JP2007002410A - Cylindrical fish pass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that many conventional fish passes are formed of concrete or steel plates and have massive and robust structures, but the installation of such a fish pass is a heavy task and the movement of the installation location is often difficult, and to provide a new fish pass which facilitates the installation thereof by increasing the degree of freedom of installation, enables the movement and reuse thereof, and exerts extremely high flexibility in a manner applicable to fishes of many types including a fish of weak migration power. <P>SOLUTION: The new fish pass has a cylindrical cross section, and sheathing boards are arranged on an inner wall through the entire circumference thereof, to thereby construct a fish pass that allows a fish to freely migrate therein in longitudinal and lateral directions. The installation of the cylindrical fish pass is carried out according to a conventional pipe arrangement technology, and by combining a linear pipe with a curved pipe, the free arrangement of the fish pass is achieved. Further by making a cylindrical fish pass body of a flexible structure, the fish pass is arranged in a manner conforming to an environmental status. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fishway for the purpose of going up and down fish and aquatic organisms.

  Conventionally, when considering the installation of a fishway, it is common to target mountain stream fish such as “Ayu” and “Iwana Yamame”, which are valuable fish species, and large fish such as “salmon trout”. However, in recent years when the overall conservation of the natural environment is becoming important, it is necessary to protect the living environment of familiar organisms such as beech, medaka and loach, not only the monetary value of fish species. It has been.

  Many conventional fishways have heavy and long structures made of concrete or steel plates, and are sturdy, but the construction of the fishways often takes a lot of days and is difficult to move from place to place. It was often the case. A denier unit fishway has been proposed as a portable fishway, but it is limited to valuable fishways such as sweetfish.

  In the present invention, by increasing the degree of freedom when installing a fishway, it is possible to facilitate the installation and reuse such as movement and re-use, and also to target a wide variety of fish species with weak swimming ability. The goal is a fishway that can respond to species.

  The cross section of the fishway is cylindrical and the weir plate is placed on the inner wall 360 ° circumference (see FIG. 1). The cylindrical fishway can be freely arranged by combining a straight pipe and a curved pipe (see FIG. 5). Furthermore, the problem is solved by structural improvements such as making the main body of the cylindrical fishway itself a flexible structure (see FIG. 7).

  In the cylindrical fishway according to the present invention, the weir plate is arranged on the circumference, so that the water control effect as a weir is effective for the entire circumference of 360 °. There is no need, and it is possible to eliminate directivity in the arrangement of the fishway.

  Many methods have been proposed for fishways, but for tubular fishways, a spiral arrangement of scallops has been proposed as a fishway tube. (See Patent Document 1)

International publication number: WO95 / 13430

  The problem with the arrangement of the spiral dams is that the falling water flows between the spiral dam and the side wall at a high speed, so the position where the falling water overflows the dam is always changing, and overflow hydraulics is not possible. The function as a fishway is reduced because it may become stable. In addition, the steep slope makes falling water run along the spiral at high speed, which may cause the dam to fail, that is, it functions as a side wall of the water channel before the dam is acting as a weir. It can be raised. In addition, in the arrangement of the fishway using a combination of straight pipes and curved pipes, there may be problems in production such as it is difficult to ensure the continuity of the spiral at the joint. For this reason, the arrangement of the slats in the present invention is simply a method of partitioning into 360 ° donuts at predetermined intervals.

  In the cylindrical fishway of the present invention, it is possible to cope with the diversity of installation locations by combining a straight pipe and a curved pipe in which a slat is arranged on the circumference with a predetermined interval size. In addition to the combination of straight pipes and curved pipes, the structure of the cylindrical fishway body itself can be flexibly and freely bent, thereby further improving the adaptability to the site.

  As mentioned above, in response to a wide range of fish species in recent years, it is necessary to deal with small fish species and fish species with weak swimming ability, and there are a wide variety of shapes and variations that enable small-scale fish paths. Correspondence to flow velocity is desired. In addition, not only the mountain stream river, but also the plan of the fishway, it is required to eliminate the drop of a small water channel called a creek and to run up and down between a paddy field and a creek.

  In order to satisfy a wide range of performance requirements for these fishways, apart from the fishways intended for relatively large fish based on the conventional three-sided structure, a cylindrical shape that is easy to accommodate medium and small-scale shapes A fishway is provided (see FIG. 1).

  One of the excellent points of the cylindrical fishway is its versatility for small-scale fishways as well as medium-scale ones. The factors determining the scale are the amount of water required for the fishway function, the target fish species, and the scallops. Although it depends on the scale, the size of the opening, the portable performance, etc., it can basically handle a wide range of sizes from about 10 cm to 60 cm or more.

  The second excellent point of the cylindrical fishway is that there is no difference from ordinary piping materials, except that it has a crest on the inner surface, and it is easy to construct a fishway with the know-how of piping work by allocating straight pipe parts and curved pipe parts Could be possible. (See Fig. 5) Furthermore, structural materials can be supplied as a unit as seen in general piping materials, and they are easy to install and move, providing a variety of installation locations and portability for movement of installation locations. It has excellent characteristics and can be reused by reuse (see FIG. 6).

  Furthermore, if the pipe material of the cylindrical fishway itself has a flexible structure, the degree of freedom in producing the fishway will be greatly improved, and it can be installed more familiar with the local terrain regardless of the installation location. This is significantly improved (see FIG. 7). On the other hand, if the hydraulic conditions and the fishway specifications are satisfied, it is possible to use a natural material such as bamboo as the pipe material, and to construct a slatboard at the node part, so that it can be an extremely friendly fishway facility. .

  A third excellent point of the cylindrical fishway is that the 360 ° closed cylindrical shape can easily ensure the safety of the target fish and biological species. As an example, many freshwater fish have a property that prefers to follow a tubular shape such as a side lobe, and there are many timid creatures that are advantageous to maintain a dark state. In addition, it is necessary to protect small fish species from predators such as carp, and the cylindrical fishway is easy to cope with from the structure. Of course, if the material is made of a permeable material, it is possible to manage the fishway visually.

  The fourth excellent point of the cylindrical fishway is that when a fishway is installed, it can be set with an arbitrary gradient by using a unit-type point. In addition to the forward slope that can satisfy the function of the fishway, it is extremely reverse in the middle of the channel, and even if the fishway is full of water, it functions as a fishway. Such a phenomenon does not occur, and this feature significantly improves the degree of freedom in the arrangement of the fishway.

  As the structure of the weir plate, as shown in FIG. 1 (b), it is a simple partition with 360.degree. Circumference and is continuously arranged on the inner wall of the cylindrical fishway at a predetermined interval. Compared to the spiral, a stair-like fishway can be constructed with a unit structure that is stable due to the arrangement of independent crests. In addition, because the entire circumference is partitioned, it is possible to eliminate the directivity of the top, bottom, left, and right, and the slats act regardless of the orientation of the cylindrical fishway. This also significantly improves the degree of freedom in the arrangement of fishways, such as no need to consider.

  The shape of the weir provides a circular and rectangular opening. The circular notch is a donut-shaped ring arranged at a predetermined pitch (see FIG. 2 (a)), and literally provides stable overflow hydraulics in the entire circumferential direction (see FIG. 2 (b)). In addition, the rectangular notch has a stable variation in the flow velocity distribution depending on the rectangular overflow position and the rectangular installation situation, and it is possible to provide a flow velocity according to the ability of the fish species and biological species (Fig. 2 (c)). That is, the central part has a relatively high flow velocity but the shortest distance, and both end parts have a low flow velocity and a low crest height, which can be a place where benthic species can run up. (See Fig. 2 (d))

  In the case of a straight structure in the shape of the dam plate, the workability is excellent (see FIG. 3A). On the other hand, when a larger overflow height is required as a fishway, it is effective to provide resistance to the flow. As an example, there has been proposed a method in which a slope is provided on the dam plate toward the upstream. (See Patent Document 1)

International publication number: WO95 / 13430

  This method of providing resistance toward the upstream can be expected to have a great effect on improving the function of the fishway, but it is difficult to determine the degree of effect due to the angle of inclination in the method of inclining the swash plate, and the determination of the optimum inclination is not possible. It is difficult (see FIG. 3B). In the present invention, it is proposed to provide a projection on the top end of the dam plate at a right angle to the dam plate and toward the upstream (see FIG. 3C). The effect of this protrusion is known from the theory of inflow loss in the pipe hydraulic phenomenon, and it is known that the resistance is 100 times that of Bellmouth and 10 times that of the corner end. (See Non-Patent Document 1)

Land Improvement Project Plan Design Standard Design “Waterway Engineering” Technical Document 6.5.2

  Further, the method of arranging the protrusions in the direction perpendicular to the top edge of the dam plate has a simple structure and good workability compared to the method of adjusting the degree of inclination. In addition, the protrusions arranged at right angles have a structure that always maintains optimum resistance regardless of the inclination of the fishway body in resistance to flow.

  As one of the methods of installing a slat plate at a predetermined pitch in a cylindrical cylinder, as shown in FIG. 4, a flange-like component along the cylindrical shape is bonded to the sill plate in advance, and this component with a slat plate The present invention proposes a method of arranging a slat in a circular cylinder by alternately inserting circular parts for spacer purposes in accordance with a predetermined pitch.

  In this case, there are proposed a method in which a part with a cover plate and a spacer part are bonded in a cylinder and not. The method of bonding is high in stability but inferior in versatility. The method that does not adhere is unstable immediately after installation, but after use as a fishway, sand mud enters the space between the parts, and after a while it settles and stabilizes. The advantage of this method is that it is easy to repair, reuse and dispose of the board because the board parts can be disassembled apart when the fishway is removed.

  As shown in FIG. 8, a device that rapidly expands and contracts from a circular shape to a wide width is arranged at the entrance and exit of a cylindrical fishway to improve the function as a fishway by providing a structure that facilitates the passage of organisms.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing for explaining the shape of a cylindrical fishway, (a) is a drawing for explaining a longitudinal section, and (b) is a drawing for explaining a sectional shape of a cylindrical fishway. It is drawing explaining the detail of the crest of a cylindrical fishway, (a) (b) is drawing explaining a circular board, (c) (d) is drawing explaining a rectangular board. It is drawing explaining the detail of the attachment state of a weir board, (a) is explanatory drawing of attachment with an upright board, (b) is explanatory drawing at the time of inclining a weir board, (c) These are drawings explaining the protrusion toward the upstream. These are drawings explaining details of an assembly-type dam plate. These are drawings explaining the installation situation of a cylindrical fishway. These are explanatory drawings at the time of arrange | positioning a cylindrical fishway to local landform. Is an arrangement example when the fishway body has a flexible structure in a cylindrical fishway. These are explanatory drawings of the doorway apparatus arrange | positioned in a cylindrical fishway.

Claims (7)

  In a fishway for the purpose of going up and down fish and aquatic organisms, the cross-sectional shape of the fishway is a cylinder, and a slat is placed along the circumference inside the cylinder, and it rotates in either direction. Even a cylindrical fishway that realizes to function as a fishway.   Non-directionality in the left and right rotation direction is realized by using a donut-shaped crest plate with a circular notch in the center of the crest plate arranged inside the cylindrical fishway with respect to the disc shape along the inner wall A damming board.   A scallop that is arranged inside a cylindrical fishway, and provides a variation in flow velocity in the fishway by providing a rectangular notch in the center of the disc shape along the circumference.   A scallop that is disposed inside a cylindrical fishway, and has a protrusion that is provided upstream at the tip of the swashplate to increase resistance to water flow and improve the function of the fishway.   For the scallops to be placed inside the cylindrical fishway, the slatboard is manufactured in advance for each part of the slatboard, and the slatboard parts are sequentially inserted into the cylinder to produce a cylindrical fishway system. Method.   A cylindrical fishway that has a flexible structure in a cylindrical fishway that is partitioned by a swash plate at a predetermined interval, thereby increasing the applicability to terrain where the fishway is installed. In the apparatus attached to the entrance / exit of the cylindrical fishway, the entrance / exit device has a shape that is widened so that fish can easily enter and exit, and has a shape that is temporarily contracted or expanded so as to match the diameter of the cylindrical fishway from the widened entrance.

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