JP2002365046A - River bed drop measuring apparatus for liquefaction line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a river bed drop measuring apparatus for a liquefaction line capable of managing data to establish a foresight or a prediction of a disaster scale occurring due to a drop of the river bed by measuring a drop amount of the river bed in the liquefaction line and an evaluation technique for a landside prevention facility. SOLUTION: In the liquefaction line of an entire region in which earth and sand movement from a mountain-side slope A of an uppermost stream of a river to a drift sand area of a coast B, the entire region is divided into three sections of the mountain-side slope A, a mountain stream.dam C and a river channel D. The river bed drop measuring apparatus 9 provided in the river channel D comprises a sensor 19 containing a small-sized radio oscillator 33 embedded in the river bed of the river channel D, a receiver 25 for receiving the radio wave oscillated from the sensor 19 through an antenna 23, and a reception recorder 27 for recording a receiving state received by the receiver 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring riverbed lowering in a sediment transport system.

[0002]

2. Description of the Related Art The sediment transport system is a general term for the entire area in which sediment movement occurs from a hillside slope at the uppermost stream of a river to a sand drift area on a coast. In the quicksand system, the entire area is divided into three sections: a hillside slope, a mountain stream / dam and a river channel, and a sabo dam is provided in the area of the mountain stream / dam.

[0003] When rain falls on the hillside of the uppermost stream of the river and floods occur, the residual sediment flows down as debris flow, and the residual sediment flows upstream of the sabo dam provided in the mountain stream / dam area. The thickness of the deposited layer is
After flooding, surveys are being conducted using human tactics.

In order to determine whether or not the riverbed in the river channel area has been lowered, for example, a plurality of colored bricks are piled up on the riverbed, and an operator can grasp the number of bricks that have been washed from above at a later date. At that time, the amount of riverbed decline was grasped.

[0005]

However, since the above-mentioned conventional amount of riverbed decline is known at a later date, it has not been possible to grasp the time series when a flood occurs. Therefore, it was not sufficient as a material for taking future measures.

Therefore, in the sediment transport system, the occurrence of sediment-related disasters on hillsides and mountain streams, the reduction of sediment supply to downstream rivers due to the construction of dams, the lowering of riverbed caused by gravel collection, etc.
In addition to safety and utilization issues such as coastal erosion, environmental issues such as impacts on ecosystems and loss of beaches have also become apparent.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to measure the amount of riverbed degradation in a sediment transport system over time and predict the scale of disaster caused by those riverbed degradations. It is an object of the present invention to provide a riverbed lowering measuring device in a sediment transport system capable of managing data for prediction, establishment of evaluation technology for sabo facilities, and the like.

[0008]

According to a first aspect of the present invention, there is provided an apparatus for measuring riverbed lowering in a sediment transport system according to the first aspect of the present invention. In the sediment transport system, which is the entire area in which the river occurs, the entire area is divided into three areas of a hillside slope, a mountain stream / dam and a river channel, and is a riverbed lowering measuring device provided in the river channel area, which is buried in the riverbed in the river channel. It is composed of a sensor unit with a built-in transmitter, a receiver that receives radio waves transmitted from this sensor unit via an antenna, and a reception recorder that records the reception status received by this receiver. It is characterized by the following.

Therefore, for example, when a flood occurs,
A radio wave transmitted from a transmitter built in a sensor section buried in a riverbed in a river channel is received by a receiver via an antenna, and the reception status received by the receiver is recorded in a reception recorder. As a result, the riverbed lowering amount is measured according to the temporal change.

According to a second aspect of the present invention, there is provided an apparatus for measuring riverbed lowering in a quicksand system according to the first aspect, wherein the sensor section has a target measuring range extending downward from the riverbed. It is characterized by comprising a plurality of sensors stacked at a height corresponding to (predicted scouring depth).

Therefore, for example, when a flood occurs,
Depending on the degree of the flood, a plurality of sensors come off in order from the top, so the riverbed degradation is measured by the number of sensors coming off and a predetermined height.

According to a third aspect of the present invention, there is provided an apparatus for measuring riverbed lowering in a quicksand system according to the second aspect, wherein each of the sensors includes a base having a circular cross section. Transmitters are provided above and below the axis on the base, and a reed switch is provided in the lower part of the transmitter, and an outer cylinder is provided on the base so as to surround the transmitter. The space between the outer cylinder and the transmitter is divided into a plurality at equal intervals in the circumferential direction, and a foam material is inserted into each of the divided portions. And one end of the wire is attached, and the other end of the wire is provided with a magnet.

[0013] Therefore, a plurality of sensors are stacked, and when a flood occurs and the riverbed is scoured,
The top sensor is relative to the sensor below it,
Removed. That is, when the magnet in the second sensor is detached from the first sensor, the first sensor is floated on water and the reed switch of the first sensor is turned off, for example. , ON, the radio wave transmitted from the first sensor is received by the receiver via the antenna, and then received and recorded in the reception recorder. By sequentially removing the sensors above, the amount of riverbed lowering is automatically measured every moment according to the change of time.

According to a fourth aspect of the present invention, there is provided an apparatus for measuring riverbed lowering in a sediment transport system according to the first, second, and third aspects of the present invention, wherein the sensor section is located near an upper position in a riverbed in which a sensor portion is embedded. Is provided with a water level measuring device.

Accordingly, since the water level is measured by the water level measuring device, the riverbed lowering amount and the water level are simultaneously measured with a temporal change.

According to a fifth aspect of the present invention, there is provided an apparatus for measuring riverbed lowering in a quicksand system according to the first, second, third, or fourth aspect, wherein the water level measuring device is an ultrasonic water level gauge. It is characterized by the following.

Accordingly, the water level can be easily and accurately measured by using the water level measuring device as an ultrasonic water level meter.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, the sediment transport system is a general term for the entire area in which sediment movement occurs from the hillside A at the most upstream part of the river to the sand drift area on the coast B. The entire area in this quicksand system is divided into three areas: hillside slope A, mountain stream / dam C, and river channel D. In the area of the mountain stream / dam C, a transmission type sabo dam 1 is provided. In the vicinity of the upstream side of the transmission type sabo dam 1 with respect to the transmission type sabo dam 1, a sedimentary layer thickness measuring device 3 and, for example, an ultrasonic water level gauge 5 as a water level measuring device are provided. In the vicinity of the downstream side of the transmission type sabo dam 1 from the boundary 1, a flow velocity / flow rate measurement device 7 for measuring the flood flow rate and the amount of sediment passing through the transmission section 7
Is provided. Further, a riverbed lowering measuring device 9 is provided in the area of the river channel D. The flow velocity / flow rate measuring device 7
In addition, for example, ultrasonic water level meters 11 and 13 as water level measuring devices are provided near the riverbed lowering measuring device 9.
Further, a management device 15 for managing data measured by each of the measurement devices is provided, and a sediment movement monitoring system 17 is configured from these devices.

As shown in FIG. 2, for example, the riverbed lowering measuring device 9 includes a sensor unit 19 having a small transmitter embedded in a riverbed of a river D and a radio wave transmitted from the sensor unit 19. The antenna 21 and the switchboard 23
And a reception recorder 27 for recording the reception status received by the receiver 25.

As shown in FIG. 3, the sensor section 19 is stacked downward at a height corresponding to a target measurement range (predicted scouring depth) by a plurality of sensors 29 from the riverbed. Buried in The height of the plurality of sensors 29 is, for example, a length L from the riverbed to the lower limit position, and the length L is, for example, about 2 to 4 m. So 1
The height of each sensor 29 is set to L / 10.

As shown in FIG. 4, a group number and an ID number indicating an individual number are set in the sensor 29 at the time of manufacture. This ID number does not use a group represented by a hexadecimal number and the sensor 29 is 0. Therefore,
The information of the sensor 29 is 1-1, 1-2... 1-F,
2-1 to 2-F,..., F-1 to F, and the sensor 6
As long as the radio wave reaches from one, information of a maximum of 15 * 15 = 175 sensors 29 can be received by one receiver 57.

As shown in FIG. 5, each of the sensors 29 has a base 31 having a circular cross section, and transmitters 33 are provided above and below the axis of the base 31. I have. A reed switch 35 is provided in the lower part of the transmitter 33. An outer cylinder 37 is provided on the base 31 so as to surround the transmitter 33. In addition, the space between the outer cylinder 37 and the transmitter 33 is divided into four in the circumferential direction at equal intervals, for example, and a foam material 39 such as styrene foam is inserted into the four divided parts. The reason for dividing into four parts and inserting the foam material 39 is that the sensor 29 maintains buoyancy even if water in which the part of the outer cylinder 37 breaks due to collision with a rock or the like when the sensor 29 floats enters. A mounting member 41 is provided on the shaft center on the outer cylinder 37.
The other end of the wire 43 is provided with a magnet 45 at the other end. Further, a spacer 47 such as a hollow paper tube is attached below the axis of the base 31.
The height of each sensor 29 is adjusted by the height of the spacer 47. Moreover, a case 49 for accommodating the magnet 45 is provided inside the spacer 47.
Is provided. This case 49 has a magnet 45
The magnet 45 is attracted to the base 31 and the reed switch 35 is not energized. In this state, the reed switch 35 is turned off.

According to the above-described configuration, for example, ten sensors 29 are stacked on two pipes extending in the vertical direction, and when a flood or the like occurs and the riverbed is removed,
The uppermost sensor 29 is disengaged from the underlying sensor 29, as shown in FIG. That is, when the magnet 47 in the second sensor 29 is detached from the first sensor 29, the first sensor 29 floats on the water and the read switch 35 of the first sensor 29 is turned off (off). ) From the state (ON), the radio wave transmitted from the first sensor 29 is received by the receiver 25 via the antenna 21, and then received and recorded in the reception recorder 27. That is, the reception time and the ID number of the sensor 29 are printed and recorded. Even when there is no transmission from the sensor 29, the regular printing is performed once an hour. In this way, the sensors are sequentially removed from the sensors 29 located above. The data received and recorded in the reception recorder 27 is as shown in FIG. FIG. 6 also shows the water level measured by the ultrasonic water level gauge 13.

As described above, the riverbed lowering can be automatically measured every moment according to the change of time.

Ultrasonic water level meter 1 as the water level measuring device
As shown in FIG. 7, for example, an arm bar 3 projecting upward from the riverbed from a pole 33 erected from the riverbank, as shown in FIG.
5, an ultrasonic transmitter / receiver 37, a thermometer 39 for sound velocity correction, and a relay box 4 for rearranging transmission / reception signals
1 and a converter 43 for calculating the water level from the received signal. Moreover, the ultrasonic transducer 37 is installed at a predetermined height above the reference height (measurement zero point) of the measurement place. This distance is measured and set as an initial value S0.

The signal transmitted from the converter 43 to the ultrasonic transducer 37 via the relay box 41 is emitted downward, reflected on the water surface, and transmitted through the ultrasonic transducer 37 and the relay box 41 to the converter 43. Is input to A signal from the thermometer 39 for correcting the sound speed is also input to the converter 43 via the relay box 41.

In the converter 43, the distance is calculated based on the time of return from the emission of the ultrasonic wave and the temperature information of the thermometer 39, and the result is initialized to the initial value stored in the converter 43 in advance. Subtract from S0 value and reference height (measurement 0 point)
, That is, the water level is calculated.

The water level calculated by the converter 43 is calculated every predetermined time, for example, every 60 minutes.
The result is represented, for example, as shown in FIG.
In this way, the water level can be obtained continuously with time.

Therefore, the apparatus 3 for measuring the thickness of the deposited layer,
Each data measured by the flow rate measuring device 7, the riverbed lowering measuring device 9 and the ultrasonic water level gauges 5, 11, 13 is stored in the management device 15
, It is possible to manage each data measured by each of the measuring devices. Thus, the state of sediment movement in the quicksand system can be grasped in a time series. In other words, it is possible to measure the temporal change in the state of sediment movement in the sediment transport system, and provide data for predicting and predicting the scale of the disaster caused by the movement and sedimentation, and establishing evaluation techniques for sabo facilities.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes.

[0032]

As will be understood from the above description of the embodiments of the present invention, according to the first aspect of the present invention, for example, when a flood occurs, the sensor is built into the sensor buried in the riverbed of the river channel. The radio wave transmitted from the transmitted transmitter is received by the receiver via the antenna, and the reception status received by this receiver is recorded in the reception recorder, so that the riverbed degradation can be measured. it can. Thus,
The riverbed degradation in the sediment transport system can be grasped according to the temporal change.

Therefore, the water level measured by the water level measuring device provided in the vicinity of the flow velocity / flow rate measuring device and the riverbed lowering measuring device can be grasped to the sediment movement state in the quicksand system.

According to the second aspect of the present invention, for example, when a flood occurs, a plurality of sensors are sequentially removed from the top depending on the degree of the flood. Therefore, the riverbed lowering amount is determined by the number of removed sensors and a predetermined height. Can be measured.

According to the third aspect of the present invention, a plurality of sensors are stacked, and when a flood or the like occurs and the riverbed is scavenged, the uppermost sensor is detached from the lower sensor. You. That is, when the magnet in the second sensor is detached from the first sensor, the first sensor is floated on water and the reed switch of the first sensor is turned off, for example. , ON, the radio wave transmitted from the first sensor is received by the receiver via the antenna, and then received and recorded in the reception recorder. By sequentially removing the sensors above, the riverbed lowering amount can be automatically measured every moment according to the change of time.

According to the fourth aspect of the present invention, since the water level is measured by the water level measuring device, the riverbed lowering amount and the water level can be measured simultaneously with time.

According to the fifth aspect of the present invention, since the water level measuring device is an ultrasonic water level meter, a more accurate water level can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire sediment movement monitoring system in a quicksand system.

FIG. 2 is a diagram showing a riverbed lowering measuring device.

FIG. 3 is an explanatory diagram of a state in which sensors of a sensor unit are stacked and buried on a riverbed.

FIG. 4 is a diagram showing a measurement block for measuring by each sensor.

FIG. 5 is a diagram showing a structure of a sensor.

FIG. 6 is a diagram showing an example graph received and recorded by a reception recorder of a riverbed lowering measurement device and an example graph recorded by a data acquisition device of a water level gauge.

FIG. 7 is a diagram showing an ultrasonic water level gauge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission type sabo dam 3 Sedimentary layer thickness measuring device 5 Ultrasonic water level meter (ultrasonic measuring device) 7 Flow rate / sediment measuring device 9 Riverbed lowering measuring device 11, 13 Ultrasonic water level meter (water level measuring device) 15 Management device 17 Sediment movement monitoring system 51 Ultrasonic transceiver 53 Controller 55 Analog recorder 57 Data acquisition device 59 Initial value / memory 61 First computing device 63 Second computing device 19 Sensor unit 21 Antenna 23 Switchboard 25 Receiver 27 Receiving recorder 29 Sensor 31 Base 33 Transmitter 35 Reed switch 37 Outer cylinder 39 Foam 41 Mounting member 43 Wire 45 Magnet 47 Spacer 49 Case

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G08C 17/00 G08C 17/00 Z (72) Inventor Atsushi Shimane 1-4-4 Uchikanda, Chiyoda-ku, Tokyo No. 15 Tawanai F term (reference) 2F014 AA09 AC00 FB00 2F073 AA01 AB01 AB12 BB01 CC01 DD02 FF01 GG01 GG04 2F076 BB09 BB12 BB16 BB17 BD17 BE18

Claims (5)

[Claims] 1. In a sediment transport system, which is the entire area in which sediment movement occurs from the hillside slope at the uppermost stream of the river to the sand drift area on the coast, this entire area is divided into three areas: a hillside slope, a mountain stream / dam and a river channel. A riverbed lowering measurement device provided in a river channel area, a sensor unit embedded with a transmitter buried in the riverbed in the river channel, and a receiver for receiving a radio wave transmitted from the sensor unit via an antenna. And a reception recorder for recording the reception status received by the receiver. 2. The method according to claim 1, wherein the sensor unit comprises a plurality of sensors stacked downward at a height corresponding to a target measurement range (predicted scouring depth) downward from the riverbed. The riverbed lowering measuring device in a quicksand system according to claim 1. 3. Each of the sensors has a base having a circular cross section, and a transmitter is provided above and below an axis on the base, and a reed switch is provided in a lower portion of the transmitter. And an outer cylinder is provided on the base so as to surround the transmitter, and the space between the outer cylinder and the transmitter is divided into a plurality of parts at equal intervals in the circumferential direction. A material is inserted, and one end of a wire is attached to a shaft center portion of the outer cylinder via a mounting member, and a magnet is provided at the other end of the wire. 2. The riverbed lowering measurement device in the quicksand system according to 2. 4. The riverbed lowering measuring device in a sediment transport system according to claim 1, wherein a water level measuring device is provided near an upper position on the riverbed in which the sensor section is buried. 5. The riverbed lowering measuring device in a quicksand system according to claim 1, wherein the water level measuring device is an ultrasonic water level meter.