JP4342546B2 - Turbidity monitoring method and turbidity monitoring device in water - Google Patents

Description

  The present invention relates to a turbidity monitoring method and a turbidity monitoring apparatus in water.

  If the turbidity generated by marine construction flows out of the construction sea area, various problems occur in the surrounding environment, which may affect the construction process. Therefore, it is necessary to measure the turbidity generated during construction. Conventionally, turbidity is mainly measured by (1) a method using a turbidimeter (see, for example, Patent Document 1) and (2) a method for measuring the turbidity of a collected sample (for example, Patent Document 2). Browse) is used.

JP 2004-354069 A JP-A-6-027014

  However, both the methods (1) and (2) do not measure the turbidity distribution in the vertical or horizontal direction, but measure the turbidity at one point in the water, so that it is distributed three-dimensionally in the construction sea area. It is impossible to measure turbidity.

  The present invention has been made in view of such problems, and the object of the present invention is to measure the three-dimensional turbidity distribution and the transport amount of turbid particles in a short time, and to investigate the turbidity generated in construction in detail. It is an object to provide a turbidity monitoring method and a turbidity monitoring apparatus that can be managed.

In order to achieve the above-mentioned object, the first invention of the present application is a fine particle that is emitted from the ultrasonic Doppler velocimeter and floats in each vertical layer in water while moving the ultrasonic Doppler velocimeter in the horizontal direction. The reflection intensity of the ultrasonic wave reflected by the laser and the horizontal position information of the ultrasonic Doppler velocimeter are acquired, and the three-dimensional distribution of the fine particles is obtained from the reflection intensity at each water depth and the horizontal position information. A method for monitoring turbidity in water,
By displaying the horizontal trajectory of the ultrasonic Doppler velocimeter and the length and direction of the straight line branched from the trajectory, the flow velocity and flow direction for each water depth are displayed.
Using the correlation between the suspended particle concentration of the fine particles determined in the water sampling analysis prepared in advance and the reflected intensity by the ultrasonic Doppler velocimeter measured at the same position as the water sampling analysis, the reflection intensity is determined as the suspended particle concentration. Converted to
The horizontal trajectory of the ultrasonic Doppler velocimeter, the flow velocity for each water depth measured by the ultrasonic Doppler velocimeter, or the distribution of flow velocity and flow direction calculated in consideration of tides, winds and river inflows, and for each water depth The amount of transport of the fine particles is calculated using the reflection intensity, the three-dimensional distribution of the fine particles is estimated , and the predicted distribution of turbidity at an arbitrary water depth, range and time is displayed . Turbidity monitoring method.

  The ultrasonic Doppler velocimeter (ADCP) is installed on an observation ship that can move on water. The ultrasonic Doppler velocimeter emits multiple ultrasonic beams into the water, reflects them with fine particles in each layer in the vertical direction, measures the flow velocity at each depth of the water, and simultaneously acquires the reflected ultrasonic reflection intensity at each depth. . The fine particles are, for example, suspended earth and sand. The ultrasonic frequency of the ultrasonic Doppler velocimeter is changed according to the water depth.

  Furthermore, equipment such as GPS (Global Positioning System) is installed in the observation ship in order to acquire position information. The position information in the horizontal direction observed with GPS and the reflection intensity of the reflected waves from the fine particles in each vertical layer observed with the ultrasonic Doppler velocimeter are sent to a computer or the like to estimate the three-dimensional distribution of the fine particles. . Further, the transport amount of the fine particles in water is calculated from the flow velocity measured by the ultrasonic Doppler velocimeter and the estimated three-dimensional distribution of fine particles.

In the first invention, while moving the ultrasonic Doppler velocimeter, the reflection intensity of the ultrasonic wave emitted from the ultrasonic Doppler velocimeter and reflected by the fine particles in the water is acquired. Also, the horizontal position information of the ultrasonic Doppler velocimeter is acquired. Then, the three-dimensional distribution of fine particles in water is estimated from the acquired reflection intensity and horizontal position information. Furthermore, the transport amount of the fine particles can be calculated using the flow rate measured by the ultrasonic Doppler velocimeter.

The second invention, an ultrasonic Doppler flow rate meter, said moving means for moving the ultrasonic Doppler velocimeter horizontally, means for obtaining a horizontal position information of the ultrasonic Doppler flow rate meter, the Obtained by sampling analysis prepared in advance from the reflection intensity at each depth of the ultrasonic wave reflected from the fine particles floating in each vertical layer in the water and emitted from the ultrasonic Doppler velocimeter and the position information in the horizontal direction. by using the correlation between the reflection intensity by the ultrasonic Doppler velocimeter of airborne particle concentration and was measured at the same position as the water sampling analysis of the fine particles, and means for converting the reflection intensity into the floating particle concentration, the ultrasonic and horizontal trajectory of the Doppler velocity meter, a first display means for displaying the flow rate and flow direction of each depth by the length and direction of the branched linear from the trajectory, the water of the ultrasonic Doppler velocimeter Above using the locus, the flow rate of each water depth measured by the ultrasonic Doppler flow rate meter, or, tidal, wind, and distribution of the flow rate is calculated by considering the river inflow and flow direction, and the reflection intensity for each depth A means for calculating a transport amount of the fine particles and estimating a three-dimensional distribution of the fine particles ; and a second display means for displaying a predicted distribution of turbidity at an arbitrary water depth, range and time. It is a turbidity monitoring device in water.

  For example, an observation ship is used as the moving means, and an ultrasonic Doppler velocimeter is installed on the side of the observation ship. In addition, a GPS or the like is installed on the observation ship as means for acquiring horizontal position information of the ultrasonic Doppler velocimeter. Furthermore, the three-dimensional distribution of the fine particles is estimated from the reflected intensity of the ultrasonic waves reflected by the fine particles floating in each layer in the water and the position information of the ultrasonic Doppler velocimeter, and the flow velocity measured by the ultrasonic Doppler velocimeter A computer or the like is used as means for calculating the transport amount of fine particles from the estimated fine particle distribution.

  In the second invention, the position information of the ultrasonic Doppler velocimeter is acquired by GPS or the like while moving the observation ship or the like. The ultrasonic Doppler velocimeter emits a plurality of ultrasonic beams and reflects them with the fine particles in the water to measure the flow velocity, and at the same time acquires the reflection intensity of the reflected wave reflected by the fine particles in the water. Then, the three-dimensional distribution of the fine particles is estimated from the position information of the ultrasonic Doppler velocimeter and the reflection intensity of the ultrasonic waves using a computer or the like. Further, the transport amount of the fine particles is calculated using the flow velocity measured by the ultrasonic Doppler velocimeter.

  According to the present invention, it is possible to provide an underwater turbidity monitoring method and a turbidity monitoring apparatus capable of measuring the three-dimensional turbidity distribution and the amount of turbid particles transported in a short time and managing the turbidity generated in construction in detail. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of the turbidity monitoring apparatus 1. The turbidity monitoring apparatus 1 includes an observation ship 3, an ADCP (ultrasonic Doppler velocimeter) 5, a computer 19, a GPS 20, and the like. The ADCP 5 is installed, for example, on the side of the anchor 7 of the observation ship 3. The computer 19 and the GPS 20 are installed on the observation ship 3, for example.

  The observation ship 3 moves the ADCP 5 to an arbitrary position. As shown in FIG. 1, a plurality of ultrasonic beams 11 are emitted from the ADCP 5 toward the water bottom 7. The ultrasonic beam 11 emitted in the direction indicated by the arrow A is reflected in the direction of the arrow B by the fine particles 15 floating at the position of the measurement cell 13. The ADCP 5 measures the flow velocity 21 immediately below the ADCP 5 on the horizontal plane including the measurement cell 13 by the Doppler shift of the reflected wave 14.

  Simultaneously with measuring the flow velocity 21, the ADCP 5 acquires the reflection intensity of the reflected wave 14 in the direction of arrow B of the ultrasonic beam 11. In FIG. 1, only the measurement cell 13 of one layer in the vertical direction is illustrated, but the ultrasonic beam 11 emitted from the ADCP 5 is reflected by the fine particles 15 floating in the measurement cell 13 of each layer in the vertical direction. The flow velocity 21 for each layer in the vertical direction and the reflection intensity of the reflected wave 14 are acquired simultaneously. The flow velocity 21 and the reflection intensity of the reflected wave 14 for each water depth measured using the ADCP 5 are input to the computer 19.

  The GPS 20 installed in the observation ship 3 acquires the position information of ADCP5. In the turbidity monitoring device 1, the observation speed of the flow velocity 21 and the reflection intensity of the reflected wave 14 are measured by ADCP 5 while expanding the navigation range of the observation ship 3 for each elapsed time centering on the turbidity source so that the entire turbidity distribution can be covered. The position of ADCP5 is observed by GPS20. The position information of ADCP 5 acquired using the GPS 20 is input to the computer 19 and displayed on the display screen.

  FIG. 2 is a diagram showing the locus 25 of the observation ship 3 observed by the GPS 20, that is, the position information of the ADCP 5. In FIG. 2, for example, the horizontal axis indicates the position in the east-west direction, and the vertical axis indicates the position in the north-south direction. A plurality of straight lines 31 branched from the curve shown in the trajectory 25 of the observation ship 3 indicate the flow velocity 21 and the flow direction in a predetermined layer of the underwater 9 measured by ADCP 5 at the branching position.

  In the example shown in FIG. 2, turbidity 29a such as earth and sand that has been introduced into the water from the introduction point 27 is carried to the positions indicated by turbidity 29b, 29c, 29d, and 29e in the southwest direction as time passes. The trajectory 25 of the observation ship 3 indicates that the observation ship 3 at sea started to move from the standby position 23 in the direction indicated by the arrow C, and then passed while reciprocating over the turbidity 29a, 29b, 29c, 29d, 29e. Show.

  FIG. 3 is a diagram showing the ultrasonic reflection intensity at the position and time indicated on the trajectory 25 of the observation ship 3. The horizontal axis represents time, and the vertical axis represents water depth. The time shown on the horizontal axis corresponds to the locus 25 of the observation ship 3 shown in FIG. 2, that is, the measurement position of the reflection intensity at the ADCP 5, and can be converted into a distance while the observation ship 3 is traveling. For example, the observation ship 3 is on standby at the standby position 23 shown in FIG. In addition, during the time periods indicated by 35a, 35b, 35c, 35d, and 35e during traveling in FIG. 3, the observation ship 3 is traveling across the sea where the turbidity 29a, 29b, 29c, 29d, and 29e illustrated in FIG. is there.

  The legend 36 shows the correspondence between the ultrasonic reflection intensity and the display pattern in FIG. The computer 19 that has received the ultrasonic reflection intensity acquired by the ADCP 5 and the position information acquired by the GPS 20 calculates the reflection intensity of the reflected wave 14 of the underwater 9 at the position and time indicated by the trajectory 25 of the observation ship 3. A display pattern as shown in the legend 36 is used to display on the display screen.

  FIG. 4 shows the S.D. S. It is a figure which shows the relationship between (floating particle) density | concentration and ADCP signal reflection intensity. The vertical axis is the S.D. S. The (floating particle) concentration is shown on the horizontal axis, and the ADCP signal reflection intensity observed with ADCP5. Point 37 indicates the S.D. of the sample collected at each position of the surface layer, the middle layer, and the lower layer. S. The density and the ultrasonic reflection intensity at the same position are shown.

  A straight line 39 is a correlation straight line of data indicated by the point 37. In any of the surface layer, the middle layer, and the lower layer, the S.P. S. A similar correlation is found between the density and the reflection intensity of the reflected wave 14 of the ultrasonic beam 11 at the same position. The ultrasonic reflection intensity from the fine particles 15 is considered to be affected by the particle diameter and the distance (density) between the particles. From the relationship of the straight line 39, the ultrasonic reflection intensity (FIG. 3) observed by ADCP5 using the computer 19 or the like. ) S. An estimated value converted to a concentration is obtained.

  FIG. 5 is a diagram showing an example of the distribution of flow velocity and flow direction in the vicinity of the airport island 41 and the silt fence 43 installed in the northwest thereof, and FIG. 6 is a diagram showing an example of predicting the turbidity distribution in the display range 45 shown in FIG. is there. The length of the plurality of lines shown in FIG. 5 indicates the flow velocity, and the direction indicates the flow direction.

  From the flow velocity and flow direction data as shown in FIG. 5 and the distribution of turbidity at a certain point in time, the transport amount of the fine particles 15 such as earth and sand is calculated using a computer 19 or the like, and the turbidity range at an arbitrary time or depth A prediction is made. As shown in FIG. S. It is displayed on the display screen using a plurality of display patterns corresponding to the density.

  As the flow velocity and flow direction data shown in FIG. 5, for example, the flow velocity / flow direction observed by ADCP 5 of the turbidity monitoring apparatus 1 and the flow velocity / flow direction calculated in consideration of tides, winds, river inflows, and the like are used. As the turbidity distribution data, information such as the concentration distribution of the fine particles 15 observed by the turbidity monitoring device 1 and the time and position at which the earth and sand are dropped from the soil carrier are used.

  Next, the operation of the turbidity monitoring device 1 will be described. In order to monitor turbidity three-dimensionally using the turbidity monitoring device 1, the observation ship 3 navigates every elapsed time centering on the turbidity source so that the entire turbidity distribution can be covered as shown in FIG. Sail while expanding the range. In the example shown in FIG. 2, while the observation ship 3 is waiting at the standby position 23, fine particles 15 such as earth and sand are introduced from an introduction point 27 that becomes a turbidity generation source using an earth ship. The observation ship 3 continued to wait until turbidity appeared on the surrounding water surface, then started moving in the direction indicated by arrow C, and passed over the sea above the turbidity 29a generated in the water 9.

  Next, the observation ship 3 turned in the direction indicated by the arrow D, and passed over the sea above the turbidity 29b as the turbidity 29a was carried to the position indicated by the turbidity 29b in the southwest flow. Furthermore, the observation ship 3 repeatedly changed its direction in the directions indicated by the arrows E, F, and G, and passed over the sea above the turbidity 29c, 29d, and 29e carried to the southwest.

  As shown in FIG. 1, a plurality of ultrasonic beams 11 are directed from the ADCP 5 installed on the anchor 7 of the observation ship 3 toward the bottom 7 while the observation ship 3 continues to move on the sea immediately after the earth and sand are introduced at the insertion position 27. Fire. The ultrasonic beam 11 emitted in the direction indicated by the arrow A is reflected in the direction of the arrow B by the fine particles 15 floating in the measurement cells 13 of each layer in the vertical direction.

  The ADCP 5 measures the flow velocity 21 immediately below the ADCP 5 on the horizontal plane including the measurement cell 13 for each layer in the vertical direction by the Doppler shift of the reflected wave 14 reflected in the direction of the arrow B. At the same time, ADCP 5 acquires the reflection intensity of the reflected wave 14 by the fine particles 15 floating in each layer. Then, information on the flow velocity 21 for each water depth and the reflection intensity of the reflected wave 14 is sent to the computer 19.

  The turbidity monitoring device 1 measures the flow velocity 21 at each water depth and the reflected intensity of the reflected wave 14 with the ADCP 5 and simultaneously acquires the movement trajectory of the observation ship 3, that is, the position information of the ADCP 5 with the GPS 20 installed on the observation ship 3. Then, the position information data is sent to the computer 19.

  Based on the input position information, the computer 19 displays the trajectory 25 of the observation ship 3 on the display screen as shown in FIG. As shown in FIG. 2, data such as the flow velocity 21 input from the ADCP 5 may be simultaneously displayed on the display screen using a straight line 31. A trajectory 25 of the observation ship 3 indicates a horizontal measurement position of the ADCP 5. The length of the straight line 31 branched from the trajectory 25 of the observation ship 3 indicates the flow velocity 21 of the water 9 at the branch position, and the direction of the straight line 31 indicates the flow direction at the branch position.

  After obtaining the position information of ADCP 5 as shown in FIG. 2 and the reflection intensity of the reflected wave 14 of the ultrasonic beam 11, the computer 19 organizes the relationship between the reflection intensity of the reflected wave 14 and its measurement position, A graph as shown in FIG. 3 is displayed on the display screen.

  In the example shown in FIG. 3, a portion 34 with a high ultrasonic reflection intensity was observed in the time zone after the second half of the standby 33. This captures the turbidity that has moved from the loading point 27 toward the standby position 23 so as to crawl the bottom 17 after the earth and sand has been loaded at the loading point 27. Further, during the traveling 35a, 35b, 35c, 35d, and 35e during traveling when high ultrasonic reflection intensity is observed, the observation ship 3 travels on the turbidity 29a, 29b, 29c, 29d, and 29e shown in FIG. Was.

  From FIG. 3, it can be considered that a portion with high ultrasonic reflection intensity corresponds to a position where turbidity exists. Moreover, it turns out that the strong turbidity 29a which generate | occur | produced first becomes thin as time passes and it moves to the position of turbidity 29b, 29c, 29d, 29e. Further, it can be seen that the turbidity is spread in a wider range in the deeper portion than in the turbidity range seen from the shallow water surface.

  As shown in FIG. S. From the correlation between the density and the ADCP signal reflection intensity, the reflection intensity of the reflected wave 14 is calculated as S.P. S. Convert to concentration. Since ADCP5 acquires the reflection intensity in each layer in the vertical direction while moving in the horizontal direction on the observation ship 3, a three-dimensional concentration distribution is estimated.

  Further, the computer 19 uses the flow velocity 21 or the like measured by the ADCP 5 or the flow velocity and flow direction distribution calculated in consideration of conditions such as tide, wind, and river inflow as shown in FIG. Display a simple screen on the display screen. Moreover, the transport amount of the fine particles 15 such as earth and sand is calculated from the information on the turbidity distribution at a certain point of time observed by the ADCP 5 and the turbidity such as the position where the earth and sand are introduced, and the time and depth of water are calculated. The cloudiness range is predicted and displayed on a display screen using a display pattern as shown in FIG.

  The target range and target time for predicting the turbidity distribution can be arbitrarily set. If necessary, the prediction result of the turbidity distribution with time may be continuously displayed using a display pattern as shown in FIG.

  As described above, in the present embodiment, the ultrasonic reflection intensity from the fine particles 15 that are the basis of turbidity is continuously observed while moving the observation ship 3 to which the ADCP 5 is attached in the horizontal direction. Since the ADCP 5 simultaneously measures the ultrasonic reflection intensity of each layer in the vertical direction while moving in the horizontal direction, the three-dimensional turbidity concentration distribution can be measured in a short time. Moreover, the transport amount of the fine particles 15 can be calculated using the flow velocity 21 measured by ADCP5 to predict the concentration distribution, and the turbidity generated in the construction can be highly managed.

  In FIG. 1, the ADCP 5 is installed on the anchor 7 of the observation ship 3. However, the installation position of the ADCP 5 is not limited to this, and it may be installed on the bottom of the ship or tow the sea surface. Further, the installation position of the computer 19 is not limited to the observation ship 3 and may be installed in another place where data from the GPS 20 or ADCP 5 can be received.

  The reflected intensity of the reflected wave 14 acquired by ADCP5 tends to react sensitively to thin turbidity, and it is desirable to use a turbidimeter in combination for quantitative grasping of turbidity.

Outline diagram of turbidity monitoring device 1 The figure which shows the locus | trajectory 25 of the observation ship 3 observed by GPS20, ie, the positional information on ADCP5. The figure which shows the ultrasonic reflected intensity in the position and time shown in the locus | trajectory 25 of the observation ship 3 S.D. obtained by water sampling analysis. S. The figure which shows the relationship between (floating particle) concentration and ADCP signal reflection intensity The figure which shows the distribution example of the flow velocity and the flow direction in the vicinity of the airport island 41 and the silt fence 43 installed in the northwest The figure which shows the example of prediction of the turbidity distribution of the display range 45 shown in FIG.

Explanation of symbols

1 ... Turbidity monitoring device 3 ... Ship 5 ... ADCP
11 ……… Ultrasonic beam 15 ……… Particulate 19 ……… Computer 20 ……… GPS
21 ......... Flow velocity 23 ......... Track 29a, 29b, 29c, 29d, 29e of observation ship 3 ... Muddy

Claims (2)

While moving the ultrasonic Doppler velocimeter in the horizontal direction, the reflection intensity of the ultrasonic wave reflected from the fine particles floating from the ultrasonic Doppler velocimeter and floating in each vertical layer in the water, and the ultrasonic Doppler velocimeter A method for monitoring turbidity in water, wherein the position information in the horizontal direction is acquired, and the three-dimensional distribution of the fine particles is estimated from the reflection intensity for each depth of water and the position information in the horizontal direction ,
By displaying the horizontal trajectory of the ultrasonic Doppler velocimeter and the length and direction of the straight line branched from the trajectory, the flow velocity and flow direction for each water depth are displayed.
Using the correlation between the suspended particle concentration of the fine particles determined in the water sampling analysis prepared in advance and the reflected intensity by the ultrasonic Doppler velocimeter measured at the same position as the water sampling analysis, the reflection intensity is determined as the suspended particle concentration. Converted to
The horizontal trajectory of the ultrasonic Doppler velocimeter, the flow velocity for each water depth measured by the ultrasonic Doppler velocimeter, or the distribution of flow velocity and flow direction calculated in consideration of tides, winds and river inflows, and for each water depth The amount of transport of the fine particles is calculated using the reflection intensity, the three-dimensional distribution of the fine particles is estimated , and the predicted distribution of turbidity at an arbitrary water depth, range and time is displayed . Turbidity monitoring method. An ultrasonic Doppler anemometer,
Moving means for moving the ultrasonic Doppler velocimeter in a horizontal direction ;
Means for acquiring horizontal position information of the ultrasonic Doppler velocimeter;
From the reflection intensity at each water depth of the ultrasonic wave reflected from the fine particles floating in the vertical layers in the water and emitted from the ultrasonic Doppler velocimeter, the position information in the horizontal direction was created in advance. Using the correlation between the determined suspended particle concentration of the fine particles and the reflected intensity by the ultrasonic Doppler velocimeter measured at the same position as the water sampling analysis, the means for converting the reflected intensity to the suspended particle concentration,
A first display means for displaying a horizontal trajectory of the ultrasonic Doppler velocimeter, and a flow velocity and a flow direction for each water depth according to the length and direction of a straight line branched from the trajectory;
The horizontal trajectory of the ultrasonic Doppler velocimeter, the flow velocity for each water depth measured by the ultrasonic Doppler velocimeter, or the distribution of flow velocity and flow direction calculated in consideration of tides, winds and river inflows, and for each water depth Means for calculating a transport amount of the fine particles using the reflection intensity and estimating a three-dimensional distribution of the fine particles;
Second display means for displaying a predicted distribution of turbidity at an arbitrary depth, range and time;
A turbidity monitoring device in water, comprising:

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