JPH05100052A - Predicting method and monitoring device for avalanche occurrence - Google Patents

Abstract

PURPOSE:To predict an avalanche immediately before its occurrence by measuring the vibration of the ground by the avalanche with seismometers, and predicting the occurrence of the harmful avalanche based on the change of its activity. CONSTITUTION:Seismometers 1, 1' are set on the dangerous slope A of an avalanche B, the occurrence of the avalanche B near this slope A is measured in real time, thus the avalanche control on a road 2 is performed. The occurring avalanche B collapses toward a valley line A from ridge lines, the seismometers 1, 1' are installed at places near the ridge lines and rarely damaged by the avalanche B, and measuring cords 3 are guided to a recording chamber 10 not to be affected by the snowfall on the slope A. Vibrations of many fine avalanches are measured by the seismometers 1, 1', the magnitudes of the vibrations and the change of the frequency are clarified, and the harmful avalanche B can be predicted immediately before its occurrence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to prediction of occurrence of damage avalanche, and is aimed at protecting human life or property living in or active in an avalanche danger area, or managing transportation means such as roads and railways. It has a very important meaning.

[0002]

2. Description of the Related Art A summary of the prior art is as follows. Avalanche warnings generally announced at each weather station
A general avalanche forecast is made based on various weather forecasts such as snowfall amount and snowfall forecast, and avalanche occurrence in a region with a certain extent such as "Gunma Prefecture Northern Mountainous Area" It calls attention to the possibility of avalanche occurrence. As a method of predicting avalanche occurrence on a specific slope, it has been attempted to predict avalanche occurrence from the topography, vegetation, and snow depth of the slope. It has been attempted to predict the occurrence of avalanche on a specific slope based on the slope of the avalanche slope and the relationship between daily snowfall depth and snow density. It has been attempted to predict the occurrence of avalanche in a certain area based on the change pattern of snowfall and the weather map patterns on the ground and in the upper layers.

[0003]

However, since the conventional prediction of avalanche occurrence is based on data with long measurement time intervals, it has only a possibility of ordering several hours even in a short term. It cannot be used as a means of predicting just before an occurrence.

From this point of view, in the present invention, attention is paid to the fact that small avalanches frequently occur before large avalanches, and the frequency of these small avalanches is measured in real time on the order of minutes, so that damage avalanches can be reduced. It is an object of the present invention to provide a method and a device that enable immediate prediction.

[0005]

[Means for Solving the Problems] In order to achieve such an object, the invention of claim 1 measures the vibrations of a large number of small avalanches with a high-sensitivity seismometer near the avalanche danger zone, and measures the activity level ( It is possible to predict the occurrence of an avalanche by clarifying the changes in the magnitude and frequency of vibrations.

Next, the invention of claim 2 is an apparatus for recording avalanche activity in real time on the order of minutes. This is the value r (Ac, t) obtained by dividing the time that the seismic avalanche vibration exceeds the reference value Ac at Δt time by Δt in the order of minutes.
It is configured to record in real time every t hours.

[0007]

The avalanche occurrence prediction method and monitoring apparatus according to the present invention has a function of monitoring the occurrence of a damaged avalanche by capturing in real time the activity of an avalanche vibration occurring on a specific slope of the avalanche risk zone.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The avalanche occurrence prediction method and monitoring device according to the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 shows the seismograph arrangement on the dangerous slope, Fig. 2 shows the seismograph installation, Fig. 3 shows the flow of risk judgment based on the measurement data, and Fig. 4 shows the avalanche activity r (Ac, t). On the other hand, Fig. 5 shows the relationship between the snowfall condition and temperature measured from January 17 to 18, 1991, and the avalanche activity, and Fig. 6 shows the snowfall condition and outside temperature measured on February 17, 1991. , Shows the relationship with avalanche activity. Figure 7 shows a small avalanche B1 on the slope of interest,
A model of the middle avalanche B2 and damaged avalanche B3 is shown in Figure 8 in Nou Town.
It shows the relationship between hourly avalanche frequency and snow depth observed from January 22 to 26, 1986.

In the present embodiment, for the slope A of the avalanche danger zone,
Set seismometers 1 and 1'as shown in Figure 1,
The avalanche management of the road 2 is performed by measuring the occurrence of the avalanche B near the slope in real time. Since the avalanche B that occurs falls from each ridge (broken line) toward the valley (A), the seismographs 1 and 1'are installed near the ridge and where there is no risk of avalanche damage. Guide the cord 3 to the recording room 10 being careful not to be affected by the snow on the sloped area. The ground noise at the seismograph installation point is 10 ^-5 kine
(Kine = cm / s).

FIG. 2 shows the installation status of the seismograph. 1a is a horizontal motion seismometer and 1b is a vertical motion seismometer, both with a natural period of 1
Second, sensitivity is 2.5v / Kine. 4 is a waterproof tank and 5 is a preamplifier, which serve to prevent hum. 6 is bedrock and 7 is concrete with a waterproof tank fixed.

FIG. 3 is a flow chart showing the risk of avalanche occurrence according to this embodiment. The avalanche risk is determined on the slope based on the avalanche activity and meteorological data obtained from the input from the seismograph. Do.

FIG. 4 is a diagram for defining the avalanche frequency from the record A (t) of the avalanche vibration. Avalanche tremors are sometimes put on continuously, but it is difficult to count the number, so
The avalanche activity r is calculated by dividing the time (bold line in the figure) where the vibration exceeds a certain reference value Ac during a certain time Δt by Δt.
(Ac, t). Sampling time sampling interval 0.02
If the time is set to seconds and Δt is set to 6 minutes, the relationship between the sampling number N and the number r included in the thick line in Δt is r = N / 18000.

FIG. 5 shows avalanche activity r (Ac, t) and snow depth from 17:00 on January 17, 1991 to 6:00 on the following day, and FIG. 6 shows from 00:00 to 23:00 on February 17, 1991. It shows a relationship between D (t) and temperature T (t). Here, the avalanche activity is Ac = 5 × 10
It is represented in three cases: ^-5 Kine, 10 ^-4 Kine and 2 × 10 ^-4 Kine. Sampling of avalanche activity in this area is 6
Minutes (10 times an hour), snow depth and temperature are sampled once an hour. This is an example where avalanche activity became active on January 17th to 18th and February 17th when the snow depth increased rapidly.

FIG. 7 shows a small avalanche (B1) and a medium-scale avalanche (B
2) and a model of a large-scale avalanche (B3), showing the tendency of frequent occurrence of micro-valanche on steep slopes when the depth of snow increases rapidly and temperature changes occur from the above examples. .. If there is more snowfall, a medium-sized avalanche with a longer mileage will occur, and if more snowfall continues, a large-scale avalanche will also pass through the gentle slope and reach the road. It seems that there is no large-scale or medium-scale avalanche under the condition that no small avalanche has occurred.

When each avalanche vibration measured as the avalanche activity contains a natural earthquake, it is necessary to automatically remove it to measure the avalanche activity. For this reason, it was possible to automatically select only earthquakes by separately installing a seismometer 1'at a position away from the slope, which is a dangerous area, and setting an AND circuit as a trigger.

[0016] Fig. 8 shows the relationship between the snow depth and the avalanche record frequency, which is shown in the document "Tsakusei Nari and Megumi Megumi: Avalanche seismicity observed by seismometers, earthquake 2, 41 47-58 1988". The hourly avalanche frequency is shown. This is a paper closely related to the present invention. This observation point was near a heavy avalanche at the fence entrance in January 1986, when it was a rare heavy snowfall. Nevertheless, the number of avalanches was not large and the number of avalanches was 3 at the maximum, so it was difficult to see the frequency on the order of minutes. Therefore, the observation system and the observation instrument (avalanche activity meter) of the present invention were devised.

[0017]

The avalanche occurrence prediction method according to the present invention monitors the occurrence of a dangerous avalanche in real time by recording minute-order recording of the frequency of occurrence of a minute avalanche captured by a high-sensitivity seismometer installed near a dangerous slope. Therefore, it will be highly reliable as an avalanche monitoring system on important roads and avalanche danger areas. The seismograph record of the avalanche was 0.02 seconds, which required sampling, but the avalanche activity meter was 6 minutes, which is appropriate, and the memory and power of the recording device are as small as those of meteorological instruments. Mu.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an arrangement state of seismographs.

FIG. 2 is a cross-sectional view showing an installed state of the seismograph.

FIG. 3 is a chart of risk determination using avalanche activity.

FIG. 4 is a graph showing how to determine the avalanche activity r (Ac, t).

FIG. 5 is a graph showing the relationship between avalanche activity, temperature, and snow depth measured from January 17 to 18, 1991.

FIG. 6 is a graph showing the relationship between avalanche activity, temperature, and snow depth measured on February 17, 1991.

FIG. 7 is a block diagram showing the scale of an avalanche and its occurrence state.

[FIG. 8] Tsukusei, Megumi Mizoue: A graph showing the relationship between avalanche frequency and snow depth of avalanche seismicity observed by seismograph, Earthquake 2, Volume 41, 47-58, 1988.

[Explanation of symbols]

 1 seismograph 2 road 3 measurement code 4 waterproof tank 5 preamplifier 6 bedrock 7 concrete 8 avalanche protection retaining wall 9 meteorological observation pole 10 recording device hut A valley of avalanche danger area B avalanche

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[Procedure amendment]

[Submission date] November 16, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Avalanche occurrence prediction method and monitoring device

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to prediction of occurrence of damage avalanche, and is aimed at protecting human life or property living in or active in an avalanche danger area, or managing transportation means such as roads and railways. It has a very important meaning.

[0002]

2. Description of the Related Art A summary of the prior art is as follows. Avalanche warnings generally announced at each weather station
A general avalanche forecast is made based on various weather forecasts such as snowfall amount and snowfall forecast, and avalanche occurrence in a region with a certain extent such as "Gunma Prefecture Northern Mountainous Area" It calls attention to the possibility of avalanche occurrence. As a method of predicting avalanche occurrence on a specific slope, it has been attempted to predict avalanche occurrence from the topography, vegetation, and snow depth of the slope. It has been attempted to predict the occurrence of avalanche on a specific slope based on the slope of the avalanche slope and the relationship between daily snowfall depth and snow density. It has been attempted to predict the occurrence of avalanche in a certain area based on the change pattern of snowfall and the weather map patterns on the ground and in the upper layers.

[0003]

However, since the conventional prediction of avalanche occurrence is based on data with long measurement time intervals, it has only a possibility of ordering several hours even in a short term. It cannot be used as a means of predicting just before an occurrence.

From this point of view, in the present invention, attention is paid to the fact that small avalanches frequently occur before large avalanches, and the frequency of these small avalanches is measured in real time on the order of minutes, so that damage avalanches can be reduced. It is an object of the present invention to provide a method and a device that enable immediate prediction.

[0005]

[Means for Solving the Problems] In order to achieve such an object, the invention of claim 1 measures the vibrations of a large number of small avalanches with a high-sensitivity seismometer near the avalanche danger zone, and measures the activity level ( It is possible to predict the occurrence of an avalanche by clarifying the changes in the magnitude and frequency of vibrations.

Next, the invention of claim 2 is an apparatus for recording avalanche activity in real time on the order of minutes. This is the value r (Ac, t) obtained by dividing the time that the seismic avalanche vibration exceeds the reference value Ac at Δt time by Δt in the order of minutes.
It is configured to record in real time every t hours.

[0007]

The avalanche occurrence prediction method and monitoring apparatus according to the present invention has a function of monitoring the occurrence of a damaged avalanche by capturing in real time the activity of an avalanche vibration occurring on a specific slope of the avalanche risk zone.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The avalanche occurrence prediction method and monitoring device according to the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 shows the seismograph arrangement on the dangerous slope, Fig. 2 shows the seismograph installation, Fig. 3 shows the flow of risk judgment based on the measurement data, and Fig. 4 shows the avalanche activity r (Ac, t). On the other hand, Fig. 5 shows the relationship between the snowfall condition and temperature measured from January 17 to 18, 1991, and the avalanche activity, and Fig. 6 shows the snowfall condition and outside temperature measured on February 17, 1991. , Shows the relationship with avalanche activity. Figure 7 shows a small avalanche B1 on the slope of interest,
A model of the middle avalanche B2 and damaged avalanche B3 is shown in Figure 8 in Nou Town.
It shows the relationship between hourly avalanche frequency and snow depth observed from January 22 to 26, 1986.

In the present embodiment, for the slope A of the avalanche danger zone,
Set seismometers 1 and 1'as shown in Figure 1,
The avalanche management of the road 2 is performed by measuring the occurrence of the avalanche B near the slope in real time. Since the avalanche B that occurs falls from each ridge (broken line) toward the valley (A), the seismographs 1 and 1'are installed near the ridge and where there is no risk of avalanche damage. Guide the cord 3 to the recording room 10 being careful not to be affected by the snow on the sloped area. The ground noise at the seismograph installation point is 10 ^-5 kine
(Kine = cm / s).

FIG. 2 shows the installation status of the seismograph. 1a is a horizontal motion seismometer and 1b is a vertical motion seismometer, both with a natural period of 1
Second, sensitivity is 2.5v / Kine. 4 is a waterproof tank and 5 is a preamplifier, which serve to prevent hum. 6 is bedrock and 7 is concrete with a waterproof tank fixed.

FIG. 3 is a flow chart showing the risk of avalanche occurrence according to this embodiment. The avalanche risk is determined on the slope based on the avalanche activity and meteorological data obtained from the input from the seismograph. Do.

FIG. 4 is a diagram for defining the avalanche frequency from the record A (t) of the avalanche vibration. Since avalanche tremors are often continuous, it is difficult to count the number, so
The avalanche activity r is calculated by dividing the time (bold line in the figure) where the vibration exceeds a certain reference value Ac during a certain time Δt by Δt.
(Ac, t). Sampling time sampling interval 0.02
If the time is set to seconds and Δt is set to 6 minutes, the relationship between the sampling number N and the number r included in the thick line in Δt is r = N / 18000.

FIG. 5 shows avalanche activity r (Ac, t) and snow depth from 17:00 on January 17, 1991 to 6:00 on the following day, and FIG. 6 shows from 00:00 to 23:00 on February 17, 1991. It shows a relationship between D (t) and temperature T (t). Here, the avalanche activity is Ac = 5 × 10
It is represented in three cases: ^-5 Kine, 10 ^-4 Kine and 2 × 10 ^-4 Kine. Sampling of avalanche activity in this area is 6
Minutes (10 times an hour), snow depth and temperature are sampled once an hour. This is an example of active avalanche activity when the snow depth increased sharply from January 17th to 18th and February 17th.

FIG. 7 shows a small avalanche (B1) and a medium-scale avalanche (B
2) and a model of a large-scale avalanche (B3), showing the tendency of frequent occurrence of micro-valanche on steep slopes when the depth of snow increases rapidly and temperature changes occur from the above examples. .. If there is more snowfall, a medium-sized avalanche with a longer mileage will occur, and if more snowfall continues, a large-scale avalanche will also pass through the gentle slope and reach the road. It seems that there is no large-scale or medium-scale avalanche under the condition that no small avalanche has occurred.

When each avalanche vibration measured as the avalanche activity contains a natural earthquake, it is necessary to automatically remove it to measure the avalanche activity. For this reason, it was possible to automatically select only earthquakes by separately installing a seismometer 1'at a position away from the slope, which is a dangerous area, and setting an AND circuit as a trigger.

[0016] Fig. 8 shows the relationship between the snow depth and the avalanche record frequency, which is shown in the document "Tsakusei Nari and Megumi Megumi: Avalanche seismicity observed by seismometers, earthquake 2, 41 47-58 1988". The hourly avalanche frequency is shown. This is a paper closely related to the present invention. This observation point was near a heavy avalanche at the fence entrance in January 1986, when it was a rare heavy snowfall. Nevertheless, the number of avalanches was not large and the number of avalanches was 3 at the maximum, so it was difficult to see the frequency on the order of minutes. Therefore, the observation system and the observation instrument (avalanche activity meter) of the present invention were devised.

[0017]

The avalanche occurrence prediction method according to the present invention monitors the occurrence of a dangerous avalanche in real time by recording minute-order recording of the frequency of occurrence of a minute avalanche captured by a high-sensitivity seismometer installed near a dangerous slope. Therefore, it will be highly reliable as an avalanche monitoring system on important roads and avalanche danger areas. The seismograph record of the avalanche was 0.02 seconds, which required sampling, but the avalanche activity meter was 6 minutes, which is appropriate, and the memory and power of the recording device are as small as those of meteorological instruments. Mu.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an arrangement state of seismographs.

FIG. 2 is a cross-sectional view showing an installed state of the seismograph.

FIG. 3 is a chart of risk determination using avalanche activity.

FIG. 4 is a block diagram showing the basis of calculation of avalanche activity r (Ac, t).

FIG. 5 is a graph showing the relationship between avalanche activity, snow depth and temperature measured from January 17 to 18, 1991.

FIG. 6 is a graph showing the relationship between avalanche activity, snow depth and temperature measured on February 17, 1991.

FIG. 7 is a block diagram showing the scale of an avalanche and its occurrence state.

[Fig. 8] Tsukusei, Megumi Mizo: A graph showing the relationship between avalanche frequency and snow depth in avalanche seismicity observed by seismograph, Earthquake 2, Volume 41, 47-58, 1988.

[Explanation of symbols] 1 seismograph 2 road 3 measurement code 4 waterproof tank 5 preamplifier 6 bedrock 7 concrete 8 avalanche protection retaining wall 9 meteorological observation pole 10 recorder's hut A valley of avalanche danger area B avalanche

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (2)

[Claims] 1. A method for predicting an avalanche occurrence, which comprises predicting the occurrence of a damaged avalanche from changes in the activity by measuring ground vibrations due to a large number of avalanches including small avalanches and measuring the changes in activity. 2. The avalanche activity is calculated by dividing the time when the seismic avalanche motion exceeds the reference value Ac at Δt time by Δt, and the avalanche activity is calculated in real time in minutes order Δt time intervals. A device for monitoring avalanche activity, which is recorded in.