Portable runoff plot with variable size for field experiment

Abstract

The invention discloses a portable size-variable runoff plot for field experiments, which comprises two telescopic coamings, a top coaming and a bottom coaming are detachably connected between the two telescopic coamings, and the bottom coaming is communicated with a drain pipe; the collecting assembly comprises a collecting barrel, the collecting barrel is detachably connected with an upper cover and a bottom sealing part, the upper cover is communicated with the drainage pipe through a hose, the bottom sealing part is communicated with a plurality of drainage mechanisms and fixedly connected to a support, a driving mechanism is arranged at the bottom of the support, and the driving mechanism is detachably connected with a plurality of bent stirring rods; the breaking assembly comprises a separator and a cutter, the separator is used for separating the interior of the collecting barrel into a plurality of equal spaces, and the cutter is used for cutting the bottom sealing part. According to the device, the area of a runoff plot can be adjusted, a sample can be more uniformly divided into a plurality of parts, and sampling is more convenient.

Description

Technical Field

[0001] This invention relates to the field of soil and water conservation experimental technology, and in particular to a portable variable-size runoff plot for field experiments. Background Technology

[0002] In the fields of soil and water conservation, ecological restoration, and agricultural non-point source pollution research, runoff plots are crucial experimental devices for monitoring and simulating rainfall-runoff-sediment processes in the field. Traditional runoff plots are mostly fixed structures, typically permanently constructed on-site using concrete or metal materials, with fixed areas, slopes, and boundary conditions. While these devices can provide relatively stable observational data, they suffer from limitations such as long construction periods, high costs, immobility, and difficulty adapting to complex terrains, severely restricting their application in multi-regional, multi-scale comparative experiments. In recent years, with the intensification of climate change and the deepening research into the impact of human activities on surface processes, researchers have an increasingly urgent need for flexible, efficient, and reusable field experimental platforms.

[0003] Although there are modular runoff collection devices on the market, they still have shortcomings in practical applications. First, the size of the enclosure panels is usually fixed and cannot be adjusted, making them inconvenient to use. Second, it is inconvenient to sample the collected rainwater, as sediment tends to settle at the bottom, which can easily lead to large deviations in the sediment content of the rainwater during sampling.

[0004] To address this issue, a portable, variable-size runoff plot for field experiments is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a portable, variable-size runoff plot for field experiments to solve the problems existing in the prior art. During use, the size of the enclosure can be easily adjusted, thereby facilitating the adjustment of the plot area. At the same time, it improves the uniformity of sediment content in rainwater during sampling, thereby improving the accuracy of experimental data.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a portable variable-size runoff plot for field experiments, comprising: Two telescopic panels are provided, with a top panel and a bottom panel detachably connected between the two telescopic panels, and a drain pipe is connected to the bottom panel. A collection component includes a collection cylinder, which is detachably connected to an upper cover and a bottom seal. The upper cover is connected to the drain pipe via a flexible hose. The bottom seal is connected to several discharge mechanisms. The bottom seal is fixedly connected to a support. A drive mechanism is provided at the bottom of the support. Several bent stirring rods are detachably connected to the drive mechanism. The breaking assembly includes a divider and a cutter. The divider is used to divide the inside of the collection cylinder into several equally divided spaces, and the cutter is used to cut open the bottom seal.

[0007] Preferably, the separator includes an inner cylinder, a plurality of partitions are fixedly connected inside the inner cylinder, and a round tube is fixedly connected to the partitions. The outer diameter of the round tube of the inner cylinder is smaller than the inner diameter of the collecting cylinder.

[0008] Preferably, the cutter includes a hand handle, on which a plurality of first connecting rods are fixedly connected, and on each of the first connecting rods are a curved blade.

[0009] Preferably, the bottom seal includes a bottom cover with a plurality of first through holes. The bottom cover is detachably connected to the collecting cylinder. The bottom cover has a threaded hole with a support threaded onto it. A pressure plate is fixedly connected to the support. A rubber membrane is laid inside the bottom cover with a second through hole. The support passes through the second through hole.

[0010] Preferably, the outer edge of the support column is provided with several guide grooves, several guide strips are fixedly connected inside the circular tube, the guide strips are adapted to the guide grooves, and the support column is detachably connected with a clamping plate.

[0011] Preferably, the driving mechanism includes a base, on which a motor is fixedly connected, a groove is provided on the base, a rotating shaft is rotatably connected within the groove, a first insertion hole is provided on the rotating shaft, a rectangular insertion rod is fixedly connected to the bracket, the rectangular insertion rod is adapted to the first insertion hole, the motor is drivenly connected to the rotating shaft, a plurality of second insertion holes are provided on the base, the second insertion holes are detachably connected to the bent stirring rod, the bent stirring rod is adapted to the second insertion holes, a switch is installed on the base, and the motor is electrically connected to the switch.

[0012] Preferably, a first gear is fixedly connected to the motor drive shaft, and a gear ring is fixedly connected to the rotating shaft. The first gear meshes with the gear ring, and the rotating shaft is rotatably connected to the groove through a bearing.

[0013] Preferably, the telescopic enclosure includes an outer panel and an inner panel. The outer panel has a first slot, and a flexible pull strip is fixedly connected to the first slot. The inner panel is inserted into the first slot. The outer panel and the top panel are detachably connected by a connector. The connector has a second slot and a third slot. The outer panel is adapted to the second slot, the top panel is adapted to the third slot, and the bottom panel has a fourth slot. The inner panel is adapted to the fourth slot.

[0014] Preferably, the bracket includes a plurality of second connecting rods and a support plate, the second connecting rods being fixedly connected to the support plate, the top end of the second connecting rods being fixedly connected to the bottom cover, and the rectangular insert being fixedly connected to the support plate.

[0015] Preferably, the excretion mechanism includes a funnel, which is fixedly connected to the bottom cover. The funnel is correspondingly arranged with the first through hole, and an excretion pipe is connected to the funnel. A valve is installed on the excretion pipe.

[0016] This invention discloses the following technical effects: In this device, two telescopic enclosures, a top enclosure, and a bottom enclosure are connected together to form a runoff zone. The telescopic enclosures can be extended or retracted to change their length, thereby changing the area of ​​the zone. The detachable connection method facilitates installation or disassembly and also facilitates transportation. When collecting runoff, the collection cylinder, top cover, and bottom seal are installed to form a sealed container for collecting surface runoff within the zone. The collected rainwater flows into the container through a hose. When sampling is required after collection, the top cover is removed from the collection cylinder, the bracket is installed on the drive mechanism, and the bent stirring rod is inserted into the collection cylinder. The drive mechanism is then activated, driving the bracket and... The collection cylinder rotates while the bent stirring rod remains stationary, extending into the collected rainwater. The rotation of the collection cylinder and the rainwater inside, combined with the stirring rod's agitation, causes the sample to settle. After agitation, the sample is allowed to stand for a period before a separator is inserted into the collection cylinder, dividing the rainwater sample into several equal portions. A cutter is then used to break the bottom seal of one portion, allowing the rainwater sample to flow out through the drainage mechanism. Because the separator vertically divides the collection cylinder, the outflowing sample washes away sediment at the bottom, facilitating sediment removal. Simultaneously, it agitates the sample within this space, ensuring thorough sediment removal and resulting in more accurate measurement data. This device not only allows for adjustment of the runoff plot area but also enables more uniform sample division, making sampling more convenient. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the portable variable-size runoff plot for field experiments according to the present invention; Figure 2 This is a schematic diagram of the structure of the collecting cylinder, the upper cover 6, and the bottom sealing element of the present invention; Figure 3 for Figure 2 Enlarged view of point a in the middle; Figure 4 This is a schematic diagram of the bracket of the present invention mounted on the base; Figure 5 This is a schematic diagram of the separator inserted into the collection tube according to the present invention; Figure 6 This is a schematic diagram of the separator structure of the present invention; Figure 7 This is a schematic diagram of the bottom cover structure of the present invention; Figure 8 This is a schematic diagram of the arc-shaped knife and hand-held lever structure of the present invention; Figure 9 This is a schematic diagram of the telescopic enclosure structure of the present invention; The components include: 1. Telescopic enclosure; 2. Top enclosure; 3. Bottom enclosure; 4. Drainage pipe; 5. Collection cylinder; 6. Top cover; 7. Hose; 8. Bracket; 9. Inner cylinder; 10. Partition; 11. Round pipe; 12. Hand handle; 13. Arc-shaped blade; 14. Bottom cover; 15. First through hole; 16. Support column; 17. Pressure plate; 18. Rubber membrane; 19. Guide groove; 20. Guide strip; 21. Base; 22. Motor; 23. Rotating shaft; 24. Rectangular insert rod; 25. Bending stirring rod; 26. Switch; 27. First gear; 28. Gear ring; 29. ​​Outer plate; 30. Inner insert plate; 31. First slot; 32. Flexible pull strip; 33. Connector; 34. Second connecting rod; 35. Valve; 36. Support plate; 37. Funnel; 38. Drainage pipe; 39. Pressing plate. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Reference Figure 1-9 This invention provides a portable variable-size runoff plot for field experiments, comprising: Two telescopic enclosure panels 1 are detachably connected to a top enclosure panel 2 and a bottom enclosure panel 3, and a drain pipe 4 is connected to the bottom enclosure panel 3. The collection component includes a collection cylinder 5, which is detachably connected to an upper cover 6 and a bottom seal. The upper cover 6 is connected to a drain pipe 4 via a hose 7. Several discharge mechanisms are connected to the bottom seal. The bottom seal is fixedly connected to a support 8. A drive mechanism is provided at the bottom of the support 8. Several bent stirring rods 25 are detachably connected to the drive mechanism. The breaking assembly includes a divider and a cutter. The divider is used to divide the inside of the collection cylinder 5 into several equal spaces, and the cutter is used to cut open the bottom seal.

[0022] In this device, two telescopic enclosures 1, a top enclosure 2, and a bottom enclosure 3 are connected together to form a runoff plot. The telescopic enclosures 1 can be extended or retracted to change their length, thereby changing the area of ​​the plot. The detachable connection method facilitates installation and disassembly, as well as transportation. When collecting runoff, the collection cylinder 5, the top cover 6, and the bottom seal are installed to form a sealed container for collecting surface runoff within the plot. The collected rainwater flows into the container through the hose 7. When sampling is required after collection, the top cover 6 is removed from the collection cylinder 5, the bracket 8 is installed on the drive mechanism, and the bent stirring rod 25 is inserted into the collection cylinder 5. The drive mechanism is then activated, causing the bracket 8 and the collection cylinder 5 to move forward. The stirring rod 25 does not rotate, but it extends into the collected rainwater. The collection cylinder 5 and the rainwater inside rotate, and the stirring rod 25 acts as a stirrer. After stirring, the sample in the collection cylinder 5 is left to stand for a period of time. Then, the separator is inserted into the collection cylinder 5 to divide the rainwater sample into several equal parts. Then, the bottom seal of one part is broken with a cutter, allowing the rainwater sample to flow out through the drainage mechanism. Since the separator divides the collection cylinder 5 vertically, the sample flowing out will have a certain flushing effect on the mud and sand at the bottom, facilitating the discharge of mud and sand. At the same time, it can also stir the sample in this space, making it easier to remove mud and sand. The measurement data after sampling is more accurate.

[0023] The scheme is further optimized. The separator includes an inner cylinder 9, and several partitions 10 are fixedly connected inside the inner cylinder 9. A round tube 11 is fixedly connected to the partitions 10. The outer diameter of the inner cylinder 9 is smaller than the inner diameter of the collection cylinder 5.

[0024] When the inner cylinder 9 is inserted into the collection cylinder 5, it will enter along the inner wall of the collection cylinder 5. The inner cylinder 9 and the round tube 11 will abut against the bottom seal. The partition 10 divides the sample into several equal parts. The round tube 11 is used to install the partition 10.

[0025] The design is further optimized so that the cutter includes a hand handle 12, on which several first connecting rods are fixedly connected, and an arc-shaped blade 13 is fixedly connected to each first connecting rod.

[0026] The staff member holds the handle 12 and inserts the curved blade 13 into one of the spaces to break the bottom seal, thereby allowing the sample to be discharged through the discharge mechanism. The curved blade 13 has no specific shape restriction; it can be curved to facilitate breaking the bottom seal.

[0027] The scheme is further optimized. The bottom seal includes a bottom cover 14, which has several first through holes 15. The bottom cover 14 is detachably connected to the collection cylinder 5. The bottom cover 14 has a threaded hole, and a support column 16 is threadedly connected to the threaded hole. A pressure plate 17 is fixedly connected to the support column 16. A rubber membrane 18 is laid inside the bottom cover 14, and a second through hole is opened on the rubber membrane 18. The support column 16 passes through the second through hole.

[0028] The rubber membrane 18 is located between the bottom cover 14 and the collection cylinder 5. After the bottom cover 14 is connected to the collection cylinder 5, the collection cylinder 5 will press on the rubber membrane 18. When the arc blade 13 cuts the rubber membrane 18, the sample in the collection cylinder 5 will flow out through the cut and the first through hole 15. When the sample flows out, it will have a certain flushing effect on the mud and sand at the bottom, which will facilitate the discharge of mud and sand. At the same time, it can also stir the sample in this space, which will facilitate the discharge of mud and sand. After the support column 16 is screwed into the threaded hole, the pressure plate 17 will press the rubber membrane 18, thereby improving the sealing performance.

[0029] The design is further optimized by providing several guide grooves 19 on the outer edge of the support column 16, and several guide strips 20 are fixedly connected inside the round tube 11. The guide strips 20 are adapted to the guide grooves 19, and the support column 16 is detachably connected to a pressure plate 39.

[0030] When the separator is inserted into the collection cylinder 5, the support column 16 will be inserted into the round tube 11, and then the clamping plate 39 will be installed on the support column 16 so that the clamping plate 39 can press the round tube 11, making the separator as a whole in close contact with the bottom rubber membrane 18, thus improving the sealing performance. The support column 16 and the clamping plate 39 are detachably connected by threads. The cooperation between the guide strip 20 and the guide groove 19 prevents the separator from falling into the position of the first through hole 15.

[0031] The scheme is further optimized. The drive mechanism includes a base 21, a motor 22 is fixedly connected to the base 21, a groove is provided on the base 21, a rotating shaft 23 is rotatably connected in the groove, a first insertion hole is provided on the rotating shaft 23, a rectangular insertion rod 24 is fixedly connected to the bracket 8, the rectangular insertion rod 24 is adapted to the first insertion hole, the motor 22 is connected to the rotating shaft 23 for transmission, a number of second insertion holes are provided on the base 21, a bent stirring rod 25 is detachably connected to the second insertion hole, the bent stirring rod is adapted to the second insertion hole, a switch 26 is installed on the base 21, and the motor 22 is electrically connected to the switch 26.

[0032] The rectangular insertion rod 24 has a rectangular cross-section. After the rectangular insertion rod 24 is inserted into the first insertion hole, the motor 22 drives the rotating shaft 23 to rotate. The rotating shaft 23 drives the rectangular insertion rod 24 and the bracket 8 to rotate, so that the collection cylinder 5 and the sample can rotate. Several bent stirring rods 25 remain stationary, thereby playing a stirring role, making the mud and rainwater in the sample more evenly mixed. After standing for a period of time, the separator can be inserted.

[0033] In a further optimized design, a first gear 27 is fixedly connected to the drive shaft of the motor 22, and a gear ring 28 is fixedly connected to the rotating shaft 23. The first gear 27 meshes with the gear ring 28, and the rotating shaft 23 is rotatably connected in the groove through a bearing.

[0034] Motor 22 drives first gear 27, and first gear 27 drives gear ring 28 and rotating shaft 23 to rotate.

[0035] Further optimization of the scheme: the telescopic enclosure 1 includes an outer panel 29 and an inner insert panel 30. The outer panel 29 has a first slot 31, and a flexible pull strip 32 is fixedly connected in the first slot 31. The inner insert panel 30 is inserted into the first slot 31. The outer panel 29 and the top enclosure 2 are detachably connected by a connector 33. The connector 33 has a second slot and a third slot. The outer panel 29 and the second slot are compatible, the top enclosure 2 and the third slot are compatible, and the bottom enclosure 3 has a fourth slot. The inner insert panel 30 is compatible with the fourth slot.

[0036] The inner plate 30 can be inserted into the first slot 31 of the outer plate 29. The position of the inner plate 30 in the first slot 31 can be adjusted to adjust the length of the telescopic enclosure 1. The connector 33 is used to connect the outer plate 29 and the top enclosure 2. When there is soil in the first slot 31, the soil in the first slot 31 can be brought out by pulling the flexible pull strip 32.

[0037] The design is further optimized so that the bracket 8 includes several second connecting rods 34 and a support plate 36. The second connecting rods 34 are fixedly connected to the support plate 36, and the top of the second connecting rods 34 is fixedly connected to the bottom cover 14. The rectangular insert rod 24 is fixedly connected to the support plate 36.

[0038] The support plate 36 and the second connecting rod 34 are used to support the bottom cover 14.

[0039] The scheme is further optimized. The discharge mechanism includes a funnel 37, which is fixedly connected to the bottom cover 14. The funnel 37 is correspondingly set with the first through hole 15. A discharge pipe 38 is connected to the funnel 37, and a valve 35 is installed on the discharge pipe 38.

[0040] When the rubber membrane 18 is broken, the sample will flow into the funnel 37 and then be discharged through the drain pipe 38. The valve 35 is used to control the drain pipe 38, and other containers can be used to catch the flowing sample.

[0041] The method of using this device is as follows: connect the outer casing 29 and the top enclosure 2 using connector 33; connect the bottom enclosure 3 and the inner insert plate 30 together; insert the outer casing 29, inner insert plate 30, top enclosure 2, and bottom enclosure 3 into the soil of the target area to form a small area; connect the drainage pipe 4 and the hose 7; lay the rubber membrane 18 on the bottom cover 14; connect the bottom cover 14 to the collection cylinder 5; screw the support column 16 into the threaded hole so that the pressure plate 17 presses down on the rubber membrane 18; connect the hose 7 and the top cover 6; and allow the collected rainwater to flow into the container through the hose 7. Inside the container, when sampling is required after collection is complete, the top cover 6 is removed from the collection cylinder 5, the rectangular insert 24 on the bracket 8 is inserted into the first insertion hole, and several bent stirring rods 25 are installed into the second insertion hole, with the bent stirring rods 25 extending into the sample in the collection cylinder 5. The motor 22 is started, and the motor 22 drives the rotating shaft 23 to rotate. The rotating shaft 23 drives the rectangular insert 24 and the bracket 8 to rotate, so that the collection cylinder 5 and the sample can rotate, while the several bent stirring rods 25 remain stationary, thus playing a stirring role and making the mud and rainwater in the sample more evenly mixed.

[0042] After letting it stand for a while, the collection cylinder 5 and the support 8 are removed from the base 21. The separator is inserted into the collection cylinder 5. When the inner cylinder 9 is inserted into the collection cylinder 5, it will enter along the inner wall of the collection cylinder 5. The inner cylinder 9 and the round tube 11 will abut against the bottom seal. The support column 16 is inserted into the round tube 11. Then the pressure plate 39 is installed on the support column 16 so that the pressure plate 39 can press the round tube 11, so that the separator as a whole is in close contact with the bottom rubber membrane 18, improving the sealing performance. The operator holds the hand rod 12 and inserts the arc-shaped knife 13 into one of the spaces to break the bottom seal, so that the sample is discharged through the discharge mechanism. When the sample flows out, it will have a certain flushing effect on the mud and sand at the bottom, which facilitates the discharge of mud and sand. At the same time, it can also stir the sample in this space, which facilitates the removal of mud and sand.

[0043] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0044] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A portable, variable-size runoff plot for field experiments, characterized in that, include: Two telescopic enclosures (1), with a top enclosure (2) and a bottom enclosure (3) detachably connected between the two telescopic enclosures (1), and a drain pipe (4) connected to the bottom enclosure (3). The collection component includes a collection cylinder (5), which is detachably connected to a top cover (6) and a bottom seal. The top cover (6) is connected to the drain pipe (4) via a hose (7). The bottom seal is connected to several discharge mechanisms. The bottom seal is fixedly connected to a bracket (8). The bottom of the bracket (8) is provided with a drive mechanism, which is detachably connected to several bent stirring rods (25). The breaking assembly includes a divider and a cutter. The divider is used to divide the inside of the collecting cylinder (5) into several equal spaces, and the cutter is used to cut open the bottom seal.

2. The portable variable-size runoff plot for field experiments according to claim 1, characterized in that: The separator includes an inner cylinder (9), and a number of partitions (10) are fixedly connected inside the inner cylinder (9). A round tube (11) is fixedly connected to the partition (10). The outer diameter of the round tube (11) of the inner cylinder (9) is smaller than the inner diameter of the collecting cylinder (5).

3. The portable variable-size runoff plot for field experiments according to claim 2, characterized in that: The cutter includes a hand handle (12), on which a plurality of first connecting rods are fixedly connected, and an arc-shaped blade (13) is fixedly connected to the first connecting rods.

4. The portable variable-size runoff plot for field experiments according to claim 3, characterized in that: The bottom seal includes a bottom cover (14), which has several first through holes (15). The bottom cover (14) is detachably connected to the collecting cylinder (5). The bottom cover (14) has a threaded hole, and a support column (16) is threaded onto the threaded hole. A pressure plate (17) is fixedly connected to the support column (16). A rubber membrane (18) is laid inside the bottom cover (14), and a second through hole is opened on the rubber membrane (18). The support column (16) passes through the second through hole.

5. The portable variable-size runoff plot for field experiments according to claim 4, characterized in that: The outer edge of the support column (16) is provided with several guide grooves (19), and several guide strips (20) are fixedly connected inside the round tube (11). The guide strips (20) are adapted to the guide grooves (19), and the support column (16) is detachably connected with a pressure plate (39).

6. The portable variable-size runoff plot for field experiments according to claim 4, characterized in that: The driving mechanism includes a base (21), on which a motor (22) is fixedly connected. A groove is provided on the base (21), and a rotating shaft (23) is rotatably connected in the groove. A first insertion hole is provided on the rotating shaft (23). A rectangular insertion rod (24) is fixedly connected on the bracket (8). The rectangular insertion rod (24) is adapted to the first insertion hole. The motor (22) is connected to the rotating shaft (23) in a transmission connection. A plurality of second insertion holes are provided on the base (21). The bent stirring rod (25) is detachably connected to the second insertion hole. The bent stirring rod is adapted to the second insertion hole. A switch (26) is installed on the base (21). The motor (22) is electrically connected to the switch (26).

7. The portable variable-size runoff plot for field experiments according to claim 6, characterized in that: A first gear (27) is fixedly connected to the drive shaft of the motor (22), and a gear ring (28) is fixedly connected to the rotating shaft (23). The first gear (27) meshes with the gear ring (28), and the rotating shaft (23) is rotatably connected in the groove through a bearing.

8. The portable variable-size runoff plot for field experiments according to claim 1, characterized in that: The telescopic enclosure (1) includes an outer panel (29) and an inner insert panel (30). The outer panel (29) has a first slot (31) and a flexible pull strip (32) is fixedly connected in the first slot (31). The inner insert panel (30) is inserted into the first slot (31). The outer panel (29) and the top enclosure (2) are detachably connected by a connector (33). The connector (33) has a second slot and a third slot. The outer panel (29) is adapted to the second slot. The top enclosure (2) is adapted to the third slot. The bottom enclosure (3) has a fourth slot. The inner insert panel (30) is adapted to the fourth slot.

9. The portable variable-size runoff plot for field experiments according to claim 6, characterized in that: The bracket (8) includes several second connecting rods (34) and a support plate (36). The second connecting rods (34) are fixedly connected to the support plate (36). The top end of the second connecting rods (34) is fixedly connected to the bottom cover (14). The rectangular insert (24) is fixedly connected to the support plate (36).

10. The portable variable-size runoff plot for field experiments according to claim 4, characterized in that: The discharge mechanism includes a funnel (37), which is fixedly connected to the bottom cover (14). The funnel (37) is correspondingly arranged with the first through hole (15). A discharge pipe (38) is connected to the funnel (37), and a valve (35) is installed on the discharge pipe (38).

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