliminary warning standard includes calculating a coefficient of variation (Pcv) for flooding-induced rainfall and calculating a flood-induced rainfall threshold determined by the coefficient of variation (Pcv) and the selected allowable inundation area ratio. characterized in that

The step of setting the preliminary warning standard includes calculating a coefficient of variation (Rcv) for the flood-induced runoff and calculating a flood-induced runoff threshold value determined by the coefficient of variation (Rcv) and the selected allowable submerged area ratio. characterized in that

The allowable immersion area ratio is characterized in that it is selected from 1 to 30%.

When the allowable submerged area ratio or threshold values are selected to be small, the hit rate is lowered and false alarms are reduced.

The flooding prediction warning step includes: calculating a rainfall time series average rainfall intensity (Pave) of a watershed arrival time length; comparing a flood-induced rainfall threshold and a magnitude of the time series average rainfall intensity; and when the magnitude of the time-series average rainfall intensity Pave is greater than the flood-induced rainfall threshold, executing a flood prediction warning.

The flooding prediction warning step includes: calculating an outflow curve index of the watershed; estimating the runoff using the NRCS runoff curve index method; calculating an average (Rave) of the runoff amount time series of the watershed arrival time length; comparing a flood-induced runoff threshold and an average (Rave) of the runoff time series; and when the magnitude of the average (Rave) of the runoff time series is greater than the flooding-induced runoff threshold, executing a flooding prediction warning.

A computer program stored in a readable recording medium may be executed to execute the method.

An urban flash flood prediction and warning system according to another embodiment of the present invention includes: a communication unit configured to receive radar precipitation data of a corresponding watershed and rainfall data of a precipitation station; And after generating synthetic rainfall through the conditional synthesis technique, the rainfall data is extracted as much as the length of the arrival time of the watershed to estimate the rainfall. or a control unit that compares the amount of outflow with the preliminary warning standard and executes a flood warning warning.

and a database unit for storing the preliminary warning standard, wherein the preliminary warning standard includes a flood-induced rainfall threshold determined by a coefficient of variation (Pcv) for flood-induced rainfall and an allowable inundation area ratio, and fluctuations in flood-induced runoff It is characterized in that it is a flood-induced runoff threshold determined by a coefficient (Rcv) and an allowable inundation area ratio.

The control unit obtains a flood-induced rainfall threshold value from the database unit, calculates a rainfall time series average rainfall intensity (Pave) of the watershed arrival time length, and determines the magnitude of the flood-induced rainfall threshold value and the time series average rainfall intensity In comparison, when the magnitude of the time-series average rainfall intensity Pave is greater than the flood-induced rainfall threshold, a flood prediction warning is implemented.

The control unit obtains a flood-induced runoff threshold value from the database unit,

Calculate the runoff curve index of the watershed, calculate the runoff by using the NRCS runoff curve index method, and calculate the average (Rave) of the runoff time series of the watershed arrival time length, and the average (Rave) of the inundation-induced runoff threshold and the runoff time series ( Rave), and when the magnitude of the average (Rave) of the runoff time series is greater than the flooding induced runoff threshold, a flood warning is implemented.

The runoff is characterized in that it is determined in consideration of the watershed impermeability and the preceding function condition.

According to the present invention, since the temporal variability of rainfall and runoff can be taken into account, the accuracy of the flood warning system can be increased, and the warning criterion is derived from the radar-gauge composite rainfall to improve the hit rate and minimize omissions and false alarms.

1 is a block diagram of an urban flash flood warning system according to the present invention;
2 is a flowchart showing a method for predicting and warning an urban flash flood according to the present invention;
3 is a flowchart showing a flood forecast warning according to an embodiment of the present invention;
4 is a flowchart showing a flood warning according to another embodiment of the present invention;
5 is a graph showing the estimation of flood-induced rainfall;
6 is a graph showing the relationship between the concentration time and the flood-induced rainfall;
7 is a graph showing the relationship between the concentration time and the flood-induced runoff;
8 is a graph showing the relationship between flood-induced rainfall and flood-induced runoff, which change according to a coefficient of variation and an allowable inundation area ratio;
9 is a graph showing the performance of a flood warning system based on FIR and FIRO and FIR and FIRO that changes by a coefficient of variation;
10 and 11 are graphs showing the performance of the conventional flood warning system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

1 is a block diagram of an urban flash flood warning system according to the present invention.

Referring to FIG. 1 , the urban flash flood prediction and warning system according to the present invention includes a database unit 110 , a communication unit 120 , and a control unit 130 .

The communication unit 120 receives the radar precipitation data of the corresponding watershed and the rainfall data of the precipitation station and transmits the received data to the control unit 130 . Here, the watershed is an urban area and means an area where damage is expected due to rainfall and/or runoff.

The radar precipitation data is provided by the Korea Meteorological Administration, and has spatial and temporal resolution of 1*1 km and 10-minute intervals. The rainfall data of the precipitation station is the rainfall data at 1-minute intervals.

The urban flash flood prediction and warning system according to an embodiment of the present invention is based on observed rainfall data, not predicted rainfall data. Considering that it takes time for rain to accumulate in the watershed to cause flooding, and it takes only a few seconds for the system to operate, the urban flash flood forecasting and warning system according to the embodiment of the present invention has an alarm lead time corresponding to the watershed concentration time. can

After generating synthetic rainfall through the conditional synthesis technique, the control unit 130 extracts rainfall data corresponding to the length of the arrival time of the watershed to estimate the rainfall, and sets the forecasting warning standard through the allowable inundation area ratio and the coefficient of variation. A flood warning is implemented by comparing the rainfall intensity and/or the amount of runoff with the warning criteria.

The database unit 110 stores the predictive alarm criteria.

2 is a flowchart illustrating an urban flash flood prediction and warning method according to the present invention, FIG. 3 is a flowchart illustrating a flood prediction warning according to an embodiment of the present invention, and FIG. 4 is an example of flooding according to another embodiment of the present invention It is a flowchart showing an alarm.

The urban flash flood prediction and warning method according to the present invention is performed by the urban flash flood prediction and warning system according to an embodiment of the present invention. More specifically, the urban flash flood prediction and warning method according to the present invention collects rainfall data through radar and rainfall gauge data of a corresponding watershed, generates synthetic rainfall through a conditional synthesis technique, and then increases the length of arrival time of the corresponding watershed. Extracting rainfall data and estimating the amount of rainfall (S100), setting the forecast warning standard through the allowable inundation area ratio and coefficient of variation (S200), and comparing the rainfall intensity and/or runoff with the forecast warning standard to provide an example of flooding Including a flood warning warning step (S300) to implement an alarm.

The conditional synthesis technique uses information about the rainfall spatial structure obtained from radar data to adjust the gauge-based rainfall field, which is used to obtain accurate spatiotemporal fields of various environmental variables including rainfall and soil moisture.

Here, the concentration time (TOC), which is the arrival time of the watershed, is the sum of the surface flow time and the channel flow time, and the concentration time (TOC) is estimated through the pipe network GIS database of the corresponding area.

During rainfall, an overland flow occurs, followed by a channelized flow. Concentration time (TOC) calculated from surface runoff time and channel flow time is a value calculated to integrate various elements of the flooding mechanism.

The conditional synthesis technique according to an embodiment of the present invention merges radar precipitation data with different temporal resolution and rainfall data of a precipitation station. First, the rainfall of a precipitation station at 1-minute intervals for 10 minutes is synchronized with the measurement interval of the radar precipitation data. accumulate data.

General clicking techniques are applied to obtain the field rainfall field, and the rainfall is observed using radar. Then, radar rainfall data values are collected at the location of the precipitation station, and a radar-based rainfall field is obtained by applying a general clicking technique. The correction field is then calculated by subtracting the radar-based rainfall field from the original radar field. To obtain composite radar-ground rainfall data, a correction field is added to the field rainfall field.

In the end, after generating synthetic rainfall through the conditional synthesis technique, rainfall data is extracted as much as the length of the arrival time of the watershed to estimate the rainfall. The gauge composite rainfall field is cut, and the average area rainfall of each cut rainfall field is calculated to obtain a time series as shown in FIG. 5B.

Here, each 1km*1km radar rainfall field is subdivided into a 100m-100m grid format to reduce errors due to the coarse resolution of the radar rainfall data, and to obtain the maximum cumulative rainfall, moved

On the other hand, the measurement interval of rainfall data is 10 minutes, but in the case of watershed TOC, it has an accuracy of 1 minute. In order to reduce the error caused by this discrepancy, the accumulated rainfall is linearly interpolated.

Because watershed impermeability and antecedent moisture conditions play a very important role in flood mechanisms, watershed impermeability is considered by considering runoff corresponding to the estimated maximum rainfall. The runoff is calculated by the NRCS curve number method (CN method).

The urban flash flood prediction and warning system according to the present invention did not follow the general CN method in which the target watershed and the time series are separated. For example, the urban flash flood prediction and warning system according to the present invention is an alternative to the case where the CN value cannot be corrected due to insufficient flow discharge data at the watershed outlet. Estimated as an area-weighted average. The runoff calculated in this way does not necessarily reflect the real runoff, because it reflects the surface area characteristics, not the flow rate data.

6 is a graph showing the relationship between the concentration time and the flood-induced rainfall amount, and FIG. 7 is a graph diagram illustrating the relationship between the concentration time and the flood-induced runoff amount.

Referring to FIG. 6A , the vertical axis represents the accumulated rainfall depth in each watershed, and the horizontal axis represents the concentration time (TOC). Both the vertical and horizontal axes are logarithmic scales. As the amount of precipitation increases, the flooded area increases, so by applying the flooded area ratio, the relationship between the inundation-induced rainfall and the concentration time can be made clearer.

Referring to (b) of FIG. 6 , again, the vertical axis represents the cumulative rainfall depth in each watershed, the horizontal axis represents the concentration time (TOC), and both the vertical and horizontal axes are logarithmic scales. The color distribution of the scatter plot in FIG. 6(b) represents the coefficient of variation of the current rainfall time series. Referring to (b) of FIG. 6 , rainfall with large temporal variability means that less total rainfall is required to induce flooding, and these results show that both the submerged area ratio and time variability are used to determine the flood-induced rainfall threshold. indicates that it should be considered for

Referring to (a) and (b) of Figure 7, the vertical axis represents the runoff depth in each watershed, the horizontal axis represents the concentration time (TOC), and the vertical axis represents the runoff depth, not the rainfall depth. It is the same as FIG. 6(a).

Since the R^2 value in FIGS. 7(a) and 7(b) is 0.81, it is larger than the R^2 value in FIGS. 6(a) and (b) is 0.74. Accordingly, by considering the additional variable that explains the watershed impermeability, the uncertainty existing in the relationship between the flood-induced rainfall concentration time (TOC) and the rainfall depth can be reduced, and the additional variable in the present invention is the watershed curve number.

In (a) and (b) of FIG. 8 , the horizontal axis indicates the submerged area ratio, and the vertical axis indicates the coefficient of variation.

Referring to (a) of FIG. 8 , it can be seen that as the time variability of rainfall increases, the intensity of rainfall causing flooding decreases, and the threshold value increases as the submerged area ratio increases. Also, looking at (b) of FIG. 8 , it can be seen that the curve of the flooding-induced runoff is smoother than that of the flooding-induced rainfall. This means that watershed impermeability and runoff values through Curve Number are more directly related to inundation.

Here, the allowable submerged area ratio may be selected from 1 to 30%, and 5% is selected as the allowable submerged area ratio in FIGS. 8 (a) and (b).

In the end, it can be confirmed that the urban watershed inundation is affected by the time variability of rainfall, the watershed impermeability, and the inundation area ratio according to the rainfall depth.

Predictive warning criteria are the inundation induced rainfall threshold determined by the coefficient of variation (Pcv) for inundation-induced rainfall and the permissible inundation area ratio, and the inundation induced by the coefficient of variation (Rcv ) for the flood-induced runoff and the permissible inundation area ratio. It is the threshold of the outflow. The threshold is, for example, the threshold shown in FIG. 8 .

The control unit 130 may calculate the predictive warning standard for each watershed individually.

First, the control unit 130 obtains a time series of rainfall for the watershed related to the duration of the concentration time (TOC) of the watershed. Then, a coefficient of variation (Pcv) is calculated.

In addition, the control unit 130 obtains a time series of rainfall for the watershed related to the duration of the concentration time (TOC) of the watershed. Then, the coefficient of variation (Rcv) is calculated.

The control unit 130 calculates a coefficient of variation (Pcv) for flooding-induced rainfall, calculates a flood-induced rainfall threshold determined by the coefficient of variation (Pcv) and an allowable inundation area ratio, and stores it in the database unit 110 .

In addition, the control unit 130 calculates the coefficient of variation (Rcv) for the flood-induced runoff, calculates the flood-induced runoff threshold determined by the coefficient of variation (Rcv) and the allowable submerged area ratio, and stores it in the database unit 110 .

Thereafter, the control unit 130 obtains a flood-induced rainfall threshold value from the database unit 110 and executes a flood prediction warning.

If the flooding prediction warning based on the flooding induced rainfall is selected, the flooding prediction warning step includes calculating the rainfall time series average rainfall intensity (Pave) of the watershed arrival time length (S310), the flooding induced rainfall threshold value and the time series average Comparing the magnitudes of the rainfall intensity (S320), and when the magnitude of the time series average rainfall intensity Pave is greater than the flood-induced rainfall threshold, the step (S330) of executing a flood prediction warning is performed.

If the flooding prediction warning based on the flooding-induced runoff is selected, the flooding prediction step includes the steps of calculating the curve number of the watershed (S340), calculating the amount of runoff using the NRCS runoff curve index method ( S350), calculating the average (Rave) of the runoff time series of the watershed arrival time length (S360), and comparing the flood-induced runoff threshold value with the average (Rave) of the runoff time series (S370). When the magnitude of the average (Rave) of the runoff time series is greater than the flood-induced runoff threshold value, a flood prediction warning is executed (S380).

9 is a graph showing the performance of an urban flash flood warning system based on FIR and FIRO and FIR and FIRO that change by the coefficient of variation, and FIGS. 10 and 11 are graphs showing the performance of the conventional flood warning system.

In order to verify the performance of the urban flash flood prediction and warning system according to the present invention, it was applied to 239 watersheds in Seoul during the verification period of recent years.

In (a) and (b) of Figure 9, the horizontal axis is the coefficient of variation, and the vertical axis is rainfall and runoff, respectively.

In addition, in (c) and (d) of FIG. 9 , the horizontal axis represents the submerged area ratio, and the vertical axis represents the number of times.

Referring to FIG. 9 , the blue line corresponds to flood-induced rainfall (FIR) and flood-induced runoff (FIRO) corresponding to about 5% of the watershed.

Referring to (a) and (b) of Figure 9, the average intensity of rainfall that overflowed about 5% of the entire watershed can have a depth of 38mm/h to 60mm/h, and as the temporal variability of rainfall increases, It can be seen that FIRO decreases. Here, the ones located above the blue line indicate rainfall events in which flooding (flood) warnings were initiated, and 43 flood/flood warnings were initiated, of which 19 were actually flooded.

The performance of the runoff-based warning was superior to that of the rainfall-based warning, suggesting that watershed impermeability and preceding moisture conditions are important variables in the inundation/flooding mechanism.

Referring to FIGS. 9 (c) and 9 (d), the performance of the flood warning system that varies according to the allowable flood area ratio is shown. That is, if the submerged area ratio is less than 1%, it can be seen that the flood alarm does not start, and the blue, red and yellow lines mean the number of warnings, hits and misses, respectively.

Here, as the flooded area ratio increases (or when the threshold of flood warning is relaxed), the number of alarms and hits decreases, while the number of omissions increases. The shaded area representing the number of false information decreases as the flood warning threshold is relaxed.

Fig. 9 (c) is a flood warning based on FIR, and Fig. 9 (d) is about a flood warning based on FIRO. Flood alerts based on FIRO outperform flood alerts based on FIR in all metrics, including hit, miss, and false alarm rates.

Determining an appropriate threshold for providing a flood warning is a large dilemma. Choosing a small submerged area ratio or low threshold will minimize false alarms with a low hit rate, and vice versa, increase the number of false alarms but increase the missed rate.

Here, the hit ratio means the ratio of actual flooding among the total initiated flood warnings.

9 (c) and (d) are important guidelines for selection of an appropriate threshold value.

In (a) and (b) of FIG. 10 , the horizontal axis represents the submerged area ratio, and the vertical axis represents the number of times.

Referring to FIG. 10, (a) and (b) show a warning system based on radar-only and gauge-only rainfall data, respectively, and the result of FIG. 10 is the present invention based on radar gauge composite rainfall data. It can be seen that the performance is significantly lower compared to the performance of the urban flash flood prediction and warning system according to the embodiment.

More precise FIR and FIRO can be derived by considering rainfall time variability, as opposed to approaches based solely on rainfall intensity.

In (a) and (b) of FIG. 11 , the rainfall intensity and the runoff intensity are respectively, and the vertical axis is the number of times.

Referring to FIG. 11 , time variability was not considered in both (a) and (b). It can be seen that the performance of FIG. 11 is significantly lower than that of FIG. 9 showing the urban flash flood warning system according to the present invention.

Those of ordinary skill in the art will be able to understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

In addition, the device according to the present invention can be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data readable by a computer system is stored. Examples of the recording medium include ROM, RAM, optical disk, magnetic tape, non-volatile memory, and the like. In addition, the computer-readable recording medium is distributed in a computer system connected to a network, so that the computer-readable code can be stored and executed in a distributed manner.

110: database unit
120: communication department
130: control unit

Claims (15)

estimating rainfall by collecting rainfall data through radar and rainfall gauge data of the corresponding watershed, generating synthetic rainfall through conditional synthesis, and extracting rainfall data corresponding to the length of the arrival time of the corresponding watershed;
setting a predictive warning standard through an allowable flood area ratio and a coefficient of variation; and
An urban flash flood prediction warning method comprising a; a flooding prediction warning step of executing a flooding prediction warning by comparing the rainfall intensity and/or runoff amount with the preliminary warning standard. According to claim 1,
The concentration time (TOC), which is the arrival time of the watershed, is the sum of the surface flow time and the channel flow time, and the concentration time (TOC) is an urban flash flood prediction warning, characterized in that it is estimated through the pipe network GIS database of the corresponding area Way. According to claim 1,
The conditional synthesis technique is an urban flash flood prediction warning method, characterized in that the gauge-based rainfall field is adjusted using information about the rainfall spatial structure obtained from radar data. According to claim 1,
The step of setting the pre-alarm criteria includes:
Calculating a coefficient of variation (P _CV ) for inundation-induced rainfall and calculating a flood-induced rainfall threshold determined by the coefficient of variation (P _CV ) and an allowable inundation area ratio Way. According to claim 1,
The step of setting the pre-alarm criteria includes:
Calculating a coefficient of variation (R _CV ) for the flooding-induced runoff and calculating a flood-induced runoff threshold determined by the coefficient of variation (R _CV ) and an allowable inundation area ratio Way. 6. The method according to claim 4 or 5,
The allowable flooded area ratio is an urban flash flood warning method, characterized in that selected from 1 to 30%. 6. The method according to claim 4 or 5,
When the allowable submerged area ratio or threshold values are selected to be small, the hit rate is lowered and false alarms are reduced. Flood warning method. According to claim 1,
The flooding warning step is
estimating the rainfall time series average rainfall intensity (P _ave ) of the watershed arrival time length;
comparing a flood-induced rainfall threshold and a magnitude of the time series average rainfall intensity; and
and executing a flood prediction warning when the magnitude of the time-series average rainfall intensity (P _ave ) is greater than the flood-induced rainfall threshold value. According to claim 1,
The flooding warning step is
calculating the runoff curve index of the watershed;
estimating the runoff using the NRCS runoff curve index method;
calculating an average (R _ave ) of the runoff time series of the watershed arrival time length;
comparing a flood-induced runoff threshold and an average (R _ave ) of the runoff time series; and
and executing a flood prediction warning when the magnitude of the average (R _ave ) of the runoff time series is greater than the flood-induced runoff threshold value. a communication unit that receives radar rainfall data of the watershed and rainfall data of a precipitation station; and
After generating synthetic rainfall through the conditional synthesis technique, the rainfall data is extracted as much as the length of the arrival time of the watershed to estimate the rainfall. The urban flash flood warning system comprising a; a control unit that compares the amount of runoff with the preliminary warning standard to implement a flood warning warning. 11. The method of claim 10,
Further comprising a database unit for storing the predictive warning criteria,
The preliminary warning criterion is based on the flood-induced rainfall threshold determined by the coefficient of variation (P _CV ) for flood-induced rainfall and the allowable inundation area ratio, and the coefficient of variation (R _CV ) for the inundation-induced runoff and the allowable inundation area ratio. Urban flash flood prediction and warning system, characterized in that the determined flood-induced runoff threshold. 12. The method of claim 11,
The control unit is
Obtaining a flood-induced rainfall threshold from the database unit,
Calculate the rainfall time series average rainfall intensity (P _ave ) of the watershed arrival time length,
Urban flash flood warning that compares the magnitude of the flood-induced rainfall threshold with the time-series average rainfall intensity, and executes a flood warning when the magnitude of the time-series average rainfall intensity (P _ave ) is greater than the flood-induced rainfall threshold system. 12. The method of claim 11,
The control unit is
Obtaining a flood-induced runoff threshold value from the database unit,
Calculate the runoff curve index of the watershed, calculate the runoff using the NRCS runoff curve index method, and then calculate the average (R _ave ) of the runoff time series of the watershed arrival time length,
Urban flash flood that compares the flood-induced runoff threshold and the average (R _ave ) of the runoff time series, and executes a flood warning when the size of the average (R _ave ) of the runoff time series is greater than the flood-induced runoff threshold Predictive warning system. 14. The method of claim 13,
The urban flash flood prediction and warning system, characterized in that the runoff is determined in consideration of the watershed impermeability and the preceding function condition. A computer program stored in a readable recording medium in combination with hardware to execute the method of any one of claims 1 to 9.

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