A farmland drainage diversion, storage, utilization, and purification system and its operation method

Abstract

A farmland drainage diversion, regulation, utilization, and purification system and its operation method are disclosed. The system includes ditches arranged around the farmland and isolation walls. The isolation walls longitudinally divide the ditches into parallel irrigation and drainage ditches and ecological ditches. The irrigation and drainage ditches are located close to the farmland. One end of the irrigation and drainage ditches is connected to a branch ditch via a first sluice gate, and the other end is connected to one end of the ecological ditch via an outlet sluice gate. The middle section of the ecological ditch is connected to the middle section of the irrigation and drainage ditches via a second sluice gate, and the other end is connected to the branch ditch via a third sluice gate. This invention connects ditches with different functions, effectively utilizing the ditches' ability to regulate irrigation and drainage and purify water quality, while simultaneously providing multiple functions such as ecological restoration, water purification, and flood storage and diversion. Furthermore, the system's operation method formulates corresponding irrigation and drainage strategies for the farmland irrigation period, drainage period, and periods of heavy rainfall, ensuring purification efficiency while effectively addressing irrigation and drainage problems in various emergencies such as rainstorms and droughts.

Description

Technical Field

[0001] This invention belongs to the field of agricultural non-point source pollution control, specifically relating to a farmland drainage diversion, storage, utilization and purification system and its operation method. Background Technology

[0002] In recent years, agricultural non-point source pollution has become one of the major sources of water pollution globally. Agricultural non-point source pollution mainly refers to pollutants generated by agricultural activities, such as farmland nutrients, pesticides, and agricultural wastewater, which enter water bodies through rainfall and irrigation water, causing water pollution. Among agricultural non-point source pollution issues, the significant loss of farmland nutrients is a major problem. This loss leads to eutrophication of water bodies, causing algal blooms, greening of water bodies, and increased levels of chemical oxygen demand (COD) and ammonia nitrogen, thus damaging aquatic ecosystems and hindering the sustainable use of water resources.

[0003] Therefore, controlling nutrient loss from farmland has become a major challenge in farmland water pollution control. To address this issue, ecological ditches, as an essential pathway for farmland water to flow into receiving water bodies, have been extensively studied. Ecological ditches are small-scale artificial wetland systems, typically planted with various plants to absorb nitrogen and phosphorus nutrients from farmland drainage, while also intercepting silt, scum, and other substances. The well-developed root systems of these plants provide a wide habitat for microorganisms, promoting their growth and reproduction. Simultaneously, these microorganisms can degrade organic pollutants and heavy metals.

[0004] However, the purification effect of traditional ecological ditches and natural ditches is not significantly different. To improve the purification effect, some studies have hardened ecological ditches and added fillers such as stones, gravel, and crushed stone for filtration and retention. This method is called filler-filled ecological ditches. Filler-filled ecological ditches can further improve the purification effect, but problems such as silt blockage and filler saturation also arise, resulting in higher maintenance costs and greater difficulty in later maintenance.

[0005] Currently, rural areas mainly use earthen and concrete ditches. Despite the emergence of various ecological ditch technologies, their widespread adoption is hampered by high costs, maintenance difficulties, and low purification efficiency. Earthen ditches utilize vegetation within the ditch to absorb and purify nutrients from the field, but this easily leads to soil erosion and ditch wall erosion. While concrete ditches offer rapid irrigation and drainage, their purification efficiency is extremely low, resulting in severe water pollution. Furthermore, traditional ecological ditches and filler-based ecological ditches are single-function ditches, serving both purification and irrigation / drainage purposes. This design suffers from low purification efficiency, severe soil erosion, high maintenance costs, high construction costs, chaotic drainage at different times, and difficulty in addressing irrigation and drainage issues during sudden events such as heavy rains and droughts. Summary of the Invention

[0006] The object of the present invention is to provide a farmland drainage diversion, storage, utilization and purification system for realizing function division and its operation method in view of the above problems existing in the prior art.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] In the first aspect, the present invention provides a farmland drainage diversion and purification system, including a ditch and a partition wall arranged around the farmland. The partition wall longitudinally divides the ditch into parallel irrigation and drainage ditches and ecological ditches. The irrigation and drainage ditches are arranged close to the farmland. One end of the irrigation and drainage ditches is connected to a branch canal through a first sluice, and the other end of the irrigation and drainage ditches is connected to one end of the ecological ditch through an outlet sluice. The middle part of the ecological ditch is connected to the middle part of the irrigation and drainage ditches through a second sluice, and the other end of the ecological ditch is connected to the branch canal through a third sluice. The first sluice, the outlet sluice, the second sluice and the third sluice are all connected to a controller.

[0009] Both the irrigation and drainage ditches and the ecological ditches include an upstream section and a downstream section. The middle part of the upstream section of the irrigation and drainage ditches is connected to the middle part of the downstream section of the ecological ditch through a second sluice, and the downstream section of the irrigation and drainage ditches is connected to the upstream section of the ecological ditch through an outlet sluice.

[0010] One end of the upstream section of the irrigation and drainage ditches is connected to the branch canal through a first sluice, and one end of the downstream section of the ecological ditch is connected to the branch canal through a third sluice.

[0011] A grit chamber is arranged in the downstream section of the irrigation and drainage ditches. The inlet of the grit chamber is connected to the downstream section of the irrigation and drainage ditches through an outlet sluice, and the outlet of the grit chamber is connected to the upstream section of the ecological ditch through an overflow weir.

[0012] The slope of the ecological ditch is a stepped inclined plane structure, including a first inclined plane, a horizontal plane and a second inclined plane. The top end of the first inclined plane is connected to the side bank, and the bottom end of the first inclined plane is connected to the bottom surface of the ecological ditch through the horizontal plane and the second inclined plane in sequence. And a slope bank buffer zone and a stepped emergent plant zone are respectively arranged on the first inclined plane and the horizontal plane, and a submerged plant zone is arranged on the bottom surface.

[0013] The capacity of the irrigation and drainage ditches is smaller than that of the ecological ditches.

[0014] In the second aspect, the present invention provides an operation method for a farmland drainage diversion and purification system, including:

[0015] In the initial state, the outlet sluice is opened, and the first sluice, the second sluice and the third sluice are closed. The water level h of the ecological ditch , B , , B ,

[0016] , ,

[0015] ,

[0014] is near its upper limit value H B ;

[0016] During heavy rainfall

[0017] When the water level in the irrigation and drainage ditches is h A When the value is 0, the water in the farmland is directly discharged into the irrigation and drainage ditches;

[0018] When 0 < h A <Upper limit of water level H in irrigation and drainage ditches A At that time, the controller determines whether the sum of the water volume in the irrigation and drainage ditch and the predicted farmland drainage volume is greater than the capacity of the irrigation and drainage ditch. If it is greater, the controller controls the sluice gate at the outlet to open, so that the farmland runoff flows into the ecological ditch.

[0019] When h A ≥H A And h B ≥H B At that time, the controller opens the first and third sluice gates to discharge farmland runoff into the branch canal.

[0020] The operating method further includes:

[0021] During the irrigation season for farmland

[0022] When h A When the value is 0, the controller determines whether the amount of irrigation required for the farmland is greater than the amount of water in the ecological ditch. If it is greater, the controller opens the first sluice gate and irrigates the farmland through the branch canal. If it is not greater, the controller opens the second sluice gate and closes the outlet sluice gate. The water in the ecological ditch is discharged into the farmland for irrigation through the irrigation and drainage ditches. The water consumed by the ecological ditch is replenished by the branch canal.

[0023] When 0 < h A <H A At this time, the controller calculates the difference A between the amount of irrigation required for the farmland and the amount of water in the irrigation and drainage ditches. If A ≤ 0, the controller closes the outlet sluice gate, and the farmland is irrigated only by the irrigation and drainage ditches. If 0 < A ≤ the amount of water in the ecological ditch, the controller opens the second sluice gate and closes the outlet sluice gate, so that the water in both the irrigation and drainage ditches and the ecological ditch is discharged for farmland irrigation. If A > the amount of water in the ecological ditch, the controller first opens the second sluice gate and closes the outlet sluice gate, and the water in the ecological ditch is discharged into the farmland for irrigation through the irrigation and drainage ditches. After all the water in the ecological ditch is discharged, the controller opens the first sluice gate to continue irrigating the farmland. The water consumed by the ecological ditch is replenished by the branch canals.

[0024] The operating method further includes:

[0025] During the farmland drainage period

[0026] When h A When the value is 0, the water in the farmland is directly discharged into the irrigation and drainage ditches;

[0027] When 0 < h A <H AAt that time, the controller determines whether the sum of the water volume in the irrigation and drainage ditch and the predicted farmland drainage volume is greater than the capacity of the irrigation and drainage ditch. If it is greater, the controller controls the sluice gate at the outlet to open, so that the farmland runoff flows into the ecological ditch.

[0028] When h A ≥H A At this time, the controller first calculates the farmland drainage volume, then controls the opening of the third sluice gate and the closing of the outlet sluice gate, so that the ecological ditch discharges water no less than the farmland drainage volume into the branch canal. Then, it controls the opening of the outlet sluice gate and the closing of the third sluice gate, and the farmland drainage is discharged into the ecological ditch through the irrigation and drainage canal.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] The farmland drainage diversion, regulation, utilization, and purification system proposed in this invention uses a partition wall to longitudinally divide the irrigation and drainage ditches into parallel irrigation and drainage ditches and ecological ditches. The irrigation and drainage ditches are located close to the farmland. One end of the irrigation and drainage ditches is connected to a branch ditch via a first sluice gate, and the other end of the irrigation and drainage ditches is connected to one end of the ecological ditch via an outlet sluice gate. The middle section of the ecological ditch is connected to the middle section of the irrigation and drainage ditches via a second sluice gate, and the other end of the ecological ditch is connected to the branch ditch via a third sluice gate. Water from the branch ditch flows into the irrigation and drainage ditches from the ecological ditch to irrigate the farmland, while farmland drainage flows into the ecological ditch from the irrigation and drainage ditches for water purification. On the one hand, a drainage system with independent irrigation, drainage, and purification functions has been constructed, connecting ditches with different functions. This system can effectively utilize the ditches' capacity for regulating irrigation and drainage and purifying water quality, while also serving multiple functions such as ecological restoration, water purification, and flood storage and diversion. On the other hand, the irrigation and drainage ditches and ecological ditches are built based on existing ditches, requiring less land, having lower costs, and being easier to maintain. Furthermore, the system's operation methods are tailored to different irrigation and drainage strategies for the farmland irrigation period, drainage period, and periods of heavy rainfall, ensuring purification efficiency while effectively addressing irrigation and drainage issues in various emergencies such as rainstorms and droughts. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0032] Figure 2 for Figure 1 Schematic diagram of cross-section of irrigation and drainage ditches and ecological ditches.

[0033] In the diagram, there are: ditch 1, irrigation and drainage ditch 11, ecological ditch 12, slope 121, bottom surface 122, first sluice gate 13, outlet sluice gate 14, second sluice gate 15, third sluice gate 16, overflow weir 17, isolation wall 2, branch canal 3, controller 4, and sedimentation tank 5. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0035] This invention provides a farmland drainage diversion, regulation, utilization, and purification system, comprising parallel irrigation and drainage ditches 11 and ecological ditches 12 formed by longitudinal separation by isolation walls. The irrigation and drainage ditches 11 are used only for irrigation and drainage. The slopes and bottoms of the ditches are paved with a layer of solid bricks and then smoothed with concrete to prevent soil erosion. The slopes are designed in a trapezoidal shape to increase the water capacity of the ditches. After the farmland drainage flows into the sedimentation tank 5 for sedimentation and interception of floating objects, the supernatant flows into the ecological ditches 12 through the overflow weir 17 for purification treatment. If the farmland needs high-nitrogen and high-phosphorus water for irrigation, the farmland drainage is retained in the irrigation and drainage ditches 11 for reuse.

[0036] Ecological ditch 12 primarily utilizes plants and microorganisms to intercept or transform nitrogen and phosphorus in the water through physical, chemical, and biological processes. This purifies farmland drainage, rainwater runoff, and branch canal water. Its slopes are designed in a trapezoidal pattern, facilitating the planting of various plants to improve purification efficiency and increasing the contact area to enhance water capacity. The slopes of the ecological ditch are paved with grass-covered bricks, and a base stone strip is placed at regular intervals at the bottom. The water in the ecological ditch is typically stationary, ensuring sufficient hydraulic retention time and reducing soil erosion caused by long-term flow. Ecological ditch 12 connects to branch canal 3 via a third sluice gate 16. Purified water from ecological ditch 12 can be discharged into branch canal 3, and after discharge, water from branch canal 3 can be reintroduced into ecological ditch 12 for further purification. This process refreshes the water in ecological ditch 12 every half month or month, maintaining a consistent water level and maximizing its ecological restoration function. The capacity of the ecological ditch 12 is greater than that of the irrigation and drainage ditch 11, which is conducive to purifying a larger volume of water and easily coping with the surge in water volume during the flood season. During the flood season, when rainfall is abundant, farmland runoff carries a large amount of nutrients into the ecological ditch 12 through the irrigation and drainage ditch 11 for timely purification. At this time, the ecological ditch 12 plays a dual role of purification and flood storage. The purified water can be used to irrigate farmland or discharged into the branch canal 3.

[0037] Example 1:

[0038] See Figure 1 , Figure 2A farmland drainage diversion, regulation, utilization, and purification system includes a ditch 1 arranged around the farmland, a partition wall 2, a first sluice gate 13, an outlet sluice gate 14, a second sluice gate 15, and a third sluice gate 16. The first sluice gate 13, outlet sluice gate 14, second sluice gate 15, and third sluice gate 16 are all connected to a controller 4. The partition wall 2 longitudinally divides the ditch 1 into parallel irrigation and drainage ditches 11 and ecological ditches 12. The irrigation and drainage ditches 11 are located close to the farmland, and their capacity is smaller than that of the ecological ditches 12. Both the irrigation and drainage ditches 11 and the ecological ditches 12 include an upstream section and a downstream section. One end of the upstream section of the irrigation and drainage ditches 11 is connected to a branch ditch 3 via the first sluice gate 13, and the middle of the upstream section of the irrigation and drainage ditches 11 is connected to a second sluice gate 16. The sluice gate 15 is connected to the middle of the downstream section of the ecological ditch 12. One end of the downstream section of the ecological ditch 12 is connected to the branch ditch 3 through the third sluice gate 16. The downstream section of the irrigation and drainage ditch 11 is equipped with a sedimentation tank 5. The inlet of the sedimentation tank 5 is connected to the downstream section of the irrigation and drainage ditch 11 through the outlet sluice gate 14. The outlet of the sedimentation tank 5 is connected to the upstream section of the ecological ditch 12 through the overflow weir 17. The slope (121) of the ecological ditch (12) is a sloping structure. Its top end is connected to the side bank, and its bottom end is connected to the bottom surface (122) of the ecological ditch (12). A slope buffer zone is arranged on the slope (121), and emergent plant belts and submerged plant belts are arranged on the bottom surface (122). The bottom surface (122) is lower than the bottom of the irrigation and drainage ditch (11).

[0039] Example 2:

[0040] An operation method for a farmland drainage diversion, storage, utilization, and purification system includes:

[0041] Initially, the outlet sluice gate 14 is open, and the first sluice gate 13, the second sluice gate 15, and the third sluice gate 16 are closed. The water level h in the ecological ditch 12 is... B Its upper limit of water level H B nearby;

[0042] During periods of heavy rainfall

[0043] When the water level of irrigation and drainage ditch 11 is h A When the value is 0, the water in the farmland is directly discharged into the irrigation and drainage ditch 11;

[0044] When 0 < h A <Upper limit of water level H in irrigation and drainage ditch 11 A At that time, the controller 4 determines whether the sum of the water volume in the irrigation and drainage ditch 11 and the predicted farmland drainage volume is greater than the capacity of the irrigation and drainage ditch 11. If it is greater, the controller controls the outlet sluice gate 14 to open, so that the farmland runoff flows into the ecological ditch 12.

[0045] When h A ≥H A And h B≥H B At that time, the controller 4 controls the opening of the first sluice gate 13 and the third sluice gate 16 to discharge farmland runoff into the branch canal 3 in a timely manner;

[0046] During the irrigation season for farmland

[0047] When h A When the value is 0, the controller 4 determines whether the amount of irrigation required for the farmland is greater than the amount of water in the ecological ditch 12. If it is greater, the controller controls the first sluice gate 13 to open, and the branch canal 3 irrigates the farmland. If it is not greater, the controller controls the second sluice gate 15 to open and the outlet sluice gate 14 to close. The water in the ecological ditch 12 is discharged into the farmland for irrigation through the irrigation and drainage ditch 11. The water consumed by the ecological ditch 12 is replenished by the branch canal 3.

[0048] When 0 < h A <H A At this time, the controller 4 calculates the difference A between the amount of irrigation required for the farmland and the amount of water in the irrigation and drainage ditch 11. If A ≤ 0, the controller controls the outlet sluice gate 14 to close, and the farmland is irrigated only by the irrigation and drainage ditch 11. If 0 < A ≤ the amount of water in the ecological ditch 12, the controller controls the second sluice gate 15 to open and the outlet sluice gate 14 to close, so that the water in both the irrigation and drainage ditch 11 and the ecological ditch 12 is discharged for farmland irrigation. If A > the amount of water in the ecological ditch 12, the controller first controls the second sluice gate 15 to open and the outlet sluice gate 14 to close, and the water in the ecological ditch 12 is discharged into the farmland for irrigation through the irrigation and drainage ditch 11. After all the water in the ecological ditch 12 is discharged, the controller controls the first sluice gate 13 to open to continue irrigating the farmland. The water consumed by the ecological ditch 12 is replenished by the branch ditch 3.

[0049] During the farmland drainage period

[0050] When h A When the value is 0, the water in the farmland is directly discharged into the irrigation and drainage ditch 11;

[0051] When 0 < h A <H A At that time, the controller 4 determines whether the sum of the water volume in the irrigation and drainage ditch 11 and the predicted farmland drainage volume is greater than the capacity of the irrigation and drainage ditch 11. If it is greater, the controller controls the outlet sluice gate 14 to open, so that the farmland runoff flows into the ecological ditch 12.

[0052] When h A ≥H A At that time, the controller 4 first calculates the farmland drainage volume, then controls the third sluice gate 16 to open and the outlet sluice gate 14 to close, so that the ecological ditch 12 discharges water no less than the farmland drainage volume into the branch ditch 3. Then, it controls the outlet sluice gate 14 to open and the third sluice gate 16 to close, and the farmland drainage is discharged into the ecological ditch 12 through the irrigation and drainage ditch 11.

Claims

1. A farmland drainage diversion, regulation, utilization, and purification system, characterized in that: The system includes a ditch (1) arranged around the farmland and a partition wall (2). The partition wall (2) longitudinally divides the ditch (1) into a parallel irrigation and drainage ditch (11) and an ecological ditch (12). The irrigation and drainage ditch (11) is arranged close to the farmland. One end of the irrigation and drainage ditch (11) is connected to a branch ditch (3) through a first sluice gate (13). The other end of the irrigation and drainage ditch (11) is connected to one end of the ecological ditch (12) through an outlet sluice gate (14). The middle part of the ecological ditch (12) is connected to the middle part of the irrigation and drainage ditch (11) through a second sluice gate (15). The other end of the ecological ditch (12) is connected to the branch ditch (3) through a third sluice gate (16). The first sluice gate (13), the outlet sluice gate (14), the second sluice gate (15), and the third sluice gate (16) are all connected to a controller (4). The irrigation and drainage ditch (11) and the ecological ditch (12) both include an upstream section and a downstream section. One end of the upstream section of the irrigation and drainage ditch (11) is connected to the branch ditch (3) through the first sluice gate (13). The middle part of the upstream section of the irrigation and drainage ditch (11) is connected to the middle part of the downstream section of the ecological ditch (12) through the second sluice gate (15). The downstream section of the irrigation and drainage ditch (11) is connected to the upstream section of the ecological ditch (12) through the outlet sluice gate (14). One end of the downstream section of the ecological ditch (12) is connected to the branch ditch (3) through the third sluice gate (16). A sedimentation tank (5) is provided in the downstream section of the irrigation and drainage ditch (11). The inlet of the sedimentation tank (5) is connected to the downstream section of the irrigation and drainage ditch (11) through the outlet sluice gate (14), and the outlet of the sedimentation tank (5) is connected to the upstream section of the ecological ditch (12) through the overflow weir (17).

2. The farmland drainage diversion, storage, utilization, and purification system according to claim 1, characterized in that: The slope (121) of the ecological ditch (12) is a sloping structure. Its top end is connected to the side bank, and its bottom end is connected to the bottom surface (122) of the ecological ditch (12). A slope buffer zone is arranged on the slope (121), and emergent plant zone and submerged plant zone are arranged on the bottom surface (122). The bottom surface (122) is lower than the bottom of the irrigation and drainage ditch (11).

3. The farmland drainage diversion, regulation, utilization, and purification system according to claim 1, characterized in that: The capacity of the irrigation and drainage ditch (11) is smaller than that of the ecological ditch (12).

4. A method for operating the farmland drainage diversion, storage, utilization, and purification system as described in claim 1, characterized in that: The operating method includes: In the initial state, the outlet sluice gate (14) is open, and the first sluice gate (13), the second sluice gate (15), and the third sluice gate (16) are closed. The water level h in the ecological ditch (12) is... B Its upper limit of water level H B nearby; During periods of heavy rainfall When the water level of the irrigation and drainage ditch (11) is h A When =0, the water in the farmland is directly discharged into the irrigation and drainage ditch (11); When 0 < h A <Upper limit of water level H in irrigation and drainage ditches (11) A At that time, the controller (4) determines whether the sum of the water volume in the irrigation and drainage ditch (11) and the predicted farmland drainage volume is greater than the capacity of the irrigation and drainage ditch (11). If it is greater, the controller controls the outlet sluice gate (14) to open, so that the farmland runoff flows into the ecological ditch (12). When h A ≥H A And h B ≥H B At that time, the controller (4) controls the opening of the first sluice gate (13) and the third sluice gate (16) to discharge farmland runoff into the branch canal (3) in a timely manner.

5. The operation method of a farmland drainage diversion, storage, utilization and purification system according to claim 4, characterized in that: The operating method further includes: During the irrigation season for farmland When h A When =0, the controller (4) determines whether the amount of irrigation required for the farmland is greater than the amount of water in the ecological ditch (12). If it is greater, the controller opens the first sluice gate (13) and irrigates the farmland through the branch canal (3). If it is not greater, the controller opens the second sluice gate (15) and closes the outlet sluice gate (14). The water in the ecological ditch (12) is discharged into the farmland for irrigation through the irrigation and drainage ditch (11). The water consumed by the ecological ditch (12) is replenished by the branch canal (3). When 0 < h A <H A At this time, the controller (4) calculates the difference A between the amount of irrigation required for the farmland and the amount of water in the irrigation and drainage ditch (11). If A≤0, the controller closes the outlet sluice gate (14) and the farmland is irrigated only by the irrigation and drainage ditch (11). If 0<A≤ the amount of water in the ecological ditch (12), the controller opens the second sluice gate (15) and closes the outlet sluice gate (14) so ​​that the water in the irrigation and drainage ditch (11) and the ecological ditch (12) is discharged for farmland irrigation. If A> the amount of water in the ecological ditch (12), the controller opens the second sluice gate (15) and closes the outlet sluice gate (14) first. The water in the ecological ditch (12) is discharged into the farmland for irrigation through the irrigation and drainage ditch (11). After all the water in the ecological ditch (12) is discharged, the controller opens the first sluice gate (13) to continue irrigating the farmland. The water consumed by the ecological ditch (12) is replenished by the branch canal (3).

6. The operation method of a farmland drainage diversion, storage, utilization and purification system according to claim 4, characterized in that: The operating method further includes: During the farmland drainage period When h A When =0, the water in the farmland is directly discharged into the irrigation and drainage ditch (11); When 0 < h A <H A At that time, the controller (4) determines whether the sum of the water volume in the irrigation and drainage ditch (11) and the predicted farmland drainage volume is greater than the capacity of the irrigation and drainage ditch (11). If it is greater, the controller controls the outlet sluice gate (14) to open, so that the farmland runoff flows into the ecological ditch (12). When h A ≥H A At that time, the controller (4) first calculates the farmland drainage volume, then controls the third sluice gate (16) to open and the outlet sluice gate (14) to close, so that the ecological ditch (12) discharges water no less than the farmland drainage volume into the branch ditch (3). Then, it controls the outlet sluice gate (14) to open and the third sluice gate (16) to close, and the farmland drainage is discharged into the ecological ditch (12) through the irrigation and drainage ditch (11).

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