River monitoring system, river monitoring method, and program

Abstract

To provide a river monitoring system monitorable in a wide range, and to provide a river monitoring method and a program therefor.SOLUTION: A river monitoring system comprises a transmission part 31 for transmitting radio waves to a reflector group formed from a plurality of reflectors 2 fixed onto a side wall 11 of a river 1, while changing a transmission direction; a reception part 32 for receiving reflection waves of the radio waves; and an output part 41 for outputting a state of the plurality of reflectors 2 with a list on the basis of values R based on the reflection waves corresponding to positions of the plurality of reflectors 2, and reference values B.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a river monitoring system, a river monitoring method, and a program.

[0002] Abnormal weather such as guerrilla heavy rain occurs frequently in various places, and it is desired to be able to monitor river characteristics such as water levels over a wide area.

[0003] Patent Document 1 discloses a flooding monitoring system for a vehicle road with an underpass structure, and it is described that it may also be applicable to flooding monitoring of rivers. However, it is unclear whether it can be applied to wide-area monitoring of rivers.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a river monitoring system, a river monitoring method, and a program capable of monitoring a wide area.

Means for Solving the Problems

[0006] The river monitoring system of the present disclosure includes a transmission unit that transmits radio waves while changing the transmission direction to a group of reflectors composed of a plurality of reflectors fixed to the side walls of a river, a reception unit that receives the reflected waves of the radio waves, and an output unit that outputs a list of the states of the plurality of reflectors based on values based on the reflected waves corresponding to the positions of the plurality of reflectors and a reference value.

[0007] With this configuration, the sensor (transmitter and receiver) sends and receives radio waves to a group of reflectors fixed to the river's side wall, changing the transmission direction. This allows a single sensor (transmitter and receiver) to monitor the status of multiple reflectors over a wide area, making it useful for monitoring large areas of rivers. [Brief explanation of the drawing]

[0008] [Figure 1] A perspective view illustrating a river monitoring system. [Figure 2] A block diagram showing a river monitoring system. [Figure 3] An explanatory diagram showing the positions of multiple reflectors installed on the riverbank. [Figure 4] An overhead view showing the placement of sensors and reflectors in relation to the river. [Modes for carrying out the invention]

[0009] <First Embodiment> Hereinafter, a river monitoring system of the first embodiment of this disclosure will be described with reference to the drawings. Figure 1 is a perspective view illustrating the river monitoring system. Figure 2 is a block diagram of the river monitoring system.

[0010] As shown in Figures 1 and 2, the river monitoring system includes a transmitting unit 31 that transmits radio waves to a group of reflectors 2 fixed to the side wall 11 of the river 1 while changing the transmission direction, and a receiving unit 32 that receives the reflected radio waves. The transmitting unit 31 and the receiving unit 32 are so-called radar (sometimes also referred to as sensor 3). In the first embodiment, the transmitting unit 31 changes the transmission direction by a rotating antenna 30. The side wall 11 of the river 1 may be submerged when the river 1 floods.

[0011] Figure 3 is an explanatory diagram of the positions of multiple reflectors 2 installed on the side wall 11 of the river 1, showing a side view of the side wall 11 (slope) and a cross-sectional view of the river 1. The reflectors 2 are radar reflectors that reflect radio waves transmitted from the transmitter 31 more efficiently than the water 10 or the side wall 11. As shown in Figure 3, the multiple reflectors 2 have at least one reflector group 20, and the reflectors 2 (201-207) constituting the reflector group 20 are fixed at a predetermined distance L1 or more in the horizontal direction LD from adjacent reflectors 2 and at different heights. It is preferable that reflectors 2 (201-207) belonging to the same reflector group 20 are arranged at different heights within the same reflector group 20. In the figure, this is denoted as the height direction VD. Here, the predetermined distance L1 is determined by the radar resolution and the distance from the radar to the reflector. The water level 12 shown in Figures 1 and 3 is the normal water level. As shown in Figure 3, a reflector set 21 may be provided that is adjacent to or separated from the reflector set 20 in the horizontal direction LD. The reflectors 2 (211 to 213) constituting the reflector set 21 are fixed at a predetermined distance L1 or more in the horizontal direction LD from adjacent reflectors 2, and at different heights within the same reflector set 21.

[0012] Thus, because the reflector 2 is separated from the adjacent reflector 2 by a predetermined distance L1 or more in the horizontal LD, and the position (azimuth) of the reflector 2 from the antenna 30 is known, it becomes possible to identify which reflector 2 the reflected radio wave originated from. Furthermore, since a group of reflectors 2 (multiple reflectors 2 belonging to the same reflector group 20, 21) are installed at different heights, the water level 12 can be detected by determining the presence or absence of reflected waves.

[0013] As shown in Figure 2, the river monitoring system has an output unit 41. The output unit 41 outputs a list of the states of multiple reflectors 2 based on a value R based on reflected waves corresponding to the positions of the multiple reflectors 2 and a reference value B. The list may be in any format as long as it includes the states of multiple reflectors 2. The value R based on reflected waves corresponding to the position of the reflector 2 may be, for example, a received signal strength value. The reference value B is a value (received signal strength value) based on reflected waves when there are no objects shielding the reflection of radio waves from the reflector 2. Alternatively, the value based on reflected waves may be a value for the position of the reflector 2 calculated based on the received signal strength value. An object that shields the reflection of radio waves may be, for example, the water 10 of the river 1. The reference value B corresponding to the position of each reflector 2 is stored in advance in the storage unit 42. For example, in the example shown in Figures 2 and 3, the reference values ​​(B201 to B207) for each of the reflectors 201 to 207 are stored in the storage unit 42.

[0014] In the first embodiment, the output unit 41 has a reflected wave presence / absence output unit 410. The reflected wave presence / absence output unit 410 compares a value R based on the reflected wave at the position of reflector 2 with a reference value B. For example, the reflected wave presence / absence output unit 410 may compare a value (R201) based on the reflected wave corresponding to the position of reflector 201 with the corresponding reference value (B201). The reflected wave presence / absence output unit 410 outputs that there is no reflected wave from reflector 2 when the value R based on the reflected wave at the position of reflector 2 is lower than the reference value B, and outputs that there is a reflected wave from reflector 2 when the value R based on the reflected wave at the position of reflector 2 is equal to or greater than the reference value B. For example, the reflected wave presence / absence output unit 410 may output that there is a reflected wave "present" for reflectors 201 to 204 and a reflected wave "absent" for reflectors 205 to 207. The output data (list) of the reflected wave presence / absence output unit 410 may be a two-dimensional distribution representing the presence or absence of reflected waves in the horizontal direction LD and the height direction VD.

[0015] Figure 4 is an overhead view showing the placement of the sensor 3 and reflector 2 relative to the river 1. In Figure 4, the flow of the river 1 is indicated by the arrow Y1. As shown in Figure 4, reflectors 2 are placed on the side walls 11 of the river 1. For example, multiple reflectors 2 constituting the first reflector group 20 are placed in the first area Ar1, multiple reflectors 2 constituting the second reflector group 22 are placed in the second area Ar2, multiple reflectors 2 constituting the third reflector group 23 are placed in the third area Ar3, multiple reflectors 2 constituting the fourth reflector group 24 are placed in the fourth area Ar4, and multiple reflectors 2 constituting the fifth reflector group 25 are placed in the fifth area Ar5. The multiple reflectors 2 constituting each reflector group are fixed at different heights and separated from adjacent reflectors 2 by a predetermined distance L1 or more in the horizontal direction LD. Here, the first area Ar1, the second area Ar2, the third area Ar3, the fourth area Ar4, and the fifth area Ar5 are located at different positions (latitude and longitude). A different position means, for example, that they are separated by a predetermined distance L1 or more.

[0016] The first reflector set 20 and the second reflector set 22 are located in a blind spot where radio waves transmitted from the first sensor 3a reach directly, but radio waves transmitted from the second sensor 3b do not. The third reflector set 23 and the fourth reflector set 24 are located in a blind spot where radio waves transmitted from the second sensor 3b reach directly, but radio waves transmitted from the first sensor 3a do not. In this way, the multiple sensors 3, including the first sensor 3a and the second sensor 3b, are installed in positions that interpolate the blind spots where transmitted radio waves do not reach each other.

[0017] Furthermore, the memory unit 42 periodically stores a value R based on past reflected waves at the position of the reflector 2. For example, depending on the memory capacity, the value for each observation may be stored, or it may be thinned out to a frequency such as once a month. In the first embodiment, the output unit 41 has a terrain change information output unit 411. The terrain change information output unit 411 outputs the change in the position of the reflector 2 as a terrain change based on a value based on the reflected waves corresponding to the state of the multiple reflectors and a value based on past reflected waves corresponding to the state of the reflectors stored in the memory unit 42. For example, the terrain change information output unit 411 may output that a terrain change has occurred in the fifth area Ar5 compared to one month ago. The terrain change information output unit 411 may also output two-dimensional distribution data indicating whether or not there has been a terrain change in each of the multiple areas with different latitudes and longitudes.

[0018] The output unit 41 includes a water level distribution output unit 412. The water level distribution output unit 412 outputs two-dimensional distribution data representing the water level 12 for each of multiple areas with different latitudes and longitudes.

[0019] As shown in Figure 2, the river monitoring system includes an estimation unit 43 and a warning unit 44. The estimation unit 43 estimates the state of any reflector 2 based on a list of the states of multiple reflectors 2 output by the output unit 41. For example, it can predict the water level 12 of the fifth area Ar5 from the water levels 12 of the first area Ar1 to the fourth area Ar4 shown in Figure 4. The warning unit 44 can issue a warning if the state estimated by the estimation unit 43 differs from the actual state of the reflector 2's position. For example, it can issue a warning if the water level 12 of the fifth area Ar5 obtained from the reflected wave received by the receiving unit 32 is greater than the water level 12 of the fifth area Ar5 estimated by the estimation unit 43 by a predetermined amount or more.

[0020] [method] The operation flow of the above river monitoring system will be described. As shown in FIG. 1, radio waves are transmitted while changing the transmission direction of the transmission unit 31 with respect to a reflector group composed of a plurality of reflectors 2 fixed to the side wall 11 of the river 1. Next, the reflected wave of the radio wave is received by the receiving unit 32. Based on the value R based on the reflected wave corresponding to the positions of the plurality of reflectors 2 and the reference value B, the states of the plurality of reflectors 2 are output in a list. Thereby, river monitoring becomes possible.

[0021] <Modification Example> (A) In the above embodiment, the transmission direction of the radio wave is changed by rotating the antenna 30. However, any transmission unit 31 may be used as long as the transmission direction of the radio wave can be changed. For example, it is also possible to use a phased array radar.

[0022] (B) In the above embodiment, the reflected wave presence / absence output unit 410, the terrain change information output unit 411, the water level distribution output unit 412, the estimation unit 43, and the warning unit 44 are implemented, but these are not essential and can be arbitrarily implemented as long as at least one of them is provided.

[0023] [1] Similar to the first embodiment, the river monitoring system may include a transmission unit 31 that transmits radio waves while changing the transmission direction with respect to a reflector group composed of a plurality of reflectors 2 fixed to the side wall 11 of the river 1, a receiving unit 32 that receives the reflected wave of the radio wave, and an output unit 41 that outputs a list of the states of the plurality of reflectors 2 based on the value R based on the reflected wave corresponding to the positions of the plurality of reflectors 2 and the reference value B. According to this configuration, since the sensor 3 transmits and receives radio waves while changing the transmission direction with respect to the reflector 2 group composed of a plurality of reflectors 2 fixed to the side wall 11 of the river 1, the states of a plurality of reflectors 2 in a wide range can be monitored by one sensor 3, which is useful for monitoring a wide range of the river 1.

[0024] [2] In the river monitoring system described in [1] above, the reference value B is a value based on the reflected wave when there is no object blocking the reflection of radio waves from the reflector 2, and the output unit 41 may output that there is no reflected wave from the reflector 2 if the value R based on the reflected wave at the position of the reflector 2 is lower than the reference value B, and output that there is a reflected wave from the reflector 2 if the value R based on the reflected wave at the position of the reflector 2 is equal to or greater than the reference value B. Since the state of reflector 2 includes a state where there are no reflected waves from reflector 2, it may be possible to detect a rise in water level 12 or a change in topography based on this state.

[0025] [3] In the river monitoring system described in [1] or [2] above, the reflector group may include a plurality of reflector sets 20, 22, 23, 24 arranged in different areas, and each reflector set 20, 22, 23, 24 may include a plurality of reflectors 2 fixed at different heights and separated by a predetermined distance L1 or more in the horizontal direction LD. Since the multiple reflectors 201-207 that make up a reflector group 20 in one area are fixed at different heights and separated by a predetermined distance L1 or more in the horizontal direction LD, it is possible to obtain a list of the states of multiple reflectors 2 in one area. Furthermore, since there are reflector groups 20, 22, 23, and 24 in different areas, it is possible to obtain a list of the states of reflectors 2 for each area. The list of reflector 2 states may represent the water level 12 or changes in terrain, so it may be possible to obtain a distribution map of the water level 12 or changes in terrain.

[0026] [4] In the river monitoring system described in any of [1] to [3] above, the output unit 41 may output the change in the position of the reflector 2 as a change in terrain, based on a value R based on reflected waves corresponding to the positions of the multiple reflectors 2 and a value R based on past reflected waves at the position of the reflector 2. This configuration makes it possible to output information about changes in terrain.

[0027] [5] In any of the river monitoring systems described in [1] to [4] above, an estimation unit 43 that estimates the state of any reflector 2 based on a list may be further provided, and a warning unit 44 that issues a warning if the state estimated by the estimation unit 43 differs from the actual state of the reflector 2's position. With this configuration, the state of any reflector 2 can be estimated based on a list of the states of surrounding reflectors 2, and if the estimated state differs from the actual state, for example, abnormal flooding can be detected and a warning can be issued.

[0028] [6] In any of the river monitoring systems described in [1] to [5] above, the list may be a two-dimensional distribution of information regarding reflected waves from the position of each reflector 2. Information regarding reflected waves (water level 12, topographic changes, etc.) can be understood as a two-dimensional distribution.

[0029] [7] In the river monitoring system described in any of [1] to [6] above, the multiple sensors 3, each equipped with a transmitting unit 31 and a receiving unit 32, may be installed in positions that complement each other to cover blind spots where the transmitted radio waves cannot reach. This enables wide-area river monitoring.

[0030] [8] In the river monitoring system described in any of [1] to [7] above, the transmitting unit 31 may change the transmission direction by a rotating antenna 30.

[0031] [9] As in the first embodiment, the river monitoring method may include transmitting radio waves to a group of reflectors 2 fixed to the side wall 11 of a river 1 while changing the transmission direction of the transmitting unit 31; receiving the reflected radio waves with the receiving unit 32; and outputting a list of the states of the multiple reflectors 2 based on a value R and a reference value B corresponding to the positions of the multiple reflectors 2.

[0032]

[10] As in the first embodiment, the program may cause one or more processors to perform the following actions: acquire data on the reflected waves of radio waves transmitted to a group of reflectors consisting of a plurality of reflectors 2 fixed to the side wall 11 of the river 1 while changing the transmission direction of the transmission unit 31 and received by the receiving unit 32; and output a list of the states of the plurality of reflectors 2 based on a value R and a reference value B corresponding to the reflected waves at the positions of the plurality of reflectors 2.

[0033] Although embodiments of this disclosure have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of this disclosure is indicated not only by the description of the embodiments above but also by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

[0034] For example, the execution order of operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings can be implemented in any order, as long as the output of a previous process is not used in a later process. Even if the flow in the claims, specifications, and drawings is described using terms such as "first," "next," etc., for convenience, it does not mean that the execution must be in that order.

[0035] Each component shown in Figure 2 may be implemented by executing a predetermined program on a single unit or processor, or each component may be configured using dedicated memory or dedicated circuitry.

[0036] Although the system in the above embodiment has its components implemented on a single computer processor, the components may be distributed and implemented on multiple computers or in the cloud. In other words, the above method may be executed on one or more processors.

[0037] The structures used in each of the above embodiments can be adopted in any other embodiment. For the sake of explanation, each part is implemented, but some of these can be omitted as needed. [Explanation of symbols]

[0038] 1: River 2: Reflector 3: Sensor 10:Water 11: Side wall 20: Reflector set 21: Reflector group 22: Reflector group 23: Reflector group 24: Reflector group 30: Antenna 31: Transmitter 32: Receiving unit 41: Output section 43:Estimation part 44: Warning section 201: Reflector 202: Reflector 203: Reflector 204: Reflector 205: Reflector 206: Reflector 207: Reflector B: Reference value L1: Predetermined distance LD: Horizontal direction

Claims

1. A transmitting unit that transmits radio waves to a group of reflectors consisting of multiple reflectors fixed to the side wall of a river while changing the transmission direction, A receiving unit that receives the reflected waves of the aforementioned radio waves, An output unit that outputs a list of the states of multiple reflectors based on values ​​derived from the reflected waves corresponding to the positions of multiple reflectors and a reference value, A river monitoring system equipped with the following features.

2. The aforementioned reference value is a value based on the reflected wave when there is no object blocking the reflection of radio waves from the reflector. The output unit outputs a state indicating that there is no reflected wave from the reflector if the value based on the reflected wave at the reflector's position is lower than the reference value, and outputs a state indicating that there is a reflected wave from the reflector if the value based on the reflected wave at the reflector's position is equal to or greater than the reference value. The river monitoring system according to claim 1.

3. The reflector group includes multiple reflector sets, each arranged in a different area. The reflector assembly includes a plurality of reflectors fixed at different heights and separated by a predetermined distance or more in the horizontal direction. The river monitoring system according to claim 1.

4. The output unit outputs the change in the position of the reflector as a change in terrain, based on a value based on the reflected wave corresponding to the position of the multiple reflectors and a value based on the past reflected wave at the position of the reflector. The river monitoring system according to claim 1.

5. An estimation unit that estimates the state of any reflector based on the above list, The system further includes a warning unit that issues a warning if the state estimated by the estimation unit differs from the actual state of the reflector's position. The river monitoring system according to claim 1.

6. The river monitoring system according to any one of claims 1 to 5, wherein the list above is a two-dimensional distribution of information regarding the reflected waves from each of the reflector positions.

7. The river monitoring system according to claim 1, wherein the plurality of sensors, each comprising a transmitting unit and a receiving unit, are installed in positions that interpolate blind spots where the transmitted radio waves cannot reach.

8. The river monitoring system according to claim 1, wherein the transmitting unit changes the transmission direction by a rotating antenna.

9. A method performed by one or more processors, Transmitting radio waves to a group of reflectors, which consists of multiple reflectors fixed to the side wall of a river, while changing the transmission direction of the transmitting unit, The receiving unit receives the reflected waves of the aforementioned radio waves, Based on the values ​​derived from the reflected waves corresponding to the positions of the multiple reflectors and a reference value, the states of the multiple reflectors are output in a list. River monitoring methods, including those mentioned above.

10. The system transmits radio waves to a group of reflectors, consisting of multiple reflectors fixed to the riverbank, while changing the transmission direction of the transmitting unit, and acquires data on the reflected waves received by the receiving unit. Based on the values ​​derived from the reflected waves corresponding to the positions of the multiple reflectors and a reference value, the states of the multiple reflectors are output in a list. A program that causes one or more processors to execute.

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