Soil erosion simulation test device based on virtual slope length

Abstract

The invention discloses a soil erosion simulation test device based on virtual slope length, and belongs to the technical field of soil erosion simulation. The device comprises a virtual slope length regulation and control system and an automatic sampling system, the virtual slope length regulation and control system comprises an overflow box arranged at the top end of a runoff groove body, a tipping bucket type rain gauge and an integrated control center, a slope adjusting support is arranged at the bottom of the runoff groove, a hydraulic lifting rod is arranged at the tail end of the slope adjusting support, and a water inlet is formed in the top of the overflow box. The water inlet is connected with a water pump, the water inlet amount is controlled through an electromagnetic valve, and the runoff groove is provided with an automatic monitoring structure. The dynamic overflow box is introduced to simulate soil erosion under different slope length conditions, meanwhile, the automatic sampling system is integrated to achieve continuous sampling, the limitation that a traditional device cannot dynamically simulate continuous slope length changes due to site space and cost restrictions and manual sampling efficiency is low is broken through, and the device can be popularized and used within a certain range.

Description

Technical Field

[0001] This invention belongs to the field of soil erosion simulation technology, specifically a soil erosion simulation test device based on virtual slope length. Background Technology

[0002] Soil erosion is the number one threat to global soil resources, leading not only to significant degradation of soil productivity but also to agricultural non-point source pollution, severely hindering global agricultural sustainable development and ecological security. Topography is a key factor influencing soil erosion processes, with slope and slope length often considered core driving forces. Therefore, accurately controlling slope and slope length factors in a controlled environment and conducting relevant simulation experiments are crucial for in-depth research into soil erosion mechanisms and the development of effective soil and water conservation technologies.

[0003] However, existing soil erosion tests have two technical limitations: First, while existing devices can freely adjust the slope, the realization of the physical slope length is limited by the space and cost constraints of the test site. A fixed slope length design is generally adopted, usually limited to 5-10 meters, which is difficult to simulate the actual slope lengths in nature, which are often tens to hundreds of meters long, and cannot dynamically simulate continuous slope length changes, leading to distorted test simulation results. Second, relying on discrete manual sampling for runoff and sediment sampling and monitoring is time-consuming, labor-intensive, and prone to data omissions. Especially under conditions of continuous rainfall or high-frequency sampling, labor costs and operational errors increase significantly, and problems such as sample mixing and overflow also seriously affect data quality.

[0004] Therefore, developing an experimental device that can overcome the limitations of physical slope length, simulate equivalent slope length (i.e., "virtual slope length") through parametric methods, and integrate high-precision automated monitoring functions is a key technical problem that urgently needs to be solved in this field. Such a device is expected to significantly overcome the core limitations of traditional methods, such as low experimental efficiency, poor simulation accuracy, and high labor costs. It has important scientific significance and application value for improving the simulation effect of soil erosion, deepening the understanding of mechanisms, and promoting the research and development of soil and water conservation technologies. Summary of the Invention

[0005] The first technical problem that this invention aims to solve is that traditional devices cannot simulate continuous slope length changes of tens to hundreds of meters under natural environmental conditions, which leads to distortion of the slope confluence process in the experimental simulation and limits the study of erosion dynamics mechanisms.

[0006] The second technical problem that this invention aims to solve is that traditional devices rely on discrete manual sampling, which results in insufficient sampling efficiency and accuracy.

[0007] To solve the above technical problems, the present invention adopts the following technical solution: A soil erosion simulation test device based on virtual slope length includes a virtual slope length control system and an automatic sampling system, wherein: The virtual slope length control system includes an overflow box located at the top of the runoff channel, a tipping bucket rain gauge, an integrated control center, a slope adjustment bracket at the bottom of the runoff channel, a hydraulic lifting rod at the end of the slope adjustment bracket, a water inlet at the top of the overflow box connected to the runoff channel, a water pump connected to the water inlet and controlled by a solenoid valve, and an automatic monitoring structure installed in the runoff channel. The automatic sampling system includes a rotating sample disk, a servo drive mechanism, a pressure level gauge, and a weighing sensor. The rotating sample disk is a disc, and sample collection bottles and guide tubes are alternately arranged under the disc. The rotating sample disk and the servo drive mechanism are connected by a fixed gear.

[0008] Preferably, the automatic monitoring structure is located next to the main body of the runoff channel and includes a tipping bucket rain gauge and an integrated control center.

[0009] Preferably, the integrated control center calculates the overflow based on the real-time rainfall data monitored by the tipping bucket rain gauge and the relationship between slope, slope length and runoff, thereby realizing the runoff scouring effect of virtual slope length. The integrated control center adopts a human-machine interaction system composed of PLC and touch screen.

[0010] Preferably, the sample tray includes several fan-shaped compartments, with a wide-mouth inlet at the top and a tapered opening at the bottom. The pressure level gauge is located at the bottom of the collection tank (for real-time measurement of the water level in the collection tank). The weighing sensor is connected to the bottom of the collection bottle via a threaded rod. The threaded rod is screwed into the threaded hole at the top of the sensor, and the other end is screwed into the threaded base at the bottom of the sample collection bottle (for detecting the overflow status of the sample bottle). The pressure level gauge and the weighing sensor are connected to an integrated control center to realize parameter setting, data storage, and remote monitoring functions.

[0011] Preferably, the servo drive mechanism includes a digital signal processor and a stepper motor. The digital signal processor controls the stepper motor to drive the sample disk to rotate according to the preset sampling frequency and the data transmitted by the pressure level gauge and the weighing sensor through a control algorithm.

[0012] Preferably, the cross-section of the flow channel body and the overflow box is provided with a sawtooth overflow port, which makes the overflow uniform and stable, effectively improving the overflow efficiency.

[0013] Preferably, the rotating sample disk is a circular disk with a diameter of 1m.

[0014] As a preferred option, the sample tray has 48 sector-shaped compartments.

[0015] This invention provides a soil erosion simulation test device based on virtual slope length. This technical solution simulates soil erosion processes under different slope length conditions by adding an overflow box that is linked to real-time rainfall control. Simultaneously, an automatic sampling system enables continuous sampling. This solves the problem that traditional soil erosion devices are limited by experimental space and cost, making it impossible to dynamically simulate continuous slope length changes close to natural conditions. It also overcomes the limitations of low efficiency and insufficient sampling frequency of manual sampling, and can be widely used within a certain scope.

[0016] This invention achieves the following functions through innovative design: (1) adjusting the virtual slope length based on overflow linked to rainfall, breaking through physical space limitations; (2) automatically collecting runoff and monitoring runoff generation, improving experimental efficiency and data reliability. This invention is applicable to indoor and outdoor soil and water conservation experiments, slope erosion mechanism research, and monitoring technology development.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: An overflow box is added to the top of the runoff channel, and its specific parameters can be optimized and adjusted according to the needs of the target application scenario. By controlling the overflow (i.e., the flow rate on the slope), the slope length can be simulated. A pressure-type water level gauge and a weighing sensor are installed. When the integrated control center detects that the sampling bottle has reached a preset volume or mass threshold, the servo drive mechanism controls the disk to rotate and switch to an empty sampling bottle, achieving continuous sampling. This device can save manpower and resources to a certain extent, reduce errors in manual sampling, and overcome the limitations of traditional devices such as low experimental efficiency and constraints imposed by experimental space and cost. It can be widely used within a certain scope. Specific advantages are as follows: (1) Virtual slope length extension: By controlling the flow rate and combining natural rainfall or artificial simulated rainfall, the soil erosion process of any equivalent slope length can be simulated, which greatly improves the simulation effect compared with traditional device test simulation. (2) Automatic sampling: The sample tray is equipped with 48 sector-shaped compartments, which, together with the intelligent sensing system, can achieve a sampling frequency of minutes, reducing labor costs by 90%; (3) Improved data accuracy: The dual-sensor verification mechanism ensures that the flow rate measurement error is ≤2% and the sample cross-contamination rate is <0.5%; (4) Multi-scenario adaptation: The modular design is compatible with runoff channels of different specifications and is suitable for diverse scenarios such as scientific research institutes and soil and water conservation monitoring stations. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 yes Figure 1 A magnified view of a portion of position A in the middle; In the picture: 1. Virtual slope length control system; 2. Automatic sampling system; 11. Runoff flume main body; 12. Overflow box; 13. Tipping bucket rain gauge; 14. Integrated control center; 15. Slope adjustment bracket; 16. Hydraulic lifting rod; 17. Serrated overflow port; 18. Water inlet; 19. Water pump; 20. Solenoid valve; 21. Rotating sample tray; 22. Servo drive mechanism; 23. Pressure water level gauge; 24. Weighing sensor; 25. Fan-shaped compartment; 26. Conical neck; 27. Sample collection bottle; 28. Guide pipe. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in detail below. To avoid excessive and unnecessary detail, well-known structures or functions will not be described in detail in the following embodiments. The approximate language used in the following embodiments is for quantitative purposes, indicating that a certain degree of variation in quantity is permissible without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which this invention pertains.

[0020] A soil erosion simulation test device based on virtual slope length includes a virtual slope length control system 1 and an automatic sampling system 2; The virtual slope length control system 1 includes an overflow box 12 located at the top of the runoff channel body 11, a tipping bucket rain gauge 13, and an integrated control center 14. The runoff channel body 11 is welded from stainless steel, and the channel dimensions are 5m long × 1.5m wide × 0.5m deep. The bottom is equipped with a slope adjustment bracket 15, and the end is equipped with a hydraulic lifting rod 16 with a lifting stroke of 0-100cm. It is equipped with an inclination sensor (accuracy ±0.1°) and linked with a PLC to achieve precise slope adjustment from 0-50° (resolution 0.5°). The top of the overflow box 12 is equipped with a water inlet 18, which is connected to the runoff channel body 11. The water inlet 18 is connected to a water pump 19, and the water inlet volume is controlled by a solenoid valve 20. The runoff channel 11 is equipped with an automatic monitoring structure. An automatic monitoring structure is located next to the main body 11 of the runoff channel, including a tipping bucket rain gauge 13 and an integrated control center 14. The tipping bucket rain gauge 13 is fixed by a base and includes an external rain catcher and an internal funnel. The funnel is connected to a tipping bucket, which is connected to a magnet. A reed switch is fixed on the magnet. The reed switch is controlled by the magnet to close or open. The tipping bucket rain gauge 13 monitors the rainfall data in real time and transmits the obtained data to the integrated control center 14 in real time. Based on the relationship between slope, slope length and runoff, the overflow is calculated, thereby realizing the runoff scouring effect of virtual slope length. The integrated control center 14 uses a PLC and a touch screen to form a human-machine interaction system, which dynamically adjusts the overflow rate (flow rate Q = soil permeability coefficient K × rainfall intensity I × slope length L × slope factor) based on the relationship between rainfall intensity, slope, slope length and runoff. The system simulates runoff characteristics under different slope lengths. After inputting the target slope length value through the touch screen, the system automatically calculates the required overflow and generates a control curve. By dynamically adjusting the opening of the solenoid valve 20, the system can simulate runoff scouring at the equivalent slope length. The automatic sampling system 2 includes a rotating sample disk 21, a servo drive mechanism 22, a pressure level gauge 23, and a weighing sensor 24. The rotating sample disk 21 is a stainless steel disk with a diameter of 1m. The disk is divided into 48 sector-shaped compartments 25. The 48 sector-shaped compartments 25 (24 sample collection holes and 24 flow guide holes) are arranged in a "1 sampling + 1 flow guide" cycle. The upper part of the compartment is a wide-mouth flow inlet, and the lower part adopts a conical constriction design 26. Sample collection bottles 27 and flow guide tubes 28 are alternately arranged under the disk. The rotating sample disk 21 is connected to the servo drive mechanism 22 by a fixed gear. The servo drive mechanism 22 includes a digital signal processor and a stepper motor. The digital signal processor controls the stepper motor to drive the sample disk to rotate according to the data transmitted by the pressure level gauge 23 and the weighing sensor 24 through the control algorithm, so as to realize the timed switching of sampling / flow guiding mode. A pressure level gauge 23 is located at the bottom of the collection tank for real-time water level measurement. A load cell 24 is equipped with a closed-loop stepper motor (step angle 0.072°, torque 3Nm) and achieves a 1.5° graduation accuracy for the sample pan via worm gear transmission. The sampling frequency can be customized within the range of 1-60 minutes. The load cell is connected to the lower part of the sample collection bottle 27 via a threaded rod. The threaded rod is screwed into the threaded hole at the top of the sensor, and the other end is screwed into the threaded base at the bottom of the sample collection bottle 27. This is used to detect the overflow status of the sample collection bottle 27. Once the sample collection bottle 27 is detected to be full, the stepper motor is driven to rotate the disk by a specific angle, bringing the new bottle position to the sampling location. If sampling is interrupted, the sample pan 21 is rotated to the guide tube 28 for standby. The pressure level gauge 23 and the load cell 24 are connected to the integrated control center 14. A sawtooth-shaped overflow port 17 is provided at the junction of the main body 11 of the runoff channel and the overflow box 12, which can generate uniform and stable overflow and effectively improve overflow efficiency.

[0021] After clarifying the slope length factor to be simulated, the soil samples collected in the field were air-dried and sieved, and then layered into the runoff flume according to the undisturbed soil bulk density to carry out soil erosion simulation experiments. The experiments were conducted under natural rainfall or artificial simulated rainfall conditions. 1. Slope Length Simulation According to the test requirements, the target slope length (e.g., 120m), slope (e.g., 15°) and sampling frequency (e.g., 5 minutes / time) can be set via the touch screen.

[0022] Start the self-test procedure: hydraulic system lifting test, solenoid valve opening and closing verification, sample tray zeroing and positioning; After the water pump starts, the integrated control center dynamically adjusts the overflow rate based on the real-time rainfall intensity. When I = 2 mm / min is detected, the system automatically increases the opening of the solenoid valve to 65% to simulate the runoff accumulation effect under the equivalent slope length.

[0023] Each experimental group was set up with three independent replicates. Systematic errors were eliminated by randomized block design to ensure that the results met the statistical significance requirement. p <0.05).

[0024] 2. Sample collection and monitoring The rotating sample tray 21 switches sampling positions according to a preset cycle. After the bottle is full, it automatically switches to the flow guiding mode and records the time. The weighing sensor uploads the sample bottle weight data in real time, and the system automatically generates a flow rate-time curve and calculates the cumulative flow rate. Production-Time Curve Settings: Horizontal Axis (X-axis) - Time (unit: seconds / minutes / hours / duration of rainfall events), Vertical Axis (Y-axis) - Production (m³) 3 The cumulative production flow (m³) is calculated using the production flow-time curve. 3 ).

[0025] 3. Full bottle warning When the pressure level gauge 23 and the weighing sensor 24 detect that the sample collection bottles 27 have reached the preset safe volume threshold (75%, 18 bottles), the integrated control center 14 immediately triggers a two-stage linkage response: Audible and visual alarm system: The integrated control center 14 features a flashing red warning light (frequency 2Hz) and an 85dB buzzer. Mechanical safety locking: When the last sample collection bottle 27 is full, the servo drive structure 22 is automatically cut off, the sample tray 21 stops rotating, and the solenoid valve 20 controls the water pump 19 to stop pumping.

[0026] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A soil erosion simulation test device based on virtual slope length, comprising a virtual slope length control system (1) and an automatic sampling system (2), characterized in that: The virtual slope length control system (1) includes an overflow box (12) located at the top of the main body of the runoff channel (11), a tipping bucket rain gauge (13), an integrated control center (14), a slope adjustment bracket (15) configured at the bottom of the runoff channel (11), a hydraulic lifting rod (16) at the end of the slope adjustment bracket (15), an inlet (18) at the top of the overflow box (12) connected to the main body of the runoff channel (11), the inlet (18) connected to the water pump (19), and the water inlet volume controlled by the solenoid valve (20). The runoff channel (11) is equipped with an automatic monitoring structure. The automatic sampling system (2) includes a rotating sample disk (21), a servo drive mechanism (22), a pressure water level gauge (23), and a weighing sensor (24). The rotating sample disk (21) is a disc, and sample collection bottles (27) and guide tubes (28) are alternately arranged under the disc. The rotating sample disk (21) and the servo drive mechanism (22) are connected by a fixed gear.

2. The soil erosion simulation test device based on virtual slope length according to claim 1, characterized in that, The automatic monitoring structure is located next to the main body of the runoff channel (11) and includes a tipping bucket rain gauge (13) and an integrated control center (14). The integrated control center (14) calculates the overflow based on the rainfall data monitored in real time by the tipping bucket rain gauge (13) and the relationship between slope, slope length and flow rate. The integrated control center (14) adopts a human-machine interaction system composed of a PLC and a touch screen.

3. The soil erosion simulation test device based on virtual slope length according to claim 2, characterized in that, The sample tray (21) includes several fan-shaped compartments (25). The upper part of the compartment is a wide-mouthed inlet, and the lower part adopts a tapered constriction design (26). The pressure level gauge (23) is located at the bottom of the collection bucket. The weighing sensor (24) is connected to the lower part of the collection bottle (27) through a threaded rod. The threaded rod is screwed into the threaded hole at the top of the sensor, and the other end is screwed into the threaded base at the bottom of the sample collection bottle (27). The pressure level gauge (23) and the weighing sensor (24) are connected to the integrated control center (14).

4. The soil erosion simulation test device based on virtual slope length according to claim 1, characterized in that, The servo drive mechanism (22) includes a digital signal processor and a stepper motor. The digital signal processor controls the stepper motor to drive the sample disk to rotate according to the preset sampling frequency and the data transmitted by the pressure level gauge (23) and the weighing sensor (24) through the control algorithm.

5. The soil erosion simulation test device based on virtual slope length according to claim 1, characterized in that, The main body of the flow channel (11) and the overflow box (12) are connected by a sawtooth overflow port (17).

6. The soil erosion simulation test device based on virtual slope length according to claim 1, characterized in that, The rotating sample disk (21) is a disk with a diameter of 1m.

7. The soil erosion simulation test device based on virtual slope length according to claim 3, characterized in that, The number of sector-shaped compartments (25) on the sample tray (21) is 48.

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