JP2000050750A - Water supply and drainage system for rice terraces - Google Patents

Abstract

(57) [Summary] [Problem] To supply water in a stable manner to the whole terraced rice field,
While maintaining a constant water level with a small amount of water,
Provided is a water supply / drainage device that can suppress outflow of pesticides and the like, is excellent in workability, and can be provided at low cost. A water supply / drainage device (20) is connected to a water supply / drainage basin (21) provided with a water supply / drainage port (22) communicating with a cultivation area (12b), via a water supply pipe (31) to a water supply / drain passage (13) in an upper cultivation area part; A service water discharge unit 24 connected to a water supply / drainage channel in the cultivation area through a drain pipe 32; a water supply valve 33 for controlling supply of water is provided in the service water inflow unit 23; Is provided with a height-adjustable water level adjusting weir 34 that opens above the plumbing basin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply / drainage system for water supply in a terraced rice field, and more particularly, to adjusting the surface water level of each cultivation area in a terraced rice field to a desired height, and supplying a minimum necessary amount of water to each cultivation area. The present invention relates to a water supply / drainage device for a water supply in a rice terrace that can supply water evenly throughout the rice terrace by supplying the water.

[0002]

2. Description of the Related Art In a terraced rice field in which paddy fields are provided in a step-like manner on a slope, a groove serving as a communication passage between the cultivation area in the upper row and the cultivation area in the lower row is formed on a ridge. In order to supply water from the upper cultivation area to the lower cultivation area through this ditch, rice paddy irrigation is adopted.In the case of rice paddy irrigation, there is a communication passage on each ridge. The operation of forming such a groove was troublesome, and the growth of rice was sometimes poor around the groove. That is, when low-temperature water continuously flows through the groove serving as the communication passage, there is a problem that the growth of rice is deteriorated in the peripheral portion of the groove due to the influence of the low-temperature water.

Furthermore, pesticides, fertilizers, and the like applied to each cultivation area flow out to the lower cultivation area together with the flow of irrigation water, so that the effects of the pesticides and the like cannot be sufficiently exerted, and the pesticides and the like flow out to the outside to cause environmental destruction. There was also a risk of inviting the problem. Also, since water is supplied sequentially from the upper cultivation area, a large amount of water is required to supply a sufficient amount of water to the lower cultivation area. Conversely, during the drought period when sunshine continues, the water supply to the lower cultivation area tends to be insufficient, and poor harvesting of rice may reduce the yield.

[0004] On the other hand, a water supply channel and a drainage channel are provided on both sides of the cultivation zone, and in each cultivation zone, water is supplied from the water supply channel into the cultivation zone, and excess water in the cultivation zone is discharged to the drainage channel. Things have also been done. However, also in this case, since the water in the cultivation area flows from the water supply channel side to the drainage channel side, it is difficult to reuse the water, the water consumption increases, and the outflow of agricultural chemicals and the like also occurs.

Therefore, the present invention can supply water in a stable manner over the entire rice terrace, maintain a constant water level on the rice field with a small amount of water, suppress outflow of agricultural chemicals and the like, and have excellent workability. It is an object of the present invention to provide a water supply / drainage device for water in a terraced rice field which can be provided at low cost.

[0006]

In order to achieve the above-mentioned object, a water supply / drainage device for water in a rice terrace according to the present invention is provided with a water supply / drainage passage in a stepwise shape along a slope of the rice terrace, and a water supply / drainage passage in an upper cultivation area is provided. A water supply / drainage device for supplying intake water to a lower cultivation area and discharging surplus water from the lower cultivation area to a water supply / drainage passage in the lower cultivation area, wherein a water supply / drain port communicating with the cultivation area is provided. The water supply / drain basin provided is provided with a water supply inflow portion connected to the water supply / drainage channel in the upper cultivation area portion, and a water supply discharge portion connected to the water supply / drainage passage in the cultivation area portion. And a water level adjusting weir that is open at the top of the water supply and drainage basin and that can be adjusted in height.

Further, in the water supply / drainage device for water in a terraced rice field according to the present invention, the water level adjusting weir is formed by connecting a cylindrical body having a bellows structure which is vertically expandable and contractable to the water discharge part which is opened upward. Alternatively, the water discharge section is formed of a tubular body which is fitted to the upper end of a pipe which is open upward and which is vertically movable. Also, the water discharge section is provided with a drain port for discharging water in the cultivated area.

[0008]

FIG. 1 is a schematic longitudinal sectional view showing one embodiment of a rice terrace to which a water supply / drainage device according to the present invention is applied, and FIG. 2 is a schematic plan view thereof.

The terraced rice fields formed on the sloping land are formed by arranging the cultivation zones 12a and 12b, which are almost leveled through the ridges 11, in a stepwise manner. A water supply / drainage pipe 13 serving as a water supply / drainage passage is buried in a stepwise manner so as to follow the inclination of. Usually, the upstream side of the water supply / drainage pipe 13 is connected to a branch waterway into which water from a river or the like is drawn, and the downstream side is connected to a drainage channel.

A water supply / drainage device 20 connected to the water supply / drainage pipe 13 is provided at a side edge of each of the cultivation zones 12a and 12b. The water supply / drainage device 20 includes a bottomed cylindrical water supply / drainage basin 2.
1, a water supply / drain port 22 communicating with the cultivation area, a water supply inflow part 23 connected to the water supply / drainage pipe 13 via a water supply pipe 31, and a water supply / discharge part 24 connected to the water supply / drainage pipe 13 via a drainage pipe 32. It has. The service water inflow portion 23 is provided with a water supply valve 33 for controlling the supply of service water, and the service water discharge portion 24 is provided with a height-adjustable water level control weir 34 opening at the top of the water supply and drainage basin 21. Have been. In addition, the drain pipe 32 is provided with a drain port 35 for discharging water in the cultivated area.

The water supply pipe 31 of the water supply / drainage device 20 provided in the lower cultivation area 12b is connected to the upper cultivation area 1b.
The drainage pipe 32 is connected to the water supply / drainage pipe 13 of the portion 2a, and is connected to the water supply / drainage pipe 1 of the lower cultivation area 12b.
3 is connected.

3 and 4 show specific examples of the shape of the water supply / drainage device 20. FIG. 3 is a plan view of the water supply / drainage device, and FIG. 4 is a longitudinal sectional view of the water supply / drainage basin portion.

The water supply and drainage basin 21 is a bottomed rectangular tube having openings 21a, 21b, and 21c at three places, that is, a bottom portion and a side wall portion. Tube 24a is connected. In addition, a short pipe 2 serving as a water supply / drain port 22 is provided in the opening 21b on the side of the cultivation area 12a.
2a is connected to the other opening 21c and the water inflow portion 2
3 is connected to the short pipe 23a.

The water supply pipe 31 is connected to the upper cultivation zone 12.
a is connected to the bottom side of the water supply / drainage pipe 13
It is formed so that the water can be taken in even if the amount of water flowing in the water supply / drainage pipe 13 is small. Also,
The drainage pipe 32 is a water supply and drainage pipe 1 in the cultivated area 12b.
3 and is formed so that drainage from the water supply and drainage basin 21 can be smoothly performed.

A gate valve is used for the water supply valve 33 provided between the water supply pipe 31 and the short pipe 23a, and the operation rod 33H protruding upward is moved up and down to move the water in the valve box 33V. The gate (valve element) is formed so as to move up and down to open and close the flow path.

A water level adjusting weir 34 is provided at the upper end of the short pipe 24a with a bellows structure having a bellows structure which can be vertically extended and contracted.
In addition to connecting P, an operation rod 34H for extending and contracting the bellows structure portion is provided on the upper part of the cylindrical body 34P.

The cylindrical body 34P is formed in a conical shape whose upper side is reduced in diameter as a whole, and the bottom is fixed to the short pipe 24a in a watertight manner via a seal material 34S. The operation rod 34H extends upward through a guide portion 25a provided on the lid 25 of the water supply and drainage basin 21, and by vertically moving the operation rod 34H,
The height of the upper edge opening of the cylindrical body 34P, that is, the height of the weir, is formed so that the height can be arbitrarily adjusted. The operation rod 34
H may be provided with a scale for indicating the position of the upper edge opening of the cylindrical body 34P.

The drain port 35 is provided with a removable cap 35C, and drainage in the cultivation area from the drain port 35 is performed by removing the soil around the drain port 35 and removing the cap 35C. be able to.

The water supply / drainage device 20 thus formed is
It is buried in the vertical direction on the slopes of farm roads and ridges facing each cultivation area 12a, 12b,
a and 12b. That is, each cultivation zone 12
The height position of the water level adjusting weir 34 in the water supply / drainage device 20 installed in the a, 12b is adjusted by the operation rod 3 provided in the cylindrical body 34P.
By moving 4H up and down, each cultivation area 12a,
Set every 12b.

Normally, in the water supply / drainage device 20 installed in each of the cultivation zones 12a and 12b, the water supply valve 33 of the water supply pipe 31 is appropriately opened, and the water level control weir 34 is formed by connecting the upper edge of the cylindrical body 34P to the rice field. Set to a height corresponding to water level L. The drain port 35 is provided with a cap 35C. In addition, at the opening of the short pipe 22a serving as a water supply and drainage port, a dam plate having an appropriate height corresponding to the ground surface G is provided in order to prevent earth and sand in the cultivated area from flowing into the water supply and drainage basin 21. Preferably.

In such a state, in the water supply / drainage device 20 installed in the cultivation area 12b, the water flowing through the water supply / drainage pipe 13 is supplied from the water supply pipe 31 connected to the upper cultivation area 12a of the water supply / drainage pipe 13. Water valve 3
3 and into the plumbing basin 21 and then into the plumbing
Water is supplied to the cultivation area 12b from. The supply of the water to the cultivation area 12b is continuously performed until the surface water level rises and reaches a height exceeding the upper edge of the cylindrical body 34P of the water level adjusting weir 34.

On the other hand, surplus water or rainwater supplied to the cultivation area 12b flows backward through the water supply / drain port 22 and flows into the water supply / drain basin 21, where the water level control weir is adjusted to a height corresponding to the rice field water level L. The water flows down in the cylindrical body 34P beyond the upper edge of the cylindrical body 34P, and flows out of the short pipe 24a of the water discharge unit 24 through the drainage pipe 32 to the water supply / drainage pipe 13 in the cultivation area 12b. The water that has flowed out to the water supply / drainage pipe 13 in the cultivation area 12b is further taken into the water supply pipe 31 of the water supply / drainage device 20 installed in the lower cultivation area, and similarly flows to the lower side while adjusting the water level of the cultivation area. To go.

Therefore, the surface water level in each of the cultivation zones 12a and 12b can be automatically adjusted by adjusting the cylinder 34P of the water level adjusting weir 34 to a predetermined height.
Then, by appropriately adjusting the opening of the water supply valve 33 of the service water inflow section 23, the amount of water for inflow into each of the cultivation areas 12a and 12b can be adjusted, and the rice field water level is kept constant with the minimum necessary amount of water. It becomes possible. In addition, since excess water on the upper side is reused on the lower side, waste of the water is reduced.

When such water management is performed, each cultivation zone 1
Since the supply amount of the water to the 2a and 12b can be reduced, the water can be supplied evenly throughout each cultivation area of the terraced rice field, and the shortage of the cultivation area on the lower side does not occur. In addition, when the water level in the cultivated area is maintained at a constant level, the water in the cultivated area is hardly discharged to the outside, so pesticides and fertilizers applied to the cultivated area may flow out together with the water and rainwater. And there is no risk of causing environmental destruction.

When draining the water from the cultivated areas 12a and 12b, the water supply valve 33 of the water supply pipe 31 is closed, and the operating rod 34H is pushed down to release the water level control weir 34.
Is lowered. As a result, the water stored in the cultivation area can be discharged from the drainage pipe 32 to the water supply / drainage pipe 13.

On the other hand, when a paddy field requiring a large amount of water at once is used, the water supply valve 33 is fully opened and the cylinder 34P of the water level regulating weir 34 is pulled up. Accordingly, the entire amount of the water flowing into the water supply and drainage basin 21 from the water supply pipe 31 is not discharged from the water discharge unit 24, and the entire amount thereof is supplied to the water supply / drain opening 2.
2 and is supplied to and stored in the cultivation area, and quickly reaches a predetermined water level. By repeating this operation for each cultivation section, it is possible to supply water sequentially from the upper cultivation section to the lower cultivation section.

Further, when draining the cultivated area by drying the middle of a paddy field or the like, the drainage can be efficiently performed by digging the ground near the water supply / drainage port 22 to open the short pipe 22a fully. Further, when it is not necessary to supply water to some cultivated areas due to loss of water or the like, the water supply valve 33 of the water supply / drainage device 20 corresponding to the cultivated area is closed, the periphery of the drain port 35 is dug down, and the cap 35C is removed. As a result, rainwater or the like in the cultivated area is discharged to the drain pipe 32 and the supply / drain pipe 13 through the drain port 35.

According to such a water supply / drainage device 20, since the amount of water flowing through the water supply / drainage pipe 13 can be reduced, a small-diameter pipe can be used. Further, the water supply / drainage device 20 can be easily and inexpensively manufactured by appropriately combining a cylindrical member made of synthetic resin and the like. In addition, while installing one plumbing pipe 13 along the terraced rice field,
A water supply / drainage system can be formed by installing a water supply pipe 31 and a drainage pipe 32 connected to the water supply / drainage device 20, so that two pipes, i.e., a pipeline for water supply and a pipeline for drainage, are conventionally provided. This eliminates the need for installation, greatly reducing construction costs and the like, increasing the area of cultivated areas and widening farm roads.

FIG. 5 is a longitudinal sectional view showing another embodiment of the water level regulating weir. This water level control weir 34A
Pipe 24 of the water discharge part 24 opening upward at the bottom of the
A cylindrical body 34T is fitted to the upper end of P via a sealing material 24S so as to be vertically movable, and this cylindrical body 34T is also provided with the same operating rod 34H as described above. Further, the pipe 24P has a length capable of pushing down the cylindrical body 34T during drainage.

The water level regulating weir 34A thus formed is also
By operating the operation rod 34H to adjust the height of the upper edge of the cylindrical body 34T, it is possible to manage the rice field water level as described above. Note that the same components as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the case of this embodiment, the drain pipe 32 and the supply / drain pipe 13 need to be buried deep by the length of the pipe 24P. That is, as described above, by forming the water level adjusting weir by the cylindrical body 34P having the bellows structure which can be expanded and contracted in the vertical direction, the size below the water supply and drainage basin 21 can be shortened.
In addition, the burial depth of the water supply / drainage pipe 13 can be reduced, and the burying work of these pipes can be facilitated, and the construction cost can be reduced. In particular, by forming the cylindrical body 34P in a conical shape, even if earth and sand flows into the water supply and drainage basin 21, the expansion and contraction of the bellows portion is hardly affected, and the height of the upper edge opening can be easily adjusted. .

The shape of the water supply and drainage basin constituting the water supply and drainage device is not particularly limited, and may be a cylindrical shape or the like. Furthermore, the structure and shape of the valve and the weir are arbitrary, and a U-shaped groove such as an open channel can be used for the water supply / drainage channel instead of the water supply / drainage pipe. Further, by forming the operation rod detachably by, for example, a screw-in structure or the like, it is possible to prevent the water level adjustment weir from being operated when it is not necessary. Further, when the area of the cultivation area is large, a plurality of water supply / drainage devices can be installed. Further, the opening / closing of the valve and the vertical position adjustment of the weir can be formed so as to be remotely operable by a motor or the like instead of the operation rod, and can be automatically controlled using a computer or the like.

[0033]

As described above, according to the water supply / drainage system for rice terraces of the present invention, it is possible to easily supply water to each cultivation area of the rice terraces, maintain the surface water level, discharge water from the cultivation areas, and the like. It is possible to perform water management such as maintenance of the water level of each cultivation zone with high efficiency. Furthermore, it is possible to cope with the reduction of the number of cultivated areas. In addition, since these functions are integrated into one water supply / drainage basin, the water supply / drainage device can be formed compactly, and can be supplied at low cost with excellent workability. Further, since only one water supply / drainage channel needs to be provided on the farm road or the like on the side of the terraced rice field, the space for the cultivated area, the farm road, and the like can be greatly expanded, and the farmland can be used effectively.

Further, water management can be performed so as to minimize discharge of the water supplied to each cultivation area as surplus water, so that pesticides, fertilizers, etc. applied to each cultivation area flow out together with the water. The amount can be reduced, and the problem of environmental destruction is not caused.

Further, since the water discharged from the water supply / drainage device installed in the upper cultivation area can be used in the lower cultivation area through the water supply / drainage channel, the efficiency of water usage can be greatly improved. it can.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view showing an example of a rice terrace to which a water supply and drainage device of the present invention is applied.

FIG. 2 is a schematic plan view similarly.

FIG. 3 is a plan view showing a specific example of the shape of the water supply / drainage device.

FIG. 4 is a longitudinal sectional view of a water supply and drainage basin portion.

FIG. 5 is a longitudinal sectional view showing another embodiment of the water level regulating weir.

[Explanation of symbols]

11 ... ridge, 12a, 12b ... cultivation area, 13 ... water supply and drainage pipe, 20 ... water supply and drainage device, 21 ... water supply and drainage basin, 22 ... water supply and drainage outlet, 23 ... water supply inflow part, 24 ... water supply discharge part, 31 ... water supply pipe, 32 ... Drainage pipe, 33 ... Water supply valve, 34 ... Water level control weir, 34H ... Operation rod, 34P ... Cylinder having bellows structure, 35 ... Drainage outlet

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masato Ogawa 5-8, Mitsuya-cho, Nagahama-shi, Shiga Prefecture Mitsubishi Plastics Co., Ltd. Nagahama Plant Co., Ltd. In company

Claims (4)

[Claims] 1. A water supply / drainage channel is provided stepwise along the slope of a terraced rice field, and water taken from the water supply / drainage channel in an upper cultivation area is supplied to a lower cultivation area, and excess water in the lower cultivation area is supplied. A water supply / drainage device for discharging water to a water supply / drainage channel in the lower cultivation area portion, wherein a water supply / drainage basin having a water supply / drainage port communicating with the cultivation area; A water discharge section connected to a water supply / drainage channel in the cultivated area, a water supply valve for controlling supply of water is provided in the water inflow section, and the water discharge section has an opening above a water supply / drain basin. A water supply / drainage device for a terraced rice field, comprising a water level control weir having a height adjustable. 2. The water level adjusting weir is formed by connecting a cylindrical body having a bellows structure that can expand and contract in the vertical direction to the water discharge part that opens upward. Water supply and drainage system for rice terraces in Japan. 3. The water level adjusting weir is formed by a tubular body which is vertically movably fitted to an upper end of a pipe which is open upward of the water discharge part.
A water supply / drainage device for water in a terraced rice field described in the above. 4. The water supply / drainage device for a terraced rice field according to claim 1, wherein the water discharge section has a drain port for discharging water in the cultivated area.