Water and soil loss quantitative monitoring device and method for production and construction project

Abstract

The invention relates to a water and soil loss monitoring technology, in particular to a water and soil loss quantitative monitoring device and method for a production and construction project. The device comprises a controller, a main body support and a foot cup fixing frame, the main body support comprises a top support, a vertical support and an I-shaped support, and the main body support is installed on a channel or a channel through the I-shaped support and the foot cup fixing frame; the upper part of the vertical bracket is connected with the top bracket; the vertical support is slotted to form a linear rail, and a lead screw is arranged on the linear rail. A stepping motor and a front fixing plate are arranged above the screw rod, and a sliding block is arranged on the screw rod; a motor support is fixed to the sliding block, and a speed reduction stepping motor is fixed to the motor support. A rod piece is hung on the motor bracket and is provided with a turbidity sensor; the controller controls the hanging height of the rod piece through the stepping motor, and when an obstacle exists in a channel where the monitoring device works, the rod piece is controlled to rotate through the speed reduction stepping motor. The device is suitable for drainage channels of different sizes, and the efficiency and precision of water and soil loss quantitative monitoring of production and construction projects are improved.

Description

Technical Field

[0001] The invention relates to a soil and water loss monitoring technology, in particular to a soil and water loss quantitative monitoring device and method for production and construction projects. Background Art

[0002] How to scientifically, quickly and accurately measure the accumulated amount of soil and water loss in production and construction projects during rainfall, and to promptly and effectively warn of soil and water loss problems has become increasingly critical.

[0003] Traditional monitoring methods mainly include mathematical model method, analogy method, field test method, empirical estimation method and erosion rate method. These are limited in application by long time period, complex measurement process and high labor cost. They are also easily affected by heavy rainfall conditions and lack wide applicability and sustainable development. They have always been the shortcoming of supervision and monitoring.

[0004] The traditional method of monitoring soil and water loss in production and construction projects is to use a bucket to take samples at a certain monitoring point (or establish multiple points as a grit pool). It is necessary to wait for the sediment and water layers in the bucket (grit pool) to become still, then pour out (drain) the surface water layer, leaving the wet sand at the bottom of the bucket (pool), and calculate the amount of soil and water loss by drying and weighing (further measuring the siltation height in the pool); then, the spatial distribution of each monitoring point is fitted to obtain the amount of soil and water loss in the entire project area. The timeliness and accuracy of the measured data are not high.

[0005] In addition, in traditional flow measurement methods, on the one hand, it is necessary to build a measuring device through the construction of monitoring points, sampling, stillness, centrifugal pumps, drying, weighing and other operating steps. The measuring device is large and bulky, and the installation, disassembly and cleaning are relatively time-consuming and labor-intensive. The operation is complicated and the timeliness is relatively poor. On the other hand, the selection of monitoring points is not necessarily representative, the errors of manual sampling and operation are uncontrollable, and the fitting result data has certain constraints, which reduces the accuracy of the measurement.

[0006] Therefore, how to develop a quantitative monitoring device for soil and water loss that is fast, portable, easy to operate, and affordable is crucial to the accurate calculation of soil and water loss in production and construction projects, and provides key data support for the timely implementation of prevention and control measures for the projects. Summary of the invention

[0007] In order to solve the problems of poor timeliness and low accuracy of data in soil and water loss monitoring of production and construction projects in the prior art, the present invention provides a quantitative monitoring device and method for soil and water loss in production and construction projects, which completes the data collection of soil and water loss monitoring during rainfall processes by using multi-point and layered quantitative information integration, improves the real-time nature and measurement accuracy of the data, and can be widely used in different production and construction projects to carry out soil and water loss measurement at different locations of intercepting drainage ditches and channel sections.

[0008] In an embodiment of the present invention, a quantitative monitoring device for soil and water loss in a production and construction project includes a controller, a main frame and a foot cup fixing frame, wherein the main frame includes a top frame, a vertical frame and an "I"-shaped frame, wherein the vertical frame is connected to the top frame and the "I"-shaped frame respectively, and the main frame is installed on a ditch through the "I"-shaped frame and the foot cup fixing frame;

[0009] A rain collecting barrel and a solenoid valve are provided on the top bracket;

[0010] The upper part of the vertical bracket is connected to the top bracket, and an ultrasonic level meter is installed at the lower part; the vertical bracket is slotted to form a linear track, and a lead screw is provided on the linear track; the vertical bracket is fixed to the lead screw through a coupling and kept parallel; a stepper motor and a front fixing plate are installed above the lead screw, and a rear fixing plate is installed below, and a slider is installed on the lead screw; a motor bracket is fixed on the slider, and a reduction stepper motor is fixed on the motor bracket; a rod is suspended on the motor bracket, and a turbidity sensor is installed on the rod;

[0011] The controller controls the hanging height of the rod through a stepper motor; when there is an obstacle in the channel where the monitoring device works, the controller controls the rotation of the rod through a decelerating stepper motor.

[0012] Preferably, the channel depth in which the monitoring device works is assumed to be H0;

[0013] The turbidity sensor includes a first turbidity sensor, a second turbidity sensor and a third turbidity sensor;

[0014] The controller controls the hanging height of the rod through a stepper motor, so that the center position of the first turbidity sensor is 0.1H0~0.3H0 away from the bottom of the channel, the center position of the third turbidity sensor is 0.2H0~0.3H0 away from the top of the channel, and the center position of the second turbidity sensor between the first turbidity sensor and the third turbidity sensor is set at 0.5H0 away from the top of the channel.

[0015] In an embodiment of the present invention, a quantitative monitoring method for soil and water loss in a production and construction project is implemented based on the above-mentioned monitoring device, and includes the following steps:

[0016] The rod and the turbidity sensor are moved in the vertical direction by a stepping motor, a screw rod and a slider, so that each turbidity sensor is located at a different water level depth in the channel;

[0017] Based on the data detected by the turbidity sensor and ultrasonic level meter, the sediment content per unit volume of the water-passing section and the cumulative amount of soil and water loss during a rainfall event are calculated.

[0018] Compared with the prior art, the technical effects achieved by the present invention include:

[0019] 1. The monitoring device of the present invention has a novel and unique structure. It uses multi-point and layered quantitative information integration to complete the data collection and transmission of soil and water loss monitoring during rainfall events, and realizes the display and monitoring of the mobile control terminal. It only needs to be properly installed on the corresponding monitoring drains and channels to realize online quantitative and real-time monitoring of soil and water loss in the project area and key monitoring areas (steep slopes, important water collection sections). The timeliness and measurement accuracy of this device are far higher than the existing related soil and water loss monitoring equipment, and it is a quantitative monitoring device for soil and water loss on the project, which is unique and unique.

[0020] 2. The monitoring device has a simple structure, low power consumption, is easy to carry, has low installation cost, strong real-time data, and can realize long-distance data transmission. It can be widely used in different production and construction projects to carry out soil and water loss measurement at different locations of drainage ditches and channel sections; it can further support the follow-up research on the effects of soil and water loss on farmland, rivers, and irrigation areas, and lay a theoretical foundation. It has certain promotion value. Combined with the rainfall monitoring data of the device, it can provide a certain data basis for soil and water loss early warning of later projects.

[0021] 3. The monitoring device of the present invention can be installed in the channel at the outlet of the project area (or the key monitoring point of the project area). The sediment concentration per unit volume can be directly measured by turbidity sensors at different heights. The weight of soil and water loss after a rainfall event in the catchment area can be calculated by using the mathematical calculation formula of the sediment content at different channel flow depths, combined with the rainfall duration and flow rate of the section. The measuring rod components can be customized according to different types of channels to adapt to the quantitative monitoring of soil and water loss in the project drainage channels, ensuring the overall specifications and accuracy of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of a quantitative monitoring device for soil and water loss in an embodiment of the present invention;

[0023] Figure 2 is a side view of a quantitative monitoring device for soil and water loss according to an embodiment of the present invention;

[0024] Figure 3 Schematic diagram of the installation of a three-dimensional channel of a soil and water loss quantitative monitoring device according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the installation position of the turbidity sensor in an embodiment of the present invention;

[0026] Figure 5 is a control block diagram of a monitoring device in an embodiment of the present invention;

[0027] In the figure, 1: rain collecting barrel; 2: solenoid valve; 3: stepper motor; 4: front fixing plate; 5: coupling; 6: angle code; 7: main body bracket; 8: reduction stepper motor; 9: rear fixing plate; 10: stainless steel pipe; 11: turbidity sensor; 12: cross joint; 13: controller; 14: motor bracket; 15: slider; 16: ultrasonic level meter; 17: linear rail; 18: adjustable foot cup; 19: foot cup fixing bracket; 20: screw rod; 21: solar panel bracket; 22: solar panel; 23: mobile display terminal; 24: support base. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, so that ordinary technicians in the field can implement the monitoring device and method of the present invention, and can use the technical solution of the present invention to measure the amount of soil and water loss in a certain period of time for intercepting and draining ditches of different projects and different specifications and realize wireless data transmission and real-time display and monitoring.

[0029] Example

[0030] This embodiment provides a quantitative monitoring device for soil and water loss in production and construction projects. Figure 1-Figure 3 , including a main frame 7 and a foot cup fixing frame 19, the main frame includes a top frame, a vertical frame and an "I"-shaped frame, the vertical frame is connected to the top frame and the "I"-shaped frame respectively, and the main frame is installed on the ditch through the "I"-shaped frame and the foot cup fixing frame. In this embodiment, the main frame adopts European standard 2040 aluminum profile and is assembled through angle code 6.

[0031] One end of the top bracket is fixed with a solar panel 22 through a solar bracket 21, and the other end is installed with a rain collecting barrel 1 and a solenoid valve 2. A controller 13 is installed on the "I"-shaped bracket, and the controller is connected to a mobile display terminal 23 for data collection and control. The "I"-shaped bracket is installed on the ditch through a foot cup fixing bracket 19.

[0032] The upper part of the vertical bracket is connected to the top bracket, and an ultrasonic level meter 16 is installed at the lower part. The vertical bracket is slotted to form a linear track 17, and a screw 20 is provided on the linear track 17. The vertical bracket is fixed to the screw 20 through a coupling 5 and kept parallel; a stepper motor 3 and a front fixing plate 4 are installed above the screw, a rear fixing plate 9 is installed below, and a slider 15 is installed on the screw. The motor bracket 14 is fixed on the slider 15, and the reduction stepper motor 8 is fixed on the motor bracket 14. One end of the stainless steel pipe 10 (i.e., the rod) is suspended and fixed on the motor bracket 14 through a cross joint 12, and a turbidity sensor 11 is installed on the stainless steel pipe. In this embodiment, the number of turbidity sensors is set to 3.

[0033] In this embodiment, the rear fixing plate 9 is located at the bottom of the screw rod, the ultrasonic level meter 16 is located at the bottom of the vertical bracket, and the slider 15 and the reduction stepping motor 8 are arranged side by side on the motor bracket 14 in the horizontal direction.

[0034] The front and rear fixing plates, angle brackets, screw rods, cross joints, etc. of this embodiment are all made of stainless steel, and the brackets, linear rails, and sliders are made of aluminum alloy. On the one hand, it ensures that the corrosion in mixed water is reduced; on the other hand, no deformation occurs during the measurement process, the accuracy of the position is protected, and the measured data of soil and water loss are highly representative and accurate. At the same time, the main bracket of the European standard aluminum profile is assembled to fix the solar panels and rainwater collection barrels and achieve stable installation; an ultrasonic level meter is installed at the bottom of the vertical bracket of the aluminum profile to measure the water level, and the internal groove of the vertical bracket of the aluminum profile is used to install the screw rod; a stainless steel pipe is fixed under the screw rod to extend into the drain ditch or channel, and the turbidity sensor is fixed on the stainless steel pipe to measure the sediment concentration at the corresponding position.

[0035] After the monitoring device is installed, the measurement can begin; the measured data will be transmitted to the mobile display terminal 23 through the controller 13, and the mobile display terminal can store historical data and display real-time data; after the measurement work is completed, the device can be disassembled through the foot cup fixing frame for easy carrying and long-distance transportation.

[0036] In order to obtain rainfall data and duration, a solenoid valve 2 is installed at the bottom of the rain collecting barrel 1 to control the rainfall and calculate the duration of the rainfall. Under normal circumstances, during the construction of large-scale production and construction projects and rainfall, the water body or water volume in the drainage channel is determined by the construction intensity and the amount of rainfall, and the water level depth in the channel also changes dynamically. In order to make the device more applicable, the stepper motor 3 drives the sediment measurement components (mainly including the stainless steel pipe 10 and the turbidity sensor 11) to move up and down in the vertical direction through the slider 15, and the stepper motor movement has high precision, which can move each turbidity sensor to a specified or typical position to carry out turbidity measurement, greatly improving the measurement accuracy of the device, combined with the turbidity installation and layout characteristics, to achieve accurate measurement of sediment concentration in sections under different water levels.

[0037] This device measures the sediment content at corresponding points online through stainless steel pipes arranged at equal intervals (vertical distance) and longitudinally, and calculates the amount of soil and water loss in the corresponding area.

[0038] The device is provided with 1 water level measuring sensor and 3 level sediment content measuring sensors, that is, 1 ultrasonic level meter and 3 turbidity sensors are provided, and the 3 turbidity sensors are fixed by a stainless steel pipe, and the length of the stainless steel pipe can be customized according to the channel depth H0.

[0039] like Figure 4As shown, firstly, the first turbidity sensor 11-1 which is closer to the channel bottom is designed in consideration of the sediment and / or soil accumulation at the channel bottom, which affects the accuracy and safety of the sensor itself. The center position of the first turbidity sensor is set to 0.1H0-0.3H0 from the channel bottom, which can avoid such problems. Secondly, the third turbidity sensor 11-3 which is closer to the channel top is designed in consideration of the fact that the sediment particles are distributed less and less in the vertical direction from the bottom to the surface of the water body. Combined with many years of field investigation and testing, it is almost difficult to measure the sediment within a certain range on the surface of the water body. Currently, there is no accurate sensor for measuring the surface sediment. In order to ensure that the sensor can effectively measure the sediment concentration in the water body and ensure its own availability and accuracy, the center position of the third turbidity sensor is set to 0.2H0-0.3H0 from the channel top, which can meet the effective measurement accuracy of the sensor. In addition, in order to ensure that the adjacent sensors can play the maximum measurement role, the center position of the second turbidity sensor 11-2 between the first turbidity sensor and the third turbidity sensor is set to 0.5H0 from the channel top.

[0040] like Figure 5 As shown, the monitoring device also includes a controller. The controller includes a microprocessor, and a drive module, a motor drive module, a soil and water loss calculation module, a 485 drive module and a Bluetooth drive module respectively connected to the microprocessor; wherein the drive module is connected to the ultrasonic level meter, the motor drive module is respectively connected to the stepper motor and the reduction stepper motor, the Bluetooth drive module is connected to the mobile terminal, and three 485 drive modules are provided, which are respectively connected to three turbidity sensors. The microprocessor controls the hanging height of the stainless steel pipe through the stepper motor, and controls the rotation angle of the stainless steel pipe through the reduction stepper motor.

[0041] Therefore, in this embodiment, the length of the stainless steel pipe 10 and the position of the turbidity sensor can be freely adjusted, which greatly improves the practicality of the device in different measurement environments, and can realize the data monitoring and transmission of the same set of equipment specifications for a single project, ensuring the consistency of the measurement benchmark and reducing the accidental measurement error. At the same time, the stainless steel pipe can avoid obstacles to foreign objects in the channel by reducing the stepping motor.

[0042] This embodiment also provides a method for quantitatively monitoring soil and water loss for a production and construction project, comprising the following steps:

[0043] S1. The stainless steel tube 10 and the turbidity sensor 11 are moved in the vertical direction by the stepping motor 3, the screw rod 20 and the slider 15, so that each turbidity sensor is located at a different water level depth in the channel.

[0044] The reduction stepper motor 8, the stainless steel tube 10, and the turbidity sensor 11 are the core measuring components of the monitoring device. The core measuring component of the device is set in the channel, and three turbidity sensors are provided, which are respectively located at different heights. Therefore, the core measuring component of the device can have different areas of contact with the water according to the change of the channel water level.

[0045] First, the round rod (stainless steel tube 10) design can reduce the impact of large changes in water flow or streamline on the cross-sectional measurement results. Secondly, the turbidity sensor is embedded in the round rod as much as possible, exposing a smaller detection part, which can also reduce certain errors. In addition, the monitoring device also has the characteristics of obstacle avoidance and contraction, that is, the deceleration stepper motor 8 is designed to drive the stainless steel tube 10 to rotate in the vertical plane. Combined with the uniqueness of the device, the stainless steel tube 10 is vertically downward during measurement, and it will remain stable in this position after power is turned on (the deceleration stepper motor 8 applies a high-strength torque after power is turned on), maintaining the core measurement components to be able to operate stably and safely under water impact. When there is an obstacle in the channel, the stainless steel tube 10 is driven by the deceleration stepper motor 8 to rotate upward by 0 to 180°, and rotates to different angles according to different obstacles until the obstacle slides off, and then restores the measurement position, greatly improving the adaptability of the device to environmental changes.

[0046] In this embodiment, when the pulsation value of the turbidity sensor is greater than a preset value, the controller determines that there is an obstacle in the channel, and starts the deceleration stepper motor to drive the stainless steel pipe to rotate to shake off the obstacle.

[0047] S2. Based on the data detected by the turbidity sensor and the ultrasonic level meter, calculate the sediment content per unit volume of the water-passing section and the cumulative amount of soil and water loss during the rainfall process.

[0048] It can be calculated by the soil and water loss calculation module in the controller.

[0049] (1) The calculation method of sediment content N per unit volume of water-passing section under different water level conditions is as follows:

[0050] when When the first turbidity sensor is in the submerged state, N is calculated as:

[0051]

[0052] when When the first turbidity sensor and the second turbidity sensor are both in the submerged state, N is calculated as:

[0053]

[0054] when When the first, second and third turbidity sensors are all submerged, N is calculated as:

[0055]

[0056] (2) The cumulative amount of soil and water loss during a rainfall process is the product of the sediment content per unit volume of the water-passing section N, the water-passing section flow rate Q, and the timing length T of the rainfall solenoid valve under different water level conditions, that is:

[0057]

[0058] in, is the water level height of the water-passing section, H0 is the channel depth; B is the channel width; H1 is the measurement value of the liquid level sensor; N1, N2, N3 are the sediment concentrations measured by the first turbidity sensor, the second turbidity sensor, and the third turbidity sensor respectively; S1, S2, S3 are the detection range areas of the first turbidity sensor, the second turbidity sensor, and the third turbidity sensor respectively; A is the channel water-passing section area; n is the channel roughness; i is the channel design slope; T is the timing length of a rainfall solenoid valve.

[0059] This embodiment uses a screw rod and a stainless steel pipe to connect the main support component, and installs a rainfall collection and transmission device, an ultrasonic level meter, and a turbidity sensor on the upper, middle, and lower parts of the main support component. Driven by a stepper motor, the slider can move freely up and down on the screw rod; a reduction stepper motor and a stainless steel pipe are fixed on the slider through a reduction stepper motor bracket, and turbidity sensors are installed at different heights below the main rod of the optical axis to measure the turbidity of water bodies at different depths to ensure the comprehensiveness and accuracy of the measurement data. The controller collects and displays the measurement data of the rainfall solenoid valve, water level sensor, and turbidity sensor, and supplies power to the intelligent controller through solar panels to ensure the stability and real-time performance of the data; by collecting data such as rainfall, water level, and turbidity of water bodies at different levels, the sediment content of the water body is obtained after further conversion and calculation, thereby obtaining the cumulative amount of soil and water loss during the rainfall process, solving the problems of cumbersome soil and water loss monitoring process in large-scale production and construction projects, many types of measuring instruments required, and poor real-time performance.

[0060] This embodiment has a simple structure and can be assembled in parts. It is suitable for drainage channels of different sizes. It combines intelligent control with remote transmission. It is an efficient and accurate measurement method for quantitative monitoring of soil erosion in large-scale production and construction projects. It is easy to install, operate and carry.

[0061] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A quantitative monitoring device for soil and water loss in production and construction projects, characterized in that: It includes a controller, a main frame and a foot cup fixing frame. The main frame includes a top frame, a vertical frame and an "I"-shaped frame. The vertical frame is connected to the top frame and the "I"-shaped frame respectively. The main frame is installed on a channel or a canal through the "I"-shaped frame and the foot cup fixing frame. A rain collecting barrel and a solenoid valve are provided on the top bracket; The upper part of the vertical bracket is connected to the top bracket, and an ultrasonic level meter is installed at the lower part; the vertical bracket is slotted to form a linear track, and a lead screw is provided on the linear track; the vertical bracket is fixed to the lead screw through a coupling and kept parallel; a stepper motor and a front fixing plate are installed above the lead screw, and a rear fixing plate is installed below, and a slider is installed on the lead screw; a motor bracket is fixed on the slider, and a reduction stepper motor is fixed on the motor bracket; a rod is suspended on the motor bracket, and a plurality of turbidity sensors are installed on the rod; The controller controls the hanging height of the rod through a stepper motor; when there is an obstacle in the channel where the monitoring device works, the controller controls the rotation of the rod through a decelerating stepper motor.

2. The soil and water loss quantitative monitoring device according to claim 1 is characterized in that The channel depth at which the monitoring device operates is H0; The turbidity sensor includes a first turbidity sensor, a second turbidity sensor and a third turbidity sensor; The controller controls the hanging height of the rod through a stepper motor, so that the center position of the first turbidity sensor is 0.1H0~0.3H0 away from the bottom of the channel, the center position of the third turbidity sensor is 0.2H0~0.3H0 away from the top of the channel, and the center position of the second turbidity sensor between the first turbidity sensor and the third turbidity sensor is set at 0.5H0 away from the top of the channel.

3. The soil and water loss quantitative monitoring device according to claim 1 or 2, characterized in that: When the turbidity sensor's vibration value is greater than a preset value, the controller determines that there is an obstacle in the channel and starts the deceleration stepper motor to drive the rod to rotate.

4. The soil and water loss quantitative monitoring device according to claim 1, characterized in that: The controller includes a microprocessor, and a drive module, a motor drive module, a soil and water loss calculation module, a 485 drive module and a Bluetooth drive module respectively connected to the microprocessor; wherein the drive module is connected to the ultrasonic level meter, the motor drive module is respectively connected to the stepper motor and the reduction stepper motor, the Bluetooth drive module is connected to the mobile terminal, and the 485 drive module is connected to the turbidity sensor.

5. The soil and water loss quantitative monitoring device according to claim 1, characterized in that: The "I"-shaped bracket is installed on the ditch or channel through a foot cup fixing frame.

6. A quantitative monitoring method for soil and water loss in production and construction projects, characterized in that: The monitoring device according to claim 2 is implemented, comprising the following steps: The rod and the turbidity sensor are moved in the vertical direction by a stepping motor, a screw rod and a slider, so that each turbidity sensor is located at a different water level depth in the channel; Based on the data detected by the turbidity sensor and ultrasonic level meter, the sediment content per unit volume of the water-passing section and the cumulative amount of soil and water loss during a rainfall event are calculated.

7. The method for quantitative monitoring of soil and water loss according to claim 6, characterized in that: When the turbidity sensor's vibration value is greater than a preset value, the controller determines that there is an obstacle in the channel and starts the deceleration stepper motor to drive the rod to rotate in order to shake off the obstacle.

8. The method for quantitative monitoring of soil and water loss according to claim 6, characterized in that: The calculation method of sediment content N per unit volume of water-passing section under different water level conditions is as follows: when When the first turbidity sensor is in the submerged state, N is calculated as: when When the first turbidity sensor and the second turbidity sensor are both in the submerged state, N is calculated as: when When the first, second and third turbidity sensors are all submerged, N is calculated as: The cumulative amount of soil and water loss during a rainfall process is the product of the sediment content per unit volume of the water-passing section N, the water-passing section flow rate Q, and the timing length T of a rainfall solenoid valve under different water level conditions, that is: in, is the water level height of the water-passing section, H0 is the channel depth; B is the channel width; H1 is the measurement value of the liquid level sensor; N1, N2, N3 are the sediment concentrations measured by the first turbidity sensor, the second turbidity sensor, and the third turbidity sensor respectively; S1, S2, S3 are the detection range areas of the first turbidity sensor, the second turbidity sensor, and the third turbidity sensor respectively; A is the channel water-passing section area; n is the channel roughness; i is the channel design slope; T is the timing length of a rainfall solenoid valve.

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