JPH0253008B2 - - Google Patents

Description

[Detailed description of the invention] ≪Industrial application field≫ This invention is intended to raise nutrients in the seafloor layer to the photic layer where sunlight can reach, promote the generation of phytoplankton, and increase the basic productivity of fishing grounds. This is related to upwelling flow generating structures.

<<Prior art>> The upwelling phenomenon in the natural world has been known empirically for a long time as indicating favorable fishing grounds, and areas where this phenomenon occurs are important for fishery production as retention areas for migratory fish. It is a high sea area.

This type of upwelling can be roughly divided into two types depending on the factors that cause it: wind-driven upwelling caused by blow currents, and topographic upwelling caused by tidal currents.

The latter, topographic upwelling, is caused by tidal currents or ocean currents whose flow is changed by the topography of the ocean floor.

Therefore, upwelling currents can be generated by artificially changing the topography of the ocean floor, and it has been known that upwelling currents can be induced by artificial reefs, but hydraulic and wind tunnel experiments have shown that upwelling currents can be generated. Around fish reefs installed in the tides and ocean currents, eddies occur due to the wraparound of the tides and ocean currents, and upward currents whose direction is changed by the fish reefs, but the generation of eddies is larger and the upwelling effect cannot be fully obtained. Nakatsuta.

Therefore, for example, as seen in Japanese Patent Publication No. 57-54098, a floating body is attached integrally with the seat,
An upwelling current generating device has been proposed in which one end of this sheet is moored to the seabed.

According to the device disclosed in this publication, the tidal current rises along the sheet or floating body and an upwelling flow is induced, but this upwelling flow occurs when the tide/ocean current collides with the sheet or floating body. It is caused only by changing the direction of the flow,
It still wasn't enough.

For this reason, the present inventors have proposed an upwelling flow generation structure capable of efficiently generating upwelling flow in Japanese Patent Application No. 174333/1982.

The upwelling flow generation structure according to this application utilizes the negative pressure of the vortex generated at the rear of the compression plate in addition to deflecting tides and ocean currents by providing a compression plate and a resistor placed opposite to the compression plate. Although this structure can effectively generate an upwelling flow, this structure also has the following problems.

≪Problems to be solved by the invention≫ That is, in the upwelling flow generation structure of the above application,
Since the inlet for tides and ocean currents was provided only on the side of the structure where the compression plate was installed, there was a problem in that upwelling only occurred for tides and ocean currents flowing in from this direction.

This invention was made in view of these conventional problems, and its purpose is to provide an upwelling current generation structure that can effectively induce upwelling currents against tides and ocean currents in at least two directions. It's about providing things.

<<Means for Solving the Problems>> In order to achieve the above object, the present invention provides an upwelling current generation structure that is installed in the sea and causes seawater on the seabed side to rise to the sea surface. The structure consists of a pair of compression plates and a resistor that are arranged to face each other, and each of the compression plates is located above the seabed ground at a predetermined interval in the horizontal direction with a gap provided therebetween, and The resistor is located at the center between the compression plates and is erected substantially vertically on the seabed ground.

<<Operation>> According to the upwelling flow generating structure with the above configuration, the tides and ocean currents flowing from outside the compression plate collide with it,
The flow is constricted in the gap below, increasing the flow velocity, and colliding with a resistor installed on the seabed.

The tide/ocean current that collides with the resistor is deflected upward and generates a vortex near the tip of the resistor.

Therefore, by using the upward flow caused by deflection and the suction force of negative pressure caused by the eddy current, a strong flow can be generated from the seabed side toward the sea surface side.

Furthermore, since a pair of compression plates are provided on both sides of the resistor so as to sandwich the resistor, upwelling can be effectively generated against tides and ocean currents from at least two directions, such as rising tides and falling tides.

<<Example>> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an upwelling flow generating structure according to the present invention.

The upwelling flow generation structure shown in the figure includes a pair of compression plates 1, 1 and a resistor 2, which are arranged to face each other.

In this embodiment, the compression plate 1 is formed into a flat plate shape, and a resistor 2 is arranged approximately at the center between a pair of compression plates 1, 1 arranged at a predetermined distance in the horizontal direction, and is inclined on both sides. The compression plate 1 and the resistor 2 are supported by a pair of side plates 3 disposed on both sides so as to be parallel to each other.

The side plate 3 has approximately the same height as the resistor 2.

Further, the pair of compression plates 1, 1 are located above the resistor 2 with a gap 4 corresponding to the height of the resistor 2.

The upwelling flow generation structure configured as above is
It is sunk on the seabed ground 5 by appropriate means, and in the sunken state, the resistor 2 is vertically erected on the seabed ground 5, and the compression plates 1, 1 are placed on both sides of the resistor 2 with a space between them above it. placed in a vertical position.

In this structure, an upwelling flow is induced by the mechanism explained below.

As shown in Fig. 1d, if a tide/ocean current were to rush in from the outside of one compression plate 1 in the X direction, the tide/ocean current would first collide with the compression plate 1 and fill the gap below. The flow is constricted by the section 4 to increase the flow velocity, and collides with the resistor 2 installed on the seabed ground 5.

The tide/sea current that collides with the resistor 2 is deflected upward as shown by the dotted line in the figure, and generates a vortex A near the top of the resistor 2.

When the eddy current A occurs, the vicinity thereof becomes a negative pressure region, so surrounding seawater flows toward the eddy current A.

Therefore, by using the upward flow caused by deflection and the suction force of negative pressure caused by the eddy current, a strong flow can be generated from the seabed side toward the sea surface side.

Moreover, since a pair of compression plates 1, 1 are provided on both sides of the resistor 2 so as to sandwich the resistor 2,
Not only the tides and currents in the direction, but also the tides and currents in the opposite direction.
Upwelling currents can be generated in the same way for tides and ocean currents of X′.

This makes it possible to effectively generate upwelling currents against tides and ocean currents from at least two directions, such as rising tides and falling tides.

FIG. 2 shows another embodiment of the upwelling flow generating structure according to the present invention, and only its features will be described below.

In the embodiment shown in the figure, the compression plates 1a, 1a are
They are sloped so that the horizontal distance between them gradually widens toward the sea surface.

When the compression plates 1a, 1a are tilted in this way,
In addition to the above-mentioned effects, the tide/sea current that collides with the compression plates 1a, 1a is guided downward along this, the flow velocity becomes higher when passing through the gap 4, and the deflection after colliding with the resistor 2 is increased. Since the generation of currents and vortices A becomes stronger, a larger upwelling flow can be generated.

<<Effects of the Invention>> As explained in the embodiments above, in the upwelling current generating structure according to the present invention that is installed in the sea and causes seawater on the seabed side to rise to the sea surface side, the upwelling current generating structures are mutually connected. It consists of a pair of compression plates and a resistor arranged opposite to each other, each of the compression plates being located above the seabed ground at a predetermined interval in the horizontal direction, and above the seabed ground, and the resistor is It is located at the center between the compressed plates and is erected almost vertically on the seabed ground, so it can be used for example when a rising tide
It is possible to effectively generate large upwelling currents in response to tides and ocean currents that push outward from both sides of the compression plate from different directions, such as a falling tide.

In addition, the structure of the present invention has a fish reef function as well as an upwelling function, so by having these functions together, it has a high ability to attract fish from the bottom layer to the surface layer fish. You can expect it.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of an upwelling flow generating structure according to the present invention. , figure a is its elevation view,
Figure b is a plan view thereof, Figure c is a sectional view thereof, Figure d is an explanatory diagram of the state of occurrence of upwelling flow, and Figure 2 is an elevational view showing the second embodiment. 1, 1a... Compression plate, 2... Resistor, 3... Side plate, 4... Gap, 5... Seabed ground.

Claims (1)

[Scope of Claims] 1. An upwelling current generating structure installed in the sea that causes seawater on the seabed side to rise to the sea surface side, the upwelling current generating structure comprising a pair of compression plates and a resistor arranged opposite to each other. each of the compression plates is located above the seabed ground at a predetermined interval in the horizontal direction, and the resistor is located above the center of the compression plates, An upwelling current generation structure characterized by being erected almost vertically on the seabed. 2. The upwelling flow generating structure according to claim 1, wherein the compression plate is provided in a vertical state substantially parallel to the resistor. 3. The upwelling flow generating device according to claim 1, wherein the compression plates are inclined so that the distance between them gradually widens upward.