JP2021165689A - River flood prediction method and river flood prediction device during heavy rain - Google Patents

Abstract

To provide a heavy rain-time river flood prediction method capable of predicting occurrence of a river flood in heavy rain in a relatively early stage.SOLUTION: A heavy rain-time river flood prediction method for predicting a river flood includes: a first step of acquiring river basin information on a side upstream from a point of interest to set a river basin; a second step of acquiring a predicted amount of rainfall at least 24 hours ahead within the river basin set in the first step to calculate an average predicted amount of rainfall within the river basin; a third step of acquiring actual rainfall amount information in the river basin set in the first step to calculate an average measured amount of rainfall within the river basin; and a fourth step of determining whether the river as an object of determination floods based upon the average predicted amount of rainfall within the river basin calculated in the second step, the average measured amount of rainfall within the river basin calculated in the third step, and a planned amount of rainfall set for each water level observation station of interest.SELECTED DRAWING: Figure 3

Description

The present invention relates to a river flood prediction technique during heavy rain, for example, a method for predicting river flood during heavy rain, which is useful for evacuating a railroad vehicle detained at a vehicle detention site where there is a risk of flooding due to river flooding. It is related to a river flood forecasting device.

In recent years, due to the frequent occurrence of torrential rains, there is an increasing risk that the detention points of vehicles will be flooded due to flooding of rivers and that the detained railway vehicles will be submerged in water. Regarding the flooding of rivers, the Ministry of Land, Infrastructure, Transport and Tourism announces the water level of major rivers nationwide approximately every hour for three hours ahead as a criterion for issuing evacuation orders. In addition, the Japan Meteorological Agency publishes a basin rainfall index about 6 hours ahead approximately every hour as an index that quantifies the possibility of river flooding for small and medium-sized rivers.
On the other hand, conventionally, as a technique for predicting flooding of a river, an invention relating to a flooding simulation system provided with a flooding analysis means for performing a flooding analysis of an arbitrary bank break point using observation data such as rainfall data and telemeters and water level prediction data. Has been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-197554

When evacuating a railroad vehicle from a vehicle detention site, it is necessary to make preparations such as arranging a driver and selecting an evacuation destination in consideration of the next day's operation schedule, and the distance to the evacuation destination and the travel time are long. Due to the circumstances peculiar to railways, it is desirable to be able to predict at the earliest possible stage.
In addition, regarding the evacuation of railway vehicles from the vehicle detention site, once the evacuation is carried out, it will have a great impact on the operation of the vehicle from the next day onward, making it difficult to operate according to the timetable, which may cause great inconvenience to users. Therefore, there is a problem that highly accurate prediction is required for river flooding.

Although the invention described in Patent Document 1 can make a prediction for several hours or several days ahead, the time range for obtaining a judgment of river flooding varies from several hours to several days before the flooding. Since it is large and accurate prediction cannot be obtained at an early stage such as 24 hours ago, there is a problem in using it for predicting the evacuation timing of railway vehicles.
The present invention was made based on the above background, and the purpose of the present invention is a method for predicting river flooding during heavy rain, which can predict the occurrence of river flooding at a point of interest at a relatively early stage. And to provide a river flood forecasting device.
Another object of the present invention is to provide a river flood prediction method and a river flood prediction device at the time of heavy rain, which can make a judgment with higher accuracy than the case where the judgment is made only by the predicted rainfall amount.

In order to solve the above problems, the present invention
In the river flood prediction method during heavy rain, which predicts the flooding of the river to be judged based on the predicted rainfall information several hours ahead acquired from the meteorological information distribution server and the measured rainfall information.
The first step to set the basin by acquiring the river basin information on the upstream side of the water level observatory of interest,
In the second step, the predicted rainfall in the basin set in the first step for at least 24 hours or more ahead is acquired at predetermined time intervals, and the average predicted rainfall in the basin is calculated.
In the third step, the measured rainfall information in the basin set in the first step is acquired at the predetermined time intervals, and the average measured rainfall in the basin is calculated.
Based on the average predicted rainfall in the basin calculated in the second step, the average measured rainfall in the basin calculated in the third step, and the planned rainfall set for each water level observatory of interest. The fourth step to determine whether or not the river to be judged will overflow,
Is included.

According to the flood prediction method as described above, since the rainfall in the river basin on the upstream side is calculated and determined based on the predicted rainfall at least 24 hours ahead, compared to the case of using the basin rainfall index issued by the Japan Meteorological Agency. At an early stage, it is possible to predict the occurrence of river flooding at the point of interest. As a result, the preparatory work for evacuating the railroad vehicle can be started early.

Alternatively, in the river flood prediction method during heavy rain, which predicts the flooding of the river to be judged based on the predicted rainfall information several hours ahead acquired from the meteorological information distribution server and the measured rainfall information.
The first step of acquiring river basin information on the upstream side of the point of interest and setting the basin,
The second step of acquiring the predicted rainfall at least 24 hours ahead in the basin set in the first step at predetermined time intervals and calculating the average predicted rainfall in the basin.
In the third step, the measured rainfall information in the basin set in the first step is acquired at the predetermined time intervals, and the average measured rainfall in the basin is calculated.
Based on the average predicted rainfall in the basin calculated in the second step and the average measured rainfall in the basin calculated in the third step, it is constant from immediately before the acquisition of the predicted rainfall to the predicted destination time. The fourth step of calculating the maximum value of cumulative rainfall for a predetermined time in a time zone, and
It is determined whether or not the maximum value of the cumulative rainfall calculated in the fourth step is larger than the rainfall determination value set in advance corresponding to the point of interest, and the maximum value of the cumulative rainfall is the rainfall amount. The fifth step of outputting a flood prediction alarm when the judgment value is exceeded, and
To include.

According to the flood prediction method as described above, since the rainfall in the river basin on the upstream side is calculated and determined based on the predicted rainfall at least 24 hours ahead, compared to the case of using the basin rainfall index issued by the Japan Meteorological Agency. At an early stage, it is possible to predict the occurrence of river flooding at the point of interest. In addition, since the judgment is made by comparing the predicted rainfall within a predetermined time in the basin on the upstream side of the river of interest with the maximum value of the cumulative rainfall of the measured rainfall and the preset judgment value, the judgment is made only by the predicted rainfall. Judgment with higher accuracy can be performed than in the case.

Here, the point of interest is a water level observatory provided in the river to be determined, and the rainfall determination value is a planned rainfall amount set for each water level observatory by the Ministry of Land, Infrastructure, Transport and Tourism.
According to such a method, it is possible to set an appropriate rainfall determination value by using the already published information and to predict the occurrence of inundation with high accuracy.

In addition, the predicted rainfall information for several hours ahead is 39 hours ahead predicted rainfall information announced by the Japan Meteorological Agency every three hours.
According to the above method, the information released by the Japan Meteorological Agency is used to calculate the predicted rainfall using a high-performance supercomputer, so compared to the case where the predicted rainfall is calculated using a personal computer. , It is possible to predict the occurrence of flooding easily and quickly.

Further, the measured rainfall information is set to be the rainfall information announced by the Japan Meteorological Agency every hour.
According to the above method, the information collected by the Japan Meteorological Agency is used to calculate the actual rainfall using the information collected using the detailed information network. Therefore, the information collected using the own information network is used. It is possible to predict the occurrence of inundation at a lower cost than when calculating the actual rainfall using.

Other inventions of this application
In the river flood prediction device during heavy rain, which predicts the flooding of the river to be judged based on the predicted rainfall information several hours ahead acquired from the weather information distribution server and the measured rainfall information.
A basin setting means that acquires river basin information on the upstream side of the water level observatory of interest and sets the basin,
A predicted rainfall calculation means for calculating an average predicted rainfall in a basin based on a predicted rainfall at least 24 hours ahead in the basin set by the basin setting means.
Measured rainfall calculation means that calculates the average measured rainfall in the basin based on the measured rainfall information in the basin set by the basin setting means, and
Based on the average predicted rainfall and the average measured rainfall, the sum of the cumulative rainfall for a predetermined time in a certain time zone from immediately before the acquisition of the predicted rainfall information to the predicted destination time is calculated, and the sum of the cumulative rainfall is calculated. Is provided with a flood prediction determination means for determining whether or not the rainfall is greater than the planned rainfall set at the water level observation station.

According to the river flood prediction method and the river flood prediction device at the time of heavy rain of the present invention, it is possible to predict the occurrence of river flood at the point of interest at a relatively early stage. In addition, by doing so, for example, when a torrential rain occurs, the railway vehicle detained at the vehicle detention site is evacuated, and the flooding of the river prevents the vehicle detention site from being flooded and causing damage to the detained railway vehicle being submerged in water. It has the effect of being able to.

It is a block diagram which shows the structural example of the flooding prediction system which applies the river flooding prediction method at the time of heavy rain which concerns on this invention. (A) is a schematic diagram showing the relationship between basin rainfall and planned high water level in the river flood prediction method during heavy rain according to the present invention, and (B) is a prediction target location to which the river flood prediction method during heavy rain according to the present invention is applied. It is a map showing examples of rivers and basins. It is a flowchart which shows an example of the procedure of the river flood prediction method at the time of heavy rain which concerns on this invention. It is a chart which shows the example of the time-series data of the measured value of the rainfall and the predicted value of the rainfall used when the prediction process is performed by the river flood prediction method of the embodiment. It is a chart which shows the example of the time series data of the predicted rainfall and the measured rainfall calculated in the middle of the prediction process by the river flood prediction method of the embodiment. It is a graph which shows the change of the rainfall for 2 days obtained by applying the river flood prediction method of embodiment to the data at the time of the river flood which occurred in the past. It is a graph which shows the change of the rainfall for 3 days obtained by applying the river flood prediction method of the embodiment to the data at the time when the river did not flood due to the heavy rain that occurred in the past. It is a graph which shows the change of the rainfall for 2 days obtained by applying the river flood prediction method of the embodiment to the data at the time when other rivers did not flood due to the heavy rain that occurred in the past.

Hereinafter, an embodiment of the river flood prediction method at the time of heavy rain according to the present invention will be described with reference to the drawings. The basic idea of the river flood prediction method at the time of heavy rainfall according to the present invention is to use the basin rainfall as a judgment index and predict the flood at the point of interest using the planned rainfall as a judgment standard.
In applying the present invention, first select the location to be judged, and from the data on rivers published by the Ministry of Land, Infrastructure, Transport and Tourism, the most selected location among the water level observation stations provided in the river adjacent to the selected location. Determine the nearest water level observatory as the point of interest. Then, the planned high water level of the water level observatory at the point of interest is investigated, and the river basin on the upstream side of the water level observatory is set.

Here, the planned high water level is the river flow rate and river width when the amount of rainfall corresponding to the planned rainfall, which is the probability rainfall (average value of rainwater falling in the river basin) for determining the river structure, is applied. The river water level is determined based on the above, and the embankment of the river is designed and constructed based on the planned high water level as shown in FIG. 2 (A). Therefore, if the amount of rainfall in the basin exceeds the planned high water level, it can be said that the risk of river flooding increases.

In addition, the basin rainfall is calculated by adding the rainfall up to now (measured value) announced by the Japan Meteorological Agency every hour and the predicted rainfall 39 hours ahead announced by the Japan Meteorological Agency every 3 hours. Is. As shown in FIG. 2 (B), the rainfall is announced as the measured rainfall and the predicted rainfall for each region divided into grids at 5 km intervals. On the other hand, regarding the range of the basin of each river, there is information published by the Ministry of Land, Infrastructure, Transport and Tourism, which can be used. The grid that overlaps even a part of the river basin B is included in the calculation of rainfall. In addition, in FIG. 2B, the place marked with a star is a place where inundation is to be predicted, such as a vehicle detention center, and the place marked with a triangle is a water level observation station closest to the predicted place.

FIG. 1 is a block diagram showing a configuration example of a flood prediction system to which the river flood prediction method at the time of heavy rain of the present embodiment is applied.
As shown in FIG. 1, the flood prediction system is composed of a river flood prediction device 10 including a microcomputer and the like, and a weather information distribution server 20 via the device and a communication network NW such as the Internet. The meteorological information distribution server 20 is a server that provides measured values of rainfall in each region and predicted rainfall 39 hours ahead, and a server managed by the Japan Meteorological Agency can be used. In addition, the communication network N is provided with a river information server 30 that provides information on rivers such as actual measurement values of water levels at water level observation stations provided in each river, basin information of each river, and planned rainfall of each water level observation station. Is connected. The river information server 30 can use a server managed by the Ministry of Land, Infrastructure, Transport and Tourism.

The river flood prediction device 10 includes an arithmetic processing device 11 such as a microprocessor (CPU), an input device 12 such as a RAM and ROM, a keyboard and a mouse, a storage device 13 such as a hard disk driver, and a display device 14 such as a liquid crystal display. A data processing device consisting of a communication device 15 that performs data communication with a weather information distribution server 20 and a river information server 30 via a communication network NW, a personal computer equipped with a bus 16 that connects these functional blocks, and the like. It is composed of.

The storage device 13 stores a program for executing the river flood prediction method during heavy rainfall according to the present invention, and various functions are provided by cooperation between the arithmetic processing device 11 and the program stored in the storage device 13. Actually measured rainfall calculation means for calculating rainfall in river basins upstream of the water level observatory of interest, predicted rainfall calculation means for calculating future predicted rainfall in river basins, river flood judgment means, etc. Will be done.

Next, an example of the processing procedure of the river flood prediction method at the time of heavy rain of the present embodiment using the river flood prediction device 10 will be described with reference to the flowchart of FIG. The processing according to the flowchart of FIG. 3 is performed by the arithmetic processing device 11 constituting the river flood prediction device 10 executing the river flood prediction program stored in the storage device 13. The processing of the flowchart of FIG. 3 is started by selecting a location to be determined (for example, a vehicle detention center), setting a water level observatory closest to the selected location, and then executing a flood prediction program. The processing procedure described below is an example and is not limited thereto.

In the river flood prediction process of FIG. 3, first, the planned rainfall of the water level observatory of the set water level observatory is acquired by searching the data in the river information server 30, and the upstream side of the water level observatory is acquired. The river basin information is acquired and the basin is set (step S1).
Next, it is determined whether or not the predicted rainfall amount 39 hours ahead of the weather information distribution server 20 has been announced (step S2). Here, if it is determined that the predicted rainfall 39 hours ahead has been announced, the predicted rainfall 39 hours ahead of the basin set in step S2 is acquired (step S3).

Subsequently, based on the predicted rainfall obtained in step S3, the average rainfall predicted to fall within the set basin within the next 39 hours is calculated (step S4). Next, the measured rainfall in the basin of interest for the last 3 hours is acquired from the weather information distribution server 20 (step S5), and the average measured rainfall in the basin is calculated (step S6).
Then, based on the average predicted rainfall calculated in step S4 and the average measured rainfall calculated in step S6, a fixed time zone (for example, 84) from immediately before the acquisition of the predicted rainfall to the predicted destination time (for example, 84). As the cumulative rainfall for a predetermined time in time), the rainfall corresponding to the 2-day average rainfall or the 3-day average rainfall is calculated and the maximum value is acquired (step S7).

Here, the two-day average rainfall or the three-day average rainfall is calculated because the planned rainfall announced by the Ministry of Land, Infrastructure, Transport and Tourism also includes the two-day rainfall or the three-day rainfall. This is because it has been decided. Specifically, for example, the planned rainfall at the water level observatories along the Chikuma and Tama rivers is determined based on the two-day rainfall, and the planned rainfall at the water level observatories along the Arakawa river is based on the three-day rainfall. Many of them have been decided.

After that, it is determined whether or not the maximum value of the cumulative rainfall acquired in step S7 is larger than the planned rainfall of the water level observatory of interest, that is, whether or not the maximum value of the cumulative rainfall exceeds the planned rainfall (step S8). ). Here, if it is determined that the maximum value of the cumulative rainfall does not exceed the planned rainfall of the water level observatory of interest (No), the process returns to step S2 and the processes of steps S2 to S7 are repeated. On the other hand, if it is determined in step S8 that the maximum value of the cumulative rainfall exceeds the planned rainfall of the water level observatory of interest (Yes), the process proceeds to step S9, and the display device 14 outputs a river flood warning. Instead of comparing the maximum value of the cumulative rainfall with the planned rainfall, each cumulative rainfall before the maximum value may be compared with the planned rainfall.

By executing the river flood prediction process according to the above procedure, it is predicted that the river flood will occur at a time considerably before the timing when the river flood actually occurs at the point of interest (for example, 24 hours before). Can be notified. As a result, if it is applied to the judgment of flooding of rivers near the vehicle detention site existing in the danger area where there is a risk of inundation in the hazard map published by the national and local governments, it will be applied at an early stage. It is possible to predict river flooding and evacuate vehicles detained at the vehicle detention site or vehicles scheduled to be detained in the future to a railroad track at a safe altitude position with relatively no inundation.

Next, using FIGS. 4 to 6, the present inventors made a heavy rain associated with typhoon No. 19 from October 10 to 13, 1945, among the heavy rains that caused river flooding in the past. The result of performing the simulation by selecting the flooding that occurred in the above procedure and applying the river flooding prediction method according to the above procedure will be described. The water level observatory of interest was the Tategahana observatory on the downstream side closest to the inundation site, and the planned rainfall was 186 mm.

FIG. 4 shows the average predicted rainfall in the set basin every 3 hours calculated in step S4 based on the predicted rainfall 39 hours ahead announced by the Japan Meteorological Agency obtained in step S3, and the basin acquired in step S5. An example is shown in which the average measured rainfall calculated in step S6 above based on the measured value of the internal rainfall is described in a time-series table format.
In FIG. 4, the numerical value in the region where the background is gray is the average rainfall based on the measured value, and the numerical value in the region where the background is white is the average rainfall based on the predicted value. In step S7, the rainfall for 2 days, that is, the rainfall for 48 hours is calculated, so 16 numerical values are accumulated for each column of FIG.

FIG. 5 shows the maximum value of the cumulative rainfall (the amount of rainfall corresponding to the average rainfall for two days) acquired in step S7, and the actual rainfall amount and the predicted rainfall amount corresponding to the breakdown of the maximum value. The ones listed in tabular form of the series are shown.
The second column from the left in FIG. 5 is the maximum cumulative rainfall for a predetermined time acquired in step S7, the second column from the right is the total measured rainfall in the maximum cumulative rainfall, and the rightmost column is the maximum cumulative rainfall. This is the total estimated rainfall. In addition, FIG. 5 shows the rainfall for 4 days from the 10th to the 13th. Due to the size of the paper, the rainfall data from 0:00 on the 10th to 18:00 on the 11th is shown in FIG. 4, and the data after 21:00 on the 11th is omitted.

Here, using FIGS. 4 and 5, the method of calculating the maximum value (maximum cumulative rainfall) of the cumulative rainfall for a predetermined time in step S7 is, as an example, at 18:00 on the 11th, which is surrounded by a square in FIG. Let's take data as an example.
In this embodiment, the maximum value of rainfall for 2 days, that is, 48 hours within 84 hours immediately before the announcement of the predicted rainfall is obtained. Therefore, in step S7, first, in FIG. 4, which represents the data for every 3 hours, it is surrounded by a solid line. From the cumulative total of 16 data to the cumulative total of 16 data surrounded by the broken line, a total of 12 cumulative values are calculated while shifting by one step (1 cell).

Next, the largest one is selected from the calculated 12 cumulative values. Then, enter this maximum value in the column of "predicted rainfall + maximum measured rainfall" in FIG. In the case of the data at 18:00 on the 11th shown in FIG. 4, the cumulative value (185.2) of the 16 data surrounded by the solid line is the largest, so this value is entered in FIG. In addition, when the inundation prediction process shown in Fig. 3 is applied, the maximum value does not exceed the planned rainfall (186 mm) at the Tategahana Observatory at this point, so no inundation prediction warning is issued, but the maximum value at 0:00 on the 12th. Since (196.3 mm) exceeds the planned rainfall (186 mm), a flood prediction warning will be issued at this point.

From the above explanation, the value (185.2) obtained by calculating (predicted rainfall + actually measured rainfall) for the most recent 48 hours at 18:00 on the 11th without calculating the maximum value of predicted rainfall + actually measured rainfall Since it is quite close to the planned rainfall (186 mm) at the Tategahana Observatory, it can be seen that it is possible to judge that there is a high risk of flooding and issue an alarm.
However, if the vehicle is evacuated by the warning issued in this way, the effect of an error in the warning is very large. Therefore, in order to improve the accuracy of the flood prediction warning, as described above, It is conceivable to calculate the maximum value of the predicted rainfall + the measured rainfall, and set the inundation determination value to, for example, a value (195 mm) obtained by adding 5% to the planned rainfall. Even if this is done, it can be seen from FIG. 6 that the inundation prediction warning can be issued at the stage of 0:00 to 3:00 on the 12th, that is, 24 hours or more before the inundation.

FIG. 6 shows the table of FIG. 5 as a bar graph. In FIG. 6, the rod with the mesh is the 39-hour average predicted rainfall in the maximum cumulative rainfall, and the rod with the hatch is the measured average rainfall in the maximum cumulative rainfall. It represents the maximum cumulative rainfall mentioned above. In addition, the broken line RL indicates the planned rainfall at the Tategahana Observatory, and the timing with the sign Ta is the time when typhoon No. 19 in the first year of Typhoon actually caused flooding in the Chikuma River. ..

As can be seen from FIG. 6, the time when the inundation actually occurred in the Chikuma River was around 3:00 on the 13th, whereas in the graph, the maximum cumulative rainfall exceeded the planned rainfall RL at 0:00 on the 12th. Therefore, it was possible to issue an alarm approximately 24 hours before the actual inundation by issuing an alarm when it was determined that the cumulative rainfall exceeded the planned rainfall RL by the processing according to the flowchart of FIG. I understand.

Next, for comparison, the events that occurred in the Arakawa and Tama rivers due to the heavy rain associated with typhoon No. 19 from October 10 to 13, 1945, were selected, and the river flood prediction method of the above example was applied. The result of performing the same simulation as above will be described. The water level observatories of interest were the Jisui Bridge Observatory in the Arakawa River and the Denenchofu Observatory in the Tama River. rice field.

Fig. 7 shows a graph showing the maximum cumulative rainfall between the 39-hour average predicted rainfall and the measured average rainfall obtained by simulating the Arakawa Flood Bridge Observatory, and Fig. 8 shows the Tamagawa countryside. A graph showing the maximum cumulative rainfall of the 39-hour average predicted rainfall and the measured average rainfall obtained by performing a simulation focusing on the Chofu Observatory is shown. For the Arakawa Jisui Bridge Observatory, the planned rainfall is set for 3 days, and for the Tama River, the planned rainfall is set for 2 days. Therefore, the graph in Fig. 7 shows the 3-day rainfall on the vertical axis. , The graph of FIG. 8 shows the rainfall for 2 days on the vertical axis.

From Fig. 7, the maximum cumulative rainfall does not exceed the planned rainfall RL for the Arakawa River, and from Fig. 8, the maximum cumulative rainfall for the Tama River has been in a state of almost matching the planned rainfall RL for a long time. It can be seen that it is similar to the situation that actually occurred in the Arakawa and Tama rivers when Typhoon No. 19 landed in October of the first year of Japan.
As described above, according to the river flood prediction method at the time of heavy rain of the above embodiment, it is possible to predict the flooding of the river fairly accurately 24 hours or more before issuing an alarm.

Although the present invention has been described above based on Examples, the present invention is not limited to the above Examples. For example, in the above embodiment, the river basin on the upstream side is treated uniformly regardless of the distance from the water level observatory, but the amount of rainfall to be calculated is determined by setting a time difference according to the distance from the water level observatory to the basin. You may try to do it.
Further, in the inundation prediction process of the above embodiment (scheme of FIG. 3), the predicted rainfall amount 39 hours ahead announced by the Japan Meteorological Agency in step S3 is acquired, but the predicted rainfall amount is not limited to that announced by the Japan Meteorological Agency. At the same time, the time is not limited to 39 hours ahead. For example, if it is desired to obtain the prediction result of the inundation occurrence before 24 hours, the predicted value at least 24 hours or more ahead may be obtained.

Further, in the flood prediction process of the above-described embodiment, if it is determined in step S7 that the maximum cumulative rainfall exceeds the planned rainfall (Yes), the process proceeds to step S8 to issue an alarm, but the maximum cumulative rainfall determines the planned rainfall. If it is determined that the rainfall has been exceeded, the process returns to step S2, and if it is determined in step S7 that the maximum cumulative rainfall exceeds the planned rainfall, that is, if it is determined that the planned rainfall has been exceeded twice in a row, the process proceeds to step S8 and the river floods. The alarm may be output.
Further, the system may be configured so that the river flood prediction device 10 determines the prediction of the occurrence of flooding, transmits the determination result to another device, and outputs an alarm by another device.

Further, in the above-described embodiment, the server managed by the Japan Meteorological Agency is used as the weather information distribution server 20, but a server operated by a private company that provides the weather information may be used. Further, although it has been described that information on rivers and basins is acquired from a server managed by the Ministry of Land, Infrastructure, Transport and Tourism, such information may be prepared in advance as a database in the storage device 13 of the river flood prediction device 10.
The present invention has been described above on the assumption that the present invention is applied to a system for determining when a vehicle is evacuated from a vehicle detention location where there is a risk of flooding during heavy rain. It can also be used as a system for determining the timing of evacuation of residents.

10 River flood prediction device 11 Arithmetic processing device 12 Input device 13 Storage device 14 Display device 15 Communication device 16 Bus 20 Meteorological information distribution server 30 River information server

Claims (6)

It is a river flood prediction method at the time of heavy rain that predicts the flooding of the river to be judged based on the predicted rainfall information several hours ahead acquired from the meteorological information distribution server and the measured rainfall information.
The first step to set the basin by acquiring the river basin information on the upstream side of the water level observatory of interest,
In the second step, the predicted rainfall in the basin set in the first step for at least 24 hours or more ahead is acquired at predetermined time intervals, and the average predicted rainfall in the basin is calculated.
In the third step, the measured rainfall information in the basin set in the first step is acquired at the predetermined time intervals, and the average measured rainfall in the basin is calculated.
Based on the average predicted rainfall in the basin calculated in the second step, the average measured rainfall in the basin calculated in the third step, and the planned rainfall set for each water level observatory of interest. The fourth step to determine whether or not the river to be judged will overflow,
A method for predicting river flooding during heavy rains, which is characterized by including. It is a river flood prediction method at the time of heavy rain that predicts the flooding of the river to be judged based on the predicted rainfall information several hours ahead acquired from the meteorological information distribution server and the measured rainfall information.
The first step of acquiring river basin information on the upstream side of the point of interest and setting the basin,
The second step of acquiring the predicted rainfall at least 24 hours ahead in the basin set in the first step at predetermined time intervals and calculating the average predicted rainfall in the basin.
In the third step, the measured rainfall information in the basin set in the first step is acquired at the predetermined time intervals, and the average measured rainfall in the basin is calculated.
Based on the average predicted rainfall in the basin calculated in the second step and the average measured rainfall in the basin calculated in the third step, it is constant from immediately before the acquisition of the predicted rainfall to the predicted destination time. The fourth step of calculating the maximum value of cumulative rainfall for a predetermined time in a time zone, and
It is determined whether or not the maximum value of the cumulative rainfall calculated in the fourth step is larger than the rainfall determination value set in advance corresponding to the point of interest, and the maximum value of the cumulative rainfall is the rainfall amount. The fifth step of outputting a flood prediction alarm when the judgment value is exceeded, and
A method for predicting river flooding during heavy rains, which is characterized by including. The point of interest is a water level observation station provided in the river to be judged, and the rainfall determination value is a planned rainfall amount set for each water level observation station by the Ministry of Land, Infrastructure, Transport and Tourism. The method for predicting river flooding during heavy rainfall described in 2. The method for predicting river flooding during heavy rainfall according to claim 2 or 3, wherein the predicted rainfall information for several hours ahead is 39 hours ahead predicted rainfall information announced by the Japan Meteorological Agency every three hours. The method for predicting river flooding during heavy rainfall according to any one of claims 2 to 4, wherein the measured rainfall information is rainfall information announced by the Japan Meteorological Agency every hour. It is a river flood prediction device at the time of heavy rain that predicts the flooding of the river to be judged based on the predicted rainfall information several hours ahead acquired from the weather information distribution server and the measured rainfall information.
A basin setting means that acquires river basin information on the upstream side of the water level observatory of interest and sets the basin,
A predicted rainfall calculation means for calculating an average predicted rainfall in a basin based on a predicted rainfall at least 24 hours ahead in the basin set by the basin setting means.
Measured rainfall calculation means that calculates the average measured rainfall in the basin based on the measured rainfall information in the basin set by the basin setting means, and
Based on the average predicted rainfall and the average measured rainfall, the sum of the cumulative rainfall for a predetermined time in a certain time period from immediately before the acquisition of the predicted rainfall information to the predicted destination time is calculated, and the sum of the cumulative rainfall is calculated. A river flood prediction device during heavy rainfall, which comprises a flood prediction determination means for determining whether or not is greater than the planned rainfall set in the water level observation station.

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