Agricultural Water Management System

Abstract

To provide an agricultural water management system capable of stably controlling a water level in a water channel.SOLUTION: A water channel 3 is arranged along a plurality of paddies 5, and has a water intake part 7 to each paddy 5. A weir 9 is arranged for each water intake part 7. A power generator 11 is installed on the downstream side of the water intake part 7 of the water channel 3, the power generator 11 is capable of generating power by water flow passing through the water channel 3. By using a water level sensor capable of measuring a water level of the water channel 3 on the upstream side of the power generator 11 or a water level of the paddies 5 on the upstream side of the power generator 11, a control part adjusts a rotation load of the power generator 11, by which the water flow resistance of water passing through the power generator 11 can be controlled. Thus, on the basis of water level information of the water level sensor, a water level of the water channel 3 on the upstream side of the power generator 11 can be adjusted.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an agricultural water management system capable of controlling the amount of water supplied to rice fields. [Background technology]

[0002] Rice fields are usually supplied with water via irrigation channels, and one channel is usually used to supply water to multiple rice fields. Water is supplied from the channel to each rice field by opening and closing weirs and water supply valves installed at the water inlets.

[0003] On the other hand, during the rice planting season, when the demand for water in the rice paddies increases relative to the amount of water supplied to the canal, the water level in the canal drops. In order to supply water to the rice paddies from the water inlet, a certain water level is required in the canal. For this reason, it is necessary to place weirs or sandbags downstream of the water inlet to raise the water level in the canal at the inlet.

[0004] However, because the amount of water supplied to the canal varies depending on the weather, it is difficult to stabilize the water level by installing weirs or sandbags. For this reason, it is desirable to be able to appropriately adjust the flow rate according to the water level in the canal.

[0005] As a method for adjusting the water level in such a waterway, a method has been proposed in which the waterwheel is raised and lowered to adjust the immersion depth of the waterwheel, thereby adjusting the amount of water passing through the waterwheel and adjusting the water level in the waterway (Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP2005-143475 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0007] However, the mechanism that moves the water turbine up and down must be strong enough to withstand the resistance of the water flow, which leads to an increase in the size of the structure. Also, when the water volume decreases and the water level becomes extremely low, it becomes difficult for the water turbine to provide water resistance, and the water level cannot be raised.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an agricultural water management system that can stably control the water level in a waterway. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the present invention is an agricultural water management system formed in a waterway having a water intake section to a rice field, and is equipped with a power generation device installed downstream of the water intake section of the waterway and capable of generating electricity using the water flowing through the waterway, and a control unit capable of adjusting the rotational load on the power generation device, characterized in that by adjusting the rotational load on the power generation device using the control unit, the water flow resistance of water passing through the power generation device can be controlled and the water level of the waterway upstream of the power generation device can be adjusted.

[0010] The power generating device may be a screw type having spiral blades formed on the outer periphery of a rotating shaft, and the rotating shaft may be arranged facing the water flow direction of the water channel.

[0011] The system may have a water level sensor capable of measuring the water level of the waterway upstream of the power generation device or the water level of the rice field upstream of the power generation device, and the control unit may be capable of adjusting the water level of the waterway based on water level information from the water level sensor.

[0012] At least one of the control unit, the water level sensor capable of measuring the water level in the waterway or rice field, the flow rate sensor for the waterway, the rice field imaging device, the operating unit of the weir located in the water intake unit, or the heating device for heating the water supplied to the rice field may be operated using electricity generated by the power generation device.

[0013] A shielding portion for blocking the flow of water may be provided in the gap between the inner wall of the water channel and the power generation device.

[0014] The control unit may be capable of controlling the flow path area blocked by the blocking unit.

[0015] The system may include a movable weir placed in the water intake section and a water level sensor capable of measuring the water level in the rice field, and the control section may be able to adjust the water level in the rice field by operating the movable weir based on water level information from the water level sensor.

[0016] The waterway is provided with a water intake section for each of a plurality of rice fields, and a power generation device is placed downstream of each water intake section, so that the water level can be set for each rice field.The control unit may control the rotational load of each power generation device set for each rice field based on the water level of the rice field or waterway in which one of the power generation devices is installed and the water level of the rice field or waterway downstream of that power generation device.

[0017] According to the present invention, by adjusting the rotational load of the power generation device, it is possible to control the flow resistance of water passing through the power generation device and adjust the water level in the water channel upstream of the power generation device, which eliminates the need for a mechanism to move the power generation device up and down.

[0018] In particular, by using a screw-type power generator with spiral blades formed on the outer periphery of the rotating shaft and positioning the power generator so that the rotating shaft faces the direction of the water flow in the waterway, stable power generation can be achieved even when the water level drops. For example, when adjusting the water volume by raising and lowering the power generator, when the water volume increases, the water wheel is raised to reduce the amount of immersion. However, when the water level subsequently drops, the water wheel is exposed above the water, and power generation by rotation ceases. For this reason, controlling the up and down movement using power generation makes it difficult to follow fluctuations in the water level. On the other hand, if the power generator is a screw-type power generator, it is used while always immersed in water, so it can easily follow fluctuations in the water level.

[0019] Furthermore, if the generator is a screw type, there is no need to place the generator or its upper and lower motors above the waterway, allowing for greater freedom in installation, and since the rotating body is not exposed above the waterway, there is less chance of contact with people, making it safer.

[0020] Furthermore, by using a water level sensor that can measure the water level in the water channel upstream of the power generation device or another water level upstream of the power generation device, the water level in the water channel can be adjusted based on the water level information from the water level sensor.

[0021] In addition, the electricity generated by the power generation device can be used to operate various equipment for managing the rice fields.

[0022] Furthermore, by providing a shielding portion that blocks the flow of water in the gap between the inner wall of the waterway and the power generation device, water can be more reliably directed to the power generation device.

[0023] In this case, if the control unit can control the flow path area blocked by the shielding unit, it is possible to adjust the amount of water that is not used for power generation and is allowed to flow backward.

[0024] Furthermore, by operating the movable weir placed at the water intake section based on water level information from a water level sensor that can measure the water level in the rice field, the water level in the rice field can be adjusted more reliably.

[0025] Furthermore, if a waterway has separate water intake sections for multiple rice fields, a power generation device can be placed downstream of each water intake section to adjust the flow rate, allowing the water level to be set and adjusted individually for each rice field. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide an agricultural water management system that is capable of stably controlling the water level in a waterway. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a diagram showing an agricultural water management system 1. [Figure 2] 1 is a block diagram showing the configuration of an agricultural water management system 1. FIG. [Figure 3] FIG. 2 is a diagram showing an installation state of the power generation device 11. [Figure 4] FIG. 10 is a diagram showing the operation of the weir 9. [Figure 5] FIG. 10 is a diagram showing another installation state of the power generating device 11. [Figure 6] FIG. 10 is a diagram showing another installation state of the power generating device 11. [Figure 7] 10A and 10B are diagrams showing the operation of the shielding unit 25a. [Figure 8] 10 is a diagram showing a method for preventing drifting objects from flowing into the power generation device 11. FIG. [Figure 9] FIG. 3 is a block diagram showing another configuration of the agricultural water management system 1. [Figure 10] A diagram showing how the amount of water intake is adjusted by the weir 9a. DETAILED DESCRIPTION OF THE INVENTION

[0028] [First embodiment] A first embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a diagram showing an agricultural water management system 1, and Fig. 2 is a block diagram showing the configuration of the agricultural water management system 1. The agricultural water management system 1 is formed in a water channel 3 having a water intake section 7 to a rice field 5, and is mainly composed of a weir 9, a power generation device 11, water level sensors 13a and 13b, a control section 17 (see Fig. 2), etc.

[0029] The waterway 3 is arranged along a plurality of rice fields 5, and has a water intake section 7 for each of the rice fields 5. A weir 9 is arranged at each of the water intake sections 7. In this embodiment, the weir 9 is a movable weir that is opened and closed by a weir operating section 15 (see Figure 2). Note that the weir 9 is not limited to a movable weir that opens and closes by moving up and down, and may also be an opening and closing valve or the like.

[0030] The power generating device 11 is installed downstream of the intake section 7 of the waterway 3. Figure 3 is a diagram showing the structure of the power generating device 11. The power generating device 11 is a screw type with a continuous spiral blade 23 formed on the outer periphery of a rotating shaft 21. For example, the technology disclosed in Japanese Patent No. 584598 can be used for the power generating device 11.

[0031] The power generating device 11 is placed on the bottom of the waterway 3 so that the rotating shaft 21 faces the direction of the water flow in the waterway 3. If even a small amount of water is flowing in the waterway 3 and part of the blades 23 is immersed in the water, the blades 23 will receive the water flow and rotate the rotating shaft 21, allowing the water to flow from the upstream side to the downstream side. At this time, the rotation of the rotating shaft 21 can generate electricity in the generator 19. The power generating device 11 is fixed to the waterway 3 by a protrusion or excavation provided in the waterway so that it will not move downstream.

[0032] Water level sensors 13a and 13b are connected to the control unit 17. Water level sensor 13a is capable of detecting the water level in the rice field 5. Water level sensor 13b is capable of detecting the water level in the water channel 3 upstream of the power generation device 11 (near the water intake unit 7). Note that at least one of water level sensors 13a and 13b may be used.

[0033] The control unit 17 can control the power generation device 11 and the weir operating unit 15 based on information from the water level sensors 13a and 13b. Figure 4 is a diagram showing the operation of the weir 9. As shown in Figure 4(a), when the water level sensor 13a determines that the water level in the rice field 5 is sufficiently high, the control unit 17 operates the weir operating unit 15 to close the weir 9. This allows the water in the waterway 3 to flow downstream, allowing water to be supplied to other rice fields 5.

[0034] On the other hand, when the water level sensor 13a determines that the water level in the rice field 5 has dropped, the control unit 17 operates the weir operating unit 15 to open the weir 9 according to the water level, as shown in Figure 4(b). This allows water to be supplied to the rice field 5 from the water intake unit 7. In this way, by using the water level sensor 13a that can measure the water level in the rice field 5, the control unit 17 can adjust the water level in the rice field 5 by operating the weir 9 based on the water level information from the water level sensor 13a.

[0035] Also, as shown in FIG. 4(c), there are cases where the water level sensor 13a detects that the water level in the rice field 5 has dropped and opened the weir 9, but the water level in the water channel 3 is insufficient. In this case, water is not supplied sufficiently to the rice field 5. In this way, when the water level sensor 13b determines that the water level in the water channel 3 has dropped, the control unit 17 increases the rotational load of the power generation device 11 (e.g., the amount of power generated per rotation). In other words, it increases the rotational load on the rotating shaft 21 caused by the water flow, making it more difficult to rotate. Note that such a change in the rotational load may be achieved, for example, by controlling a converter to increase the power generation load, or by control using gears or the like.

[0036] In the screw-type power generator 11, water moves from upstream to downstream as the blades 23 rotate, and flows down the power generator 11. Therefore, when the rotational load of the power generator 11 increases and the rotation amount of the rotating shaft 21 decreases, the water flow resistance increases and the amount of water transported downstream per unit time decreases. As a result, the water level in the water channel 3 upstream of the power generator 11 can be raised. This makes it possible to supply water from the water intake 7 to the rice field 5.

[0037] In this way, the control unit 17 is able to adjust the rotational load on the power generation device 11. In this way, using a water level sensor capable of measuring the water level in the water channel 3 upstream of the power generation device 11 or the water level in the rice field 5 upstream of the power generation device 11, when it is determined that the water level in the rice field 5 or the water channel 3 has dropped, the control unit 17 adjusts the rotational load on the power generation device 11, thereby controlling the water flow resistance of the water passing through the power generation device 11 and adjusting the water level in the water channel 3 upstream of the power generation device 11. In other words, the water level of the rice field 5 or the water channel 3 can be adjusted based on the water level information from the water level sensor.

[0038] The electricity generated by the power generation device 11 can be used in the agricultural water management system 1. For example, it can be used to operate the control unit 17, the water level sensors 13a and 13b that can measure the water level in the waterway 3 or the rice field 5, the weir operating unit 15 that operates the weir 9, etc. Furthermore, at least one of the flow rate sensor in the waterway 3, the imaging device in the rice field 5, or the heating device that heats the water to be supplied to the rice field 5 may be operated using the electricity generated by the power generation device 11.

[0039] According to the agricultural water management system 1 of the first embodiment, the water level in the water channel 3 can be adjusted by adjusting the rotation load of the power generation device 11. Therefore, even if the water level in the water channel 3 drops, the water level in the water channel 3 at the water intake section 7 can be maintained, and water can be reliably supplied to the rice paddy 5.

[0040] Furthermore, because the power generating device 11 is a screw type, it can be used while always submerged in water. This allows power generation even with a small amount of water. Furthermore, there is no need to move the power generating device 11 up and down to adjust the amount of water passing through, and no vertical movement mechanism for the power generating device 11 is required, minimizing the structure that needs to be installed above the waterway. Furthermore, because the screw type power generating device 11 is very lightweight, it can be moved away as a whole during the winter (when there is snowfall), for example, in snowy regions. Alternatively, in conditions where the amount of snowfall and temperature drops in winter are not too severe, the water flowing in the waterway and the power generating equipment can be heated to survive the winter.

[0041] In addition, by using a water level sensor to control the operation of the power generation device 11 and the weir 9 according to the water level of the water channel 3 and the water level of the rice field 5, the water level of the rice field 5 can be more reliably controlled under specified conditions.

[0042] Furthermore, the electricity generated by the power generation device 11 can be used to operate various sensors and the control unit 17. This eliminates the need for a separate power source. For example, a flow rate sensor may be placed in the waterway 3, and the operation of the power generation device 11 and the weir 9 may be controlled based on the flow rate information. Furthermore, an imaging device may be installed for the rice field 5, and images of the condition of the rice field 5 may be taken at predetermined intervals, and the imaging data may be managed wirelessly (for example, via LPWA communication). In addition, based on the water temperature data of the rice field 5, the water supplied to the rice field 5 may be heated by a heating device to prevent cold damage. In addition, it may also be used to charge electric agricultural tools.

[0043] As mentioned above, the power generator 11 can generate electricity as long as part of the blades 23 is immersed in water, and can generate electricity even with an extremely small amount of water. However, when the electricity generated by the power generator 11 is used for the agricultural water management system 1, if the amount of water flowing through the water channel 3 falls below the minimum amount of water required for power generation, power generation will stop, and there is a risk that it will become impossible to control the various sensors and the weir 9.

[0044] Therefore, when power generation ceases and the electricity supply is stopped, the power generation device 11 is maintained in the state of the highest rotational load, and the weir 9 is maintained in the open state. In other words, the rotational load of the power generation device 11 is reduced by the power supply, and when the power supply is stopped, the circuit or mechanically shifts to a state of high rotational load. Similarly, the weir 9 is maintained in the closed state by the power supply, but when the power supply is stopped, it is automatically mechanically opened.

[0045] In this way, when the power supply is stopped, the rotational load of the power generation device 11 becomes high and the weir 9 opens, making it difficult for water to pass through the power generation device 11, and the water level upstream of the power generation device 11 gradually rises. Furthermore, because the weir 9 is open, water is supplied to the rice field 5 when the water level reaches a predetermined level or above. This prevents the water supply to the rice field 5 from being stopped even when the water volume is low and the amount of power generation is insufficient. Furthermore, when the water level reaches a certain level, the rotating shaft 21 of the power generation device 11 begins to rotate and power generation begins, so control can be performed using the various sensors and the like described above. In addition to power generation by the power generation device 11, it is also possible to use it in conjunction with a local solar panel facility or to complement each other.

[0046] [Second embodiment] Another example of the present invention will be described below as the second embodiment. The second embodiment will be described by focusing on the differences from the first embodiment, and the same components will be denoted by the same reference numerals in the drawings and will not be described again. The components described in each embodiment can be combined as needed.

[0047] 5 is a layout diagram of the vicinity of the power generation device 11 according to the second embodiment. In this embodiment, a shielding portion 25 that blocks the flow of water is provided in the gap between the inner wall of the water channel 3 and the power generation device 11. By providing the shielding portion 25, the water flowing through the water channel 3 can be efficiently introduced into the power generation device 11, allowing it to contribute to power generation.

[0048] In particular, as mentioned above, when the amount of water decreases, the rotational load of the power generation device 11 increases, and if a gap occurs between the power generation device 11 (the housing of the power generation device 11) and the inner wall of the water channel 3, water will flow through this gap, making it difficult to generate power efficiently. In response to this, by providing the shielding portion 25, it is possible to prevent water from flowing from areas other than the power generation device 11, and more reliably perform water level control, etc.

[0049] According to the second embodiment, it is possible to obtain the same effects as those of the first embodiment. In addition, by blocking the water flowing through the gap between the power generation device 11 and the inner wall of the water channel 3, it is possible to generate power more efficiently using the water flowing through the water channel 3, and it is also possible to easily control the water level of the water channel 3.

[0050] [Third embodiment] Next, a third embodiment will be described. Fig. 6 is a layout diagram of the vicinity of a power generation device 11 according to the third embodiment. In this embodiment, the power generation device 11 is arranged on the wall side (left side in the drawing) on ​​the side where the water intake section 7 of the water channel 3 is provided, and a gap is formed between the power generation device 11 and the wall surface of the water channel 3 on the other wall side (right side in the drawing). In addition, a partition member 27 is arranged on an extension line toward the upstream side of the side of the power generation device 11 on the side where a gap is formed with the wall surface of the water channel 3.

[0051] The partition member 27 is a plate-shaped member that is provided to a predetermined height from the bottom surface of the water channel 3 and that divides the water channel 3 in the width direction. The partition member 27 is also arranged in a range from the upstream end of the power generation device 11 to the upstream side of the water intake section 7.

[0052] As mentioned above, water channels 3 usually have water intakes 7 for multiple rice fields 5. In this case, when trying to supply sufficient water to rice fields 5 on the upstream side, very little water flows to rice fields 5 on the downstream side, making it difficult to ensure the required amount of water supply.

[0053] In this embodiment, the partition member 27 forms a shortcut route where water flows to the power generation device 11 and flows directly downstream without being introduced into the power generation device 11, so a predetermined amount of water can flow directly downstream regardless of the rotational load of the power generation device 11. This makes it possible to ensure a sufficient amount of water supply to the downstream side.

[0054] Furthermore, because water is stored on the side of power generation device 11 separated by partition member 27, the water level in water intake section 7 can be adjusted by controlling the rotational load of power generation device 11 described above. That is, the water level can be increased on the water intake section 7 side of partition member 27, and water can be made to flow downstream on the shortcut route side of partition member 27.

[0055] According to the third embodiment, it is possible to obtain the same effects as in the first embodiment. In addition, by intentionally letting a predetermined amount of water flow downstream through the gap between the power generation device 11 and the inner wall of the waterway 3, it is possible to ensure the amount of water supplied to the downstream rice field 5 and to adjust the water level of the waterway 3 at the water intake section 7 by the power generation device 11.

[0056] [Fourth embodiment] Next, a fourth embodiment will be described. Fig. 7 is a layout diagram of the vicinity of the power generation device 11 according to the fourth embodiment. In this embodiment, as in the third embodiment, the power generation device 11 is arranged on the wall side (left side in the drawing) on ​​the side where the water intake section 7 of the water channel 3 is provided, and a gap is formed between the power generation device 11 and the wall surface of the water channel 3 on the other wall side (right side in the drawing). In addition, a shielding section 25a is arranged in the gap between the power generation device 11 and the wall surface of the water channel 3.

[0057] As shown in Figure 7(a), the shielding portion 25a is normally in a contracted state, and in this state, water can flow downstream from between the power generation device 11 and the inner wall surface of the waterway 3. On the other hand, when it is necessary to raise the water level in the upstream rice field 5, the control unit 17 can expand the shielding portion 25a to eliminate the gap between the power generation device 11 and the inner wall of the waterway 3. In this way, the control unit 17 can control the flow path area between the power generation device 11 and the inner wall of the waterway 3 that is blocked by the shielding portion 25a.

[0058] The shielding portion 25a is, for example, a bag or bellows member into which a fluid is introduced, and is kept contracted by a spring or magnet, etc., and becomes expandable when control by the control unit 17 or electricity is cut off.

[0059] According to the fourth embodiment, the same effects as those of the first embodiment can be obtained. Furthermore, depending on the situation, the control unit 17 can adjust the amount of water flowing downstream by changing the flow path area defined by the shielding portion 25a. Therefore, for example, when power generation by the power generation device 11 is no longer performed, the shielding portion 25a can be expanded to reliably introduce the water flowing through the water channel 3 into the power generation device 11, thereby operating the power generation device 11.

[0060] [Fifth embodiment] Next, a fifth embodiment will be described. Fig. 8 is a layout diagram of the vicinity of the power generation device 11 according to the fifth embodiment. In this embodiment, similar to the third embodiment, the power generation device 11 is arranged on the wall side (left side in the drawing) on ​​the side where the water intake section 7 of the water channel 3 is provided, and a gap is formed between the power generation device 11 and the wall surface of the water channel 3 on the other wall side (right side in the drawing). In addition, a partition member 27 is arranged as necessary.

[0061] A beam 29 is arranged on the upstream side of the power generation device 11 (partition member 27) so as to straddle both side walls of the waterway 3. The beam 29 is arranged diagonally with respect to the width direction of the waterway 3 so that the side on which the partition member 27 is arranged is inclined toward the downstream side. Shaft members 31 are fixed to the beams 29 at predetermined intervals, and a rotating member 33 is arranged on the outer periphery of each shaft member 31. In other words, the rotating members 33 are rotatable around the shaft members 31.

[0062] When drifting objects (solids flowing through the waterway 3) flow from the upstream side of the waterway 3, drifting objects 35a that are smaller than a predetermined size slip through the gaps between the rotating members 33 and flow directly toward the power generation device 11. On the other hand, drifting objects 35b that are larger than a predetermined size and cannot pass through the gaps between the rotating members 33 are guided by the rotation of the rotating members 33 toward the waterway wall surface beyond the partition member 27 and are washed away into the gap between the power generation device 11 and the inner wall surface of the waterway. In addition to the rotation of the rotating members 33, vibrations may be applied to the rotating members 33. This reduces the entanglement and adhesion of debris to the rotating members 33. Furthermore, water spray (such as that from a high-pressure washer) may be automatically (or remotely) applied to the power generation device 11 at predetermined intervals to provide a cleaning function.

[0063] According to the fifth embodiment, it is possible to obtain the same effects as those of the first embodiment. In addition, it is possible to prevent drifting objects 35b of a predetermined size or larger from being introduced into the power generation device 11 and causing clogging.

[0064] [Sixth embodiment] Next, a sixth embodiment will be described. Fig. 9 is a block diagram showing the configuration of an agricultural water management system according to the sixth embodiment. As mentioned above, a plurality of rice fields are connected to one water channel 3 via a water intake section 7. For simplicity, an example will be described in which three rice fields 5a to 5c are connected to the same water channel, starting from the upstream side. Note that Fig. 9 shows only the configuration of rice field 5a, omitting the configurations of 5b and 5c, but rice fields 5b and 5c have the same configuration as rice field 5a.

[0065] As mentioned above, by installing an agricultural water management system 1 for each rice field, it is possible to control the water level of the irrigation channels and rice fields for each rice field. On the other hand, the upstream rice field 5a has a relatively high degree of control freedom, but the downstream rice field 5c has a lower degree of control freedom because the amount of water flowing there is less. Table 1 shows an image of the balance of water levels in rice fields 5a to 5c.

[0066] [Table 1]

[0067] The percentages in the table represent water levels, with 100% representing the required water level, and the water levels in each rice field are shown as percentages for illustrative purposes only. For simplicity's sake, for example, if the water level is 90%, the desired yield in terms of quality and yield can be achieved, if it is 80% or higher, harvesting is possible even if there is a slight decrease in quality or yield, if it is 70% or higher, the yield will be minimal due to a decrease in quality or yield, and if it is below 70%, harvesting will be impossible. However, the water level percentages in the table do not relate to the actual water levels and growing conditions of rice paddies.

[0068] Pattern 1 shows the image of the water level in rice fields 5a, 5b, and 5c when normal control is performed on each. If control is performed independently on each rice field, for example, the necessary water level can be sufficiently maintained in rice field 5a, the most upstream, but in rice field 5b, one field downstream, the amount of water flowing through the waterway decreases, making it difficult to maintain a 100% water level. Furthermore, rice field 5c will be completely short of water and will not be able to produce a harvest.

[0069] In this way, if the water level were adjusted freely for each rice field, there is a risk that the downstream rice field 5c would not be able to harvest. Therefore, in this embodiment, a control unit 17a is provided to control the control units 17 of each of the rice fields 5a, 5b, and 5c.

[0070] In this embodiment, when a water intake section 7 is provided in the waterway 3 for each of a plurality of rice fields 5a to 5c, a power generation device 11 is disposed downstream of each water intake section 7, making it possible to set the water level for each rice field. In this case, the control section 17a controls the rotation load of each power generation device 11 set for each rice field and the opening degree of each weir 9, thereby making it possible to set a different water level for each rice field. Note that instead of the control section 17, each power generation device 11, etc. may be directly controlled only by the control section 17a.

[0071] For example, if the water level information from the water level sensors 13a in each of the rice fields 5a, 5b, and 5c indicates that the water level downstream is below a predetermined level, the target water level in the upstream rice field 5a can be lowered to reduce the amount of water supplied. Pattern 2 in Table 1 shows the result of control to average the water levels in each of the rice fields 5a to 5c. That is, based on the water level information from the water level sensors 13a in each of the rice fields 5a to 5c, the rotational load of each power generation device 11 and the opening degree of each weir 9 are controlled so that water is preferentially flowed to the rice field with the lowest water level. For example, by lowering the target water levels in 5a to 5c from 100% to 80%, an average harvest can be achieved for all of the rice fields 5a to 5c.

[0072] In addition, in pattern 3 of Table 1, harvesting in rice field 5c is abandoned and control is performed to maintain the water level in rice field 5b. For example, as shown in Figure 7(b), the water flow downstream is completely blocked and the water level upstream of power generation device 11 in rice field 5b is raised, thereby maintaining the water level in rice field 5b. By doing this, the yield will decrease, but it is possible to harvest without compromising quality.

[0073] In addition, in pattern 4 of Table 1, the water level in rice field 5a is aimed for at 100%, but the target water level in rice field 5b is lowered, and a minimum harvest is achieved in rice fields 5b and 5c. For example, if high-brand rice is to be harvested in rice field 5a, it is not possible to lower the quality in rice field 5a, and if a minimum harvest is sufficient in rice fields 5b and 5c, this type of control can be used.

[0074] As described above, according to this embodiment, the water level of the upstream rice field is reset taking into consideration not only the water level of the upstream rice field but also water level information of the downstream rice field, and the water level for each of the multiple rice fields from upstream to downstream is appropriately set, thereby making it possible to adjust the desired water level for each rice field. For example, by controlling the power generation device 11 located downstream of the water intake 7 for rice field 5a not only based on the water level of rice field 5a or the water channel 3 upstream of the power generation device 11, but also taking into consideration the water level information of the downstream rice field 5b or the water channel 3 at the water intake 7 of rice field 5b, it is possible to adjust the water level to an appropriate level for each rice field.

[0075] More specifically, if all rice fields are to be averaged, control should be performed as in pattern 2 in Table 1, if quality is the priority, control should be performed as in pattern 3, and if priority is to be given to each rice field, control should be performed as in pattern 4. The user can check the water level of each rice field daily, review the water level setting for each rice field, and adjust the water level for each rice field by controlling each power generation device 11, weir 9, etc. with the control unit 17.

[0076] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas disclosed in this application, and it is understood that these modifications and alterations also fall within the technical scope of the present invention.

[0077] For example, in the above example, a movable weir was used and its opening and closing operation was controlled by the control unit 17. However, a siphon may be used in place of the movable weir in the water intake unit 7. Furthermore, the weir may be opened and closed manually. Figure 10 shows an example of a method for adjusting the amount of water supply using a manual weir. For example, a weir 9a consisting of multiple plates can be placed, and when water supply is not required or the amount of water supply is to be reduced, all plates can be used to set the weir 9a high (Figure 10(a)). When the amount of water supply is to be increased, the upper plates can be removed to supply water to the rice field (Figure 10(b)). When the amount of water supply is to be further increased, further plates can be removed to increase the amount of water supply (Figure 10(c)).

[0078] In this case, the control unit 17 (17a) adjusts the rotation load of the power generation device 11 according to the water level in the waterway 3 upstream of the power generation device 11, and adjusts the water level at the water intake unit 7. If the weir 9a is set at a predetermined height, the amount of water supplied to the rice field can be controlled according to the water level upstream of the power generation device 11. [Explanation of symbols]

[0079] 1. Agricultural water management system 3...Waterway 5, 5a, 5b, 5c...... field 7...Water intake section 9, 9a……weir 11...Generator 13a, 13b...Water level sensor 15...Weir operating section 17, 17a...Control unit 19...Generator 21...Rotation axis 23...Feather 25, 25a……shielding part 27...Partition member 29......beam 31……Shaft member 33...Rotating member 35a, 35b……Flotsam

Claims

1. An agricultural water management system formed in a waterway having a water intake section to a rice field, a power generation device that is installed downstream of the intake portion of the waterway and that is capable of generating electricity using a water flow through the waterway; a control unit capable of adjusting a rotation load on the power generation device; Equipped with An agricultural water management system characterized in that the control unit adjusts the rotational load of the power generation device, thereby controlling the water flow resistance of water passing through the power generation device and adjusting the water level of the waterway upstream of the power generation device.

2. 2. The agricultural water management system according to claim 1, wherein the power generating device is a screw type with spiral blades formed on the outer periphery of the rotating shaft, and the rotating shaft is arranged facing the water flow direction of the waterway.

3. a water level sensor capable of measuring the water level of the waterway upstream of the power generation device or the water level of the rice field upstream of the power generation device; 2. The agricultural water management system according to claim 1, wherein the control unit is capable of adjusting the water level of the waterway based on water level information from the water level sensor.

4. The agricultural water management system described in claim 1, characterized in that at least one of the control unit, the water level sensor capable of measuring the water level in the waterway or rice field, the flow rate sensor for the waterway, the rice field imaging device, the operating unit of a weir located in the water intake unit, or the heating device for heating the water supplied to the rice field operates using electricity generated by the power generation device.

5. 2. The agricultural water management system according to claim 1, wherein a shielding portion for blocking the flow of water is provided in the gap between the inner wall of the waterway and the power generation device.

6. 6. The agricultural water management system according to claim 5, wherein the control unit is capable of controlling the flow path area blocked by the shielding unit.

7. a movable weir disposed in the intake section; A water level sensor capable of measuring the water level of a rice field, 2. The agricultural water management system according to claim 1, wherein the control unit is capable of adjusting the water level in the rice paddy by operating the movable weir based on water level information from the water level sensor.

8. The waterway is provided with the water intake section for each of a plurality of rice fields, The power generation devices are respectively disposed downstream of the water intake sections, The agricultural water management system described in claim 1, characterized in that the water level can be set for each rice field, and the control unit controls the rotational load of each of the power generation devices set for each rice field based on the water level of the rice field or the waterway in which one of the power generation devices is installed and the water level of the rice field or the waterway downstream of the power generation device.

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