Submergence estimation system, submergence estimation device, submergence estimation program, and submergence estimation method

Abstract

To properly estimate a flooding start date and time which are a date and time when flooding of a ground surface starts.SOLUTION: A flood estimation system 100 includes: a first water level sensor 21 which is a water level sensor 2 disposed at a first distance L1 from a ground level SF; a second water level sensor 22 which is a water level sensor 2 disposed at a second distance L2 shorter than the first distance L1 from the ground level SF; and a flood estimation device 1. The flood estimation device 1 includes: a first estimation unit 112 that estimates an ascending speed V which is a speed at which the groundwater ascends, based on an inter-sensor distance LS which is the distances from the first water level sensor 21 to the second water level sensor 22, and an ascending time TU which is the time for the groundwater to ascend from the position of the first water level sensor 21 to the position of the second water level sensor 22; and a second estimation unit 113 that estimates a flood start date and time TW which is the date and time at which flooding of the ground level SF starts, based on the ascending speed V.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a flood estimation system, a flood estimation device, a flood estimation program, and a flood estimation method for estimating the occurrence of flooding. [Background technology]

[0002] Various techniques for detecting flooding are known (see, for example, Patent Document 1). Patent document 1 describes that a flooding detection device attached to a hollow pole comprises a water surface sensor attached to a lid that opens and closes part of the outer surface of the pole and generates a detection signal depending on the state of contact with the water surface, and a processing and communication unit attached to the outer surface of the pole and including a processing circuit that generates detection data indicating whether flooding has occurred from the detection signal and a communication module that transmits the detection data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-182187 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the flooding detection device described in Patent Document 1 detects a state in which the water level is above the ground surface, but people who require assistance with evacuation and who need to evacuate immediately need to be aware of the occurrence of flooding early on, before the water level reaches above the ground surface. An object of the present invention is to provide a flood estimation system, a flood estimation device, a flood estimation program, and a flood estimation method that can accurately estimate the flood start date and time, which is the date and time when flooding of the ground surface begins. [Means for solving the problem]

[0005] An embodiment of the present invention is a flood estimation system comprising: a first water level sensor which is a water level sensor placed underground at a first distance from the ground surface; a second water level sensor which is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance; and a flood estimation device which acquires detection signals from the first water level sensor and the second water level sensor and estimates the occurrence of flooding, wherein the flood estimation device has a first estimation unit which estimates a rising speed which is the rate at which the groundwater will rise based on an inter-sensor distance which is the distance from the first water level sensor to the second water level sensor and a rise time which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor; and a second estimation unit which estimates a flood start date and time which is the date and time at which flooding of the ground surface will begin based on the rise speed.

[0006] Another embodiment of the present invention is a flooding estimation device that acquires detection signals from a first water level sensor that is a water level sensor placed underground at a first distance from the ground surface, and a second water level sensor that is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance, and estimates the occurrence of flooding, and is equipped with a first estimation unit that estimates the rising speed, which is the rate at which the groundwater will rise, based on the sensor-to-sensor distance, which is the distance from the first water level sensor to the second water level sensor, and the rise time, which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor, and a second estimation unit that estimates the flooding start date and time, which is the date and time at which flooding of the ground surface will begin, based on the rise speed.

[0007] Another embodiment of the present invention is a flooding estimation program that acquires detection signals from a first water level sensor that is a water level sensor placed underground at a first distance from the ground surface, and a second water level sensor that is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance, and estimates the occurrence of flooding, and causes a processor to function as a first estimation unit that estimates the rising speed, which is the rate at which the groundwater will rise, based on the sensor-to-sensor distance, which is the distance from the first water level sensor to the second water level sensor, and the rise time, which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor, and a second estimation unit that estimates the flooding start date and time, which is the date and time at which flooding of the ground surface will begin, based on the rise speed.

[0008] Yet another embodiment of the present invention is a flood estimation method using a flood estimation device that communicates with a first water level sensor that is a water level sensor placed underground at a first distance from the ground surface, and a second water level sensor that is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance, and estimates the occurrence of flooding, the flood estimation method including: a first estimation step of estimating a rising speed, which is the rate at which the groundwater will rise, based on an inter-sensor distance that is the distance from the first water level sensor to the second water level sensor and a rise time that is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor; and a second estimation step of estimating a flood start date and time, which is the date and time at which flooding of the ground surface will begin, based on the rise speed. [Effects of the Invention]

[0009] According to the present invention, the flooding start date and time, which is the date and time when the ground surface will start to be flooded, is estimated based on the rising speed, which is the rate at which groundwater rises, so the flooding start date and time can be estimated appropriately. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of the configuration of a flood estimation system according to a first embodiment. [Figure 2]FIG. 2 is a diagram illustrating an example of the configuration of a water level sensor. [Figure 3] FIG. 1 is a diagram illustrating an example of the configuration of a flood estimation device. [Figure 4] 5 is a flowchart showing an example of processing by a control unit of the submergence estimation device according to the first embodiment. [Figure 5] FIG. 10 is a diagram illustrating an example of the configuration of a flood estimation system according to a second embodiment. [Figure 6] 10 is a flowchart showing an example of processing by a control unit of a submergence estimation device according to a second embodiment. [Figure 7] FIG. 10 is a diagram illustrating an example of the configuration of a flood estimation system according to a third embodiment. [Figure 8] 10 is a flowchart showing an example of processing by a control unit of a submergence estimation device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present embodiment will be described below with reference to the drawings. The present embodiment includes a first embodiment, which will be described mainly with reference to Figures 1 to 4, a second embodiment, which will be described mainly with reference to Figures 5 and 6, and a third embodiment, which will be described mainly with reference to Figures 7 and 8.

[0012] [1. Flood Estimation System According to the First Embodiment] [1-1. Overall configuration of the flood estimation system] First, the configuration of a submergence estimation system 100 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a submergence estimation system 100 according to the first embodiment. 1, the flood estimation system 100 includes a flood estimation device 1 and a water level sensor 2. The water level sensor 2 includes a first water level sensor 21, a second water level sensor 22, and a third water level sensor 23.

[0013] The first water level sensor 21 is a water level sensor placed underground UG at a position a first distance L1 from the ground surface SF. In other words, the first water level sensor 21 is a water level sensor that detects when the groundwater level reaches a position the first distance L1 from the ground surface SF. The first distance L1 is, for example, 450 mm. The second water level sensor 22 is a water level sensor placed underground UG at a second distance L2 from the ground surface SF, which is shorter than the first distance L1. In other words, the second water level sensor 22 is a water level sensor that detects when the groundwater level reaches a position at the second distance L2 from the ground surface SF. The second distance L2 is, for example, 250 mm. The third water level sensor 23 is a water level sensor placed underground UG at a third distance L3 from the ground surface SF, which is shorter than the second distance L2. In other words, the third water level sensor 23 is a water level sensor that detects when the groundwater level reaches a position at the third distance L3 from the ground surface SF. The third distance L3 is, for example, 50 mm. The water level sensor 2 is further described with reference to FIG.

[0014] As shown in Figure 1, the underground UG has, for example, a first layer LY1, a second layer LY2, and a third layer LY3. The first layer LY1 and the second layer LY2 have better permeability than the third layer LY3, and are, for example, sandy soil. The third layer LY3 has worse permeability than the first layer LY1 and the second layer LY2, and is, for example, a bedrock layer. The first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 are arranged, for example, on the first layer LY1 and the second layer LY2.

[0015] The flood estimation device 1 estimates the occurrence of flooding by acquiring detection signals from the first water level sensor 21 and the second water level sensor 22. The flood estimation device 1 according to the first embodiment acquires detection signals from the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23, for example, and estimates the occurrence of flooding. The submergence estimation device 1 is placed, for example, on a wall surface of the house HS. Although Fig. 1 illustrates a case where the submergence estimation device 1 is placed on an outer wall surface of the house HS, the submergence estimation device 1 may be placed anywhere in the house HS. The submergence estimation device 1 may be placed, for example, on a wall surface of a room in the house HS, or may be placed, for example, on the floor surface of a room in the house HS. The flood estimation device 1 is configured, for example, by a personal computer. The flood estimation device 1 will be further described with reference to FIG.

[0016] In the first embodiment, a case is described in which the detection signals of the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 are output to the flood estimation device 1 via a signal cable, but the embodiment is not limited to this. The first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 may each be communicably connected to the submergence estimation device 1 by, for example, a USB (registered trademark) (Universal Serial Bus) cable. In this case, power can be supplied from the submergence estimation device 1 to each of the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23. Note that each of the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 may have a battery, and power may be supplied from the battery. Furthermore, each of the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 may be communicably connected to the flood estimation device 1 via wireless communication such as Wi-Fi (registered trademark).

[0017] [1-2. Water level sensor configuration] Next, the configuration of the water level sensor 2 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the configuration of the water level sensor 2. The first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 have substantially the same configuration, so Fig. 2 will describe the first water level sensor 21, and will omit descriptions of the second water level sensor 22 and the third water level sensor 23. In the following description, when there is no need to distinguish between the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23, they may be referred to as the water level sensor 2.

[0018] The first water level sensor 21 is a so-called float type water level sensor. As shown in FIG. 2, the first water level sensor 21 includes a housing 211, a water-permeable sheet 212, a float 213, and a position detection sensor 214.

[0019] Housing 211 houses float 213 and supports float 213 so that it can move up and down freely. Housing 211 is configured, for example, in a cylindrical shape. Housing 211 is made of metal such as stainless steel or aluminum. A water-permeable sheet 212 is arranged on the bottom surface of housing 211, and a position detection sensor 214 is arranged on the top surface of housing 211.

[0020] The water-permeable sheet 212 is fixed to the underside of the housing 211 and covers the underside of the housing 211. The water-permeable sheet 212 is made of, for example, a nonwoven fabric. The water-permeable sheet 212 allows water to pass through but blocks the passage of solids such as sand and stones. When the groundwater level rises, the groundwater penetrates the water-permeable sheet 212 from the underside of the housing 211 and enters the inside of the housing 211.

[0021] Since the water-permeable sheet 212 is fixed to the lower surface of the housing 211, it is possible to prevent solids such as sand and stones from entering the inside of the housing 211. Therefore, it is possible to prevent the rising and falling movement of the float 213 from being obstructed by solids such as sand and stones.

[0022] Float 213 is configured to float on groundwater and is formed in a disk shape. The diameter of float 213 is smaller than the diameter of the inner surface of housing 211. Float 213 is configured to be able to move up and down along the inner surface of housing 211. For example, float 213 is configured to be able to move up and down between a standby position PW indicated by a dashed line and a detection position PD indicated by a solid line.

[0023] The position detection sensor 214 detects that the float 213 has reached the detection position PD. The position detection sensor 214 is, for example, a proximity sensor, and detects that the float 213 has reached a position equal to or higher than the detection position PD. The detection position PD corresponds to a position that is a first distance L1 from the ground surface SF. That is, the position detection sensor 214 detects that the groundwater level has reached a position that is the first distance L1 from the ground surface SF. The position detection sensor 214 outputs a detection signal to the flood estimation device 1 when the float 213 reaches the detection position PD.

[0024] The configuration of the water level sensor 2 has been described with reference to Figure 2, and as the water level sensor 2, for example, model numbers "OHL-101W" and "OHL-102W" manufactured by Optex Group Co., Ltd. can be suitably used.

[0025] Next, the operation of the first water level sensor 21 will be described. For example, when the groundwater level is lower than the position of the underside of the float 213 disposed at standby position PW, the float 213 is positioned at standby position PW. As the groundwater level rises, the float 213 rises from standby position PW, indicated by the dashed line, to detection position PD, indicated by the solid line. Upon reaching detection position PD, the position detection sensor 214 detects that the groundwater level has reached a position that is a first distance L1 above the ground surface SF, and the position detection sensor 214 outputs a detection signal to the submergence estimation device 1.

[0026] [1-3. Configuration of the flood estimation device] Next, the configuration of the submergence estimation device 1 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of the submergence estimation device 1. As shown in FIG. 3, the submergence estimation device 1 includes a control unit 11, a display 12, and a speaker 13.

[0027] The control unit 11 controls the operation of the submergence estimation device 1 . The control unit 11 includes a processor 11A such as a CPU (Central Processing Unit) or a microcomputer, and a memory 11B such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The memory 11B stores data such as a control program PG. The memory 11B also includes a storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The control unit 11 also has a clocking function.

[0028] The display 12 includes an LCD (Liquid Crystal Display) or the like, and displays various images according to instructions from the control unit 11 . The speaker 13 outputs various sounds in accordance with instructions from the control unit 11 .

[0029] The control unit 11 includes an acquisition unit 111, a first estimation unit 112, a second estimation unit 113, a notification unit 114, and a date and time storage unit 115. Specifically, the processor 11A of the control unit 11 executes the control program PG to function as an acquisition unit 111, a first estimation unit 112, a second estimation unit 113, and a notification unit 114. The processor 11A of the control unit 11 also executes the control program PG to cause the memory 11B to function as a date and time storage unit 115. The control program PG corresponds to an example of a "flood estimation program." In the following description, a case will be described in which, in the initial state, the groundwater level is below a position that is a first distance L1 from the ground surface SF.

[0030] The date and time memory unit 115 stores a first date and time T1, a second date and time T2, and a third date and time T3. The first date and time T1 indicates the date and time when the first water level sensor 21 detected that the groundwater level reached a position that is a first distance L1 from the ground surface SF. The second date and time T2 indicates the date and time when the second water level sensor 22 detected that the groundwater level reached a position that is a second distance L2 from the ground surface SF. The third date and time T3 indicates the date and time when the third water level sensor 23 detected that the groundwater level reached a position that is a third distance L3 from the ground surface SF. The first date and time T1, the second date and time T2, and the third date and time T3 are acquired by the acquisition unit 111 and stored in the date and time storage unit 115.

[0031] The acquisition unit 111 acquires a detection signal from the first water level sensor 21. Furthermore, when acquiring the detection signal from the first water level sensor 21, the acquisition unit 111 acquires a first date and time T1 using the clock function of the control unit 11. The acquisition unit 111 stores the first date and time T1 in the date and time storage unit 115. The acquisition unit 111 acquires a detection signal from the second water level sensor 22. Furthermore, when acquiring a detection signal from the second water level sensor 22, the acquisition unit 111 acquires a second date and time T2 using the clock function of the control unit 11. The acquisition unit 111 stores the second date and time T2 in the date and time storage unit 115. The acquisition unit 111 acquires a detection signal from the third water level sensor 23. Furthermore, when acquiring a detection signal from the third water level sensor 23, the acquisition unit 111 acquires a third date and time T3 using the clock function of the control unit 11. The acquisition unit 111 stores the third date and time T3 in the date and time storage unit 115.

[0032] The first estimation unit 112 estimates the rising speed V based on the inter-sensor distance LS and the rising time TU. The inter-sensor distance LS is the distance from the first water level sensor 21 to the second water level sensor 22. The inter-sensor distance LS corresponds to the difference between the first distance L1 and the second distance L2. The rise time TU is the time it takes for the groundwater level to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22. The rise time TU corresponds to the difference between the second date and time T2 and the first date and time T1. The rising speed V is the speed at which the groundwater level rises. The first estimation unit 112 calculates the rising speed V, for example, by the following formula (1). V=(L1-L2) / (T2-T1) (1)

[0033] The second estimation unit 113 estimates the flood start date and time TW, which is the date and time when flooding of the ground surface SF will begin, based on the rising speed V. The second estimation unit 113 estimates the flood start date and time TW based on the third distance L3 and the rising speed V. The second estimation unit 113 estimates the flood start date and time TW, for example, using the third date and time T3, the third distance L3, and the rising speed V. The second estimation unit 113 calculates the flood start date and time TW, for example, by the following equation (2). TW=T3+L3 / V (2)

[0034] The second estimation unit 113 also estimates the first notification date and time TA1 based on the distance obtained by adding the third distance L3 to a fourth virtual distance LU4 on the ground surface SF and the rising speed V. The first notification date and time TA1 is the date and time at which first evacuation information ES1 urging people to evacuate is notified. The first notification date and time TA1 corresponds to the date and time at which the groundwater level reaches a position at a height of the fourth virtual distance LU4 above the ground surface SF. The fourth virtual distance LU4 is, for example, 200 mm. In other words, the first notification date and time TA1 corresponds to the date and time at which children and others will no longer be able to walk on the ground surface SF due to the rise in the groundwater level. The second estimation unit 113 calculates the first notification date and time TA1, for example, by the following equation (3). TA1=T3+(L3+LU4) / V (3) The fourth virtual distance LU4 corresponds to an example of a "fourth distance."

[0035] The second estimation unit 113 also estimates the second notification date and time TA2 based on the third distance L3 plus a fifth virtual distance LU5, which is longer than the fourth virtual distance LU4 on the ground surface SF, and the rising speed V. The second notification date and time TA2 is the date and time at which the second evacuation information ES2, which urges evacuation more strongly than the first evacuation information ES1, is issued. The second notification date and time TA2 corresponds to the date and time at which the groundwater level reaches a position at a height of the fifth virtual distance LU5 above the ground surface SF. The fifth virtual distance LU5 is, for example, 500 mm. In other words, the second notification date and time TA2 corresponds to the date and time at which the groundwater level rises to the point where adults cannot walk on the ground surface SF. The second estimation unit 113 calculates the second notification date and time TA2, for example, by the following equation (4). TA2=T3+(L3+LU5) / V (4) The fifth virtual distance LU5 corresponds to an example of a "fifth distance."

[0036] The notification unit 114 notifies, for example, the flooding start date and time TW. The notification unit 114, for example, displays the flooding start date and time TW on the display 12. For example, when the second estimation unit 113 estimates the flooding start date and time TW, the notification unit 114 displays the flooding start date and time TW on the display 12. For example, the notification unit 114 displays text information such as "The ground surface will be flooded at approximately 18:00 on May 15th. Please evacuate early." The notification unit 114 outputs, for example, the flooding start date and time TW as sound from the speaker 13. For example, when the second estimation unit 113 estimates the flooding start date and time TW, the notification unit 114 outputs the flooding start date and time TW as sound from the speaker 13. For example, the notification unit 114 outputs, from the speaker 13, a sound saying, "The ground surface will be flooded at approximately 18:00 on May 15th. Please evacuate as soon as possible."

[0037] The notification unit 114 notifies, for example, the first notification date and time TA1 and the first evacuation information ES1. The notification unit 114 displays, for example, the first notification date and time TA1 and the first evacuation information ES1 on the display 12. For example, when the second estimation unit 113 estimates the first notification date and time TA1, the notification unit 114 displays the first notification date and time TA1 and the first evacuation information ES1 on the display 12. For example, the notification unit 114 displays text information such as "The water level will reach 200 mm above ground level at approximately 6:30 PM on May 15th. Please evacuate immediately." Furthermore, the notification unit 114 outputs, for example, the first notification date and time TA1 and the first evacuation information ES1 by voice from the speaker 13. For example, when the second estimation unit 113 estimates the first notification date and time TA1, the notification unit 114 outputs the first notification date and time TA1 and the first evacuation information ES1 by voice from the speaker 13. For example, the notification unit 114 outputs, from the speaker 13, a voice message saying, "The water level will reach 200 mm above ground level at approximately 6:30 PM on May 15th. Please evacuate immediately."

[0038] The notification unit 114 notifies, for example, the second notification date and time TA2 and the second evacuation information ES2. The notification unit 114 displays, for example, the second notification date and time TA2 and the second evacuation information ES2 on the display 12. For example, when the second estimation unit 113 estimates the second notification date and time TA2, the notification unit 114 notifies the second notification date and time TA2 and the second evacuation information ES2. For example, the notification unit 114 displays text information such as "The water level will reach 500 mm above ground level at around 9:30 PM on May 15th. Evacuation will be impossible, so please evacuate immediately." Furthermore, the notification unit 114 outputs, for example, the second notification date and time TA2 and the second evacuation information ES2 by voice from the speaker 13. For example, when the second estimation unit 113 estimates the second notification date and time TA2, the notification unit 114 outputs the second notification date and time TA2 and the second evacuation information ES2 by voice from the speaker 13. For example, the notification unit 114 outputs, from the speaker 13, a voice message saying, "The water level will reach 500 mm above ground level at around 9:30 PM on May 15th. Evacuation will be impossible, so please evacuate immediately."

[0039] In the first embodiment, the case where the first estimating unit 112 estimates the rising speed V based on the detection signals of the first water level sensor 21 and the second water level sensor 22 has been described, but the embodiment is not limited to this. The first estimation unit 112 may estimate the rising speed V, for example, based on the detection signals of the first water level sensor 21 and the third water level sensor 23. In this case, the first estimation unit 112 calculates the rising speed V, for example, by the following equation (5). V=(L1-L3) / (T3-T1) (5) Furthermore, the first estimation unit 112 may estimate the rising speed V based on, for example, the detection signals of the second water level sensor 22 and the third water level sensor 23. In this case, the first estimation unit 112 calculates the rising speed V by, for example, the following equation (6). V=(L2-L3) / (T3-T2) (6) Furthermore, the first estimation unit 112 may estimate the rising speed V based on, for example, the detection signals of the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23. In this case, the first estimation unit 112 calculates the rising speed V, for example, by the following equation (7). V = α × (L1 - L2) / (T2 - T1) +(1-α)×(L2-L3) / (T3-T2) (7) The coefficient α is a value between 0 and 1. For example, the coefficient α is 0.3.

[0040] [1-4. Processing by the flood estimation device] Next, the processing of the control unit 11 of the submergence estimation device 1 according to the first embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of the processing of the control unit 11 of the submergence estimation device 1 according to the first embodiment. As shown in FIG. 4, first, in step S101, the acquisition unit 111 determines whether or not a detection signal has been acquired from the first water level sensor 21. If the acquisition unit 111 determines that a detection signal has not been acquired from the first water level sensor 21 (step S101; NO), the process enters a standby state. If the acquisition unit 111 determines that a detection signal has been acquired from the first water level sensor 21 (step S101; YES), the process proceeds to step S103. Next, in step S103, the acquisition unit 111 acquires the first date and time T1.

[0041] Next, in step S105, the acquisition unit 111 determines whether or not a detection signal has been acquired from the second water level sensor 22. If the acquisition unit 111 determines that a detection signal has not been acquired from the second water level sensor 22 (step S105; NO), the process goes to a standby state. If the acquisition unit 111 determines that a detection signal has been acquired from the second water level sensor 22 (step S105; YES), the process proceeds to step S107. Then, in step S107, the acquisition unit 111 acquires the second date and time T2. Next, in step S109, the first estimation unit 112 estimates the rising speed V. The rising speed V is the speed at which the groundwater level rises.

[0042] Next, in step S111, the acquisition unit 111 determines whether or not a detection signal has been acquired from the third water level sensor . If the acquisition unit 111 determines that a detection signal has not been acquired from the third water level sensor 23 (step S111; NO), the process enters a standby state. If the acquisition unit 111 determines that a detection signal has been acquired from the third water level sensor 23 (step S111; YES), the process proceeds to step S113. Then, in step S113, the acquisition unit 111 acquires the third date and time T3.

[0043] Next, in step S115, the second estimation unit 113 estimates, based on the rising speed V, the flooding start date and time TW, which is the date and time when the flooding of the ground surface SF will start. Next, in step S117, the second estimation unit 113 estimates the first notification date and time TA1. The first notification date and time TA1 is the date and time when the first evacuation information ES1 encouraging evacuation is notified. The first notification date and time TA1 corresponds to the date and time when the groundwater level reaches a position at a height of a fourth virtual distance LU4 above the ground surface SF. Next, in step S119, the second estimation unit 113 estimates the second notification date and time TA2. The second notification date and time TA2 is the date and time at which the second evacuation information ES2, which urges evacuation more strongly than the first evacuation information ES1, will be notified. The second notification date and time TA2 corresponds to the date and time at which the groundwater level reaches a position at a height of a fifth distance L5 above the ground surface SF. Next, in step S121, the notification unit 114 notifies the flooding start date and time TW, the first notification date and time TA1, the first evacuation information ES1, the second notification date and time TA2, and the second evacuation information ES2. The notification unit 114, for example, displays the flooding start date and time TW, the first notification date and time TA1, the first evacuation information ES1, the second notification date and time TA2, and the second evacuation information ES2 on the display 12. Thereafter, the processing ends.

[0044] Step S109 corresponds to an example of a “first estimation step.” Furthermore, step S115 corresponds to an example of a “second estimation step.”

[0045] [2. Flood Estimation System According to the Second Embodiment] [2-1. Overall configuration of the flood estimation system] Next, the configuration of a submergence estimation system 100A according to a second embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of the configuration of a submergence estimation system 100A according to the second embodiment. In the following explanation, the differences between the configuration of the flood estimation system 100A according to the second embodiment and the flood estimation system 100 according to the first embodiment explained with reference to Figure 1 will be mainly explained, and explanations of the configuration that is the same as that of the flood estimation system 100 will be omitted.

[0046] The submergence estimation system 100A differs from the submergence estimation system 100 in that it includes an earthquake detection device 3 in addition to the submergence estimation device 1 and the water level sensor 2. The earthquake detection device 3 detects the occurrence of an earthquake. Furthermore, when an earthquake occurs, the earthquake detection device 3 transmits earthquake occurrence information to the submergence estimation device 1. The earthquake occurrence information includes seismic intensity information.

[0047] The flood estimation system 100A also differs from the flood estimation system 100 in that it includes a pipe 2A that houses a water level sensor 2. The pipe 2A is cylindrical and made of metal such as stainless steel, aluminum, etc. The pipe 2A is buried in the ground and extends in a substantially vertical direction. The pipe 2A houses the water level sensor 2. In the second embodiment, the pipe 2A houses a first water level sensor 21, a second water level sensor 22, and a third water level sensor .

[0048] In the second embodiment, the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 are each fixed to the inner surface of the pipe 2A. Also, the distances from the ground surface SF at which the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 are placed are different from the distances shown in FIG. That is, the first water level sensor 21 is a water level sensor placed at a position a first distance L1 from the ground surface SF. In other words, the first water level sensor 21 is a water level sensor that detects when the groundwater level reaches a position the first distance L1 from the ground surface SF. The first distance L1 is, for example, 500 mm. The second water level sensor 22 is a water level sensor that is placed at a position that is a second distance L2 from the ground surface SF. In other words, the second water level sensor 22 is a water level sensor that detects that the groundwater level has reached a position that is the second distance L2 from the ground surface SF. The second distance L2 is, for example, 300 mm. The third water level sensor 23 is a water level sensor located at a third distance L3 from the ground surface SF. In other words, the third water level sensor 23 is a water level sensor that detects when the groundwater level reaches a position at the third distance L3 from the ground surface SF. The third distance L3 is, for example, 100 mm.

[0049] A water-permeable sheet 2B is placed on the lower surface of the pipe 2A. The permeable sheet 2B is fixed to the underside of the pipe 2A and covers the underside of the pipe 2A. The permeable sheet 2B is made of, for example, a nonwoven fabric. The permeable sheet 2B allows water to pass through but blocks the passage of solids such as sand and stones. When the groundwater level rises, groundwater penetrates the underside of the pipe 2A through the permeable sheet 2B and enters the inside of the pipe 2A. As the nonwoven fabric constituting the water-permeable sheet 2B, for example, a product name "Baron Water-Permeable Sheet" manufactured by Koizumi Seima Co., Ltd. can be suitably used.

[0050] Because the water-permeable sheet 2B is fixed to the underside of the pipe 2A, it is possible to prevent solids such as sand and stones from entering the inside of the pipe 2A. This prevents the flow of groundwater in the pipe 2A from being obstructed by solids such as sand and stones. Therefore, the first water level sensor 21, the second water level sensor 22, and the third water level sensor 23 can properly detect the water level.

[0051] The upper surface of pipe 2A is disposed at a position higher than ground surface SF. For example, the upper surface of pipe 2A is disposed at a position about 500 mm higher than ground surface SF. The reason for disposing the upper surface of pipe 2A at a position higher than ground surface SF is to prevent groundwater from entering pipe 2A through the opening at the upper surface of pipe 2A when the groundwater level rises and the area becomes flooded.

[0052] 1 to 4 has been described as not including the pipes 2A and the water-permeable sheet 2B, the embodiment is not limited to this. The flood estimation system 100 may also include the pipes 2A and the water-permeable sheet 2B described with reference to FIG. 5.

[0053] [2-2. Configuration of the flood estimation device] Next, the configuration of the submergence estimation device 1 of the submergence estimation system 100A according to the second embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of the submergence estimation device 1. In the following explanation, the differences between the configuration of the submergence estimation device 1 of the second embodiment and the submergence estimation device 1 of the first embodiment explained with reference to Figure 3 will be mainly explained, and explanations of the configuration that is the same as that of the submergence estimation device 1 of the first embodiment will be omitted. The acquisition unit 111 differs from the acquisition unit 111 of the flood estimation device 1 of the first embodiment in that, in addition to the functions of the acquisition unit 111 of the flood estimation device 1 of the first embodiment, it also receives earthquake occurrence information from the earthquake detection device 3.

[0054] The first estimation unit 112 is the same as the first estimation unit 112 in the submergence estimation device 1 according to the first embodiment. The second estimation unit 113 differs from the second estimation unit 113 in the submergence estimation device 1 according to the first embodiment in that it has the following functions in addition to the functions of the second estimation unit 113 in the submergence estimation device 1 according to the first embodiment. The second estimation unit 113 estimates the liquefaction occurrence date and time TL, which is the date and time when liquefaction will occur, based on the sensor-to-sensor distance LS and the rising speed V. The sensor-to-sensor distance LS is the distance from the first water level sensor 21 to the second water level sensor 22. The sensor-to-sensor distance LS corresponds to the difference between the first distance L1 and the second distance L2. The rising speed V is the speed at which the groundwater level rises.

[0055] The second estimation unit 113 executes a process of estimating the liquefaction occurrence date and time TL when the seismic intensity of the earthquake is equal to or greater than the seismic intensity threshold. The seismic intensity threshold is, for example, "seismic intensity 6." The second estimation unit 113 also executes a process to estimate the liquefaction occurrence date and time TL during the period from the first period P1 to the second period P2 that has elapsed since the occurrence of the earthquake. The first period P1 is the period that elapses from the occurrence of the earthquake to the start of the occurrence of the liquefaction phenomenon. The second period P2 is the period that elapses from the occurrence of the earthquake to the end of the occurrence of the liquefaction phenomenon. The first period P1 is, for example, "3 minutes," and the second period P2 is, for example, "30 minutes." The first period P1 corresponds to the start point of the occurrence of the liquefaction phenomenon, and the second period P2 corresponds to the end point of the occurrence of the liquefaction phenomenon.

[0056] In addition, if the acquisition unit 111 receives detection signals from the first water level sensor 21 and the second water level sensor 22 when the period since the earthquake occurs is between the first period P1 and the second period P2, the second estimation unit 113 estimates the date and time TL when liquefaction occurred. Furthermore, the second estimation unit 113 calculates the liquefaction occurrence date and time TL, for example, by the following formula (8). TL=T2+(L2-LL) / V (8)

[0057] Here, the liquefaction trigger water level LL is the distance from the ground surface SF to the water level at which it is determined that liquefaction has occurred. In the second embodiment, a case will be described in which the liquefaction trigger water level LL satisfies the following formula (9). L3 <LL<L2 (9) The liquefaction water level LL is, for example, 200 mm.

[0058] Furthermore, for example, if the liquefaction occurrence date and time TL corresponds to a period of time that has elapsed since the occurrence of an earthquake that is equal to or greater than the second period P2, the second estimation unit 113 estimates that liquefaction will not occur. Furthermore, for example, if the liquefaction occurrence date and time TL corresponds to a period of time that has elapsed since the occurrence of an earthquake that is less than the second period P2, the second estimation unit 113 estimates that liquefaction will occur.

[0059] The notification unit 114 differs from the notification unit 114 of the submergence estimation device 1 according to the first embodiment. When the second estimation unit 113 estimates that liquefaction will occur, the notification unit 114 notifies the liquefaction occurrence date and time TL. For example, when the second estimation unit 113 estimates that liquefaction will occur, the notification unit 114 displays the liquefaction occurrence date and time TL on the display 12. For example, the notification unit 114 displays text information such as "Liquefaction will occur at approximately 6:30 PM on May 15th. Please evacuate." For example, when the second estimation unit 113 estimates that liquefaction will occur, the notification unit 114 outputs the liquefaction occurrence date and time TL as a voice from the speaker 13. For example, the notification unit 114 outputs a voice from the speaker 13 saying, "Liquefaction will occur at approximately 18:30 on May 15th. Please evacuate."

[0060] [2-3. Processing by the flood estimation device] Next, the processing of the control unit 11 of the submergence estimation device 1 according to the second embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the processing of the control unit 11 of the submergence estimation device 1 according to the second embodiment. In the following description, a case will be described in which, in the initial state, the groundwater level is below a position that is a first distance L1 from the ground surface SF.

[0061] As shown in FIG. 6, first, in step S201, the acquisition unit 111 determines whether or not earthquake occurrence information has been acquired. If the acquisition unit 111 determines that earthquake occurrence information has not been acquired (step S201; NO), the process goes to a standby state. If the acquisition unit 111 determines that earthquake occurrence information has been acquired (step S201; YES), the process proceeds to step S203.

[0062] Next, in step S203, the second estimation unit 113 determines whether or not the seismic intensity of the earthquake is equal to or greater than the seismic intensity threshold, based on the earthquake occurrence information. If the second estimation unit 113 determines that the seismic intensity of the earthquake is not equal to or greater than the seismic intensity threshold (step S203; NO), the process returns to step S201. If the second estimation unit 113 determines that the seismic intensity of the earthquake is equal to or greater than the seismic intensity threshold (step S203; YES), the process proceeds to step S205. Next, in step S205, the second estimation unit 113 determines whether or not a first period P1 has elapsed since the occurrence of the earthquake. If the second estimation unit 113 determines that the first period P1 has not elapsed since the occurrence of the earthquake (step S205; NO), the process goes to a standby state. If the second estimation unit 113 determines that the first period P1 has elapsed since the occurrence of the earthquake (step S205; YES), the process proceeds to step S207.

[0063] Next, in step S207, the acquisition unit 111 determines whether or not a detection signal has been acquired from the first water level sensor 21. If the acquisition unit 111 determines that a detection signal has been acquired from the first water level sensor 21 (step S207; YES), the process proceeds to step S215. If the acquisition unit 111 determines that a detection signal has not been acquired from the first water level sensor 21 (step S207; NO), the process proceeds to step S209. Then, in step S209, the second estimation unit 113 determines whether or not a second period P2 has elapsed since the occurrence of the earthquake. If the second estimation unit 113 determines that the second period P2 has not elapsed since the occurrence of the earthquake (step S209; NO), the process returns to step S207. If the second estimation unit 113 determines that the first period P1 has elapsed since the occurrence of the earthquake (step S209; YES), the process proceeds to step S211. Then, in step S211, the second estimation unit 113 estimates that liquefaction will not occur. Next, in step S213, the notification unit 114 notifies that liquefaction will not occur. For example, the notification unit 114 displays text information indicating that liquefaction will not occur on the display 12. Thereafter, the process ends.

[0064] If the answer is YES in step S207, in step S215, the acquiring unit 111 acquires the first date and time T1. Next, in step S217, the acquisition unit 111 determines whether or not a detection signal has been acquired from the second water level sensor 22. If the acquisition unit 111 determines that a detection signal has been acquired from the second water level sensor 22 (step S217; YES), the process proceeds to step S221. If the acquisition unit 111 determines that a detection signal has not been acquired from the second water level sensor 22 (step S217; NO), the process proceeds to step S219. Then, in step S219, the second estimation unit 113 determines whether or not a second period P2 has elapsed since the occurrence of the earthquake. If the second estimation unit 113 determines that the second period P2 has not elapsed since the occurrence of the earthquake (step S219; NO), the process returns to step S217. If the second estimation unit 113 determines that the second period P2 has elapsed since the occurrence of the earthquake (step S219; YES), the process proceeds to step S211. Then, the above-described processes of steps S211 and S213 are executed, and then the process ends.

[0065] If the determination in step S217 is YES, in step S221, the acquiring unit 111 acquires the second date and time T2. Next, in step S223, the first estimation unit 112 estimates the rising speed V. The rising speed V is the speed at which the groundwater level rises. Next, in step S225, the second estimation unit 113 estimates the liquefaction occurrence date and time TL based on the liquefaction occurrence water level LL and the rising speed V. The liquefaction occurrence date and time TL is the date and time when the groundwater level reaches the liquefaction occurrence water level LL. The liquefaction occurrence water level LL is the distance from the ground surface SF to the water level at which it is determined that liquefaction has occurred.

[0066] Next, in step S227, the second estimation unit 113 determines whether or not the second period P2 will have elapsed at the liquefaction occurrence date and time TL. If the second estimation unit 113 determines that the second period P2 will have elapsed at the liquefaction occurrence date and time TL (step S227; YES), the process proceeds to step S211. Then, the above-described processes of steps S211 and S213 are executed, and then the process ends. If the second estimation unit 113 determines that the second period P2 has not elapsed at the liquefaction occurrence date and time TL (step S227; NO), the process proceeds to step S229. Then, the notification unit 114 notifies the liquefaction occurrence date and time TL. The notification unit 114 displays, for example, text information indicating the liquefaction occurrence date and time TL on the display 12. Thereafter, the process ends.

[0067] [3. Flood Estimation System According to the Third Embodiment] [3-1. Overall configuration of the flood estimation system] Next, the configuration of a submergence estimation system 100B according to a third embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram showing an example of the configuration of a submergence estimation system 100B according to the third embodiment. In the following explanation, the differences between the configuration of the flood estimation system 100B according to the third embodiment and the flood estimation system 100A according to the second embodiment explained with reference to Figure 5 will be mainly explained, and explanations of the same configuration as the flood estimation system 100A will be omitted.

[0068] The submergence estimation system 100B differs from the submergence estimation system 100A according to the second embodiment in that it does not include an earthquake detection device 3 but includes a rain gauge 5. In addition, the flood estimation system 100B differs from the flood estimation system 100A of the second embodiment in that the water level sensor 2 is composed of a first water level sensor 21, a second water level sensor 22, a third water level sensor 23, a fourth water level sensor 24, and a fifth water level sensor 25. The first water level sensor 21, the second water level sensor 22, the third water level sensor 23, the fourth water level sensor 24, and the fifth water level sensor 25 are housed in the pipe 2A, similar to the flood estimation system 100A according to the second embodiment.

[0069] The first water level sensor 21 is a water level sensor placed underground UG at a position a first distance L1 from the ground surface SF. In other words, the first water level sensor 21 is a water level sensor that detects when the groundwater level reaches a position the first distance L1 from the ground surface SF. The first distance L1 is, for example, 450 mm. The second water level sensor 22 is a water level sensor placed underground UG at a second distance L2 from the ground surface SF, which is shorter than the first distance L1. In other words, the second water level sensor 22 is a water level sensor that detects when the groundwater level reaches a position at the second distance L2 from the ground surface SF. The second distance L2 is, for example, 350 mm. The third water level sensor 23 is a water level sensor placed underground UG at a third distance L3 from the ground surface SF, which is shorter than the second distance L2. In other words, the third water level sensor 23 is a water level sensor that detects when the groundwater level reaches a position that is the third distance L3 from the ground surface SF. The third distance L3 is, for example, 250 mm.

[0070] The fourth water level sensor 24 is a water level sensor placed underground UG at a fourth distance L4, which is shorter than the third distance L3, from the ground surface SF. In other words, the fourth water level sensor 24 is a water level sensor that detects when the groundwater level reaches a position at the fourth distance L4 from the ground surface SF. The fourth distance L4 is, for example, 150 mm. The fifth water level sensor 25 is a water level sensor placed underground UG at a position a fifth distance L5 from the ground surface SF, which is shorter than the fourth distance L4. In other words, the fifth water level sensor 25 is a water level sensor that detects when the groundwater level reaches a position the fifth distance L5 from the ground surface SF. The fifth distance L5 is, for example, 150 mm.

[0071] The rain gauge 5 measures the rainfall per unit time RF (mm / Hr) and outputs a rainfall signal indicating the measured rainfall RF to the submergence estimation device 1.

[0072] [3-2. Configuration of the flood estimation device] Next, the configuration of the submergence estimation device 1 of the submergence estimation system 100B according to the third embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of the submergence estimation device 1. As described with reference to FIG. 3, the control unit 11 of the submergence estimation device 1 includes an acquisition unit 111, a first estimation unit 112, a second estimation unit 113, a notification unit 114, and a date and time storage unit 115. However, the control unit 11 of the submergence estimation device 1 has the following functions in addition to the functions of the control unit 11 of the submergence estimation device 1 according to the first embodiment described with reference to FIG.

[0073] The date and time memory unit 115 stores a first date and time T1, a second date and time T2, a third date and time T3, a fourth date and time T4, and a fifth date and time T5. The first date and time T1 indicates the date and time when the first water level sensor 21 detected that the groundwater level reached a position a first distance L1 from the ground surface SF. The second date and time T2 indicates the date and time when the second water level sensor 22 detected that the groundwater level reached a position a second distance L2 from the ground surface SF. The third date and time T3 indicates the date and time when the third water level sensor 23 detected that the groundwater level reached a position a third distance L3 from the ground surface SF. The fourth date and time T4 indicates the date and time when the fourth water level sensor 24 detected that the groundwater level reached a position a fourth distance L4 from the ground surface SF. The fifth date and time T5 indicates the date and time when the fifth water level sensor 25 detected that the groundwater level reached a position a fifth distance L5 from the ground surface SF. The first date and time T1, the second date and time T2, the third date and time T3, the fourth date and time T4, and the fifth date and time T5 are acquired by the acquisition unit 111 and stored in the date and time storage unit 115.

[0074] The date and time storage unit 115 stores date and time information and rainfall information in association with each other. The date and time information and rainfall information are acquired by the acquisition unit 111 and stored in the date and time storage unit 115.

[0075] The acquisition unit 111 acquires a detection signal from the first water level sensor 21. Furthermore, when acquiring the detection signal from the first water level sensor 21, the acquisition unit 111 acquires a first date and time T1 using the clock function of the control unit 11. The acquisition unit 111 stores the first date and time T1 in the date and time storage unit 115. The acquisition unit 111 acquires a detection signal from the second water level sensor 22. Furthermore, when acquiring a detection signal from the second water level sensor 22, the acquisition unit 111 acquires a second date and time T2 using the clock function of the control unit 11. The acquisition unit 111 stores the second date and time T2 in the date and time storage unit 115. The acquisition unit 111 acquires a detection signal from the third water level sensor 23. Furthermore, when acquiring a detection signal from the third water level sensor 23, the acquisition unit 111 acquires a third date and time T3 using the clock function of the control unit 11. The acquisition unit 111 stores the third date and time T3 in the date and time storage unit 115.

[0076] The acquisition unit 111 acquires a detection signal from the fourth water level sensor 24. Furthermore, when acquiring a detection signal from the fourth water level sensor 24, the acquisition unit 111 acquires a fourth date and time T4 using the clock function of the control unit 11. The acquisition unit 111 stores the fourth date and time T4 in the date and time memory unit 115. The acquisition unit 111 acquires a detection signal from the fifth water level sensor 25. Furthermore, when acquiring the detection signal from the fifth water level sensor 25, the acquisition unit 111 acquires a fifth date and time T5 using the clock function of the control unit 11. The acquisition unit 111 stores the fifth date and time T5 in the date and time storage unit 115. The acquisition unit 111 acquires a rainfall signal from the rain gauge 5. When the acquisition unit 111 acquires the rainfall signal from the rain gauge 5, the acquisition unit 111 acquires date and time information using the clock function of the control unit 11, associates the date and time information with the rainfall information, and stores the associated information in the date and time storage unit 115. The rainfall information indicates the rainfall RF corresponding to the rainfall signal.

[0077] The first estimation unit 112 estimates the rising speed V based on the inter-sensor distance LS and the rising time TU. The inter-sensor distance LS is, for example, the distance from the first water level sensor 21 to the second water level sensor 22. The inter-sensor distance LS corresponds to, for example, the difference between the first distance L1 and the second distance L2. The rise time TU is, for example, the time it takes for the groundwater level to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22. The rise time TU corresponds to, for example, the difference between the second date and time T2 and the first date and time T1. The rising speed V is the speed at which the groundwater level rises. The first estimation unit 112 calculates the rising speed V, for example, by the following equation (9). Note that equation (9) is the same as equation (1) above. V=(L1-L2) / (T2-T1) (9)

[0078] The first estimation unit 112 calculates the rising speed V using the following equations (10), (11), and (13), in the same manner as equation (9). For example, when the acquisition unit 111 acquires a detection signal from the third water level sensor 23, the first estimation unit 112 calculates the rising speed V by the following equation (10). V=(L2-L3) / (T3-T2) (10) Furthermore, for example, when the acquisition unit 111 acquires a detection signal from the fourth water level sensor 24, the first estimation unit 112 calculates the rising speed V by the following equation (11). V=(L3-L4) / (T4-T3) (11) Furthermore, for example, when the acquisition unit 111 acquires a detection signal from the fifth water level sensor 25, the first estimation unit 112 calculates the rising speed V by the following equation (12). V=(L5-L4) / (T5-T4) (12)

[0079] The second estimation unit 113 estimates the water absorption capacity of the ground based on the rainfall RF detected by the rain gauge 5 and the rising speed V. The rising speed V is calculated by, for example, any one of the above formulas (9) to (12). It is preferable to use the latest rising speed V as the rising speed V.

[0080] For example, if the rate of increase V is slower than the amount of rainfall RF, the second estimation unit 113 estimates that the ground has some margin for water absorption. Also, for example, if the amount of rainfall RF and the rate of increase V are approximately equal, the second estimation unit 113 estimates that the ground's water absorption capacity is at its limit. The amount of rainfall RF and the rate of increase V being approximately equal means that the difference between the amount of rainfall RF and the rate of increase V is, for example, 3 mm / Hr or less.

[0081] Furthermore, for example, when the rate of increase V is faster than the rainfall RF, the second estimation unit 113 estimates that the water absorption capacity of the ground is at its limit and there is a possibility of flooding of drainage channels and rivers. Furthermore, for example, when the rainfall RF is approximately zero and the rising speed V is equal to or greater than a preset speed threshold THV, the second estimation unit 113 estimates that there is a risk of water intrusion from other areas, river flooding, landslides, and liquefaction. The rainfall RF being approximately zero means, for example, that the rainfall RF is equal to or less than 1 mm / Hr. The speed threshold THV is, for example, 10 mm / Hr.

[0082] The notification unit 114 notifies the estimation result obtained by the second estimation unit 113. The notification unit 114 displays, for example, text information indicating the estimation result estimated by the second estimation unit 113 on the display 12. In addition, the notification unit 114 outputs, for example, a sound indicating the estimation result estimated by the second estimation unit 113 from the speaker 13.

[0083] [3-3. Processing by the flood estimation device] Next, the processing of the control unit 11 of the submergence estimation device 1 according to the third embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of the processing of the control unit 11 of the submergence estimation device 1 according to the third embodiment. 8, for convenience, a case will be described in which the first estimating unit 112 calculates the rising speed V by the above equation (9).

[0084] As shown in FIG. 8, first, in step S301, the acquisition unit 111 determines whether or not a detection signal has been acquired from the first water level sensor 21. If the acquisition unit 111 determines that a detection signal has not been acquired from the first water level sensor 21 (step S301; NO), the process enters a standby state. If the acquisition unit 111 determines that a detection signal has been acquired from the first water level sensor 21 (step S301; YES), the process proceeds to step S303. Next, in step S303, the acquisition unit 111 acquires the first date and time T1.

[0085] Next, in step S305, the acquisition unit 111 determines whether or not a detection signal has been acquired from the second water level sensor 22. If the acquisition unit 111 determines that a detection signal has not been acquired from the second water level sensor 22 (step S305; NO), the process enters a standby state. If the acquisition unit 111 determines that a detection signal has been acquired from the second water level sensor 22 (step S305; YES), the process proceeds to step S307. Then, in step S307, the acquisition unit 111 acquires the second date and time T2. Next, in step S309, the first estimation unit 112 estimates the rising speed V. The rising speed V is the speed at which the groundwater level rises.

[0086] Next, in step S311, the acquisition unit 111 acquires a rainfall signal from the rain gauge 5. The rainfall signal indicates the amount of rainfall RF. Next, in step S313, the second estimation unit 113 determines whether the rainfall RF is approximately zero. If the second estimation unit 113 determines that the rainfall RF is not substantially zero (step S313; NO), the process proceeds to step S317. If the second estimation unit 113 determines that the rainfall RF is substantially zero (step S313; YES), the process proceeds to step S315. Then, in step S315, the second estimation unit 113 determines whether or not the rising speed V is equal to or greater than a preset speed threshold THV. If the second estimation unit 113 determines that the rising speed V is equal to or greater than the preset speed threshold THV (step S315; YES), the process proceeds to step S323. Then, in step S323, the second estimation unit 113 estimates that there is a risk of water intrusion from other areas, river flooding, landslides, and liquefaction, and then the process ends. If the second estimation unit 113 determines that the rising speed V is not equal to or greater than the preset speed threshold THV (step S315; NO), the process then ends.

[0087] If the determination in step S313 is NO, the second estimation unit 113 determines in step S317 whether the rate of increase V is slower than the rainfall RF. If the second estimation unit 113 determines that the rate of increase V is slower than the rainfall RF (step S317; YES), the process proceeds to step S327. Then, in step S327, the second estimation unit 113 estimates that the water absorption capacity of the ground is sufficient, and then the process ends. If the second estimation unit 113 determines that the rate of increase V is not slower than the rainfall RF (step S317; NO), the process proceeds to step S319. Then, in step S319, the second estimating unit 113 determines whether the rainfall RF and the rate of increase V are approximately equal. If the second estimation unit 113 determines that the rainfall RF and the rate of increase V are approximately equal (step S319; YES), the process proceeds to step S325. Then, in step S325, the second estimation unit 113 estimates that the water absorption capacity of the ground is at its limit.

[0088] If the second estimation unit 113 determines that the rainfall RF and the rate of increase V are not approximately equal (step S319; NO), the process proceeds to step S321. Then, in step S321, the second estimation unit 113 determines whether the rate of increase V is faster than the rainfall RF. If the second estimation unit 113 determines that the rate of increase V is faster than the rainfall RF (step S321; YES), the process proceeds to step S323. Then, in step S323, the second estimation unit 113 estimates that the water absorption capacity of the ground has reached its limit and that there is a possibility of flooding of drainage channels and rivers.Then, the process ends. If the second estimation unit 113 determines that the rate of increase V is not faster than the rainfall RF (step S321; NO), the process then ends.

[0089] 4. Effects of this embodiment As described above with reference to Figures 1 to 8, the flood estimation system 100 of this embodiment comprises a first water level sensor 21, which is a water level sensor 2 located underground UG at a first distance L1 from the ground surface SF, a second water level sensor 22, which is a water level sensor 2 located underground UG at a second distance L2 from the ground surface SF that is shorter than the first distance L1, and a flood estimation device 1 that acquires the detection signals of the first water level sensor 21 and the second water level sensor 22 and estimates the occurrence of flooding.The flood estimation device 1 comprises a first estimation unit 112 that estimates the rising speed V, which is the speed at which the groundwater will rise, based on the inter-sensor distance LS, which is the distance from the first water level sensor 21 to the second water level sensor 22, and the rise time TU, which is the time it takes for the groundwater to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22, and a second estimation unit 113 that estimates the flood start date and time TW, which is the date and time at which flooding of the ground surface SF will begin, based on the rise speed V.

[0090] That is, based on the inter-sensor distance LS, which is the distance from the first water level sensor 21 to the second water level sensor 22, and the rise time TU, which is the time it takes for the groundwater to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22, the rise speed V, which is the rate at which the groundwater rises, is estimated, and based on the rise speed V, the flooding start date and time TW, which is the date and time at which flooding of the ground surface SF begins, is estimated. Therefore, by appropriately setting the first distance L1 and the second distance L2, the flooding start date and time TW can be estimated appropriately. Therefore, the flooding start date and time TW can be notified, thereby improving convenience for the user.

[0091] In addition, the flood estimation system 100 is provided with a third water level sensor 23, which is a water level sensor 2 positioned underground UG at a third distance L3 from the ground surface SF that is shorter than the second distance L2, and the flood estimation device 1 acquires a detection signal from the third water level sensor 23, and the second estimation unit 113 estimates the flood start date and time TW based on the third distance L3 and the rising speed V. Therefore, since the flooding start date and time TW is estimated based on the third distance L3 and the rising speed V, the flooding start date and time TW can be estimated appropriately by appropriately setting the third distance L3.

[0092] In addition, in the flood estimation system 100, the second estimation unit 113 estimates the first notification date and time TA1, which is the date and time at which the first evacuation information ES1 encouraging evacuation will be notified, based on the distance obtained by adding the fourth virtual distance LU4 on the ground surface SF to the third distance L3 and the rising speed V. Therefore, by appropriately setting the fourth virtual distance LU4, it is possible to appropriately estimate the first notification date and time TA1, which is the date and time when the first evacuation information ES1 is to be notified.

[0093] In addition, in the flood estimation system 100, the second estimation unit 113 estimates the second notification date and time TA2, which is the date and time at which the second evacuation information ES2, which urges evacuation more strongly than the first evacuation information ES1, will be announced, based on the distance obtained by adding the third distance L3 to a fifth virtual distance LU5 that is longer than the fourth virtual distance LU4 on the ground surface SF, and the rising speed V. Therefore, by appropriately setting the fifth virtual distance LU5, it is possible to appropriately estimate the second notification date and time TA2, which is the date and time when the second evacuation information ES2 is to be notified.

[0094] As explained with reference to Figures 5 and 6, the flood estimation system 100A according to the second embodiment includes an acquisition unit 111 that acquires earthquake occurrence information, and the second estimation unit 113 estimates whether liquefaction will occur based on the sensor-to-sensor distance LS and the rising speed V when the acquisition unit 111 acquires the earthquake occurrence information. Therefore, when earthquake occurrence information is acquired, whether or not liquefaction will occur is estimated based on the sensor distance LS and the rising speed V, so that it is possible to properly estimate whether or not liquefaction will occur.

[0095] In the flood estimation system 100 according to this embodiment, the water level sensor 2 is a float-type water level sensor. Therefore, the groundwater level can be properly detected by the water level sensor 2. Furthermore, the frequency of breakdowns in the water level sensor 2 can be reduced compared to water level sensors of other types.

[0096] Furthermore, the flood estimation system 100A according to the second embodiment includes a pipe 2A that is buried in the ground UG and extends in a substantially vertical direction, and the water level sensor 2 is housed inside the pipe 2A. Therefore, for example, when at least a part of the ground moves due to an earthquake or the like, the change in the position of the water level sensor 2 can be suppressed.

[0097] As explained with reference to Figures 7 and 8, the flood estimation system 100B according to the third embodiment comprises a pipe 2A buried in the ground UG and extending in a substantially vertical direction, and a rain gauge 4 for measuring rainfall, the first water level sensor 21 and the second water level sensor 22 being housed inside the pipe 2A, and the second estimation unit 113 estimating the water absorption capacity of the ground based on the rainfall RF detected by the rain gauge 4 and the rising speed V. Therefore, because the first water level sensor 21 and the second water level sensor 22 are stored inside the pipe 2A, it is possible to suppress changes in the positions of the first water level sensor 21 and the second water level sensor 22 when at least a portion of the ground moves due to, for example, an earthquake, etc. Furthermore, because the water absorption capacity of the ground is estimated based on the rainfall RF detected by the rain gauge 4 and the rising speed V, it is possible to properly estimate the water absorption capacity of the ground.

[0098] Furthermore, as explained with reference to Figures 7 and 8, in the flood estimation system 100B of the third embodiment, the second estimation unit 113 estimates that when the rate of rise V is slower than the rainfall RF, the ground has some margin for water absorption capacity, and when the rainfall RF and the rate of rise V are approximately equal, the ground's water absorption capacity is at its limit. Therefore, if the rate of rise V is slower than the rainfall RF, it is estimated that the ground has sufficient water absorption capacity, and if the rainfall RF and the rate of rise V are approximately equal, it is estimated that the ground's water absorption capacity is at its limit, so the ground's water absorption capacity can be estimated appropriately.

[0099] Furthermore, as explained with reference to Figures 7 and 8, in the flood estimation system 100B of the third embodiment, the second estimation unit 113 estimates that when the rate of increase V is faster than the rainfall RF, the water absorption capacity of the ground is at its limit and there is a possibility of flooding of drainage channels and rivers. Therefore, when the rate of increase V is faster than the rainfall RF, it is estimated that the ground's water absorption capacity has reached its limit and there is a possibility of flooding of drainage channels and rivers, so the ground's water absorption capacity and the possibility of flooding of drainage channels and rivers can be accurately estimated.

[0100] Furthermore, as explained with reference to Figures 7 and 8, in the flood estimation system 100B according to the third embodiment, when the rainfall RF is approximately zero and the rising speed V is equal to or greater than a preset speed threshold THV, the second estimation unit estimates that there is a risk of water intrusion from other areas, river flooding, landslides, and liquefaction. Therefore, when the rainfall RF is approximately zero and the rising speed V is equal to or greater than a preset speed threshold THV, it is estimated that there is a risk of water intrusion from other areas, river flooding, landslides, and liquefaction, so the risk of water intrusion from other areas, river flooding, landslides, and liquefaction can be properly estimated.

[0101] As described with reference to Figures 1 to 8, the flooding estimation device 1 of this embodiment is a flooding estimation device 1 that acquires detection signals from a first water level sensor 21, which is a water level sensor 2 located underground UG at a first distance L1 from the ground surface SF, and a second water level sensor 22, which is a water level sensor 2 located underground UG at a second distance L2 shorter than the first distance L1 from the ground surface SF, and estimates the occurrence of flooding, and is equipped with a first estimation unit 112 that estimates a rising speed V, which is the speed at which the groundwater rises, based on the sensor-to-sensor distance LS, which is the distance from the first water level sensor 21 to the second water level sensor 22, and the rise time TU, which is the time it takes for the groundwater to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22, and a second estimation unit 113 that estimates a flooding start date and time TW, which is the date and time at which flooding of the ground surface SF will begin, based on the rise speed V. Therefore, the submergence estimation device 1 according to this embodiment has the same effects as the submergence estimation system 100 according to this embodiment.

[0102] Furthermore, as explained with reference to Figures 1 to 8, the control program PG of this embodiment is a control program PG that acquires detection signals from a first water level sensor 21, which is a water level sensor 2 located underground UG at a first distance L1 from the ground surface SF, and a second water level sensor 22, which is a water level sensor 2 located underground UG at a second distance L2 shorter than the first distance L1 from the ground surface SF, and estimates the occurrence of flooding, and causes the processor 11A to function as a first estimation unit 112 that estimates the rising speed V, which is the speed at which the groundwater rises, based on the sensor-to-sensor distance LS, which is the distance from the first water level sensor 21 to the second water level sensor 22, and the rise time TU, which is the time it takes for the groundwater to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22, and a second estimation unit 113 that estimates the flooding start date and time TW, which is the date and time at which flooding of the ground surface SF will begin, based on the rise speed V. Therefore, the control program PG according to this embodiment has the same effects as the flood estimation system 100 according to this embodiment.

[0103] Furthermore, as explained with reference to Figures 1 to 8, the flooding estimation method by the flooding estimation device 1 of this embodiment is a method for estimating the occurrence of flooding by acquiring detection signals from a first water level sensor 21, which is a water level sensor 2 arranged underground UG at a first distance L1 from the ground surface SF, and a second water level sensor 22, which is a water level sensor 2 arranged underground UG at a second distance L2 shorter than the first distance L1 from the ground surface SF, and includes a first estimation step of estimating a rising speed V, which is the speed at which the groundwater rises, based on the inter-sensor distance LS, which is the distance from the first water level sensor 21 to the second water level sensor 22, and the rise time TU, which is the time it takes for the groundwater to rise from the position of the first water level sensor 21 to the position of the second water level sensor 22, and a second estimation step of estimating a flooding start date and time TW, which is the date and time at which flooding of the ground surface SF will begin, based on the rise speed V. Therefore, the submergence estimation method by the submergence estimation device 1 according to this embodiment has the same effects as the submergence estimation system 100 according to this embodiment.

[0104] 5. Other Embodiments The present invention is not limited to the configurations of the above-described embodiments, and can be implemented in various forms without departing from the spirit and scope of the present invention.

[0105] In this embodiment, a case will be described in which the submergence estimation device 1 is configured as a personal computer, but the embodiment is not limited to this. The submergence estimation device 1 may be any so-called "information processing device." For example, the submergence estimation device 1 may be configured as a smartphone or a tablet computer.

[0106] In the first embodiment, a case will be described in which the flood estimation system 100 is equipped with a first water level sensor 21, a second water level sensor 22, and a third water level sensor 23, but the embodiment is not limited to this. It is sufficient that the flood estimation system 100 is equipped with the first water level sensor 21 and the second water level sensor 22. Furthermore, the flood estimation system 100 may be equipped with four or more water level sensors 2.

[0107] In the second embodiment, a case will be described in which the submergence estimation system 100A is equipped with a first water level sensor 21, a second water level sensor 22, and a third water level sensor 23, but the embodiment is not limited to this. It is sufficient that the submergence estimation system 100A is equipped with the first water level sensor 21 and the second water level sensor 22. Furthermore, the submergence estimation system 100 may be equipped with four or more water level sensors 2.

[0108] In the second embodiment, a case will be described in which the acquisition unit 111 receives earthquake occurrence information from the earthquake detection device 3, but the embodiment is not limited to this. For example, the submergence estimation device 1 may be communicably connected to a server device of the Japan Meteorological Agency or the like via a network such as the Internet, and the acquisition unit 111 may acquire earthquake occurrence information from the server device of the Japan Meteorological Agency or the like. In this case, the submergence estimation system 100A does not need to be equipped with the earthquake detection device 3.

[0109] In the third embodiment, a case will be described in which the flood estimation system 100B is equipped with five water level sensors 2, but the embodiment is not limited to this. The flood estimation system 100B only needs to be equipped with at least two water level sensors 2. The flood estimation system 100B may also be equipped with six or more water level sensors 2.

[0110] In the third embodiment, a case will be described in which the acquisition unit 111 acquires a rainfall signal from a rain gauge 5, but the embodiment is not limited to this. For example, the submergence estimation device 1 may be communicably connected to a server device of the Japan Meteorological Agency or the like via a network such as the Internet, and the acquisition unit 111 may acquire rainfall information from the server device of the Japan Meteorological Agency or the like. In this case, the submergence estimation system 100B does not need to be equipped with a rain gauge 5.

[0111] Furthermore, at least some of the functional blocks of the control unit 11 of the flood estimation device 1 shown in Figure 3 may be realized by hardware, or may be configured to be realized by a combination of hardware and software, and are not limited to a configuration in which independent hardware resources are arranged as shown in the figure. The control program PG executed by the control unit 11 may be stored in another storage unit within the memory 11B. Alternatively, the control program PG stored in an external device such as a server device may be acquired via a communication unit or the like and executed.

[0112] Furthermore, the processing units in the flowcharts shown in Figures 4, 6, and 8 are divided according to the main processing content in order to make it easier to understand the processing of the control unit 11 of the submergence estimation device 1. The embodiments are not limited to the manner in which the processing units shown in the flowcharts shown in Figures 4, 6, and 8 are divided or their names are used. Furthermore, the processing of the control unit 11 can be divided into even more processing units according to the processing content, or one processing unit can be divided so that it includes even more processing. Furthermore, the processing order of the above flowcharts is not limited to the example shown in the figures. [Explanation of symbols]

[0113] 100, 100A, 100B Flooding Estimation System 1. Flooding estimation device 11 Control section 11A processor 11B memory 12 Display 13 Speaker 111 Acquisition Department 112 1st estimation part 113 Second estimation part 114 Information Department 115 Date and time storage section 2 Water level sensor 21 First water level sensor 211 Case 212 Permeable sheet 213 Float 214 Position detection sensor 22 Second water level sensor 23 Third water level sensor 2A Pipe 2B Permeable sheet 3 Earthquake detection equipment ES1 First evacuation information ES2 Second evacuation information HS house L1 1st distance L2 2nd distance L3 Third distance LL Liquefaction occurrence water level LS Sensor Distance LU4 Fourth virtual distance (fourth distance) LU5 5th virtual distance (5th distance) P1 1st period P2 2nd period PG control program (flooding estimation program) RF rainfall SF ground surface T1 1st Date and Time T2 2nd Date and Time T3 3rd Date and Time TA1 First notification date and time TA2 Second notification date and time TL Liquefaction occurrence date and time TU Ascent Time TW Flooding start date and time V Ascent Speed

Claims

1. a first water level sensor disposed underground at a first distance from the ground surface; a second water level sensor disposed underground at a second distance from the ground surface that is shorter than the first distance; a flooding estimation device that acquires detection signals from the first water level sensor and the second water level sensor and estimates the occurrence of flooding; Equipped with The flood estimation device includes: a first estimation unit that estimates a rising speed, which is the speed at which the groundwater rises, based on an inter-sensor distance, which is the distance from the first water level sensor to the second water level sensor, and a rising time, which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor; a second estimation unit that estimates a flooding start date and time, which is a date and time when flooding of the ground surface will start, based on the rising speed; A flood estimation system having the above.

2. a third water level sensor disposed underground at a third distance from the ground surface that is shorter than the second distance; the flood estimation device acquires a detection signal from the third water level sensor, The second estimation unit estimating the flooding start date and time based on the third distance and the rising speed; The flood estimation system according to claim 1 .

3. The second estimation unit a first notification date and time, which is a date and time at which first evacuation information for encouraging evacuation will be issued, is estimated based on the distance obtained by adding the fourth distance on the ground surface to the third distance and the rising speed; The flood estimation system according to claim 2 .

4. The second estimation unit a second notification date and time, which is a date and time at which second evacuation information that more strongly urges evacuation than the first evacuation information, will be issued, based on the third distance plus a fifth distance that is longer than the fourth distance on the ground surface and the rising speed; The flood estimation system according to claim 3 .

5. The flood estimation device includes: An acquisition unit for acquiring earthquake occurrence information, The second estimation unit When the acquisition unit acquires earthquake occurrence information, it estimates whether or not liquefaction will occur based on the inter-sensor distance and the rising speed. The flood estimation system according to claim 1 .

6. The water level sensor is a float-type water level sensor. The flood estimation system according to any one of claims 1 to 5.

7. A pipe is buried underground and extends in a substantially vertical direction, The water level sensor is housed inside the pipe. The flood estimation system according to any one of claims 1 to 5.

8. a pipe buried underground and extending in a substantially vertical direction; A rain gauge that measures rainfall, the first water level sensor and the second water level sensor are housed inside the pipe; The second estimation unit The water absorption capacity of the ground is estimated based on the amount of rainfall detected by the rain gauge and the rate of rise. The flood estimation system according to claim 1 .

9. The second estimation unit When the rate of rise is slower than the amount of rainfall, it is estimated that the ground has a sufficient water absorption capacity, and when the rate of rise is approximately equal to the amount of rainfall, it is estimated that the ground has reached its limit of water absorption capacity. The flood estimation system according to claim 8 .

10. The second estimation unit If the rate of increase is faster than the amount of rainfall, it is estimated that the water absorption capacity of the ground is at its limit and there is a possibility of flooding of drainage channels and rivers. The flood estimation system according to claim 8 or 9.

11. The second estimation unit When the rainfall is substantially zero and the rate of increase is equal to or greater than a preset rate threshold, it is estimated that there is a risk of water intrusion from other areas, river flooding, landslides, and liquefaction. The flood estimation system according to claim 8 or 9.

12. A flood estimation device that estimates the occurrence of flooding by acquiring detection signals from a first water level sensor that is a water level sensor placed underground at a first distance from the ground surface, and a second water level sensor that is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance, a first estimation unit that estimates a rising speed, which is the speed at which the groundwater rises, based on an inter-sensor distance, which is the distance from the first water level sensor to the second water level sensor, and a rising time, which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor; a second estimation unit that estimates a flooding start date and time, which is a date and time when flooding of the ground surface will start, based on the rising speed; A flood estimation device comprising:

13. A flood estimation program that acquires detection signals from a first water level sensor that is a water level sensor placed underground at a first distance from the ground surface, and a second water level sensor that is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance, and estimates the occurrence of flooding, The processor, a first estimation unit that estimates a rising speed, which is the speed at which the groundwater rises, based on a sensor distance, which is the distance from the first water level sensor to the second water level sensor, and a rising time, which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor; and a second estimation unit that estimates a flooding start date and time, which is a date and time when flooding of the ground surface will start, based on the rising speed; This is a flood estimation program that functions as a

14. A flood estimation method using a flood estimation device that communicates with a first water level sensor that is a water level sensor placed underground at a first distance from the ground surface, and a second water level sensor that is a water level sensor placed underground at a second distance from the ground surface that is shorter than the first distance, and estimates the occurrence of flooding, a first estimation step of estimating a rising speed, which is the speed at which the groundwater rises, based on a sensor distance, which is the distance from the first water level sensor to the second water level sensor, and a rising time, which is the time it takes for the groundwater to rise from the position of the first water level sensor to the position of the second water level sensor; a second estimation step of estimating a flooding start date and time, which is a date and time when the ground surface will start to be flooded, based on the rising speed; A flood estimation method, including:

Images