JP3701859B2 - River observation system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a river observation system, and more particularly to a river observation system for observing sediment deposited in a river in preparation for disasters such as debris flow caused by heavy rain and river flooding.
[0002]
[Prior art]
It has been pointed out that the sediment deposited in rivers has a great influence on the occurrence of disasters depending on the amount and location of the sediment, so it is necessary to observe the amount of sediment change, the amount of sediment, and the location of the sediment. It is important to observe the movement of sediment when large water or debris flows occur in designing and constructing river structures downstream.
Conventionally, when observing sediments of such rivers, a staff member went to the site to measure the size of the riverbank and observe the amount of sediment deposited.
[0003]
[Problems to be solved by the invention]
However, the conventional method of observing on-site by staff is not easy to observe because of the heavy work load, and there is a risk of an accident when the water level increases, so the weather is stable. However, there is a problem that the observation data cannot be obtained in real time, and the observation data cannot be obtained in real time. It is possible to install a dredging downstream of the weir and estimate the sediment flow rate from the amount of gravel deposited on the dredging, but this method changed how much sediment was deposited and how much. I can't observe it.
The present invention is for solving such problems, and it is an object of the present invention to provide a river observation system that can observe sediment deposited in rivers, can be observed when necessary, and obtain observation data in real time. Yes.
[0004]
[Means for Solving the Problems]
In order to achieve such an object, a river observation system according to the present invention includes a water level measuring unit that measures the water level of a river, a sediment imaging unit that captures sediment deposited in the river from a position above the river, and the sediment imaging. An image processing means for dividing the sediment and water from the image data captured by the means and calculating the sediment area, and an estimation means for estimating the sediment change amount of the sediment are provided. By the estimation means, the water level measuring means and the image processing are provided. The amount of sediment accumulation change is estimated based on the sediment area for each of a plurality of different water levels obtained by the means.
[0005]
The estimating means may estimate the amount of sediment deposition change between these two water levels by obtaining the product of the difference between two different water levels and the difference in the sediment area at each water level. The amount of sediment accumulation between these water levels may be estimated by adding the amount of sediment accumulation change to the product of the difference in water level and the area of sediment that can exist at both water levels.
As the timing for starting actual processing, the water level measurement means always observes the water level of the river, and according to the rapid increase of the water level, the earth and sand imaging means, the image processing means calculates and estimates the sediment area. You may make it start estimation of the sediment accumulation change amount by a means.
As the water level measurement means, the marker and water surface standing on the river may be imaged by the water level imaging means, and the water level may be calculated by the water level calculation means from the image data obtained by the water level imaging means.
[0006]
In addition, a communication unit that communicates with a remote management center connected via a communication line is provided, and in response to an observation start instruction from the management center received by the communication unit, imaging by the earth and sand imaging unit, an image The calculation of the sediment area by the processing means and the estimation of the sediment accumulation change amount by the estimation means may be started.
As for the observation data obtained by the observation device, the observation data including at least the estimation result estimated by the estimation means may be transmitted by the communication means to the remote management center connected via the communication line. .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a river observation system according to the first embodiment of the present invention, and FIG. 2 is an arrangement example of the river observation system of FIG.
This river observation system includes ultrasonic water level meters 4 and 5 that measure the water level of the river 1, a soil and sand imaging camera 6 that images the sediment deposited in the river 1 from above the river 1, and the earth and sand imaging camera 6. An observation device 10 is provided that calculates the sediment area by dividing the sediment and water from the captured image data, and estimates the sediment change amount and the sediment amount based on the sediment area obtained for each of a plurality of different water levels. ing.
[0008]
As shown in FIG. 2, the ultrasonic water level gauges (water level measuring means) 4 and 5 are supported by poles 4 </ b> A and 5 </ b> A standing on the bank 2 of the river 1 so as to protrude above the river 1. The ultrasonic water level meters 4 and 5 send ultrasonic waves to the water surface of the river 1, calculate the distance from the water surface based on the delay time of the reflected waves, and measure the water level. Although one ultrasonic water level meter may be provided, the water level at each position can be accurately measured by providing a plurality of ultrasonic water level meters.
The earth and sand imaging camera 6 is supported at a position above the river 1 by poles 2A and 3A erected on the shore 2 and the opposite shore 3 of the river 1 and wires (or arms) 6A installed on these poles 2A and 3A. Has been. This earth and sand imaging camera 6 is suspended from the wire 6A and captures a planar image of the river 1.
[0009]
The observation device 10 is installed on the shore 2 side, takes in water level data from the ultrasonic water level gauges 4 and 5 and image data taken by the earth and sand imaging camera 6, and deposits of sediment deposited in the river 1. Observe the change.
The observation device 10 is picked up by a water level take-in unit 11 for taking in water level data from the ultrasonic water level gauges 4 and 5, an image take-in unit 12 for taking in image data taken by the earth and sand imaging camera 6, and the earth and sand imaging camera 6. The image processing unit 13 that calculates the sediment area by dividing the sediment and water from the obtained image data, the storage unit 14 that accumulates the captured water level data and image data, the storage unit 15 that stores data necessary for various processes, and the time Communicating with a timekeeping unit 16 for measuring, a display unit 17 for displaying the captured water level data and image data, and the estimated amount of sediment accumulation, and a management center such as a river observation center in a remote location connected via a communication line 18A A communication unit 18 is provided.
[0010]
The observation device 10 is provided with a control unit 19 that controls each unit of the observation device 10. The control unit 19 is provided with an estimation unit 19A that estimates the sediment accumulation amount based on the sediment area obtained for each of a plurality of different water levels as a function processing unit. The control unit 19 is configured by an arithmetic processing unit (CPU) or the like, and provides a function as the estimation unit 19A by reading and executing a program stored in advance in the storage unit 14 as necessary. .
The image processing unit 13 may be a digital signal processor (DSP) or may be realized by executing a program as a function processing unit of the control unit 19.
[0011]
Next, the operation of the river observation system will be described with reference to FIG. FIG. 3 is a flowchart showing the sediment observation process, where (a) is a data acquisition process and (b) is a sediment accumulation amount estimation process.
The control unit 19 of the observation apparatus 10 always executes a data capture process as shown in FIG. First, the water level data from the ultrasonic water level gauges 4 and 5 is taken in via the water level taking-in part 11, and it checks whether there is any abnormality in the water level of the river 1.
[0012]
Here, when the water level is increasing rapidly (step 100: YES), the image data from the earth and sand imaging camera 6 is captured via the image capturing unit 12 at a predetermined time interval timed by the time measuring unit 16, and the water level is also measured. Water level data at that time is taken in from the ultrasonic water level gauges 4 and 5 via the take-in part 11 (step 101) and accumulated in the accumulation part 14 (step 102).
As a determination of whether the water level has increased rapidly, it may be determined that the water level has increased rapidly when the water level exceeds a predetermined threshold value preset in the storage unit 15, and the amount of change in the water level per unit time may be determined. It may be determined that the water level has suddenly increased when a predetermined threshold value is exceeded. In consideration of the undulation of the water surface, the water level measured a plurality of times may be statistically processed, for example, averaged data may be accumulated as water level data. Thereafter, it is confirmed that the water level has dropped to the normal water level (step 103: YES), and the series of data fetching processes is terminated.
[0013]
The control unit 10 executes a sediment accumulation amount estimation process as shown in FIG. 3B in parallel with such a data fetch process. Below, the case where the accumulation amount of earth and sand is estimated using the image data in two different water levels Ha and Hb is demonstrated as an example. First, image data at two different water levels Ha and Hb are read from the storage unit 14 (step 110). Then, for each of these image data, the image processing unit 13 performs a process of partitioning water and earth and sand (step 111), and calculates the area Sa of the accumulated earth and sand (step 112). For example, water and earth and sand can be partitioned using a known image processing technique such as differential processing based on the difference in pixel density of image data. The area of the earth and sand may be set in advance by the ratio of the area on the image data to the actual area.
[0014]
In this manner, the image processing unit 13 obtains the earth and sand area Sa at the water level Ha as shown in FIG. This processing is also executed for image data at a water level Hb higher than the water level Ha, and as shown in FIG. 5, the area Sb of earth and sand at the water level Hb is obtained.
The estimation means 19A of the control unit 19 estimates the amount of sediment deposited using the obtained sediment areas Sa and Sb at two different water levels Ha and Hb (step 113).
[0015]
FIG. 6 shows a method for estimating the amount of sediment. When the amount of sediment increases while the water level of the river 1 rises from the water level Ha to the water level Hb (Ha <Hb), the area of the earth and sand increases from Sa to Sb (Sa <Sb). Assuming that the amount of sediment change of the sediment is ΔV, the area Sa ′ at the water level Hb is not known, but since at least Sb of sediment is deposited by the height Hb−Ha, the deposition variation amount ΔV is Sa and It can be estimated by the product of the difference in Sb area and the difference in water level.
ΔV = (Hb−Ha) × (Sb−Sa)
[0016]
Furthermore, since the sediment of Sa is also accumulated at least by the height Hb-Ha, it can be estimated by the product of Sb and the height Hb-Ha, and if ΔV is added to this, the sediment deposition amount V at the water level Hb Can be estimated.
V = (Hb−Ha) × Sa + ΔV
Image data including the estimated deposition change amount ΔV, sediment deposition amount V, water level data, observation date and time, and sediment deposition position may be displayed on the display unit 17 or remotely via the communication unit 18. It may be transmitted to the local river observation center.
[0017]
As described above, the ultrasonic water level meters 4 and 5 that measure the water level of the river 1 and the earth and sand imaging camera 6 that images the sediment deposited on the river 1 from the upper position of the river are provided. Then, the sediment and water are divided from the image data obtained for each different water level, the sediment area is calculated, and the estimation means 19A of the control unit 19 calculates the sediment accumulation change ΔV based on the sediment area for each water level, or the sediment. Since the amount of sedimentation V is estimated, it is possible to observe where and how much sediment has accumulated in the river without actually measuring it, as in the past. It can be observed easily without any problems.
[0018]
Moreover, since the water level of the river 1 is always observed and the image data is captured in response to the rapid increase of the water level, the earth and sand can be automatically observed when warning is required. This eliminates the need for the attendant to constantly monitor the river situation. This is also true when the observation of earth and sand is stopped when the water level of the river 1 drops to the normal water level.
The operation of the control unit 19 has been described as an example in which the data acquisition process and the sediment accumulation amount estimation process of FIG. 3 are executed in parallel. For example, each time two different image data are captured, the sediment accumulation amount So that the data acquisition process and the sediment accumulation amount estimation process may be executed in series.
[0019]
In the estimation method of FIG. 6 described above, the accumulation change amount ΔV and the sediment accumulation amount V are estimated on the assumption that the sediment is deposited in a columnar shape, and errors are included, but the water levels Ha, Hb By reducing the difference, the error can be reduced.
In the above description, the case where the water level of the river 1 rises and the amount of sediment accumulation changes is described as an example, but the present invention can also be applied to the case where the water level falls. In this case, since the sediment accumulation amount does not change much, the sediment accumulation amount V can be estimated with relatively high accuracy.
[0020]
If the amount of sediment deposited does not change very much with changes in the water level, such as when the water level drops, the amount of sediment that includes the sloped portion of the accumulated sediment is assumed assuming that the shape of the sediment area changes in a similar manner as the water level increases. Can be estimated.
For example, in FIG. 6, it is assumed that the water level has decreased from Hb to Ha and the earth and sand area has increased from Sb to Sa ′. At this time, Sa ′ is gradually reduced to Sb on the image data to generate a plurality of reduced images, and the product of the earth and sand area calculated for each of the images and the unit change amount of the water level divided by the number of the reduced images is added up. To do. As a result, the sediment accumulation amount can be integrated in units of reduced images, and the accumulation amount including the inclined portion of the accumulated sediment can be accurately estimated. Instead of reducing Sa ′, Sb may be enlarged.
[0021]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a block diagram showing a river observation system according to the second embodiment, and FIG. 8 is an arrangement example showing the river observation system of FIG. In the figure, the same or equivalent parts as those described above (FIGS. 1 and 2) are denoted by the same reference numerals.
In this embodiment, as means for measuring the water level of the river 1, instead of the ultrasonic water level gauges 4 and 5, a plurality of markers 8 standing in the river 1 and the relationship between these markers 8 and the water level are expressed. A water level imaging camera (water level imaging means) 7 for imaging and a water level calculation means 19B for calculating the water level from image data captured by the water level imaging camera 7 are provided. The water level calculation unit 19B is a function processing unit of the control unit 19 that functions by executing a program in the same manner as the estimation unit 19A.
[0022]
The water level imaging camera 7 is installed on the shore 2 side of the river 1 and images a field angle including a marker in the river 1 and the water level at a slight angle from the horizontal. The marker 8 is composed of a column member in which two colors whose pixel shades are clearly expressed on the image data are applied in a striped pattern.
When the water level is actually measured, image data is taken from the water level imaging camera 7 via the image taking unit 12 of the observation apparatus 10, the marker 8 is pattern-recognized by the image processing unit 13, and the water level of the control unit 19 is recognized. The calculation unit 19B calculates the water level from the lower end position of the marker 8 and the reference water level. Hereinafter, the estimation process of the accumulation change amount ΔV and the sediment accumulation amount V is the same as described above, and a description thereof will be omitted here.
[0023]
FIG. 9 shows an example of image data captured by a water level imaging camera. The water level 9A of the sediment 9 deposited in the river 1 is substantially the same as the water level 8A at the marker 8 located in the vicinity thereof, and the water level 9A can be calculated by setting a reference water level for each marker 8 in advance. . The marker 8 is not limited to the pillar member, but may be a striped pattern applied to the revetment block or bridge girder on the opposite bank 3, and a striped pattern is applied to a large rock existing in the river 1 instead of the revetment block. You may have done.
[0024]
Thus, since the water level of the river 1 is calculated by the marker 8 and the water level imaging camera 7, the water level can be calculated without requiring expensive equipment such as an ultrasonic water level meter, the system can be realized at low cost, and debris flow Suitable for observation points where damage is often caused by In this embodiment, the case where one water level imaging camera is used has been described as an example. However, the number of water level imaging cameras is not limited, and observation in a river with a wide river width or a camera with a narrow angle of view is possible. When is adopted, a plurality of water level imaging cameras may be provided, and the water level can be calculated in the same manner as described above.
[0025]
In the above, the case where the water level suddenly increases is described as the timing for starting the river observation process (see FIG. 3), but the observation start instruction from the remote management center connected via the communication line 18A is given. In response to the observation start instruction received by the communication unit 18, river observation processing in the control unit 19, that is, imaging with the earth and sand imaging camera 6, calculation of the earth and sand area in the image processing unit 13, and estimation means 19A The estimation of the sediment accumulation change amount may be started. As a result, river observation can be performed from a remote management center at an arbitrary timing as necessary, and more detailed and effective river management work can be realized.
[0026]
In addition, the estimation results estimated by the estimating means 19A based on the river observation as described above, that is, the sediment accumulation change amount and the sediment accumulation amount are connected as observation data by the communication unit 18 via the communication line 18A. It is transmitted to a remote management center (not shown). As observation data to be transmitted, in addition to the estimation results, image data obtained by imaging a river with the earth and sand imaging camera 6 and the water level imaging camera 7, and image data of the ultrasonic water level gauges 4 and 5 and the water level imaging camera 7 The water level obtained from may be transmitted. This enables the remote management center to properly grasp the local river situation in real time.
[0027]
【The invention's effect】
As described above, the present invention is provided with water level measuring means for measuring the water level of a river and earth and sand imaging means for imaging the sediment deposited on the river from above the river, and image data captured by the earth and sand imaging means. The sediment area is calculated by dividing the sediment and water from the ground, and the sediment accumulation change amount is estimated based on the sediment area for each of the different water levels obtained by the water level measurement means and the image processing means. In this way, it is possible to observe how much sediment has accumulated in the river without actual measurement by the staff, and it is possible to observe easily and in real time without violating the danger of an accident even when the river is flooded.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a river observation system according to a first embodiment of the present invention.
FIG. 2 is an arrangement example of the river observation system of FIG.
FIG. 3 is a flowchart showing sediment observation processing.
FIG. 4 is an example of image data (water level Ha) when calculating the sediment area.
FIG. 5 is an example of image data (water level Hb) when calculating the sediment area.
FIG. 6 is an explanatory diagram showing an example of sediment observation processing.
FIG. 7 is a block diagram showing a river observation system according to a second embodiment of the present invention.
8 is an arrangement example of the river observation system of FIG.
FIG. 9 is an example of image data at the time of water level calculation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... River, 2 ... Bank, 3 ... Opposite bank, 4, 5 ... Ultrasonic water level meter, 6 ... Sediment imaging camera, 7 ... Water level imaging camera, 8 ... Marker, 9 ... Sediment, 10 ... Observation device, 11 ... Water level taking Capture unit, 12 ... Image capture unit, 13 ... Image processing unit, 14 ... Accumulation unit, 15 ... Storage unit, 16 ... Timing unit, 17 ... Display unit, 18 ... Communication unit, 19 ... Control unit, 19A ... Estimation means , 19B ... Water level calculation means.

Claims (7)

A water level measuring means for measuring the water level of the river;
Sediment imaging means for imaging sediment deposited in the river from above the river,
Image processing means for dividing the earth and sand from the image data imaged by the earth and sand imaging means and calculating the earth and sand area;
A river observation system comprising: estimation means for estimating a sediment accumulation change amount based on soil area for each of a plurality of different water levels obtained by the water level measurement means and the image processing means. In the river observation system according to claim 1,
The estimation means estimates a sediment accumulation change amount between these water levels by obtaining a product of a difference between two different water levels and a difference in sediment area at each water level. In the river observation system according to claim 2,
The estimation means estimates the amount of sediment deposition between these two water levels by adding the amount of sediment deposition change to the product of the difference between the two different water levels and the area of sediment that can exist at both water levels. A river observation system characterized by In the river observation system according to claim 1,
The water level measurement means always observes the water level of the river, and according to the rapid increase of the water level, the earth and sand image pickup means picks up the image, the image processing means calculates the sediment area, and the estimation means changes the sediment accumulation. A river observation system further comprising control means for starting estimation of the quantity. In the river observation system according to claim 1,
The water level measurement means comprises a water level imaging means for imaging a marker and a water surface standing on a river, and a water level calculation means for calculating a water level from image data obtained by the water level imaging means. system. In the river observation system according to claim 1,
A communication means for communicating with a remote management center connected via a communication line;
In response to an observation start instruction from the management center received by the communication unit, imaging by the sediment imaging unit, calculation of sediment area by the image processing unit, and estimation of sediment accumulation change amount by the estimation unit A river observation system further comprising a control means for starting the operation. In the river observation system according to claim 1,
A river observation system further comprising communication means for transmitting observation data including at least the estimation result estimated by the estimation means to a remote management center connected via a communication line.

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