JPH10243749A - Water level controller and irrigation water management system for paddy field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive water level controller and irrigation water management system for a paddy field including a terrace one, which help stably supply water to the entire paddy field and automatically control it at a given level, and is easily set up. SOLUTION: This water level controller is equipped with a water supply/ discharge section 61 which is in communication with a farming section 42 to which water is to be supplied, and also with a water supply section 62 and water discharge section 63, connected to an underground water supply pipe 51 and water discharge pipe 52, respectively, running along a farm road. The water supply section 62 is equipped with a water supply valve 64 and backflow preventing dam 65, the former controlling flow rate of irrigation water, and the latter being open to the upper section of a water supply/discharge measure 60 and adjustable in height. The water discharge section 63 is equipped with a water discharge valve 63 and water level controlling dam 67, the former being provided at near the bottom of the water supply/discharge measure 60, and the latter being open to the upper section of the water supply/discharge measure 60 and adjustable in height.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level control device for a paddy field and a water management system, and more particularly, to a water level control device capable of easily adjusting the surface water level of each cultivation zone in a paddy field to a desired height. In addition, it is a paddy water management system that can automatically control the supply and discharge of irrigation water to the paddy field.More specifically, by supplying the minimum necessary water to each cultivation area, the irrigation water is evenly distributed over the entire paddy field. The present invention relates to a water management system for paddy fields that can supply and maintain a constant water level in each cultivated area.

[0002]

2. Description of the Related Art FIG. 14 is a schematic plan view showing a conventional paddy field structure, in which water flowing through a river 1 is guided from a channel 2 to an upstream main water supply channel 3 and supplied to a paddy field 4. It has become. The paddy fields 4 are divided into a plurality of cultivated areas 4
2, the open-side water supply channel 3 along each cultivation area 42 is provided on the side edge of the farm road 40 extending in the longitudinal direction.
1 is provided. An upstream side of the water supply channel 31 is connected to the main water supply channel 3, and a water supply port 32 is provided on a side wall of the water supply channel 31 facing each cultivated area 42. As shown in a perspective view in FIG. 15, the water flowing through the water supply channel 31 is supplied from each water supply port 32 to each cultivation area 42.

[0003] An open drainage channel 33 is provided between the paddy fields 4 and 4 located on the opposite side of the water supply channel 31. The drainage outlet of the drainage channel 33 facing each cultivation area 42 includes:
A water level setting device 34 is provided.
By adjusting the height of the cultivation area 42, the surface water level of each cultivation area 42 can be maintained at a constant height. The downstream side of the drainage channel 33 is connected to the main drainage channel 35, and excess water and rainwater discharged into the drainage channel 35 are returned to the river from the water channel 36.

[0004]

In the case of this paddy field,
The water flowing through the water supply channel 31 flows into each cultivation area 42 from a water supply port 32 located on the upstream side of the water supply channel 31. And
The water supplied to the cultivation area 42 is maintained at a constant water level by the water level setting device 34, and excess water is discharged to the drainage channel 33. In this way, the water is supplied sequentially from the upstream side to the cultivation section 42 on the downstream side, so that the supply of the water tends to be short in the cultivation section 42 on the downstream side. In particular, during the drought period when sunshine continues, the cultivation zone 4 on the downstream side
Water was hardly supplied to No. 2 and the yield was reduced due to poor rice growth.

In a conventional paddy field in which each water channel is formed as an open type, the cultivation area 42 and the farm road 40 are narrowed by the width occupied by the water supply channel 31 and the drain channel 33. There were also problems. Furthermore, since sediment or the like easily falls and accumulates in each of the water channels having an open upper part, there is a problem that the operation of discharging the soil and the like must be frequently performed, and the water channel management is troublesome.

Further, in a so-called terraced rice field in which paddy fields are provided in a stepped manner on a slope, a groove serving as a communication passage between the upper paddy field and the lower paddy field is provided on a ridge which separates the upper paddy field from the lower paddy field. Paddy field irrigation is used to supply water from paddy fields to lower paddy fields.However, in the case of paddy field irrigation, the work of forming ridges that serve as communication passages on each ridge is troublesome, In addition, the growth of rice was sometimes poor in the periphery of the groove. That is, when the low-temperature water flows continuously through the groove serving as the communication passage, at the periphery of the groove,
There was a problem that the growth of rice became poor due to the influence of low-temperature water.

On the other hand, with the urbanization of rural areas, farmers are becoming part-time workers, and the demand for automation and labor saving of agricultural work is increasing due to reduction and limitation of working hours. Labor saving is desired.

Accordingly, the present invention provides a paddy field which can supply irrigation water in a stable state over the entire paddy field including the terraced rice field, can automatically maintain a constant water level on the paddy field, can provide excellent workability, and can be provided at low cost. It aims to provide a water level control device and a water management system.

[0009]

In order to achieve the above object, a water level adjusting device for a paddy field according to the present invention has a water supply pipe and a drainage pipe buried along a farm road, and the water supplied from the water supply pipe is cultivated. A water level control device for a paddy field that supplies surplus water from the cultivation area to a drain pipe, and the water supply to the bottomed tubular water supply and drainage basin having a cultivation area water supply and drain port communicating with the cultivation area of the paddy field. A water inlet connected to the pipe,
A drainage pipe connected to the drainage pipe, a water supply valve for adjusting the supply of water is provided at the water inlet, and a drainage valve that can be opened near the bottom of the water supply and drainage basin is provided at the water discharge part. And a water level control weir that can be adjusted in height and that opens above the plumbing basin.

Further, the water level adjusting device of the present invention is characterized in that the cultivation area water supply / drainage port communicates with the cultivation area through an overflow gate whose height can be adjusted, and that the water inflow portion is located above the water supply / drain basin. The water level adjustment weir and the backflow prevention weir are connected to the service water discharge unit or the service water inflow unit and move upward and downward at the upper end of a pipe opened upward. It is characterized by being formed by a cylindrical body fitted as possible.

Further, the water management system for paddy fields according to the present invention is a water management system for paddy fields in which a farm road is provided on a side edge and is divided into a plurality of cultivated areas by ridges, and a water supply pipe is provided along the farm road. A drainage pipe is buried, and a water level adjustment device connected to the water supply pipe and the drainage pipe is installed in each of the cultivation areas. A cultivation area water supply / drain opening communicating with the ward, a water inflow section connected to the water supply pipe, and a water discharge section connected to the water pipe,
The service water inflow portion includes a water supply valve that controls supply of service water, and the service water discharge portion includes a drain valve that can be opened near a bottom portion of the water supply and drainage basin and a water level that can be adjusted at a height that is open at an upper portion of the water supply and drainage basin. A regulating weir, and water is supplied to the cultivation area from the cultivation area water supply and drainage port, by opening the water supply valve, the water flowing into the water supply and drainage basin from the water supply pipe through the water supply inflow section,
Excess water or rainwater supplied to the cultivation area flows into the plumbing basin from the cultivation area water supply / drain port, and is discharged from the irrigation water discharge section to the drain pipe through the water level control weir whose height has been adjusted to the surface of the rice field, and By opening the valve, the water in the water supply and drainage basin and the earth and sand flowing into the water supply and drainage basin is configured to be discharged, furthermore, the paddy is a paddy provided stepwise on the slope, The water discharged from the water discharge part of the water level adjusting device installed in the paddy field to the drain pipe is supplied to a water supply pipe of a lower paddy field through a water supply / drain passage.

[0012]

FIG. 1 is a schematic plan view showing an example of a water management system using a water level adjusting device according to the present invention, and FIG.
1 is a schematic cross-sectional view near the line II-II in FIG. 1, and FIG.
FIG. 3 is a schematic sectional view near the line III.

As shown in FIGS. 2 and 3, the paddy field 4 shown in this embodiment has a downward slope toward the lower side and the right side in FIG. 1, and the upper left direction in FIG. The direction is the lowest. The inside of the paddy field 4 is divided into a plurality of cultivation areas 42 by ridges 41 extending in the short direction. Each cultivation area 42 has, for example, a long side of 100 to 200.
m, short side is divided into a rectangular shape of about 30-100m,
Each cultivation area 42 has a step-like shape with the adjacent cultivation area 42, but the inside of each cultivation area 42 is substantially leveled even if it is gently inclined as a whole. .

On the side edge of the paddy field 4, an agricultural road 43 is provided along the longitudinal direction. The upper surface of the farm road 43 has a central portion formed on a flat surface having substantially the same width as that of the conventional farm road, and a paddy field 4 is provided on one or both sides of the flat surface.
An inclined surface having a downward slope toward the side is formed. This inclined surface is a portion where the irrigation canals and drainage channels conventionally provided along the agricultural roads have been removed and backfilled.
For this reason, the farm road 43 is considerably wider than the conventional farm road, and the direction of the farm road 43 can be changed by turning a tractor or the like, and one side of the farm road 43 can be used as a parking space.

In each farm road 43, a water supply pipe 51 and a drain pipe 52, which are water flow pipes for passing water, are buried below the inclined surface. The upstream side of the water supply pipe 51 and the drainage pipe 52 is connected to an upper side water supply / drainage channel (however, the uppermost stage is a branch line waterway, and the lowermost stage is a drainage channel) 37 via valves 51a and 52a. It is connected to the lower supply / drainage channel 37 via valves 51b and 52b. The water supply and drainage channel 37 is provided with a water basin 38 corresponding to the position of each farm road 43, and both ends of the water supply pipe 51 and the drainage pipe 52 are connected to the water basin 38. Further, a water supply pipe 54 provided with a water supply valve 53 for supplying water as needed can be provided in the cultivation area 42 at the top of the terraced rice field.
Although not shown, a waterway for drawing water from a river or the like is connected to the uppermost branch waterway, and a discharged waterwater or rainwater is returned to the river at the lowermost waterway. A waterway is connected.

A water level adjusting device 6 connected to each cultivation area 42 through a cultivation area water supply / drain port is provided on a side edge of each cultivation area 42.
Are connected to the water supply pipe 51 and the drain pipe 52, respectively.

FIG. 4 is a schematic piping diagram showing an example of the water level adjusting device 6 used for water management in one cultivation area 42. The water level control device 6 includes a bottomed cylindrical water supply / drainage basin 60, a cultivation area water supply / drainage port 61 communicating with the cultivation area 42, and a water supply pipe 5.
1 and a water discharge unit 63 connected to the drain pipe 52. The service water inflow portion 62 is provided with a water supply valve 64 and a backflow prevention weir 65 that can be adjusted in height and opens above the water supply and drainage basin 60. Further, the water discharge section 63 is provided with a drain valve 66 that can be opened near the bottom of the water supply and drainage basin 60 and a water level adjustment weir 67 that is open at the top of the water supply and drainage basin 60 and that can be adjusted in height.

5 to 7 show specific examples of the shape of the water level adjusting device 6, FIG. 5 is a plan view, and FIG. 6 is a vertical sectional view showing a water inlet 62 and a cultivation area water supply / drain 61. FIG. 7 is a longitudinal sectional view showing the water discharge section 63.

The water level adjusting device 6 is provided with various water supply / drainage means in a cylindrical water supply / drainage basin 60 having a bottom. As described above, the water supply / drainage means includes the cultivation area water supply / drainage port 61 communicating with the cultivation area 42, the water inflow section 62 connected to the water supply pipe 51, and the water discharge section 63 connected to the drainage pipe 52. The water supply inlet 62 has a water supply valve 6
4 and a backflow prevention weir 65 having an adjustable height which is open at the top of the water supply and drainage basin 60. The water discharge unit 63 has a drain valve 66 and a water supply and drainage basin 6 which can be opened near the bottom of the water and drainage basin 60.
A height-adjustable water level control weir 67 is provided at the top of the zero. In addition, the cultivation zone water supply and drainage port 61 includes:
A height-adjustable and detachable overflow gate 68 is provided.

The water supply valve 64 is inserted into a vertical pipe 64P connected to the pipe 62P of the service water inflow section 62 with a vertically slidable cylindrical body 64T capable of closing the opening of the pipe 62P. It was done. This cylinder 64
An appropriate seal packing is attached to T,
An operation rod 64H extending above the water supply and drainage basin 60 is provided. As shown in FIG. 6, by pulling up the operation rod 64H and moving the cylindrical body 64T upward, the valve is opened, and the operation rod 64H is pushed down. The valve closing state is established by positioning the cylinder 64T at the opening of the pipe 62P.

The backflow prevention weir 65 is connected to the pipe 64.
A cylindrical body 65T is fitted in the upward opening of the upper end of P via a rubber seal packing for obtaining watertightness and sliding resistance so as to be vertically movable. Is provided. Further, the water level adjusting weir 67 is provided with a horizontal pipe 63 of the water discharge unit 63.
A pipe 67T which is vertically movably fitted through a rubber seal packing in the upward opening of the upper end of the pipe 67P rising vertically from the pipe 67P. Also, the same operation rod 67 as described above
H is provided. By expanding the upper edge of the cylindrical body 67T in a trumpet shape, it is possible to efficiently discharge the water.

As the drain valve 66, a slide valve 70 as shown in a perspective view in FIG. 8 is used. In this slide valve 70, a plate-shaped valve element 74 is provided between two plate-shaped members 72, 73 having a through-hole 71 corresponding to the pipe 63P so as to be movable up and down. Valve stem 7
The valve rod 75 is provided with an operation rod 66H similar to that described above.

Each of the operating rods 64H, 65H, 66
H and 67H may be provided with a scale for displaying the open / closed state of the valve and the like. Further, a lid can be mounted on the upper part of the water supply and drainage basin 60.

The overflow gate 68 provided at the cultivation section water supply / drain port 61 is formed by two upper and lower dam plates 81 and 82 provided at the cultivation section side opening of the outlet box 80 which is open at the cultivation section 42 side. I have. The weir plates 81 and 82 are removably inserted into two concave grooves 83 provided on both sides so as to be vertically adjustable and detachable, and adjust and remove the up and down positions of the weir plates 81 and 82. This prevents the inflow of earth and sand into the water supply and drainage basin 60, or drains the cultivation area 42 quickly.

The water level adjusting device 6 constructed as described above
Is buried in a vertical state on the inclined surface of the farm road 43 facing each cultivation area 42, and the surface water level is set for each cultivation area 42. That is, the water level control device 6 installed in each cultivation area 42
By moving the operation rod 67H provided on the cylindrical body 67T up and down,
It is set for each cultivation area 42.

Normally, in the water level adjusting device 6 installed in each cultivation area 42, the backflow prevention weir 65 of the service water inflow portion 62 connected to the water supply pipe 51 has the upper edge of the cylindrical body 65T slightly lower than the rice field water level L. The water level adjusting weir 67 of the water discharge unit 63 set at a high position and connected to the drain pipe 52 has a cylindrical body 67.
The upper edge of T is set to a height corresponding to the rice field water level L. Further, the water supply valve 64 is appropriately opened, and the drain valve 66 is fully closed. Further, the height of the overflow gate 68 is set at a position lower than the rice field water level L and higher than the ground surface.

In the above-described setting state, the water from the water supply pipe 51 passes through the water supply valve 64 opened by a predetermined amount, rises in the pipe 64P from the water supply inflow portion 62, and is raised above the cylindrical body 65T of the backflow prevention weir 65. After flowing into the water supply and drainage basin 60 across the edge, water is supplied from the cultivation area water supply and drain port 61 to the cultivation area 42 through the overflow gate 68. The supply of irrigation water to the cultivation area 42 is caused by the rise of the rice field surface
This is continued until the height exceeds the upper edge of 7T.

On the other hand, surplus water or rainwater supplied to the cultivation area 42 flows back through the cultivation area water supply / drain port 61 to supply / drain basins 60.
The pipe 6 passes over the upper edge of the cylindrical body 67T of the water level adjusting weir 67 adjusted to a height corresponding to the rice field water level L.
It flows down in 7P and is discharged from the water discharge part 63 to the drain pipe 52.

At this time, since the upper edge of the cylindrical body 65T of the backflow prevention weir 65 is set at a position slightly higher than the rice field water level L, even if the supply of the water to the water supply pipe 51 is stopped, the water is supplied to the water supply pipe 51. There is no backflow to the side. Further, since the overflow gate 68 is set at a position higher than the ground surface, it is possible to prevent the earth and sand in the cultivated area 42 from flowing into the water supply and drainage basin 60.

Therefore, the surface water level in each cultivation area 42 can be automatically adjusted by adjusting the cylinder 67T of the water level adjusting weir 67 of the service water discharge unit 63 to a predetermined height. Then, by appropriately adjusting the opening of the water supply valve 64 of the service water inflow section 62, the amount of water for inflow into the cultivation area 42 can be adjusted, and the rice field water level can be maintained constant with the minimum necessary water amount. Becomes

When such water management is performed, each cultivation zone 4
Since the supply amount of the water to the second cultivation area 42 can be reduced, the water can be uniformly supplied from the cultivation area 42 on the upstream side to the cultivation area 42 on the downstream side, and the shortage of water in the cultivation area 42 on the downstream side does not occur. In addition, when the water level in the cultivated area 42 is maintained at a constant level, the water in the cultivated area 42 is hardly discharged to the outside, so that the pesticides and fertilizers applied to the cultivated area 42 are discharged to the outside together with the water and rainwater. There is little outflow, and there is no risk of causing environmental destruction.

When draining the water from the cultivation area 42, the water supply valve 64 of the water inflow section 62 is closed, and the cylinder 67T of the water level regulating weir 67 of the water discharge section 63 is pushed down or the drain valve 66 is discharged. open. As a result, the water stored in the cultivation area 42 is discharged from the water discharge section 63 to the drain pipe 52.
Can be discharged.

In addition, the cultivation area supply / drainage port 6
The sediment or the like that has entered the plumbing basin 60 through the plenum 1 opens the drainage valve 66 at the bottom of the plumbing basin 60, thereby causing the drainage valve 6 to open.
6 can be discharged to the drain pipe 52 together with the water.

On the other hand, when a paddy field requiring a large amount of water at once is used, the water supply valve 64 is fully opened to push down the cylinder 65T of the backflow prevention weir 65, and the cylinder of the water level adjusting weir 65 of the water discharge unit 63. Pull up the body 65T. Thereby, the water supplied from the water supply pipe 51 flows into the cultivation area 42 from the water inflow section 62 and is not discharged from the water discharge section 63, but is entirely supplied and stored in the cultivation area 42. And quickly reaches the predetermined water level. By repeating this operation for each cultivation area 42, it is possible to supply water sequentially from the cultivation area 42 on the upstream side to the cultivation area 42 on the downstream side.

Further, when it is not necessary to supply water to some of the cultivated areas 42 due to the loss of water or the like, the water supply valve 64 of the water level adjusting device 6 corresponding to the cultivated area 42 is closed, and the drain valve 66 is fully opened. Then, the weir plates 81 and 82 of the overflow gate 68 are removed. As a result, rainwater or the like in the cultivated area 42 is discharged from the cultivated area 42 to the drain pipe 52 through the water level adjusting device 6.

According to the water level adjusting device 6 configured as described above, the amount of water flowing through the water supply pipe 51 can be reduced, so that a small-diameter pipe can be used. Also,
The water level adjusting device 6 can be manufactured by appropriately combining synthetic resin cylindrical members and the like, and is integrally incorporated in the water supply and drainage basin 60. Since it is only necessary to connect the water discharge section 63 to the water supply pipe 51, the drain pipe 52, and the drain valve 66 directly or via an appropriate joint, construction costs and the like can be significantly reduced.

Further, by forming the overflow gate 68 as a two-stage sliding dam plate 81, 82, it is possible to prevent earth and sand and the like from entering the water supply and drainage basin 60 at the time of scraping. Effective drainage during cropping. In other words, if the upper dam plate 81 is raised, it is possible to prevent earth and sand and the like from entering the plenum 60 during scraping. When the paddy field is to be dried, drainage can be performed by pushing down the upper dam plate 81 and excavating the nearby ground as indicated by reference numeral P1 in FIG. Further, at the time of reduction or crop rotation, the upper and lower dam plates 81, 82 are used.
Lift or remove the
As shown by reference numeral P2, by digging down about 30 cm, there is an advantage that the water in the paddy field can be dropped smoothly.

The water discharge section 63 of the water level control device 6 installed in each cultivation area 42 of the paddy field 4 located above the sloped land.
The water discharged from the drainage pipe 52 flows down into the water supply / drainage channel 37 provided between the paddy field 4 located below, and flows from the left side to the right side in FIG. As described above, this water supply / drainage channel 37
A water basin 38 for connecting a water supply pipe 51 and a drain pipe 52 is provided corresponding to the position of each farm road 43.

FIGS. 9 and 10 show examples of the shape of the water basin 38. FIG. 9 is a plan view and FIG. 10 is a longitudinal sectional view. A weir 38 a is provided in the water basin 38 so that a predetermined amount of water flowing through the water supply / drainage channel 37 can be stored. The water supply pipe 51 and the drainage pipe 52 are connected to the weir 3.
8a is connected to the upstream side. By providing the water basin 38 having the weir 38 a in the water supply / drain passage 37, a predetermined amount of the water flowing down from the drainage pipe 52 can be reliably supplied to the water supply pipe 51. In addition,
The weir 38a can be formed so as to be adjustable in height by appropriate means, and is formed so as to be removable during the non-irrigation season.

In the irrigation on such a slope, the cultivation zone 4 at the top of the paddy field 4 located above the slope is used.
In 2, the height difference with the water basin 38 becomes smaller,
There is a possibility that a sufficient amount of water cannot be supplied into the cultivation area 42 from the water inflow portion 62 of the water level adjusting device 6. Therefore, in this case, by opening the water supply valve 53 appropriately, the water can be supplied to the uppermost cultivation area 42 from the water supply pipe 54 connected to the water supply / drain passage 37.

On the other hand, even in the lowermost cultivation area 42, the height difference between the water basin 38 and the water basin 38 becomes small, and drainage from the water discharge section 63 of the water level adjusting device 6 may become difficult. In this case, as shown by the imaginary line in FIG. 2, by providing an auxiliary drain pipe 55 connected to the drain pipe 52 installed in the paddy field below the water discharge section 63, the lowermost cultivation area 42 Can be reliably drained.

11 to 13 show another embodiment of the water level adjusting device of the present invention. FIG. 11 is a schematic diagram of piping, FIG. 12 is a plan view, and FIG. 13 is a vertical sectional view showing a water inflow portion. It is. The water level adjusting device 6A shown in this embodiment uses a floating valve in the water inlet portion 62 instead of the water supply valve 64 and the backflow prevention weir 65 of the water inlet portion 62 in the water level adjusting device 6 shown in the above embodiment. A water supply valve 69 is provided.

The water supply valve 69 shown in this embodiment is a vertical pipe 69P connected to the pipe 62P of the water inflow section 62.
The spherical float valve 91 is opened by pressing down a spherical float valve 91 with a valve shaft 93 operated by a handle 92, and when the handle 92 is rotated to raise the valve shaft 93, the valve rises in the pipe 62 </ b> P. Float valve 91 is pressed against valve seat 94 by water to close the valve. Therefore, by adjusting the amount of rise of the valve shaft 93, the amount of inflow of service water can be controlled.

The water level adjusting device 6A using the water supply valve 69
Is advantageous in that the air pool generated in the water supply pipe 51 can be eliminated to prevent water shortage beforehand, and that the water supply pipe 51 can be prevented from being damaged due to momentary negative pressure in the pipe.

It should be noted that the water level adjusting device 6A in the present embodiment example
Regarding the other components, the same reference numerals are given to the same components as the components in the water level adjusting device 6 of the embodiment, and the detailed description is omitted. Further, since the operations in water level adjustment and drainage are the same, the description of the operation of the water level adjustment device 6A is omitted.

In both of the above embodiments, the water supply and drainage basin constituting the water level adjusting device has a cylindrical shape.
The shape may be rectangular, and the shape of the water supply and drainage basin is not particularly limited. Further, the structures of the backflow prevention weir and the water level adjusting weir are not limited to the above-mentioned cylindrical body, but may be formed in a bellows shape or a weir plate type. Furthermore, by forming each operation rod detachably by, for example, a screw-in structure, it is possible to prevent the water level adjusting weir and the like from being operated when it is not necessary.

Further, FIG. 1 shows an example in which water level adjusting devices are installed on both sides of each cultivation area extending along the longitudinal direction of the paddy field, but the present invention is not limited to this. In other words, if water level control devices are installed on both sides of the cultivation area, there is an advantage that fine water management can be performed over the entire cultivation area, but if the area of the cultivation area is not so large, only one side of the cultivation area Just installing the water level control device can provide sufficient water management, and if the area of the cultivation area is large, the water level control device may be installed at a plurality of locations depending on the capacity of the water level control device. When a plurality of water level adjustment devices are provided, they may be used separately for water supply and drainage.

Further, the opening and closing of each valve and the vertical position adjustment of the weir can be formed so as to be remotely controllable by a motor or the like instead of the operation rod, and can be automatically controlled using a computer or the like. is there.

[0049]

As described above, according to the water level adjusting device and the water management system for the paddy field of the present invention, the water supply pipe and the drain pipe are buried on the agricultural road provided along the side edge of the paddy field. The space of cultivated areas and farm roads can be greatly expanded, and farmland can be used effectively.

Further, the water level adjusting device can reliably supply water to the cultivated areas, maintain the water level on the rice fields, discharge the water from the cultivated areas, etc., with a simple operation. Water management such as maintenance of water can be performed efficiently. 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 and drainage basin, the water level adjusting device can be formed compactly, and can be supplied with excellent workability and at low cost.

Further, according to the present invention, water management can be performed so as to minimize discharge of water supplied to each cultivated area as surplus water, so that pesticides, fertilizers, and the like applied to each cultivated area can be used together with the water. The amount flowing out can be reduced, and there is no problem of environmental destruction.

In a paddy field on a sloping land, water supplied to a drain pipe from a water level control device installed in an upper paddy field is supplied to a water pipe in a lower paddy field via a water supply / drainage channel to thereby provide a water supply. Usage efficiency can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an example of a water management system using a water level adjusting device of the present invention.

FIG. 2 is a schematic cross-sectional view near the line II-II in FIG.

FIG. 3 is a schematic cross-sectional view near the line III-III in FIG. 1;

FIG. 4 is a schematic piping diagram showing one embodiment of a water level adjusting device.

FIG. 5 is a plan view showing a specific example of the shape of the water level adjusting device.

FIG. 6 is a vertical sectional view showing a water inflow portion and a cultivation area water supply / drainage portion.

FIG. 7 is a longitudinal sectional view showing a water discharge section.

FIG. 8 is a perspective view of a slide valve used in the water level adjusting device.

FIG. 9 is a plan view showing an example of the shape of a water basin.

FIG. 10 is a longitudinal sectional view of the same.

FIG. 11 is a schematic piping diagram showing another embodiment of the water level adjusting device.

FIG. 12 is a plan view showing another example of the shape of the water level adjusting device.

FIG. 13 is a longitudinal sectional view of the same.

FIG. 14 is a schematic plan view showing a conventional paddy structure.

FIG. 15 is a perspective view of a conventional water supply channel.

[Explanation of symbols]

37: water supply / drainage channel, 38: water basin, 38a: weir, 4: paddy field, 41: ridge, 42: cultivation area, 43: farm road, 51: water supply pipe, 52: drainage pipe, 51a, 51b, 52
a, 52b: valve, 53: water supply valve, 54: water supply pipe, 55: auxiliary drain pipe, 6, 6A: water level control device, 60: water supply and drainage basin, 61: cultivation area water supply and drainage port, 62 ...
Water inlet, 63 ... Water outlet, 64 ... Water supply valve, 64H
... Operation rod, 64T ... Cylinder, 65 ... Backflow prevention weir, 65
T: cylindrical body, 66: drain valve, 66H: operating rod, 67 ...
Water level control weir, 67T ... cylindrical body, 68 ... overflow gate, 69 ...
Water supply valve, 70: slide valve, 80: outlet measure, 81, 82
… Weir plate, 91… float valve, 93… valve shaft, 94… valve seat

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasunori Hashimoto 5-8, Mitsuya-cho, Nagahama-shi, Shiga Prefecture Mitsubishi Plastics Co., Ltd. Nagahama Plant (72) Inventor Kiminori Takao 75 Nojiri, Ritsuto-cho, Kurita-gun, Shiga Prefecture Sekisui Chemical Co., Ltd. In company

Claims (7)

[Claims] A water level control device for a paddy field in which a water supply pipe and a drainage pipe are buried along a farm road, supplies water supplied from the water supply pipe to a cultivation area, and discharges excess water from the cultivation area to the drainage pipe. A bottomed cylindrical water supply / drain basin provided with a cultivation area water supply / drainage port communicating with a cultivation area of a paddy field, provided with a water supply inflow section connected to the water supply pipe, and a water discharge section connected to the drainage pipe. A water supply valve for adjusting the supply of water is provided in the water inflow section, and a drain valve that can be opened near the bottom of the water supply and drainage basin, and a height adjustment that opens at the top of the water supply and drainage basin, in the water supply and drainage section. A water level control device for a paddy field, comprising a possible water level control weir. 2. The water level control device for a paddy field according to claim 1, wherein the cultivation area water supply / drainage port communicates with the cultivation area through a height-adjustable overflow gate. 3. The water level adjusting weir is formed by a tubular body which is connected to the water discharge section and which is vertically movably fitted to an upper end of a pipe opened upward. The water level control device for paddy fields according to claim 1. 4. The water level adjusting device for a paddy field according to claim 1, wherein the service water inflow portion includes a backflow prevention weir having an adjustable height that opens at an upper portion of the water supply and drainage basin. 5. The backflow prevention weir is formed of a tubular body which is connected to the water inflow portion and which is vertically movably fitted to an upper end portion of an upwardly opened pipe. 4. The water level adjusting device for a paddy field according to 4. 6. A water management system for a paddy field in which a farm road is provided on a side edge and divided into a plurality of cultivated areas by ridges, wherein a water supply pipe and a drain pipe are buried along the farm road. In the cultivation area, a water level adjustment device connected to the water supply pipe and the drain pipe is installed, and the water level adjustment device is a bottomed cylindrical water supply and drainage basin, a cultivation area water supply and drain port communicating with the cultivation area, A service water inflow section connected to the water supply pipe, and a service water discharge section connected to the drainage pipe; the service water inflow section includes a water supply valve for adjusting supply of service water; It has a drain valve that can be opened near the bottom of the basin and a height-adjustable water level control weir that opens at the top of the water supply and drainage basin. By opening the water supply valve, water is supplied and drained from the water supply pipe through the water inlet. For those who flowed into the basin Water is supplied to the cultivation area from the cultivation area water supply / drainage port, and excess water and rainwater supplied to the cultivation area flow into the water supply / drainage basin from the cultivation area water supply / drainage port, and cross the water level control weir whose height has been adjusted to the rice field water level. A water management system for a paddy field, wherein the water is discharged from a water discharge section to a drain pipe and the drain valve is opened to discharge water in the water supply and drainage basin and earth and sand flowing into the water supply and drainage basin. . 7. The paddy field is a paddy field provided in a step-like manner on an inclined land, and the water discharged from a water discharge section of the water level control device installed in an upper paddy field to a drain pipe is supplied via a water supply / drain passage. 7. The water management system for a paddy field according to claim 6, wherein the water is supplied to a water supply pipe of a lower paddy field.