JP2018096784A - Tsunami observation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple tsunami observation system capable of comprehending the height of tsunami at offshore at early stage at a low cost.SOLUTION: A tsunami observation system 100 for observing the height of tsunami or sea level WL includes: water pressure acquisition means 10 which is installed offshore seabed for acquiring the water pressure at an installation point by introducing sea water; water level observation means 12 which is installed in the vicinity of shore for observing the sea level WL at the installation point on the basis of the water pressure acquired by the water pressure acquisition means 10; and duct means 14 which is laid under the sea to communicate the water level observation means 12 and the water pressure acquisition means 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tsunami observation system for observing the height of a tsunami and the like.

  Conventionally, as a system for measuring the height of a tsunami, an ocean buoy and a GPS (Global Positioning System: satellite positioning system) are used to analyze sea surface vertical movement (see, for example, Patent Document 1), A submarine tsunami meter system using a water pressure sensor for measuring water pressure (see, for example, Patent Document 2) has been proposed. However, these are comparatively expensive measurement systems, and may involve analysis, etc., so that the disclosure speed of measurement information may be slow. It is also expected that the system will become inoperable due to power outages due to the earthquake. For this reason, these conventional measurement systems are hardly suitable as means for grasping the height of the tsunami for the purpose of disaster prevention.

JP 2006-170920 A JP 2001-264056 A

  The government, local governments, research institutes, etc. are predicting tsunamis due to the Tokai, Tonankai and Nankai earthquakes that are likely to occur in the future. If the actual tsunami height immediately after the occurrence of the earthquake can be observed from offshore as much as possible, it is possible to promptly transmit a tsunami warning and contribute to prompt evacuation behavior of local residents. For users such as local governments, it is desirable that the system be easy to maintain and inexpensive.

  For this reason, the development of a simple and inexpensive tsunami observation system that can grasp the height of the offshore tsunami at an early stage has been demanded.

  The present invention has been made in view of the above, and an object of the present invention is to provide a simple and inexpensive tsunami observation system that can quickly grasp the height of an offshore tsunami.

  In order to solve the above problems and achieve the object, a tsunami observation system according to the present invention is a tsunami observation system for observing the height of a tsunami or seawater surface, A water pressure acquisition means for acquiring the water pressure of the installation location by introducing the water level, and a water level observation means for observing the position of the sea level at the installation location based on the water pressure installed near the coast and acquired by the water pressure acquisition means, It is laid in the sea, and is provided with a conduit means for communicating the water level observation means and the water pressure acquisition means.

  Further, in the tsunami observation system according to the present invention, in the above-described invention, a plurality of water pressure acquisition means are installed at intervals in the offshore direction, and the pipe means connects adjacent water pressure acquisition means so as to communicate with each other. The water pressure acquisition means includes a water pressure chamber connected to the pipe means through the connection port, a communication port for introducing external seawater into the water pressure chamber, and a first check that opens and closes the communication port. It has a valve and a second check valve that opens and closes a connection port to which pipe means on the offshore side as viewed from the water pressure chamber is connected.

  Further, in the tsunami observation system according to the present invention, in the above-described invention, the first check valve opens when the water pressure in the water pressure chamber is lower than the external water pressure, and allows inflow of seawater into the water pressure chamber. On the other hand, when the water pressure in the water pressure chamber is higher than the external water pressure, it closes to prevent the inflow of seawater, and the second check valve opens when the water pressure in the offshore pipe means is higher than the water pressure in the water pressure chamber. On the other hand, it is characterized in that it closes when the water pressure in the offshore pipe means is lower than the water pressure in the water pressure chamber.

  Another tsunami observation system according to the present invention is the above-described invention, in the above-described invention, a pipe means for connecting a plurality of water pressure acquisition means installed at intervals in the offshore direction and adjacent water pressure acquisition means so as to communicate with each other. The first system and the second system are respectively configured in parallel, and the first system and the second system are installed in parallel with each other, and the water pressure acquisition means of each system is mutually separated by a predetermined separation distance in the shore offshore direction. Estimating means for estimating the wave propagation speed based on the position of the sea level at the location where the water pressure acquisition means of each system is installed, the separation distance, and the observation time, which are shifted and observed by the water level observation means It is further provided with the feature.

  Further, in the tsunami observation system according to the present invention, in the above-described invention, the estimation unit is configured such that the wave is based on the distance from the predetermined reference position on the coast side to the water pressure acquisition unit and the wave propagation speed. An arrival time until the reference position is reached is predicted.

  Another tsunami observation system according to the present invention is characterized in that, in the above-described invention, the conduit means is a flexible pipe that is laid on the seabed and can follow the changes in the seabed ground during an earthquake.

  The tsunami observation system according to the present invention is a tsunami observation system for observing the height of a tsunami or sea level, and is installed in the sea offshore, and introduces seawater to obtain the water pressure at the installation location. An acquisition means, a water level observation means installed in the vicinity of the coast and observing the sea level of the installation location based on the water pressure acquired by the water pressure acquisition means, and a water level observation means and a water pressure acquisition means laid in the sea Therefore, the water pressure acquired offshore is immediately observed by the water level observation means on the shore side through the pipeline means. Since this water pressure corresponds to the offshore sea level, the offshore wave height can be obtained by subtracting the reference sea level from this water level. For this reason, the height of waves such as offshore tsunami can be observed immediately by means of water level observation means installed near the coast. Moreover, the structure of this tsunami observation system is simple because it is composed of the above-described water level observation means, water pressure acquisition means, and pipe means, and is inexpensive because it does not require special electronic equipment or analysis. Therefore, it is possible to provide a simple and inexpensive tsunami observation system that can grasp the height of the offshore tsunami at an early stage.

  Further, according to another tsunami observation system according to the present invention, a plurality of water pressure acquisition means are installed at intervals in the offshore direction, and the pipe means connects adjacent water pressure acquisition means so that they can communicate with each other. The means includes a water pressure chamber connected to the pipe means via a connection port, a communication port for introducing external seawater into the water pressure chamber, a first check valve for opening and closing the communication port, Because it has a second check valve that opens and closes the connection port connected to the offshore pipe means when viewed from the hydraulic chamber, the height of offshore waves can be observed immediately at multiple locations along the coast. There is an effect that can be.

  Further, according to another tsunami observation system according to the present invention, the first check valve opens when the water pressure in the water pressure chamber is lower than the external water pressure and allows the inflow of seawater into the water pressure chamber. When the water pressure in the chamber is higher than the external water pressure, it closes to block the inflow of seawater, and the second check valve opens when the water pressure in the offshore pipe means is higher than the water pressure in the water pressure chamber, When the water pressure in the side pipe means is lower than the water pressure in the water pressure chamber, the water pressure inside the pipe means on the coast side when viewed from the water pressure chamber is equal to the maximum water pressure in the water pressure chamber. It is observed as the maximum wave height at the water pressure acquisition point in the water level observation means. For this reason, the maximum offshore wave height can be observed immediately at a plurality of locations along the shore offshore direction.

  In addition, according to another tsunami observation system according to the present invention, a plurality of water pressure acquisition means installed at intervals in the shore offshore direction, and a pipeline means for connecting adjacent water pressure acquisition means so as to communicate with each other, respectively. The first system and the second system are configured, and the first system and the second system are installed in parallel with each other, and the water pressure acquisition means of each system are arranged with a predetermined separation distance from each other in the shore offshore direction. And an estimation means for estimating the wave propagation speed based on the position of the sea level at the location where the water pressure acquisition means of each system is installed, the separation distance, and the observation time observed by the water level observation means. It has the effect of being able to estimate the propagation speed of offshore tsunamis.

  Further, according to another tsunami observation system according to the present invention, the estimation unit is configured such that the wave is the reference position based on the distance from the predetermined reference position on the coast side to the water pressure acquisition unit and the wave propagation speed. Since the arrival time until reaching the tsunami is predicted, the arrival time of the tsunami can be predicted.

  Further, according to another tsunami observation system according to the present invention, the pipe means is a flexible pipe that is laid on the seabed and can follow the changes in the seabed ground during an earthquake. -The pipe can be flexibly moved and deformed with respect to the settling, so that the risk of the pipe breaking can be avoided.

FIG. 1 is a schematic configuration diagram showing a tsunami observation system according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the water pressure measurement device (water pressure acquisition means). FIG. 3 is a conceptual diagram of the observation principle according to the present invention. (1) is a longitudinal sectional view of the tsunami observation system, and (2) is a diagram showing the relationship between the observation time and the observation water level. FIG. 4 is a partially enlarged view of a water level observation device (water level observation means) installed on the coast, (a) is a normal time, and (b) is a diagram at the time of tsunami observation. FIG. 5 is a conceptual diagram of the principle of estimation of tsunami propagation speed and arrival time by the tsunami observation system according to Embodiment 2 of the present invention. (1) is a longitudinal sectional view of the tsunami observation system, and (2) is an observation time. It is a figure which shows the relationship between an observation water level.

  Hereinafter, embodiments of a tsunami observation system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
First, the first embodiment of the present invention will be described.
As shown in FIG. 1, the tsunami observation system 100 according to Embodiment 1 of the present invention is a system for simply measuring the height of a tsunami or sea level WL that pushes from offshore due to an earthquake or the like, A plurality of water pressure measuring devices 10 (water pressure acquisition means) installed on the seabed G with a certain interval in the offshore direction D, and a water level observation device 12 (water level observation means) installed on the coast C, and adjacent water pressures The measuring device 10 and the water level observation device 12 are connected in communication with each other, and a pipe 14 (duct means) laid on the seabed G is provided. In the present embodiment, the case where the pipe 14 and the water pressure measuring device 10 are arranged across the continental shelf R1 and the trench R2 will be described as an example, but the present invention is not limited to this.

  The water pressure measuring device 10 is for acquiring the water pressure at the installation location by introducing seawater at the installation location, and is composed of a structure having high pressure resistance. The installation location of the water pressure measuring device 10 can be easily designed by adjusting the length of the pipe 14. In designing, it is preferable to consider the propagation speed of the tsunami obtained from the tsunami prediction analysis result in advance.

  FIG. 2 shows a cross-sectional view of the water pressure measuring device 10. As shown in this figure, the water pressure measuring device 10 is configured to connect a water pressure chamber 18 connected to an offshore pipe 14a and a coastal pipe 14b via connection ports 16a and 16b, respectively, and external seawater. A seawater inlet 20 (communication opening) for introduction into the chamber 18, a check valve 1 (first check valve) for opening and closing the seawater inlet 20, and a connection port 16a to which the offshore pipe 14a is connected. And a check valve 2 (second check valve) that opens and closes.

  The check valve 1 opens when the water pressure in the water pressure chamber 18 is lower than the external water pressure, and allows the inflow of seawater from the seawater inlet 20 to the water pressure chamber 18, while the water pressure in the water pressure chamber 18 is greater than the external water pressure. When it is too high, it closes to prevent the inflow of seawater. The check valve 2 opens when the water pressure of the offshore pipe 14 a is higher than the water pressure of the water pressure chamber 18, while closing when the water pressure of the offshore pipe 14 a is lower than the water pressure of the water pressure chamber 18. Yes. For this reason, the water pressure inside the pipe 14b on the coast side as viewed from the water pressure chamber 18 is equal to the maximum water pressure at the water pressure measurement point acquired in the water pressure chamber 18, and this maximum water pressure is as shown in FIG. Is observed as the maximum wave height at the water pressure acquisition point. Since the water level measuring device 10 is installed at a plurality of locations along the coastal offshore direction D, the maximum wave heights at the plurality of locations along the coastal offshore direction D are immediately observed at the coastal area C. Become.

  The water level observation device 12 is provided in the vicinity of an arbitrary coast such as a tide gauge station in the coastal part C, and is used for observing the position of the sea level WL at the installation location based on the water pressure acquired by the water pressure measurement device 10. is there. The water level observation device 12 can be configured using, for example, a piezo tube connected to the pipe 14 or a thin tube communicating with the atmosphere. Since the water level observation device 12 and the offshore water pressure measurement device 10 communicate with each other via the pipe 14, the water pressure acquired by the water pressure measurement device 10 is immediately observed as a water level in the water level observation device 10. The value obtained by subtracting the water level H0 of the reference seawater level at that time from the observed water level H (H-H0) corresponds to the position of the seawater level WL at the installation location of the water pressure measuring device 10, that is, the wave height. Become.

  The pipe 14 is a pipe having a flexible structure, and is connected to the water pressure measuring device 10 at regular intervals, and is laid on the seabed G in a soft and fixed manner. By not fixing the pipe 14 to the seabed G, the pipe 14 can be flexibly moved and deformed following changes such as uplift and subsidence of the seabed ground during an earthquake. Thereby, the disconnection risk of the pipe 14 can be avoided. The end of the pipe 14 on the coast side is connected to a water level observation device 12 installed on the coast, and when the tsunami occurs, the water level change (increase value) in the pipe 14 is observed and recorded by the water level observation device 12. As a constituent material of the pipe 14, any material may be used as long as the material has corrosion resistance and water pressure resistance in seawater. Further, the pipe diameter is also arbitrary, and an inexpensive material can be applied.

The operation and action of the above configuration will be described.
As shown in FIG. 3 (1), when a tsunami W generated in the deep sea area such as the trench R2 progresses toward the coast C, shallow water deformation occurs in the shallow sea area such as the continental shelf R1, and the wave height increases as the coast C approaches. Gradually increases. Here, when the peak of the tsunami W passes right above the water pressure measuring device 10, as shown in FIG. 2, the check valve 1 opens and seawater flows into the water pressure chamber 18 from the seawater inlet 20. The check valve 2 is closed, and the communication between the water pressure chamber 18 and the offshore pipe 14a is cut off. As a result, the water pressure in the water pressure chamber 18 and the shore side pipe 14b becomes the maximum water pressure corresponding to the water depth when the peak of the tsunami W is located directly above.

  As shown in FIG. 3, the maximum water pressure of the first wave of the tsunami W acquired at the observation time T <b> 1 is obtained by the water level observation device 12 on the coast C through the pipe 14 (14 b) on the coast side and the adjacent water pressure measurement device 10. It will be observed immediately as the water level H1. Thereafter, when the peak of the tsunami W advances to the position immediately above the adjacent water pressure measuring device 10 at the observation time T2, the adjacent water pressure measuring device 10 operates in the same manner. As a result, the water pressure in the water pressure chamber 18 and the shore side pipe 14b of the adjacent water pressure measuring device 10 becomes the maximum water pressure corresponding to the water depth when the peak of the tsunami W is located directly above, and the water level observation device 12 Observed immediately as water level H2. Thereafter, as shown in FIG. 3, the maximum water pressure is acquired by the water pressure measuring device 10 at each location in accordance with the progress of the tsunami, and the corresponding water levels H3, H4. It becomes.

  As described above, the water pressure measuring device 10 includes the check valves 1 and 2, so that even when the tsunami W passes, the water pressure corresponding to the maximum wave height remains in the coastal pipe 14 b. Therefore, the maximum wave height (tsunami height) at the observation point can be observed and recorded. Further, after the tsunami W reaches the vicinity of the coast, the maximum height of the tsunami at the measurement point can be measured and recorded from the water pressure value in the pipe 14.

  According to the present embodiment, the water pressure at the seabed G acquired offshore is immediately observed as the water level H by the water level observation device 12 in the coastal area C via the pipe 14. Since the water level H corresponds to the water level of the offshore sea level, the offshore tsunami or wave height (H−H0) can be obtained by subtracting the water level H0 of the reference sea level from the water level H. For this reason, the height of the offshore tsunami can be observed immediately by the water level observation device 12 installed in the coastal area C. Further, the structure of the tsunami observation system 100 is simple because it includes the water level observation device 12, the water pressure measurement device 10, and the pipe 14, and is inexpensive because it does not require special electronic equipment or analysis. Therefore, according to the present embodiment, it is possible to provide a simple and inexpensive tsunami observation system that can grasp the height of an offshore tsunami at an early stage.

  In the above embodiment, a water pressure sensor may be installed inside the water pressure chamber 18 of the water pressure measuring device 10 or the pipe 14b on the coast. And based on the water pressure measured with this water pressure sensor, you may make it the water level observation apparatus 12 observe the water level H of the sea level of a measurement location, or the height of a wave.

(Modification of Embodiment 1)
Next, a modification of the first embodiment of the present invention will be described.
In this modification, the water level observation device 12 of the first embodiment is configured as shown in FIG. That is, as shown in FIG. 4, the water level observation device 12 includes a water pressure gauge 22 for measuring the water pressure in the pipe 14 and a display device capable of displaying tsunami information based on the water pressure measured by the water pressure gauge 22. 24, a recording device 26 that records measurement data, a small battery 28 that supplies power to each device, and a small photovoltaic power generator 30 that can supply power to each device in the event of a power failure. Of these, the water pressure gauge 22, the recording device 26, and the small battery 28 are preferably accommodated in the watertight container 32. By doing in this way, long-term durability can be ensured.

  This tsunami observation system 100 is configured to use power supplied from the small battery 28 and the solar power generation device 30. In this way, since there is no need to supply power from the outside, the tsunami observation system 100 can operate even during a power failure.

  Further, as data to be recorded in the recording device 26, an appropriate trigger may be set to record only a predetermined large tsunami. Further, according to this tsunami observation system 100, it is possible to observe not only the height of the tsunami but also the height of the offshore waves in normal times. For this reason, the display device 24 may transmit wave height information at normal times together with a simple information display function for fishermen and the like.

  Since the water pressure in the pipe 14 does not decrease once it rises, if a drop phenomenon is recorded as data of the recording device 26, a system failure is assumed. In preparation for such a case, for example, an in-pipe depressurizing valve device 34 may be provided on the quay C1 or the like, and the inside of the pipe 14 may be periodically depressurized through the device 34. In this way, it is possible to record the latest normal data from within the pipe 14.

  The display device 24 can be configured by, for example, a piezo tube that can display the height of a tsunami or a water level at a measurement location, a display that can display an arrival time, and the like. When the display device 24 displays the tsunami information in conjunction with the water pressure gauge 22 and the recording device 26, the user can visually grasp the tsunami information such as the height of the tsunami and the arrival time. When a piezo tube is used as the display device 24, the height of the piezo tube is set to a sufficient height based on a tsunami prediction analysis result that has been grasped in advance. Further, by using a piezo pipe communicating with the pipe 14, the air in the pipe 14 can be exhausted. After the tsunami converges, the water pressure in the pipe 14 is reduced by lowering the water pressure in the pipe 14 to a water pressure corresponding to the water level H0 of the reference seawater surface.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
As shown in FIG. 5 (1), the tsunami observation system 200 according to the second embodiment of the present invention is a system composed of the plurality of water pressure measuring devices 10 and the pipes 14 according to the first embodiment. 1 system) and system B (second system). Therefore, the system A includes a plurality of water pressure measuring devices 10A and pipes 14A, and the system B includes a plurality of water pressure measuring devices 10B and pipes 14B. In addition, the system A and the system B are installed in parallel to each other, and the water pressure measuring devices 10A and 10B of each system are arranged so as to be shifted from each other by a predetermined separation distance L in the offshore direction D. The system A and the system B are connected to the same water level observation device 12 in the coastal part C.

  In this tsunami observation system 200, based on the position of the sea level WL at the location where the water pressure measurement devices 10A and 10B of the systems A and B are observed by the water level observation device 12, the separation distance L, and the observation time T. , An estimation means (not shown) for estimating the propagation velocity V of the tsunami W is provided. The estimation means may be a function of the water level observation device 12. This estimation means determines the arrival time TT until the tsunami W reaches the coast C based on the distance LL from the coast C (reference position) to the water pressure measuring devices 10A and 10B and the propagation velocity V of the tsunami W. May be predicted. For example, as shown in FIGS. 5 (1) and 5 (2), the observation time of the water pressure measurement apparatus 10A of the system A is T5, and the water pressure of the system B at a position shifted to the coast side by a separation distance L from the measurement location. When the observation time of the measuring apparatus 10B is T5 ′, the propagation speed V of the tsunami W in that section and the arrival time TT predicted from that time can be obtained by the following equation.

Tsunami propagation velocity: V = L / (T5′−T5) (1)
Tsunami arrival time: TT = LL / V Equation (2)

  In addition, if the water depth of a measurement location is set to h (m), the propagation speed V of the tsunami in a measurement location can also be calculated | required from the following formula | equation (3).

Here, g is a gravitational acceleration (9.8 m / s ² ).

An example of calculating the tsunami propagation speed using equation (3) is shown below.
When the water depth is 2000m, V = 504km / h
When the water depth is 200m, V = 159km / h
When the water depth is 10m, V = 36km / h

  In other words, considering the continental shelf (water depth 200 m), if a tsunami can be confirmed near 160 km offshore, an evacuation time of about 1 hour can be secured.

According to the tsunami observation systems 100 and 200 of the present embodiment described above, the following effects can be obtained.
1) The tsunami observation systems 100 and 200 of the present embodiment are passive observation systems, and the cost of the system is lower than that of the conventional measurement system.

2) Since the pipe 14 can be laid far offshore, the occurrence of a tsunami can be grasped at an early stage.

3) By considering the seafloor topography, the position of the first wave of the tsunami is determined from the measured water pressure near the point where the height of the tsunami changes abruptly (such as a point where the ridge shelf R1 changes from the trench R2) be able to.

4) If observation data is linked with disaster prevention radio, etc., information for tsunami disaster prevention in the area can be transmitted quickly. By providing a display device 24 such as a piezo tube or a tsunami height indicator in the coastal area C, it is possible to visually transmit tsunami information to residents near the coastal area C.

5) By evaluating not only the maximum height of the tsunami but also the moving speed, the arrival time of the tsunami can be predicted and transmitted.

6) The pipe 14 laid on the seabed G, the water pressure measuring device 10 having the check valves 1 and 2 and the like are maintenance-free, and the object of maintenance is the water level observation device 12 installed on the coastal area C, and the data logger provided for this. The recording device 26 only.

7) The piezo tube as the display device 24 may be damaged by the tsunami effect, but can be easily replaced. The water pressure gauge 22 and the recording device 26 can be reduced in size, and if installed in the watertight container 32, the possibility of damage due to a tsunami is small.

8) Since the inside of the pipe 14 is seawater and the water pressure is measured near the coastline (EL0m), the influence of seawater density on the tsunami height evaluation is sufficiently small. For example, the water pressure influence of seawater and fresh water with a salt concentration of 2.5% with respect to a water depth of 20 m is 50 cm, and when converted to fresh water pressure, it becomes a large value, so it is safe data for disaster prevention.

9) Sending and displaying observation data to a fishing port, etc. can transmit the maximum wave height offshore during normal times other than tsunamis, so it has daily utility value.

10) Since the power supply of the tsunami observation system is independent even during a power failure, the observation function can be maintained. The display device 24 can also cope with a power failure by using an independent power source.

  As described above, the tsunami observation system according to the present invention is a tsunami observation system for observing the height of a tsunami or sea level, and is installed in the offshore sea, where seawater is introduced and installed. Water pressure acquisition means for acquiring the water pressure of the water, and a water level observation means installed near the coast and observing the position of the sea level of the installation location based on the water pressure acquired by the water pressure acquisition means, Since the pipe means for communicating the observation means and the water pressure acquisition means is provided, the water pressure acquired offshore is immediately observed by the water level observation means on the coast via the pipe means. Since this water pressure corresponds to the offshore sea level, the offshore wave height can be obtained by subtracting the reference sea level from this water level. For this reason, the height of waves such as offshore tsunami can be observed immediately by means of water level observation means installed near the coast. Moreover, the structure of this tsunami observation system is simple because it is composed of the above-described water level observation means, water pressure acquisition means, and pipe means, and is inexpensive because it does not require special electronic equipment or analysis. Therefore, it is possible to provide a simple and inexpensive tsunami observation system that can grasp the height of the offshore tsunami at an early stage.

  Further, according to another tsunami observation system according to the present invention, a plurality of water pressure acquisition means are installed at intervals in the offshore direction, and the pipe means connects adjacent water pressure acquisition means so that they can communicate with each other. The means includes a water pressure chamber connected to the pipe means via a connection port, a communication port for introducing external seawater into the water pressure chamber, a first check valve for opening and closing the communication port, Because it has a second check valve that opens and closes the connection port connected to the offshore pipe means when viewed from the hydraulic chamber, the height of offshore waves can be observed immediately at multiple locations along the coast. be able to.

  Further, according to another tsunami observation system according to the present invention, the first check valve opens when the water pressure in the water pressure chamber is lower than the external water pressure and allows the inflow of seawater into the water pressure chamber. When the water pressure in the chamber is higher than the external water pressure, it closes to block the inflow of seawater, and the second check valve opens when the water pressure in the offshore pipe means is higher than the water pressure in the water pressure chamber, When the water pressure in the side pipe means is lower than the water pressure in the water pressure chamber, the water pressure inside the pipe means on the coast side when viewed from the water pressure chamber is equal to the maximum water pressure in the water pressure chamber. It is observed as the maximum wave height at the water pressure acquisition point in the water level observation means. Therefore, the maximum offshore wave height can be observed immediately at multiple locations along the coast.

  In addition, according to another tsunami observation system according to the present invention, a plurality of water pressure acquisition means installed at intervals in the shore offshore direction, and a pipeline means for connecting adjacent water pressure acquisition means so as to communicate with each other, respectively. The first system and the second system are configured, and the first system and the second system are installed in parallel with each other, and the water pressure acquisition means of each system are arranged with a predetermined separation distance from each other in the shore offshore direction. And an estimation means for estimating the wave propagation speed based on the position of the sea level at the location where the water pressure acquisition means of each system is installed, the separation distance, and the observation time observed by the water level observation means. The propagation speed of offshore tsunami can be estimated.

  Further, according to another tsunami observation system according to the present invention, the estimation unit is configured such that the wave is the reference position based on the distance from the predetermined reference position on the coast side to the water pressure acquisition unit and the wave propagation speed. Since the arrival time until reaching the tsunami is predicted, the arrival time of the tsunami can be predicted.

  Further, according to another tsunami observation system according to the present invention, the pipe means is a flexible pipe that is laid on the seabed and can follow the changes in the seabed ground during an earthquake. -The risk of pipe disconnection can be avoided by flexible deformation of the pipe against sedimentation.

  As described above, the tsunami observation system according to the present invention is useful for quickly grasping offshore tsunamis on the land side, and in particular, tsunami information such as tsunami height and time of arrival to local residents on the land side. Suitable for providing quickly.

1 Check valve (first check valve)
2 Check valve (second check valve)
10, 10A, 10B Water pressure measuring device (water pressure acquisition means)
12 Water level observation device (water level observation means)
14, 14A, 14B Pipe (pipeway means)
14a Offshore pipe 14b Coastal pipe 16a, 16b Connection port 18 Hydraulic chamber 20 Seawater inlet (communication port)
22 Water pressure meter 24 Display device 26 Recording device 28 Battery 30 Solar power generation device 32 Watertight container 34 Valve device for pressure reduction in pipe 100,200 Tsunami observation system A system (first system)
System B (second system)
C Coastal part C1 Quay D D Offshore G Sea bottom H Water level H0 Water level of the reference sea level R1 Continental shelf R2 Trench W Tsunami WL Sea level

Claims (6)

A tsunami observation system for observing tsunami or sea level
A water pressure acquisition means installed in the sea offshore and introducing seawater to acquire the water pressure at the installation location;
A water level observation means that is installed in the vicinity of the coast and observes the position of the sea level of the installation location based on the water pressure acquired by the water pressure acquisition means;
A tsunami observation system, characterized in that the tsunami observation system includes a conduit means that is laid in the sea and communicates a water level observation means and a water pressure acquisition means. A plurality of water pressure acquisition means are installed at intervals in the offshore direction, and the pipe means connects adjacent water pressure acquisition means so that they can communicate with each other,
The water pressure acquisition means includes a water pressure chamber connected to the pipe means through a connection port, a communication port for introducing external seawater into the water pressure chamber, and a first check valve for opening and closing the communication port. The tsunami observation system according to claim 1, further comprising: a second check valve that opens and closes a connection port to which pipe means on the offshore side as viewed from the hydraulic chamber is connected. The first check valve opens when the water pressure in the water pressure chamber is lower than the external water pressure and allows seawater to flow into the water pressure chamber, and closes when the water pressure in the water pressure chamber is higher than the external water pressure. The inflow of
The second check valve opens when the water pressure of the offshore pipe means is higher than the water pressure of the water pressure chamber, and closes when the water pressure of the offshore pipe means is lower than the water pressure of the water pressure chamber. The tsunami observation system according to claim 2. A first system and a second system, each of which is constituted by a plurality of water pressure acquisition means installed at intervals in the shore offshore direction, and pipe means for connecting adjacent water pressure acquisition means so as to communicate with each other;
The first system and the second system are installed in parallel with each other, and the water pressure acquisition means of each system is arranged with a predetermined separation distance in the shore offshore direction,
Characterized by further comprising estimation means for estimating the wave propagation speed based on the position of the sea level at the location of the water pressure acquisition means of each system observed by the water level observation means, the separation distance, and the observation time. The tsunami observation system according to claim 2 or 3.   The estimation means predicts the arrival time until the wave reaches the reference position based on the distance from the predetermined reference position on the coast side to the water pressure acquisition means and the wave propagation speed. The tsunami observation system according to claim 4.   The tsunami observation system according to any one of claims 1 to 5, wherein the conduit means is a flexible pipe that is laid on the seabed and that can follow changes in the seabed ground during an earthquake.

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