JP2024036697A5 - - Google Patents

Description

The present invention relates to a field water management system .

Patent Document 1 discloses a water supply valve or drainage valve equipped with an electric actuator for a field that operates a displacement mechanism for controlling the supply of water to a field or the drainage of water from the field. By using these water supply valves and drainage valves, it becomes possible to remotely control the supply of water to a field or the drainage of water from the field via a field water management device.

The electric actuator for farm fields is a control device that controls water supply taps and drain valves, and is equipped with an actuator equipped with an electric motor that operates the water supply taps or drain valves, and an electronic circuit that controls the actuator and communicates with the field water management device.

Patent Document 2 discloses a field water management system that includes a water supply control device that supplies irrigation water to a field from the water supply tap, an actuator that operates the water supply tap, an electronic control circuit having a water supply control unit that controls the actuator and a communication unit that communicates with a field water management server, a storage battery that supplies power to the electronic control circuit and the actuator, a remote control terminal that sets and inputs remote operation information for the water supply control device, and a field water management server that receives the remote operation information from the remote control terminal and remotely controls the corresponding water supply control device.

JP 2017-193914 A JP 2020-103285 A

By utilizing the technology disclosed in Patent Documents 1 and 2, it is possible to construct a field water management system that includes a field water management device that remotely controls a water supply device with a water tap, a drainage device with a drainage weir, and water supply and drainage equipment including a water level gauge for each field where the equipment is installed, the water supply device and the drainage device based on the water level detected by the water level gauge, and a terminal device that transmits a water supply request or drainage request for the field to the field water management device.

However, the surface of a field is not always kept level; when it is inclined, the standards for the installation height of the water level gauge and the installation height of the drainage device may differ. In such cases, if the set water level by the water level gauge and the height of the drainage weir installed in the drainage device do not match, it becomes difficult to maintain the water level in the field at the set water level.

For example, if the origin of the drainage weir is higher than the origin of the water level gauge, or conversely, if the origin of the drainage weir is lower than the origin of the water level gauge, the water level in the field cannot be adjusted to the set water level even if water is supplied to or drained from the field based on the reference water level of the water level gauge.

As a result, it was necessary to store calibration information that matched the installation height of the water level gauge and the installation height of the drainage device in the memory unit of the electronic circuit that controlled the raising and lowering of the drainage weir installed in each drainage device, which required complicated processing.

However, because water is not supplied to the field at the time the drainage device is installed, it is difficult to accurately match the installation height of the water level gauge with the installation height of the drainage device unless a measuring device such as a laser level gauge is used. Also, in order to write accurate calibration information to the memory unit in the electronic circuit after water is supplied to the field, it is necessary to remove the cover of the drainage device and connect a calibration computer to the electronic circuit to run a dedicated application program, which creates the problem that performing similar operations in each field is extremely cumbersome.

In view of the above-mentioned problems, an object of the present invention is to provide a field water management system that can easily and accurately adjust the installation height of a water level gauge and the installation height of a drainage device.

In order to achieve the above-mentioned object, a first characteristic configuration of the field water management system according to the present invention is a field water management system comprising water supply and drainage equipment installed in each field, including a water supply device with a water tap, a drainage device with a drainage weir, and a water level gauge, a field water management device equipped with a remote control unit that remotely controls the water supply device and the drainage device so that the water level in each field becomes a set water level, and a terminal device equipped with a control information processing unit that exchanges control information including water supply and drainage for the field with the field water management device, wherein the control information is transmitted from the terminal device to the field water management device and includes a water level gauge origin deviation amount for calibrating the water level gauge installed in each field, and a drainage weir origin deviation amount for calibrating the height of the drainage weir provided in the drainage device .

When supplying water to a field, the field water management device remotely controls the drainage device so that the height of the drainage dam of the field to be controlled becomes a predetermined water storage height corresponding to the set water level, and remotely controls the water supply device so that the water level measured by the water level gauge becomes the set water level. Also, when draining water from the field, the drainage device is remotely controlled so that the height of the drainage dam becomes a predetermined drainage height.

However, if the origin of the water level gauge and the origin of the drainage weir are misaligned , the height of the drainage weir will be adjusted to a height different from the actual water storage height, which may result in cases where water cannot be supplied or drained to reach the set water level.

Even in such cases, for example, a farmer can check the height of the drainage dam near the field and transmit the water level gauge origin deviation amount for calibrating the water level gauge and the drainage dam origin deviation amount for calibrating the height of the drainage dam provided in the drainage device to the field water management device via a control information processing unit provided in a terminal device owned by the farmer, making it possible to set the origin of the water level gauge and the origin of the drainage dam provided in the field to appropriate values .

The second characteristic configuration has, in addition to the first characteristic configuration described above, that the drainage dam origin deviation amount is transmitted from the terminal device to the field water management device based on a set water level calibrated based on the water level gauge origin deviation amount transmitted from the terminal device to the field water management device, and the water supply device is controlled to supply water based on the set water level calibrated based on the water level gauge origin deviation amount transmitted from the terminal device to the field water management device after the water level in the field has been adjusted to the set water level.

Since it is based on the water level supplied according to the set water level calibrated based on the water level gauge origin deviation, an accurate amount of deviation of the drainage weir origin can be obtained.

The third characteristic configuration is, in addition to the first characteristic configuration described above, that the field water management device is configured to limit the lifting height of the drainage weir after calibration based on the drainage weir origin deviation amount to within the lifting and lowering allowable value when the lifting and lowering height of the drainage weir after calibration based on the drainage weir origin deviation amount exceeds the lifting and lowering allowable value of the drainage weir.

If the lift height of the drainage weir set by the lift height setting unit based on the drainage water level calibration information and the set water level deviates from the drainage weir lift tolerance, the drainage device will be unable to exceed that value and control the drainage weir's drainage height, which is an inconvenience. In such a case, if the drainage device sends status information indicating that control is impossible to the field water management device, there is a risk that the system will stop, and complicated procedures will be required to return to normal. Therefore, if the lift height of the drainage weir exceeds the drainage weir lift tolerance, the lift height can be limited to within the lift tolerance to prevent such inconveniences from occurring.

The fourth characteristic configuration is, in addition to the third characteristic configuration described above, that when water is stored in each field, if the upper limit of the lifting and lowering allowable value is exceeded, the lifting and lowering allowable value is limited to the upper limit, and when the stored water in each field is drained, if the lower limit of the lifting and lowering allowable value is exceeded, the lifting and lowering allowable value is limited to the lower limit.

As described above, according to the present invention, it is possible to provide a field water management system that can easily and accurately adjust the installation height of the water level gauge and the installation height of the drainage device.

Diagram of the field water management system An explanatory diagram of the functional blocks of the water supply control device and the drainage control device (a) is an explanatory diagram of a state in which the origin deviation amount of the water level gauge and the drainage weir installed in the field has been properly calibrated, and (b) is an explanatory diagram of a state in which the drainage weir has been adjusted to a drainage water level corresponding to the set water level in the state of (a). (a) is an explanatory diagram of a state in which the origin deviation of the water level gauge and the drainage weir installed in the field is overcalibrated, and (b) is an explanatory diagram of a state in which the drainage weir is adjusted to the set water level in the state of (a). (a) is an explanatory diagram of a state in which the origin deviation of the water level gauge and the drainage weir installed in the field is undercalibrated, and (b) is an explanatory diagram of the drainage weir height when the drainage weir is adjusted to the set water level in the state of (a). A flowchart showing an example of a procedure for flooding control to keep the water level in a farm field constant. A flowchart showing an example of a procedure for a drainage water level calibration process by a terminal device. A flowchart showing an example of a procedure for a drainage water level calibration process by a field water management device.

The field water management system, the terminal device, and the field water management device according to the present invention will be described below.
[Configuration of the field water management system]
As shown in FIG. 1, each field 1 where rice cultivation is carried out is provided with water supply and drainage equipment such as a water supply device 12 that directs irrigation water flowing in a water supply pipe 10 through a water conduit 11 to the field 1, a drainage device 22 that drains the water in the field 1 through a water outlet 21 to a drainage channel 20, and a water level gauge 2 that measures the water level in the field 1.

The water supply device 12 and the drainage device 22 are connected to the field water management server 40 via a wireless router 32 arranged near the field 1 and a wireless communication network including the Internet 30 so that they can communicate with each other. In addition, a terminal device 50 such as a smartphone owned by the manager of each field 1 is connected to the field water management server 40 so that they can communicate with each other via a wireless communication network including the Internet 30.

The field water management system 100 is composed of the water supply devices 12, the water level gauge 2, the drainage device 22, the terminal device 50, the field water management server 40, and the Internet 30 that connects them so that they can communicate with each other. The field water management server 40 functions as the field water management device of the present invention. The terminal device 50 is composed of either a portable terminal device such as a smartphone or a tablet computer, or a general-purpose computer such as a desktop or laptop. In this embodiment, the water level measured by the water level gauge 2 is transmitted to the field water management server 40 via the water supply device 12, but this is not limited to this embodiment, and the water level gauge 2 may be transmitted to the field water management server 40 via the drainage device 22, or the water level gauge 2 may be configured to communicate directly with the field water management server 40.

Taking rice cultivation as an example, the stored water level in field 1 needs to be variably adjusted for each stage of rice cultivation, such as plowing, transplanting, rooting period, tillering period (early and late), panicle formation period, ear emergence and flowering period, and ripening period. For example, during the plowing period, water is conducted simultaneously to multiple fields, so efficient water supply management is required for flooding. In addition, the timing and water level for adjusting the stored water level in each field needs to be different depending on the variety cultivated in each field. For this purpose, the field water management system 100 is utilized.

As shown in FIG. 2, the field water management server 40 includes a memory unit 48 that stores information about each field 1, a remote control unit 42 that remotely controls the water supply device 12 and the drainage device 22 so that the water level in each field 1 is set to a set water level, and the remote control unit 42 includes a lift height setting unit 44 that sets the lift height of the drainage weir 22A provided in the drainage device 22.

The terminal device 50 operated by the manager of each field 1 is equipped with a control information processing unit 52 that exchanges control information, including water supply and drainage for the field 1, with the field water management server 40. The control information processing unit 52 has a function as a browser that inputs control information from the field water management server 40 and outputs necessary information to the field water management server 40.

The control information includes a field ID that uniquely identifies each field 1, the origin deviation amount of the water supply device 12, drainage device 22, and water level gauge 2 installed in each field 1, and the origin deviation amount of the drainage weir 22A. Furthermore, the control information includes specification values such as the water supply capacity linked to each water supply device and specification values such as the drainage capacity linked to each drainage device, and is used to adjust the opening degree of the water supply tap provided in the water supply device and the height and position of the drainage weir provided in the drainage device. This control information is initially transmitted from the terminal device 50 to the field water management server 40 and stored in the memory unit 48 provided in the field water management server 40.

The control information further includes water supply and drainage information, such as a water supply request including the water supply date and time and the set water level, and a drainage request including the drainage date and time, linked to each field ID, and the water supply and drainage information is transmitted to the field water management server 40 as necessary by the control information processing unit 52 provided in the terminal device 50.

As shown in FIG. 3(a), the origin deviation of the water level gauge 2 refers to the difference between the water level indicated by the water level gauge 2 and the actual measured value, the difference WLc between the actual water level WL1 based on the paddy field surface WL0 at the point where the water level gauge 2 is installed and the sensor origin (zero value) of the water level gauge 2, and the calibration value WLc for matching the water level indicated by the water level gauge 2 with the actual water level. If calibrated correctly, the origin WLb of the calibrated water level gauge 2 will match the paddy field surface WL0. The set water level of the field 1 is managed based on the water level based on the calibrated water level gauge origin WLb.

The origin deviation of the drainage weir 22A refers to the difference Dc between the lowest point Dmin set as the origin of the drainage weir 22A at the installation position of the drainage device 22 and the paddy field surface WL0 at the point where the water level gauge 2 is installed, and refers to the calibration value Dc for adjusting the elevation height of the drainage weir 22A set corresponding to the set water level to an appropriate height. In the early stages when water is not being supplied to the field 1, the water level cannot be actually measured, so provisional values are set for the calibration values WLc and Dc. Note that the origin of the drainage weir 22A may be set to the paddy field surface at the installation position of the drainage weir instead of the lowest point. The calibration values WLc and Dc can be either positive or negative.

The following description will be given on the assumption that the calibration value WLc of the water level gauge 2 is set to an appropriate value.
When the set water level of the field 1 is WL1, the elevation height H of the drainage weir 22A is set to the sum of the calibration value Dc, the set water level WL1, and the water fall margin ΔWL (H = Dc + WL1 + ΔWL). The water fall margin ΔWL is a margin set to compensate for fluctuations in the water level in case the water surface is wavy due to wind. The water fall margin ΔWL can be set via the terminal device 50, and is usually set to about 2 cm.

As shown in FIG. 3(b), when the set water level is set to WL1 and the calibration values WLc and Dc are appropriate values, the lifting height setting unit 44 provided in the remote control unit 42 transmits Dc+WL1+ΔWL as the lifting height to the drainage device 22, and the drainage weir 22A is set to the height Dc+WL1+ΔWL.

Returning to FIG. 2, the remote control unit 42 provided in the field water management server 40 instantly controls each field 1 based on control information including water supply and drainage transmitted from the control information processing unit 52 of the terminal device 50, or generates a water supply schedule or drainage schedule for each field 1 and stores it in the memory unit 48, and remotely controls the water supply device 12 and drainage device 22 provided in each field 1 according to the water supply schedule or drainage schedule.

The drainage device 22 includes a drainage weir 22A and a drainage control device 22B. The drainage control device 22B includes an actuator 220 that raises and lowers the drainage weir 22A, a drainage water level control unit 222 that controls the actuator 220, and a communication unit 224 that communicates with the field water management server 40. It also includes a storage battery 226 that supplies power to the motor provided in the actuator 220, the drainage water level control unit 222, the communication unit 224, etc., and a solar cell 228 that charges the storage battery 226.

The water supply device 12 is composed of a water supply tap 12A and a water supply control device 12B. The water supply control device 12B is equipped with an actuator 120 that operates the water supply tap 12A, a water supply control unit 122 that controls the actuator 120, and a communication unit 124 that communicates with the field water management server 40. It also has a storage battery 126 that supplies power to the motor provided in the actuator 120, the water supply control unit 122, the communication unit 124, etc., and a solar cell 128 that charges the storage battery 126. Note that the solar cells 128 and 228 are not essential.

As shown in FIG. 6, when the water supply date and time specified in the water supply schedule stored in the memory arrives, or when an immediate water supply request, in this case a request for a certain amount of water retention, is received from the field water management server 40 via input from the terminal device 50 (SA1), the field water management server 40 determines the current water level measured and calibrated by the water level gauge 2 of the corresponding field 1 (SA2), and outputs a height adjustment command to the drainage device 22 of the field 1 to adjust the lift height H (H = Dc + WL1 + ΔWL) of the drainage weir 22A corresponding to the set water level WL1 (SA3).

The field water management server 40 determines whether the measurement value of the water level gauge 2 has reached the set water level, and if the set water level has been reached (SA4, Y), outputs a water stop command to the water supply device 12 (SA5), and if the set water level has not been reached (SA4, N), outputs a water supply command to the water supply device 12 (SA8).

While the water supply request continues (SA6, Y), the field water management server 40 repeats the processing of steps SA4 to SA6 to maintain the water level of the field 1 at the set water level. When the water supply request is released (SA6, N), it outputs a water stop command to the water supply device 12 (SA7).

If there is no water supply request in step SA1 (SA1, N) but there is a drainage request (SA9, Y), the drainage device 22 is instructed to raise the height of the drainage weir 22A to the drainage water level (SA10).

In the above explanation, an example was described in which the field water management server 40 grasps the water level in the field 1 and controls the water supply device 12 to open and close the water supply tap 12A, and controls the drainage device 22 to raise and lower the drainage weir 22A. However, the water supply device 12 and the drainage device 22 may also control themselves autonomously upon receiving commands from the field water management server 40.

In other words, when a control command is sent from the field water management server 40 to the water supply device 12 and the drainage device 22, the water supply device 12 and the drainage device 22 perform a predetermined control based on the control command. The control command includes each control mode such as "constant flooding", "run-off", "intermittent irrigation", "stop", and "drainage", as well as parameter values such as "set water level", "control width", "water fall margin", and "drainage water level".

When the water supply device 12 receives a control command, for example "constant water retention," from the field water management server 40, the water level measured by the water level gauge 2 becomes the "set water level," and the water supply device 12 autonomously controls itself to open or close the water tap 12A to a specified opening so that the water level at that time falls within the "control range."

The drainage device 22 controls the height of the drainage weir 22A based on control commands sent from the field water management server 40. For example, when a control command for "constant flooding" is received, the height of the drainage weir 22A is adjusted to the sum of the "set water level" and the "water fall margin", and when a control command for "drainage" is received, the height of the drainage weir 22A is adjusted to the "drainage water level". The "water fall margin" is a value that takes into account fluctuations in the water level caused by factors such as wind blowing across the field, and is usually set to a few centimeters.

As shown in FIG. 4(a), if the initially set calibration value of the drainage weir 22A is set to an excessively large calibration value Dc' such that the position Dmin' is lower than the original lowest point Dmin of the drainage weir 22A, then as shown in FIG. 4(b), the drainage weir 22A will rise and fall to a height H (H = Dc' + WL1 + ΔWL), which is WL1' deeper than the original set water level WL1, and the set water level will effectively rise by ΔH (ΔH = Dmin' - Dmin = WL1' - WL1).

As shown in FIG. 5(a), if the initially set calibration value of the drainage weir 22A is set to an insufficient calibration value Dc'' such that the position Dmin'' is higher than the lowest point Dmin of the original drainage weir 22A, then as shown in FIG. 5(b), the lift height of the drainage weir 22A becomes H (H = WL1 + Dc'' + ΔWL), which is WL1'' shallower than the original set water level WL1, and the set water level effectively drops by ΔH (ΔH = Dmin - Dmin'' = WL1 - WL1'').

Therefore, the terminal device 50 is configured to transmit, via the control information processing unit 52, to the field water management server 40, drainage water level calibration information that adjusts the amount of deviation between the origin of the water level gauge 2 installed in the field 1 and the origin of the drainage weir 22A. The calibration processing unit 46 installed in the field water management server 40 stores the drainage water level calibration information in the memory unit 48, and the lifting height setting unit 44 is configured to set the lifting height of the drainage weir 22A based on the drainage water level calibration information and the set water level. The "lifting height of the drainage weir set based on the drainage water level calibration information and the set water level" refers to the height H (H = Dc + WL1 + ΔWL) that takes into account the water fall margin ΔWL. However, it goes without saying that the height H (H = Dc + WL1) that does not take into account the water fall margin ΔWL may also be used. In this manner, by setting an appropriate calibration value Dc using the drainage water level calibration information, the water level in the field 1 is adjusted to the set water level.

However, if the lift height of the drainage weir 22A set by the lift height setting unit 44 based on the drainage water level calibration information and the set water level deviates from the lift tolerance of the drainage weir 22A, the drainage control device 22B will be unable to exceed that value and control the drainage height of the drainage weir 22A. In such a case, if the drainage device 22 sends status information indicating that control is impossible to the field water management server 40, there is a risk that the system will stop, and complicated procedures will be required to return to a normal state.

Therefore, when the lift height of the drainage weir 22A exceeds the lift allowable value of the drainage weir 22A, the lift height setting unit 44 limits the lift height to within the lift allowable value, thereby preventing such an inconvenience from occurring. When the upper limit of the lift allowable value is exceeded when storing water in the field 1, the lift height is rounded up to the upper limit, and when the lower limit of the lift allowable value is exceeded when draining stored water in the field 1, the lift height is rounded up to the lower limit.

Figure 7 shows the process executed by the configuration processing unit 54 provided in the terminal device 50. The field manager reads the water level and the height of the drainage weir 22A sent from the field water management server 40 and displayed on the terminal device 50 (SB1, SB2). The water level displayed on the terminal device 50 is the water level of the water level gauge, and the height of the drainage weir 22A is the height excluding the calibration value (WL1 + ΔWL).

If water is overflowing from the drainage weir 22A, the field manager determines that the calibration value is too low (SB3, Y) and sets a provisional calibration value higher than the current water level from the control information processing unit 52 of the terminal device 50 and transmits this to the field water management server 40 (SB8). The field water management server 40 updates the elevation height of the drainage weir 22A based on the provisional calibration value, thereby preventing overflow from the drainage weir 22A.

In this state, or when it is not determined in step SB3 that the calibration value is too low (SB3, N), the field manager measures the height from the water surface to the top of the drainage weir 22A based on the water level transmitted from the field water management server 40 and displayed on the terminal device 50 (SB4). The field manager determines whether the actual measurement is appropriate, including the water fall margin ΔWL, and if there is an excess or deficiency (SB5, N), calculates a calibration value to set the true drainage water level (SB6) and transmits the calibration value from the control information processing unit 52 to the field water management server 40 (SB7).

FIG. 8 shows the processing executed by the calibration processing unit 46 and the lifting height setting unit 44 provided in the field water management server 40.
When a drainage water level calibration value is received from the terminal device 50 (SC1), the drainage water level calibration value is stored in the memory unit 48 as a new calibration value (SC2), and the lifting height H (H = Dc + WL1 + ΔWL) to be sent to the drainage device 22 is calculated based on the currently set water level (SC3).

If the calculated lift height H exceeds the lift tolerance of the drainage weir 22A (SC4, N), the lift height is corrected to fall within the lift tolerance (SC5), and the corrected set water level is sent to the drainage device 22 (SC6). If the calculated lift height H falls within the lift tolerance of the drainage weir 22A (SC4, Y), the lift height is sent to the drainage device 22 (SC6).

In the above example, the lift height setting unit 44 sets the lift height of the drainage weir based on the drainage water level calibration information and the set water level and transmits the lift height to the drainage device 22. However, the lift height setting unit 44 may be configured to correct the set water level based on the drainage water level calibration information and the set water level and transmit the set water level to the drainage device 22. Specifically, in step SC3, the set water level is set to Dc+WL1, in step SC5, the set water level is corrected so that the lift height falls within the lift tolerance, and in step SC6, a target water level that is the lift height is transmitted to the drainage device 22. In other words, the "lift height setting unit that sets the lift height of the drainage weir based on the drainage water level calibration information and the set water level" of the present invention also includes a mode in which the lift height of the drainage weir to be set is set by substituting the set water level.

In the above explanation, it is assumed that the calibration value WLc of the water level gauge 2 is set to an appropriate value, but if the calibration value WLc of the water level gauge 2 is not appropriate, the calibration value WLc of the water level gauge 2 is recalibrated via the terminal device 50 owned by the field manager.

For example, the field manager can measure the water level at the installation position of the water level gauge 2, calculate a new calibration value WLc based on the difference between the water level sent from the field water management server 40 and the water level displayed on the terminal device 50, and send the new calibration value to the field water management server 40 via the control information processing unit 52, so that the field water management server 40 updates the calibration value of the water level gauge 2.

At this time, the field water management server 40 calculates the difference between the new calibration value of the water level gauge 2 and the previous calibration value, and corrects the previously set calibration value for the drainage weir 22A by this difference. In addition, the field manager who updated the calibration value of the water level gauge 2 may perform the calibration process for the drainage weir 22A again using the procedures in Figures 7 and 8.

The embodiment described above is merely one example of the present invention, and is not intended to limit the technical scope of the present invention. It goes without saying that the specific configuration of each part can be appropriately modified and designed within the scope of the effects of the present invention.

1: Field 2: Water level gauge 10: Water supply pipe 12: Water supply device 12A: Water supply tap 12B: Water supply control device 20: Drainage channel 22: Drainage device 22A: Drainage weir 22B: Drainage control device 40: Field water management server (field water management device)
42: Remote control unit 44: Lift height setting unit 46: Calibration processing unit 48: Memory unit 50: Portable terminal (terminal device)
52: Control information processing unit 100: Field water management system

Claims (4)

Water supply and drainage equipment is installed in each field, the equipment including a water supply device having a water tap, a drainage device having a drainage weir, and a water level gauge;
A field water management device including a remote control unit that remotely controls the water supply device and the drainage device so that the water level of each field becomes a set water level;
a terminal device including a control information processing unit that exchanges control information including water supply and drainage for the field with the field water management device;
A field water management system comprising:
The control information is transmitted from the terminal device to the field water management device and includes a water level meter origin deviation amount for calibrating the water level meter installed in each field, and a drainage dam origin deviation amount for calibrating the height of the drainage dam provided in the drainage device. The field water management system according to claim 1, wherein the drainage dam origin deviation is transmitted from the terminal device to the field water management device based on a set water level calibrated based on the water level meter origin deviation transmitted from the terminal device to the field water management device, and the water supply device is controlled by the field water management device to supply water based on the set water level calibrated based on the water level meter origin deviation transmitted from the terminal device to the field water management device after the water level in the field is adjusted to the set water level. The field water management system according to claim 1, wherein the field water management device is configured to limit the lifting height of the drainage weir after calibration based on the amount of deviation of the drainage weir origin to within the lifting and lowering allowable value when the lifting and lowering height of the drainage weir exceeds the lifting and lowering allowable value of the drainage weir. 4. The field water management system according to claim 3, wherein when storing water in each field, if the upper limit of the lifting and lowering allowable value is exceeded, the lifting and lowering allowable value is limited to the upper limit, and when draining stored water in each field, if the lower limit of the lifting and lowering allowable value is exceeded, the lifting and lowering allowable value is limited to the lower limit.