JP3474515B2 - Debris flow / mud flow detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a debris flow / mud flow generation detecting device capable of reliably detecting the generation of debris flow and mud flow.

[0002]

2. Description of the Related Art Conventionally, a contact type debris flow detector using a wire and a non-contact type debris flow detector using a light beam have been used to detect the occurrence of a debris flow or the like. These debris flow detectors are configured to detect the occurrence of debris flow or the like by detecting that the debris flow has cut a wire or by detecting that the debris flow has blocked the light flux.

However, in these debris flow detectors,
There are inconveniences such as complicated installation work and maintenance work. In particular, a debris flow detector using a wire has a disadvantage that it is necessary to reattach the wire every time a debris flow occurs.

Further, there is also used a debris flow detector constituted by combining two or more kinds of sensors, for example, an ultrasonic water level meter, a sound velocity correcting thermometer, a radio wave velocity meter and the like. In this debris flow detector, first, by observing the fluctuation of the water level with an ultrasonic water level meter with temperature correction, a rapid rise in the water level due to a step wave is captured, and further an increase in the flow velocity is captured with a radio wave anemometer. By doing so, it is configured to detect the occurrence of a debris flow or the like.

However, in this debris flow detector, it is necessary to perform smoothing processing or the like on the time axis in order to detect the abrupt change in the water level due to the step wave. Therefore, there is a time delay until the detection result is obtained. Occurrence may occur, and as a result, the immediacy of detection may be impaired.

Therefore, recently, the development and practical use of a debris flow detection device configured to send and receive radio waves to and from a monitored position and detect the occurrence of debris flows and the like based on the Doppler effect of the radio waves. Has been.

This debris flow detection device is configured to detect the occurrence of a debris flow or the like based on the magnitude of the Doppler frequency component within the range corresponding to the debris flow extracted by using a bandpass filter, for example. (JP-A-63-1
9534 publication).

However, in this debris flow detection device,
Since the range of the Doppler frequency component to be considered is limited, it is not possible to reliably capture the Doppler frequency component corresponding to the step wave of debris flow, etc. where the velocity changes rapidly, and as a result, the detection of debris flow etc. It may be delayed.

Further, the debris flow detecting apparatus utilizing the Doppler effect of the above-mentioned radio wave, for example, from the spectrum distribution of the Doppler frequency component obtained by the spectrum analysis processing for the received wave, the spectrum level is higher than the predetermined threshold level. Is configured to detect the occurrence of debris flow and the like based on the size of the width of the frequency range (Japanese Patent No. 273506).
No. 9).

However, this debris flow detecting device is mainly designed for the detection of pyroclastic flow, and the debris flow detection is performed by utilizing the fact that the velocity distribution of rock fall and the like are greatly different from the velocity distribution of the pyroclastic flow. I am trying. Therefore, when this debris flow detection device is used to detect debris flow that normally flows down along a river where water is flowing, when the difference in velocity distribution between water and debris flow is small. Then
There is a possibility that the debris flow cannot be detected reliably.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned inconvenience, and provides a debris flow / mud flow generation detection device capable of reliably detecting the generation of debris flow or mud flow. The purpose is to provide.

[0012]

[Means for Solving the Problems] Debris flow according to the present invention
The mud flow generation detection device transmits ultrasonic waves and radio waves to a declining body flowing down on an inclined surface, and a transmitter / receiver that receives a reflected wave from the declining body, based on information included in the reflected wave. In the spectral distribution of the Doppler frequency component as information contained in the reflected wave, the controller has a control device for detecting the occurrence of debris flow or mud flow, in the step wave of the debris flow or mud flow. A step wave generation determining unit is provided for determining whether or not the debris flow or the mud flow is generated based on the behavior of the corresponding step wave component group (claim 1).

As described above, by paying attention to the behavior of the step wave component group in the spectral distribution and determining whether or not the debris flow or the mud flow is generated, the generation of the debris flow or the mud flow can be reliably detected. .

In this case, the stage wave generation determining means determines the stage wave based on a change in the width of the group of the Doppler frequency components whose spectral power exceeds a predetermined reference value in the spectral distribution of the Doppler frequency components. The behavior of the component group is detected (the invention according to claim 2).

The step wave component group is a component group corresponding to a step wave slope of the step wave (claim 3).
Invention described). In this way, by using the group of components corresponding to the slope of the step wave where the Doppler velocity component greatly changes as the group of step components in the spectral distribution, it is possible to more reliably detect the occurrence of debris flows and mud flows. .

Further, the control device has a flow rate scale determining means for determining whether or not the debris flow or the mud flow is generated based on the flow rate scale of the falling body obtained from the intensity of the reflected wave. (Invention of Claim 4).

Further, the control device has a flow velocity determining means for determining whether or not the debris flow or the mud flow is generated based on the velocity of the falling body obtained from the Doppler frequency component. Invention of 5.).

Then, the control device determines whether or not the debris flow or the mud flow is generated in accordance with the combination of the determination results obtained by the stage wave generation determination means, the flow rate scale determination means, and the flow velocity determination means. Comprehensive determination means for comprehensive determination is provided (the invention according to claim 6). Therefore, the reliability of the determination result can be improved.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the construction of a debris flow / mud flow generation detection device 10 to which an embodiment of the present invention is applied.

The debris flow / mud flow generation detecting device 10 comprises a transceiver 12 for transmitting and receiving ultrasonic waves, radio waves and the like, and a control device 14 electrically connected to the transceiver 12.

The transmitter / receiver 12 is installed substantially in front of and above the inclined surface A so that the transmission direction of the transmitted wave faces the upper surface of the falling body B flowing down on the inclined surface A which is the observed position C. There is. In this case, the falling body B is, for example, a continuous body of flowing water B1 flowing through the river, debris flow or mud flow (also simply referred to as debris flow) B2 flowing down along the river, and the like. Note that the falling body B may be a pyroclastic flow or the like.

The transmitter / receiver 12 is supplied with the transmission voltage from the control device 14, and the transmitter / receiver 12 transmits the transmission wave of the transmission frequency fa to the upper surface of the falling body B based on the transmission voltage. To do. In addition, this transmitted wave is
When reflected as a reflected wave (received wave) having the reception frequency fb, the transceiver 12 receives the received wave and converts the received wave into a received voltage to control the controller 14.
Output to.

FIG. 2 shows the configuration of the control device 14. The control device 14 includes a transmission / reception control unit 20 that controls the transceiver 12, and a determination unit 22 that determines whether or not a debris flow B2 or the like has occurred based on information included in a received wave received by the transceiver 12. A result output unit 24 that outputs a determination result or the like in the determination unit 22 is provided.

The transmission / reception control unit 20 outputs to the transceiver 12 a transmission voltage for transmitting a transmission wave from the transceiver 12. Further, the transmission / reception control unit 20 takes in the reception voltage output from the transceiver 12 based on the reception wave received by the transceiver 12. Then, this received voltage is sampled and A / D (analog to digita)
l) The voltage value V obtained by the conversion is supplied to the determination unit 22.

The determination unit 22 is a spectrum analysis processing means 3
0, stage wave generation determination means 32, flow velocity determination means 34, flow rate scale determination means 36, and comprehensive determination means 38.

The spectrum analysis processing means 30 uses the FFT (Fast Fourier Trans
The spectrum of the reception frequency fb is generated by performing spectrum analysis processing such as form analysis. Further, based on the transmission frequency fa, the spectrum of the reception frequency fb is converted into the spectrum of the Doppler frequency component Δf (Δf = fb-fa).

Based on the spectrum of the Doppler frequency component Δf obtained by the spectrum analysis processing means 30, the stage wave generation determination means 32 is at the observed position C (see FIG. 1) to which the transceiver 12 is directed, such as debris flow B2. It is determined whether or not has occurred.

First, a method for determining whether or not the debris flow B2 is generated based on the spectrum of the Doppler frequency component Δf will be described.

FIGS. 3A to 3C show different types of falling bodies B.
And the Doppler velocity component vb of the velocity va (that is, the component of the velocity va in the direction from the observed position C toward the transceiver 12). Also, FIG.
And FIG. 4B shows the spectral distribution of the Doppler frequency component Δf corresponding to the Doppler velocity component vb of FIGS. 3A and 3B.

In this case, the type of the falling body B at the observed position C is running water B1 in the example of FIG. 3A, and debris flow B2 in the examples of FIGS. 3B and 3C. That is, FIG. 3A
Represents the state of the normal observed position C, while FIGS. 3B and 3C show the state of the observed position C when the debris flow B2 occurs. Further, in FIG. 3B, a step wave slope D1 that is the tip surface of the debris flow B2 is located at the observed position C, and in FIG. 3C, a step wave upper surface D2 that is the top surface of the tip portion of the debris flow B2 is located. is doing.

In FIGS. 3A to 3C, the angle (directivity angle) θi between the direction in which the transmission wave is transmitted from the transceiver 12 and the inclined surface A is, for example, θi = 30 ° to 4
It is preferably 5 °. When determining the directivity angle θi, the ease of installation and maintainability of the transceiver 12 and constraints on the distance from the transceiver 12 to the inclined surface A are taken into consideration. Further, it is preferable that the actual value of the directivity angle θi is set to a value such that the step wave slope Doppler velocity component vb2 described later has a negative value.

As shown in FIG. 3A, the velocity va of the flowing water B1
Is the running water velocity va1, and the moving direction of the running water B1 is the inclined surface A
If the direction is parallel to, the running water Doppler velocity component vb1 which is the Doppler velocity component vb of the running water velocity va1 is v
b1 = va1 × cos (θi).

In this case, the flowing water velocity va1 and its direction are
This is obtained by linearly approximating the velocity distribution of running water B1.

Further, as shown in FIG. 3B, the step slope D1
Of debris flow in B
When the moving direction of the debris flow B2 on the step slope D1 is inclined with respect to the slope A by the step slope angle θd, the step slope Doppler velocity that is the Doppler velocity component vb of the stage slope velocity va2. The component vb2 is vb2 = va
It becomes 2 × cos (θi + θd).

Further, as shown in FIG. 3C, the step wave upper surface D
The velocity va of the debris flow B2 in 2 is the upper surface velocity va of the step wave.
3, and when the moving direction of the debris flow B2 on the upper surface D2 of the step is parallel to the inclined surface A, the upper step velocity v
The step wave upper surface Doppler velocity component vb3, which is the Doppler velocity component vb of a3, is vb3 = va3 × cos (θi).

In this case, the step wave slope velocity va2 and its direction (step wave slope angle θd), and the step wave upper surface velocity va3 and its direction are the rocks contained in the tip portion of the debris flow B2, the muddy water envelope surface, and the like. , Is obtained by linearly approximating movements such as scattered breaking waves and rotations.

In the example shown in FIGS. 3A to 3C, the transceiver 1
The directivity angle θi of 2 is θi = 30 ° to 45 °. Therefore, the running water Doppler velocity component vb1 in FIG. 3A has a positive value. Then, as shown in FIG. 4A, in the spectral distribution of the Doppler frequency component Δf corresponding to the flowing water B1 (distribution of the spectral power of the Doppler frequency component Δf), the value of the Doppler frequency component Δf corresponding to the flowing water Doppler velocity component vb1 is The spectrum power of the positive component group E1 becomes dominant.

On the other hand, the step wave slope Doppler velocity component vb2 shown in FIG. 3B has the condition (π> θi + θd> π /
When 2) is satisfied, it becomes a negative value. Then, as shown in FIG. 4B, in the spectral distribution of the Doppler frequency component Δf when the step wave slope D1 reaches the observed position C, the value of the Doppler frequency component Δf corresponding to the step wave slope Doppler velocity component vb2 is Negative component group (stage wave component group) E3
The spectrum power of becomes dominant. At the same time as this component group E3, the value of the component group E2 corresponding to the flowing water Doppler velocity component vb1 or the step wave upper surface Doppler velocity component vb3 and having a positive value of the Doppler frequency component Δf may be projected. This is because the transmitted wave in FIG.
This is because it may reach the side or the flowing water B1 side.

Utilizing this fact, the stage wave generation judging means 3
2 corresponds to the step wave slope Doppler velocity component vb2,
Focusing on the behavior of the component group E3 in which the value of the Doppler frequency component Δf is negative, it is determined whether or not the debris flow B2 occurs.

First, a group of Doppler frequency components Δf whose spectral power exceeds a predetermined threshold level (reference value) S is extracted from the spectral distribution, and the width of Doppler frequency components Δf included in this group (hereinafter referred to as spectrum width). Also referred to as). In this case, the spectral width ΔF is obtained as a value obtained by subtracting the minimum value from the maximum value of the Doppler frequency component Δf included in this group.

For example, in the example of FIG. 4A, the spectral width Δ
F becomes ΔF = ΔF1 = a2-a1, and in the example of FIG. 4B, the spectrum width ΔF becomes ΔF = ΔF2 = a4-a5. In this case, ΔF1 <ΔF2.

The spectrum width ΔF may be obtained as the width of the Doppler frequency component Δf whose spectrum power substantially exceeds the predetermined threshold level S. In this case, the spectral width Δ in FIG. 4B
F2 is ΔF2 = ΔF21 + ΔF22 = (a4-a3)
It becomes + (a6-a5).

As shown in FIG. 4A, the spectral width ΔF2 when the step slope D1 reaches is determined by the existence of the component group E3, and the spectral width ΔF2 when the running water B1 flows down is shown in FIG. 4B.
The value is larger than F1. Therefore, by detecting the change in the spectral width ΔF representing the behavior of the component group E3 in this way, it is possible to determine whether or not the debris flow B2 or the like has occurred.

The stage wave generation judging means 32 makes a judgment especially by comparing the amount of change ΔF / ΔT in the predetermined time ΔT of the spectral width ΔF with a predetermined judgment value K. In this case, the determination value K is set based on the change amount ΔF / ΔT when the debris flow B2 is not generated (that is, when the running water B1 is flowing down).

As shown in FIG. 4B, the step slope D1
The range G (a7) where the change of the component group E3 corresponding to
Up to a8) is preset, and within this range G, the temporal change amount ΔF22 / of the spectral width ΔF (for example, ΔF22).
The presence / absence of occurrence of debris flow B2 may be determined by monitoring ΔT.

Further, the fact that the spectral power of the component group E3 temporarily increases when the step slope D1 passes through the observed position C is used to determine the presence or absence of the debris flow B2. May be. In this case, the step slope D
Change amount ΔF before and after 1 passes through the observed position C
The change in / ΔT is monitored. Specifically, when it is confirmed that the change amount ΔF / ΔT changes from the steady state to the increase and then decreases, it is determined that the step wave slope D1 has passed.

Furthermore, the change in the average value of the Doppler frequency component Δf within the spectral width ΔF and the spectral width ΔF
For example, the presence or absence of the debris flow B2 may be determined based on the change in the value of the Doppler frequency component Δf at the center position.

Next, the debris flow B etc. is detected by the step wave generation judging means 32.
An example of the processing for determining whether or not the step wave 2 is generated will be described with reference to the flowcharts of FIGS. 5 and 6.

First, in step S11, the step wave generation judging means 32, based on the spectrum of the Doppler frequency component Δf obtained by the spectrum analysis processing means 30, determines the spectrum width ΔF (for example, the spectrum power is the threshold level S). A value obtained by subtracting the minimum value from the maximum value of the Doppler frequency component Δf that exceeds is obtained (see FIGS. 4A and 4B).

Then, in step S12, the presence or absence of the component group E3 (see FIG. 4B) corresponding to the step wave, in particular the step wave slope D1, is determined based on the spectral width ΔF, that is, the step wave is generated. To judge.

As shown in FIG. 6, in the subroutine of step S12, first, in step S21, the amount of change ΔF / ΔT in the predetermined time ΔT of the spectral width ΔF is obtained.

Subsequently, in step S22, it is determined whether or not the amount of change ΔF / ΔT exceeds a predetermined determination value K (ΔF / ΔT> K).

If the determination result in step S22 is affirmative (YES), it is determined that the step slope D1 exists at the observed position C, and the determination result H1 is H1 = H1y in step S23. It is set to (stage wave generation).

On the other hand, if the decision result in the step S22 is negative (NO), the decision result H1 is set to H1 = H1n (stage wave non-occurrence) in the step S24.

When the processing of the step S23 or S24 is completed, in the next step S25, the judgment result H
1 (= H1y, H1n) is output to the comprehensive determination means 38 (see FIG. 2).

Next, in the flow velocity judging means 34 of FIG.
An example of the process for determining the presence or absence of the debris flow B2 based on the velocity va of the falling body B will be described with reference to the flowchart in FIG. 7.

The flow velocity determining means 34 firstly performs step S3.
1, the velocity va of the falling body B is obtained based on the spectrum of the Doppler frequency component Δf obtained by the spectrum analysis processing means 30. Specifically, the speed va is obtained from the following equation (1).

Va = c × Δfα / (2 × fa × cos
(Θi)) (1) Here, the transceiver 1
2 is configured to send and receive radio waves, c
Is the speed of light (about 3 × 10 ⁸ m / s), while c is the speed of sound (about 340 m / s) when configured to transmit and receive ultrasonic waves. In addition, Δfα is the falling body B
Is the Doppler frequency component Δf corresponding to the Doppler velocity component vb.

Doppler frequency component Δf in the equation (1)
α is obtained based on the spectral distribution of the Doppler frequency component Δf. Specifically, the Doppler frequency component Δf
Is obtained by extracting the Doppler frequency component Δf corresponding to the peak of the spectral power as Δfα from the spectral distribution of, or the Doppler frequency component Δf at which the spectral power becomes a certain value or more is extracted from the spectral distribution, and the Doppler frequency The Doppler frequency component Δfα is obtained by obtaining the average value of the component Δf.

Next, in step S32, it is judged whether or not the speed va obtained by the equation (1) is larger than a predetermined judgment value v0 (va> v0). in this case,
The determination value v0 is the running water velocity va which is the speed va of the running water B1.
It is set to a value larger than 1 and smaller than a step wave upper surface speed va3 which is a speed va of the step wave upper surface D2 of the debris flow B2. That is, the step wave upper surface velocity va3 is the running water velocity v
It is determined whether or not the debris flow B2 is generated by utilizing the fact that it is larger than a1.

If the determination result in step S32 is affirmative (YES), it is determined that the debris flow B2 exists at the observed position C, and the determination result H2 in step S33 is H2 = H2y ( Debris flow etc.) is set.

On the other hand, if the determination result in step S32 is negative (NO), the determination result H2 is set to H2 = H2n (debris flow etc. is not generated) in step S34.

When the processing of the step S33 or S34 is completed, the determination result H is obtained in the next step S35.
2 (= H2y, H2n) is output to the comprehensive determination means 38 (see FIG. 2).

Next, with reference to the flow chart of FIG. 8, an example of the processing for determining the presence or absence of the debris flow B2 based on the flow rate scale of the falling body B in the flow rate scale determination means 36 of FIG. 2 will be described. explain.

The flow rate scale determining means 36 utilizes that the amplitude (intensity) of the received wave changes according to the distance from the upper surface of the falling body B to the transceiver 12, that is, the moving distance of the received wave. Whether or not B2 such as debris flow has occurred is determined.

More specifically, when the position of the upper surface of the falling body B is low (the flow rate is small), the amplitude of the received wave is small, and conversely, the position of the upper surface of the falling body B is high (the flow rate is small). Large), the amplitude of the received wave becomes large.

Further, the position of the falling body B when the debris flow B2 is generated, that is, the position of the upper surface D2 of the step of the debris flow B2 is the falling body B when the debris flow B2 is not generated,
That is, it is higher than the position of the upper surface of the running water B1. Therefore, based on the voltage value V corresponding to the amplitude of the received wave, it can be determined whether or not the debris flow B2 is generated.

First, in step S41, the flow rate scale determination means 36 determines the flow rate scale I of the falling body B based on the voltage value V from the transmission / reception control section 20. In this case, the flow rate scale I is obtained as an average value of the voltage values V, for example.

Then, in the next step S42,
Based on the flow rate scale I, it is determined whether or not the debris flow B2 is generated. Specifically, it is determined whether the flow rate scale I is larger than a predetermined determination value I0 (I>
I0).

If the determination result of step S42 is affirmative (YES), it is determined that the debris flow B2 exists at the observed position C and the determination result H3 is H3 = H3y (at step S43). Debris flow etc.) is set.

On the other hand, if the decision result in the step S42 is negative (NO), the decision result H3 is set to H3 = H3n (no debris flow etc.) in step S44.

When the processing of the step S43 or S44 is completed, in the next step S45, the judgment result H
3 (= H3y, H3n) is output to the comprehensive determination means 38 (see FIG. 2).

Next, an example of the comprehensive judgment processing in the comprehensive judgment means 38 of FIG. 2 will be described with reference to the flowchart of FIG.

The comprehensive judging means 38 firstly carries out step S5.
1, the determination result H from the stage wave generation determination means 32
1. A combination of the determination result H2 from the flow velocity determination means 34 and the determination result H3 from the flow rate scale determination means 36 is determined.

Then, the combination of the judgment result H1, the judgment result H2, and the judgment result H3 is, for example, (H1, H
2, H3) = (H1y, H2y, H3y), the process proceeds to step S52, and (H1, H2, H3) = (H1
y, H2y, H3n) or (H1y, H2n, H
In the case of 3y), the process proceeds to step S53 and (H1, H
2, H3) = (H1y, H2n, H3n), the process proceeds to step S54, and (H1, H2, H3) = (H1
n, H2y, H3y), the process proceeds to step S55 and (H1, H2, H3) = (H1n, H2y, H3
n) or (H1n, H2n, H3y),
The process moves to step S56, and (H1, H2, H3) = (H
1n, H2n, H3n), the process proceeds to step S57.

In steps S52 to S57, the result output unit 24 is instructed to perform output processing by different methods, for example.

For example, in step S52, the first output method is instructed, in step S53, the second output method is instructed, in step S54, the third output method is instructed, and in step S55, the fourth output method is instructed. The output method is instructed, the fifth output method is instructed in step S56, and the sixth output method is instructed in step S57.

In this case, the condition for performing the process of step S52 is that the determination result H1, the determination result H2, and the determination result H3 are all affirmative. Therefore, if this condition is satisfied, the debris flow B2, etc. It can be determined that there is a very high possibility that

Further, the importance of the judgment result H1 is determined by the judgment result H
2 and the determination result H3 are set to be higher in importance, and debris flow B2 is generated depending on the proportion of positive determinations among the determination result H1, the determination result H2, and the determination result H3. If it is assumed that the probability of occurrence of the debris flow increases or decreases, it can be determined that the probability of occurrence of the debris flow B2 decreases in the order of each condition in which the steps S53 to S56 are performed.

Furthermore, the condition for performing the process of step S57 is that the determination result H1, the determination result H2, and the determination result H3 are all negative, so if this condition is satisfied, the debris flow B2, etc. It can be determined that the possibility of occurrence is very low (or the possibility is “0”).

Therefore, the urgency levels assigned to the first to sixth output methods set in steps S52 to S57 are assigned from the maximum value to the minimum value ("0" in the order of the first to sixth output methods). Value)).

The first to sixth output methods are "debris flow B2 generation", "debris flow B2 generation may occur",
You may divide into the classifications, such as "debris flow etc. B2 non-occurrence." In this case, it is preferable to perform the classification mainly based on the determination result H1 (whether or not a step wave is generated).

By the processes of steps S52 to S57, the result output unit 24 (see FIG. 2) is given the first to sixth values.
When any one of the output methods is instructed, the result output unit 24 follows the instruction of this output method.
Output processing such as alarm sound generation, display display, and alarm signal output to remote monitoring stations. In this case, the type and volume of the alarm sound, the contents of the display and the alarm signal, etc. are changed according to the urgency levels assigned to the first to sixth output methods. Note that the speed va or the flow rate scale I may be output as the alarm signal.

As described above, in the embodiment of the present invention, attention is paid to the behavior of the component group E3 corresponding to the step wave slope D1 in the spectral distribution of the Doppler frequency component Δf, and the occurrence of the debris flow B2 is generated. The presence or absence is determined. In this case, the component group E3 changes greatly when reaching the step slope D1, and therefore the occurrence of the debris flow B2 can be reliably detected by paying attention to the behavior of the component group E3.

Further, since the occurrence of the debris flow B2 can be detected at the time when the step wave which is the tip of the debris flow B2 passes through the observed position C, the occurrence of the debris flow B2 can be immediately known.

Furthermore, the presence or absence of the debris flow B2 is comprehensively determined based on the behavior of the component group E3 and the change of the flow rate I of the effluent B and the change of the velocity va. It is possible to improve reliability.

[0088]

According to the present invention, the presence or absence of debris flow or mud flow is judged based on the Doppler frequency component corresponding to the step wave of debris flow or mud flow. It is possible to reliably detect the occurrence.

[Brief description of drawings]

FIG. 1 is a debris flow to which an embodiment of the present invention is applied.
It is explanatory drawing which shows the structure of a mud flow generation detection apparatus.

FIG. 2 is a block diagram showing a configuration of a control device shown in FIG.

FIG. 3A is an explanatory diagram showing a relationship between running water and a flowing water velocity, FIG. 3B is an explanatory view showing a relationship between a step slope and a step slope speed, and FIG. 3C is a step diagram. It is explanatory drawing which shows the relationship between an upper surface and a step wave upper surface speed.

FIG. 4A is a graph showing a spectral distribution of Doppler frequency components corresponding to running water, and FIG. 4B is a graph showing a spectral distribution of Doppler frequency components corresponding to a step slope.

5 is a flowchart showing a process for determining whether or not a step wave is generated by the step wave generation determining means in FIG.

FIG. 6 is a flowchart showing a process for determining whether or not a step wave is generated by the step wave generation determining means in FIG.

7 is a flowchart showing a process for determining whether or not a debris flow or the like has occurred by the flow velocity determining means of FIG.

FIG. 8 is a flowchart showing a process for determining whether or not a debris flow or the like has occurred by the flow rate scale determination means of FIG.

9 is a flowchart showing a comprehensive determination process in a comprehensive determination means 38 of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Debris flow / mud flow generation detection device 12 ... Transceiver 14 ... Control device 20 ... Transmission / reception control unit 22 ... Judgment unit 24 ... Result output unit 30 ... Spectral analysis processing means 32 ... ... Flow rate scale determining means 38 ... Comprehensive determining means B ... Flowing body B1 ... Flowing water B2 ... Debris flow D1 ... Step wave slope Δf ... Doppler frequency component ΔF ... Spectral width

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Daisuke Akamine 5-11, Shimorenjaku, Mitaka-shi, Tokyo Nihon Radio Co., Ltd. (72) Katsuhiro Nagaya 5-1-1, Shimorenjaku, Mitaka, Tokyo Within this radio Co., Ltd. (56) Reference JP-A-63-19534 (JP, A) JP-A-10-2779 (JP, A) Patent 2735069 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01D 21/00 E02D 17/20 G01P 5/00 G01S 13/88

Claims (6)

(57) [Claims] 1. A transceiver that transmits ultrasonic waves and radio waves to a falling body flowing down on an inclined surface and receives a reflected wave from the falling body, and based on information contained in the reflected wave, In a debris flow / mud flow generation detection device having a control device for detecting the generation of debris flow and mud flow, the control device is provided in the spectral distribution of the Doppler frequency component as the information included in the reflected wave, Debris flow / mud flow characterized by having a step wave generation determination means for determining whether or not the debris flow or the mud flow is generated based on the behavior of the step wave component group that is a component group corresponding to the mud flow Occurrence detection device. 2. The debris flow / mud flow generation detection device according to claim 1, wherein the step wave generation determination unit has a spectral power of a Doppler frequency component in a spectral distribution of the Doppler frequency component that exceeds a predetermined reference value. A debris flow / mud flow generation detection device which detects the behavior of the step wave component group based on a change in the width of the group. 3. The debris flow / mud flow generation detecting device according to claim 1, wherein the step wave component group is a group of components corresponding to a step wave slope of the step wave. Flow generation detection device. 4. The debris flow / mud flow generation detection device according to claim 1, wherein the control device is based on a flow rate scale of the falling body obtained from the intensity of the reflected wave. A debris flow / mud flow generation detection device having a flow rate scale determination means for determining whether or not the debris flow or the mud flow is generated. 5. The debris flow / mud flow generation detection device according to claim 4, wherein the control device determines whether or not the debris flow or the mud flow is generated based on the velocity of the falling body obtained from the Doppler frequency component. A debris flow / mud flow generation detection device having a flow velocity determination means for determining. 6. The debris flow / mud flow generation detection device according to claim 5, wherein the control device is a combination of determination results obtained by the stage wave generation determination unit, the flow rate scale determination unit, and the flow velocity determination unit. A debris flow / mud flow generation detection device having a comprehensive determination means for comprehensively determining whether or not the debris flow or the mud flow has occurred.