Soil erosion test system and test method for superposition of surface runoff and pipe flow

Abstract

This invention relates to the field of soil erosion monitoring technology, and discloses a soil erosion test system and method based on the superposition of surface runoff and conduit flow. The aforementioned soil erosion test system includes a test trench, a first water supply device, a second water supply device, and embedded components. The test trench contains test soil. The embedded components are used to construct conduit channels within the test soil, extending along the runoff direction within the test trench. The first water supply component supplies water to the surface layer of the test soil, and the second water supply component supplies water to the conduit channels. This invention can realistically simulate the erosion process of soil caused by the superposition of surface runoff and conduit flow. Its operation is simple and convenient, which helps improve the accuracy and reliability of test results, provides methodological support for the quantitative study of soil erosion processes, and provides scientific guidance for the precise prevention and control of soil erosion.

Description

Technical Field

[0001] The invention relates to the technical field of soil erosion monitoring, and in particular to a soil erosion test system and test method for superimposed surface runoff and pipeline flow. Background Art

[0002] Soil erosion is the process in which soil or other ground materials are eroded, destroyed, separated, transported and deposited under the action of external forces. Soil erosion can be divided into hydraulic erosion, gravity erosion, freeze-thaw erosion and wind erosion according to the type of external forces. Hydraulic erosion is the most important form of soil erosion, which is usually called soil and water loss.

[0003] Studies have found that under natural precipitation conditions, surface runoff and pipe flow will directly wash and carry soil particles, and are the main driving factors for soil erosion. In order to prevent soil erosion, it is necessary to monitor soil erosion data, analyze and master the laws of soil erosion, and then guide soil and water conservation practices. However, most current studies only focus on the laws of slope soil erosion driven by surface runoff, while studies on the driving mechanism of the superposition of surface runoff and pipe flow on the soil erosion process are relatively rare, making it difficult to accurately implement soil and water conservation prevention and control measures and achieve sustainable utilization of soil and water resources. Summary of the invention

[0004] The present invention provides a soil erosion test system and test method for superimposing surface runoff and pipeline flow, which are used to simulate soil erosion caused by surface runoff and pipeline flow, provide methodological support for quantitative research on soil erosion process, and provide scientific guidance for precise prevention and control of soil erosion.

[0005] The present invention provides a soil erosion test system with superposition of surface runoff and pipeline flow, comprising: a test soil trough, a first water supply device, a second water supply device and embedded parts;

[0006] The test soil trough is filled with test soil; the embedded parts are used to construct a pipeline channel in the test soil, and the pipeline channel extends along the runoff direction in the test soil trough; the first water supply device is used to supply water to the surface layer of the test soil, and the second water supply device is used to supply water to the pipeline channel.

[0007] According to a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention, the first water supply device includes a first water supply component; the first water supply component is arranged at one end of the test soil trough along the runoff direction to realize water supply to the surface layer of the test soil along the runoff direction.

[0008] According to a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention, the first water supply component includes a flow stabilization trough, the flow stabilization trough is connected to the test soil trough, and an overflow surface is formed between the flow stabilization trough and the test soil trough, and the overflow surface is flush with the surface of the test soil.

[0009] According to a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention, the first water supply device includes a second water supply component, and the second water supply component is used to be arranged on at least one side of the test soil trough along a direction perpendicular to the runoff direction to realize water supply to the surface layer of the test soil along a direction perpendicular to the runoff direction.

[0010] According to a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention, the second water supply component includes a water supply main pipe and a plurality of water supply branches;

[0011] The water supply main pipe is connected to a plurality of water supply branch pipes respectively, the water supply main pipe extends along the runoff direction, the plurality of water supply branch pipes are arranged in sequence at intervals along the runoff direction, and the water supply branch pipes extend to the inner side of the test soil trough perpendicular to the runoff direction.

[0012] According to a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention, two sets of the second water supply components are provided, and the two sets of the second water supply components are arranged on opposite sides of the test soil trough, and the water supply branches of the two sets of the second water supply components are arranged one by one opposite to each other.

[0013] According to a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention, the test soil is formed into a test soil layer in the test soil trough, and a gauze layer and a sand layer are laid in sequence on the lower side of the test soil layer; the pipeline channel is constructed in the test soil layer.

[0014] A soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention also includes: a slope adjustment device, which is connected to the test soil trough to adjust the inclination of the test soil trough relative to the ground.

[0015] A soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention also includes: a rainfall device, which is arranged above the test soil trough to perform artificial simulated rainfall on the test soil in the test soil trough.

[0016] The present invention also provides a test method for the soil erosion test system with superposition of surface runoff and pipeline flow as described above, comprising:

[0017] Control the rainfall device to artificially simulate rainfall on the test soil so that the water content of the test soil reaches saturation, and then let the test soil stand for a preset time so that the water in the test soil is evenly distributed;

[0018] In the absence of a pipeline channel in the test soil, controlling at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to a first preset condition, and collecting a first runoff sediment sample flowing out of the test soil;

[0019] Constructing a pipeline channel in the test soil, controlling at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to the first preset condition, and collecting a second runoff sediment sample flowing out of the test soil;

[0020] The soil erosion rates of the test soil were obtained according to the first runoff sediment sample and the second runoff sediment sample, respectively, and then the erosion of the test soil by the surface runoff and the pipeline channel was analyzed.

[0021] A test method provided by the present invention also includes:

[0022] In the case where a pipeline channel is constructed in the test soil, controlling at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to the second preset condition, and controlling the second water supply device to supply water to the pipeline channel according to the third preset condition;

[0023] After surface runoff and pipeline flow occur in the test soil, the third runoff sediment sample and pipeline flow sediment sample flowing out of the test soil are collected; and after the pipeline channel collapses, the fourth runoff sediment sample flowing out of the test soil is collected;

[0024] According to the third runoff sediment sample, pipeline flow sediment sample and the fourth runoff sediment sample, the soil erosion rate of the test soil was obtained respectively, and then the erosion of the test soil by surface runoff and pipeline flow, as well as the contribution rate of pipeline channel collapse to the erosion of the test soil were analyzed.

[0025] The present invention provides a soil erosion test system and test method for superimposed surface runoff and pipeline flow. By setting a test soil trough, a first water supply device, a second water supply device and embedded parts, the first water supply device and the second water supply device can be used to supply water to the entire test soil trough during the shallow ditch development process, and the soil erosion caused by surface runoff and pipeline flow can be truly simulated. The operation is simple and convenient, which is conducive to improving the accuracy and reliability of the test results, providing method support for quantitative research on soil erosion process, and providing scientific guidance for precise prevention and control of soil erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of a soil erosion test system with superposition of surface runoff and pipeline flow provided by the present invention;

[0028] Figure 2 It is a schematic diagram of the arrangement of the second water supply device provided by the present invention relative to the flow stabilizing trough;

[0029] Figure 3 It is a schematic diagram of the cross-sectional structure of the test soil trough provided by the present invention;

[0030] Figure 4 It is one of the flow diagrams of the test method of the soil erosion test system based on the superposition of surface runoff and pipeline flow provided by the present invention;

[0031] Figure 5 This is the second flow diagram of the test method of the soil erosion test system based on the superposition of surface runoff and pipeline flow provided by the present invention.

[0032] Reference numerals:

[0033] 1. Test soil trough; 101. Sand layer; 102. Gauze layer; 103. Test soil layer; 2. First water supply device; 21. First water supply assembly; 211. Flow stabilization trough; 212. Baffle; 2111. Overflow surface; 22. Second water supply assembly; 221. Water supply main pipe; 222. Water supply branch pipe; 3. Second water supply device; 31. Water supply pipeline; 311. Hard pipe section; 312. Hose section; 4. Embedded parts; 5. Constant pressure water tank; 6. Collecting port; 7. Rainfall device. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Combine the following Figures 1 to 5 The soil erosion test system and test method for superposition of surface runoff and pipeline flow provided in the embodiments of the present invention are described in detail through specific embodiments and their application scenarios.

[0036] like Figure 1 As shown, the present invention provides a soil erosion test system with superposition of surface runoff and pipeline flow, comprising: a test soil trough 1, a first water supply device 2, a second water supply device 3 and an embedded part 4.

[0037] Furthermore, the test soil trough 1 is filled with test soil; the embedded part 4 is used to construct a pipeline channel in the test soil, and the pipeline channel extends along the runoff direction in the test soil trough 1; the first water supply device 2 is used to supply water to the surface of the test soil, and the second water supply device 3 is used to supply water to the pipeline channel.

[0038] It is understandable that the embedded part 4 may be a pre-embedded pipe or pre-embedded rod known in the art.

[0039] When it is necessary to simulate the erosion of soil caused by surface runoff alone, it is not necessary to bury the embedded parts 4 in the test soil. Correspondingly, when it is necessary to simulate the erosion of soil caused by pipeline flow, the embedded parts 4 can be buried in the test soil first, and after the test soil is filled in the test soil groove 1, the embedded parts 4 can be pulled out from the test soil to construct a pipeline channel in the test soil.

[0040] At the same time, the test soil of this embodiment is used to simulate the soil structure of real terrain conditions. When performing the simulation test, the water content of the test soil reaches saturation, and the water in the test soil is evenly distributed.

[0041] When supplying water to the surface of the test soil, the first water supply component 21 can supply water to the surface of the test soil along the runoff direction, or supply water to the surface of the test soil perpendicular to the runoff direction, or supply water to the surface of the test soil along other directions. There is no specific limitation on this, but it is determined according to specific test requirements.

[0042] In addition, in this embodiment, the pre-buried pipe can be pre-buried in the test soil at a preset depth so that the center of the pipe channel reaches a preset depth from the surface of the test soil, and the preset depth can be 20 to 40 cm. The preset depth can be set according to the depth of the pipe flow in the soil of the actual terrain, and the preset depth can be set to 20 cm, 25 cm, 30 cm, 40 cm, etc., without specific limitation.

[0043] As can be seen from the above, the present invention, by setting a test soil trough 1, a first water supply device 2, a second water supply device 3 and an embedded part 4, can realize water supply to the entire test soil trough 1 during the shallow ditch development process through the first water supply device 2 and the second water supply device 3, and truly simulate the soil erosion caused by surface runoff and pipeline flow. The operation is simple and convenient, which is conducive to improving the accuracy and reliability of the test results, providing method support for the quantitative research of the soil erosion process, and providing scientific guidance for the precise prevention and control of soil erosion.

[0044] In some embodiments, Figure 1 As shown, the first water supply device 2 of this embodiment includes a first water supply component 21; the first water supply component 21 is arranged at one end of the test soil trough 1 along the runoff direction to realize water supply to the surface layer of the test soil along the runoff direction.

[0045] Specifically, the first water supply assembly 21 of the present embodiment may be a water supply pipe, a water supply tank, or other water supply structures known in the art.

[0046] At the same time, the runoff direction of this embodiment is along the length direction of the test soil trough 1. When the test soil trough 1 is inclined relative to the horizontal plane, a first water supply assembly 21 can be arranged at the first end of the test soil trough 1 along the length direction to supply water to the surface of the test soil.

[0047] The height of the first end of the test soil trough 1 along the length direction relative to the horizontal plane is greater than the height of the second end of the test soil trough 1 along the length direction relative to the horizontal plane.

[0048] In some embodiments, Figure 1 and Figure 2 As shown, in order to ensure the uniformity of the water supply from the first water supply component 21 to the surface layer of the test soil, the first water supply component 21 of this embodiment includes a flow stabilizing trough 211, which is connected to the test soil trough 1, and an overflow surface 2111 is formed between the flow stabilizing trough 211 and the test soil trough 1, and the overflow surface 2111 is flush with the surface of the test soil.

[0049] Specifically, a baffle 212 is provided in the flow stabilizing trough 211 of this embodiment, and the baffle 212 divides the flow stabilizing trough 211 into a first unit trough and a second unit trough; the bottom end of the baffle 212 is spaced from the bottom of the flow stabilizing trough 211 so that the first unit trough and the second unit trough are connected. An overflow surface 2111 is formed between the second unit trough and the test soil trough 1.

[0050] In practical applications, water can be added to the first unit tank through the constant pressure water tank 5, and the water in the first unit tank gradually reaches the second unit tank through the gap between the bottom end of the baffle 212 and the bottom of the flow stabilizing tank 211 to ensure the smoothness of the water flow in the second unit tank. When the water in the second unit tank overflows into the test soil tank 1 through the overflow surface 2111, the uniformity and stability of the water supply to the surface of the test soil can be ensured.

[0051] It should be pointed out here that in this embodiment, a horizontal plate can be set between the flow stabilizing trough 211 and the test soil trough 1 along the width direction of the test soil trough 1, so that the side (upper surface) of the horizontal plate facing away from the flow stabilizing trough 211 or the test soil trough 1 forms the above-mentioned overflow surface 2111.

[0052] At the same time, in this embodiment, a drain pipe can also be provided at the bottom end of the stabilizing trough 211 . After the test is completed, the water in the stabilizing trough 211 can be discharged through the drain pipe so as to clean and inspect the stabilizing trough 211 .

[0053] In some embodiments, Figure 1 As shown, the first water supply device 2 of this embodiment includes a second water supply component 22, which is used to be arranged on at least one side of the test soil trough 1 along a direction perpendicular to the runoff direction to supply water to the surface of the test soil along a direction perpendicular to the runoff direction.

[0054] In this embodiment, two sets of the second water supply components 22 can be provided, and the two sets of the second water supply components 22 are arranged at opposite sides of the test soil trough 1.

[0055] In some embodiments, Figure 1 As shown, in order to ensure uniformity of water supply to the test soil trough 1 in a direction perpendicular to the runoff, the second water supply assembly 22 of this embodiment includes a water supply main pipe 221 and a plurality of water supply branch pipes 222. The water supply main pipe 221 is respectively connected to the first ends of the plurality of water supply branch pipes 222, the water supply main pipe 221 extends in the runoff direction, the plurality of water supply branch pipes 222 are sequentially arranged at intervals in the runoff direction, and the second end of each water supply branch pipe 222 extends to the inner side of the test soil trough 1 in a direction perpendicular to the runoff direction.

[0056] In some examples, the present embodiment can set the water outlets of each water supply branch pipe 222 of the second water supply assembly 22 at the same height. In this way, when the test soil trough 1 is placed horizontally, the water outlets of the two sets of second water supply assemblies 22 are at the same height position, which can achieve uniformity of water supply in the test soil trough 1, ensure the authenticity of the simulation test, and improve the accuracy and reliability of the test results.

[0057] It should be noted here that the present embodiment can also set the water supply ports of the two sets of second water supply components 22 to be at the same height position. For example, in the case where the two sets of second water supply components 22 are equipped with a constant pressure water tank 5, the water supply main pipe 221 of one set of the second water supply components 22 can be connected to the first water supply port on the constant pressure water tank 5, and the water supply main pipe 221 of the other set of the second water supply components 22 can be connected to the second water supply port on the constant pressure water tank 5, and the first water supply port and the second water supply port are at the same height position.

[0058] In some examples, in order to further ensure that the water supply is evenly distributed in the test soil trough 1, when two sets of the second water supply components 22 are provided, the present embodiment can arrange the water supply branches 222 of the two sets of the second water supply components 22 to be arranged one by one opposite to each other, and in each set of the second water supply components 22, a plurality of water supply branches 222 can be arranged at equal intervals in the runoff direction, so that each water supply branch 222 in the two sets of the second water supply components 22 are arranged in sequence at the same intervals in the runoff direction.

[0059] In some examples, in order to facilitate the adjustment of the water supply flow rate, the present embodiment may provide a valve control device on the water supply main 221 of the second water supply assembly 22. Where two sets of the second water supply assembly 22 are provided, the specifications of the valve control devices on the water supply mains 221 of the two sets of the second water supply assembly 22 should be ensured to be the same.

[0060] In actual application, the dimensions of the test soil trough 1 can be specifically set to be 8m in length, 2m in width, and 0.6m in height. Two sets of second water supply assemblies 22 are relatively arranged on the two length sides of the test soil trough 1. The height of the two sets of second water supply assemblies 22 from the bottom of the test soil trough 1 is 65cm. The distance between two adjacent water supply branches 222 on each set of second water supply assemblies 22 is 65cm. The water supply main pipe 221 and each water supply branch pipe 222 of each set of second water supply assemblies 22 can use PVC pipes with a diameter of 5cm.

[0061] In some embodiments, Figure 1 As shown, in order to facilitate the construction of the pipeline channel and the supply of water into the pipeline channel, the embedded component 4 of this embodiment includes a pre-buried pipeline; the pre-buried pipeline has a first state and a second state.

[0062] When the pre-buried pipeline is in the first state, the pre-buried pipeline is buried in the test soil, and the pre-buried pipeline is connected to the second water supply device 3; when the pre-buried pipeline is in the second state, the pre-buried pipeline and the second water supply device 3 are separated and pulled out of the test soil, so that a pipeline channel is formed in the test soil, and the second water supply device 3 is connected to the pipeline channel.

[0063] Specifically, the second water supply device 3 of this embodiment can specifically adopt a water supply pipe 31; when the pre-buried pipe is in the first state, one end of the pre-buried pipe and one end of the water supply pipe 31 are plugged into each other, and the pre-buried pipe and the water supply pipe 31 extend in the same direction.

[0064] It should be pointed out here that the water supply pipe 31 of this embodiment can be made of a flexible pipe to facilitate the layout of the water supply pipe 31 and to connect the water supply pipe 31 with the constant pressure water tank 5 .

[0065] Of course, the water supply pipe 31 may also include a hard pipe section 311 and a soft pipe section 312. The first end of the hard pipe section 311 is connected to the constant pressure water tank 5, the second end of the hard pipe section 311 is connected to one end of the soft pipe section 312, and the other end of the soft pipe section 312 is plugged into one end of the pre-buried pipe.

[0066] In some examples, when the first water supply component 21 includes a flow stabilizing groove 211, the water supply pipe 31 of this embodiment passes through the flow stabilizing groove 211 along the above-mentioned runoff direction, the water supply pipe 31 and the pre-buried pipe are set at the same height, and a valve control device is provided on the water supply pipe 31 to adjust the water supply flow of the water supply pipe 31.

[0067] In some examples, this embodiment can connect the end of the water supply pipe 31 away from the pre-buried pipe to the third water supply port on the constant pressure water tank 5, and the height of the third water supply port is lower than the height of the first and second water supply ports mentioned above.

[0068] In some embodiments, the test system shown in this embodiment is also provided with a slope adjustment device, which is connected to the test soil trough 1 to adjust the inclination angle of the test soil trough 1 relative to the ground, so as to realize simulation adjustment of various natural slopes and improve the accuracy of the test results.

[0069] The slope adjustment device may be a telescopic device such as a hydraulic cylinder or a pneumatic cylinder known in the art, or may be a lead screw lift or other lifting device.

[0070] In some examples, the slope adjustment device is selected to be a hydraulic cylinder, one end of which is supported on the ground, and the other end is supported on the bottom of the test soil trough 1. The hydraulic cylinder can be set to be specifically supported at 1 / 3 of one end of the test soil trough 1 close to the flow stabilization trough 211, so as to adjust the inclination angle of the test soil trough 1 relative to the ground by driving the bottom end of the test soil trough 1 to rise or fall.

[0071] In some embodiments, Figure 1 As shown, in order to ensure that the water content of the test soil reaches saturation during the test, the present embodiment is further provided with a rainfall device 7, which is arranged above the test soil trough 1 to perform artificial simulated rainfall on the test soil in the test soil trough 1.

[0072] The rainfall device 7 may include a water tank, which is connected to a water supply system, and a plurality of water outlets are provided at the bottom of the water tank. The water supply system may be a tap water system known in the art, and after the water supply system supplies water to the water tank, the water in the water tank may flow out through the water outlets and fall naturally to form artificial simulated rainfall.

[0073] Based on the solution of the above embodiment, Figure 3 As shown, the test soil of this embodiment is formed into a test soil layer 103 in the test soil trough 1, and a gauze layer 102 and a sand layer 101 are laid in sequence on the lower side of the test soil layer 103; a pipeline channel is constructed in the test soil layer 103.

[0074] Specifically, according to the specific simulated ground conditions, the embodiment can select the particle size of the sand corresponding to the sand layer 101. The gauze layer 102 is used to separate the sand layer 101 and the test soil layer 103. The gauze layer 102 can be made of gauze with good water permeability and is composed of multiple gauze layers 102 stacked and arranged.

[0075] In practical applications, the test soil layer 103 of this embodiment can specifically be a black soil layer, and a loess layer can also be provided between the sand layer 101 and the gauze layer 102 .

[0076] It should be pointed out here that in order to facilitate the collection of runoff sediment samples flowing out of the test soil, the present embodiment may set a collecting port 6 at one end of the test soil trough 1 away from the flow stabilization trough 211. The collecting port 6 is trumpet-shaped, and the large end of the collecting port 6 faces the test soil trough 1 to facilitate the collection of runoff sediment samples flowing out of the test soil.

[0077] At the same time, a plurality of collecting ports 6 can be provided, and the plurality of collecting ports 6 are arranged in layers, and the collecting ports 6 of each layer are arranged along the width direction of the test soil trough 1 .

[0078] In some embodiments, Figure 4 As shown, this embodiment also provides a test method for a soil erosion test system with superposition of surface runoff and pipeline flow as described above, comprising the following steps:

[0079] Step 410, controlling the rainfall device to artificially simulate rainfall on the test soil so that the water content of the test soil reaches saturation, and then leaving the test soil to stand for a preset time so that the water in the test soil is evenly distributed.

[0080] Step 420, in the absence of a pipeline channel in the test soil, control at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to a first preset condition, and collect a first runoff sediment sample flowing out of the test soil.

[0081] Among them, when the first water supply device is used to supply water to the surface of the test soil, the first preset condition is specifically the water supply flow and water supply time of the first water supply device, and the first water supply device can select at least one of the first water supply component and the second water supply component.

[0082] When a rainfall device is used to supply water to the surface layer of the test soil, the first preset condition is specifically the rainfall intensity and rainfall time of the artificial simulated rainfall performed by the rainfall device.

[0083] Step 430, construct a pipeline channel in the test soil, control at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to the first preset condition, and collect a second runoff sediment sample flowing out of the test soil.

[0084] Step 440, obtaining soil erosion rates of the test soil based on the first runoff sediment sample and the second runoff sediment sample, respectively, and analyzing the erosion of the test soil by surface runoff and the pipeline channel.

[0085] Before step 410, the method further includes the step of filling the test soil into the test soil trough, which is specifically as follows:

[0086] (1) Prepare a well-mixed test soil.

[0087] (2) Determine the moisture content of the test soil and calculate the total weight of the test soil filled in the test soil groove.

[0088] (3) Fill the weighed test soil into the test soil tank.

[0089] When the test soil is filled to a plane 20 cm away from the slot of the test soil slot, the pre-buried pipe is buried in the center line of the test soil along the length direction of the test soil.

[0090] In some examples, the step of filling the test soil into the test soil trough includes: laying a sand layer of a first set thickness on the bottom of the test soil trough, laying a gauze layer on the upper side of the sand layer, laying the test soil on the upper side of the gauze layer in six layers according to the set bulk density, and laying each layer of the test soil according to the second set thickness. The first set thickness is 10 cm, and the second set thickness is 5 cm.

[0091] In some examples, the step of filling the test soil into the test soil tank includes:

[0092] Black soil samples were collected, stones, root residues, straw, etc. in the black soil samples were picked out and air-dried, large clods in the black soil samples were broken up according to the natural joints of the soil to protect its original structure, the black soil samples were mixed evenly, and the preparation of the test soil was completed.

[0093] Determine the moisture content of the test soil and calculate the mass of the test soil required for the test based on the soil bulk density.

[0094] A 30 cm thick sand layer was laid at the bottom of the test soil trough as a permeable layer, and gauze was laid on the upper surface of the sand layer. The test soil was diluted to 1.2 g / cm 3 The bulk density of the test soil was laid on the gauze layer in six layers, and the thickness of each layer of test soil was 5 cm.

[0095] After each layer of test soil is laid, the surface of the layer of test soil is scratched with a 1 cm thick wooden board before laying the next layer of test soil to prevent stratification between two adjacent layers of test soil and ensure the uniformity and integrity of the loaded test soil.

[0096] Furthermore, in step 410, artificial simulated rainfall is applied to the test soil in the test soil trough by a rainfall device, and the rainfall intensity of the artificial simulated rainfall is set to 30 mm / h.

[0097] When the test soil reaches saturated water content and runoff begins to occur in the test soil trough, stop artificial rainfall simulation.

[0098] Next, the test soil was covered with plastic sheeting (plastic colored striped cloth) and left to stand for 12-24 hours to allow the moisture in the test soil in the test soil trough to be evenly distributed, so as to simulate the test of shallow ditch development driven by surface runoff and pipe flow.

[0099] Among them, the static time of the test soil can be specifically set to 24 hours.

[0100] Furthermore, in step 420 and step 430, the present embodiment can set a preset time for supplying water to the test soil trough through the stabilizing trough alone, and set the second water supply assembly and the second water supply device to be in a closed state. The water supply flow rate of the stabilizing trough can be set to 15L / min, 30L / min, 45L / min, 60L / min and 75L / min, and the preset time can be 120min.

[0101] Based on the above configuration, this embodiment can use a flow stabilization trough to supply water to the surface of the test soil with or without a pipeline channel to obtain comparative data of slope erosion rate. The comparative data can be referred to in the following Table 1.

[0102] Table 1: Comparative data of soil erosion on slopes

[0103]

[0104] Based on the above Table 1, it can be seen that in this embodiment, the erosion of the test soil by the surface runoff can be evaluated by the erosion rate measured when the pipeline channel is not set, and the erosion of the test soil by the pipeline channel can be evaluated by the pipeline flow contribution rate.

[0105] in,

[0106] In the above formula, Q2 represents the erosion rate measured when there is pipeline flow, and Q1 represents the erosion rate measured when there is no pipeline flow.

[0107] like Figure 5 As shown, the test method shown in this embodiment also includes the following steps:

[0108] Step 510, when a pipeline channel is constructed in the test soil, control at least one of the first water supply device and the rainfall device to supply water to the surface of the test soil according to the second preset condition, and control the second water supply device to supply water to the pipeline channel according to the third preset condition.

[0109] Step 520, after surface runoff and pipeline flow occur in the test soil, a third runoff sediment sample and a pipeline flow sediment sample flowing out of the test soil are collected; and after the pipeline channel collapses, a fourth runoff sediment sample flowing out of the test soil is collected.

[0110] Step 530, based on the third runoff sediment sample, the pipeline flow sediment sample and the fourth runoff sediment sample, the soil erosion rate of the test soil is obtained respectively, and then the erosion of the test soil by surface runoff and pipeline flow, as well as the contribution rate of pipeline channel collapse to the erosion of the test soil are analyzed.

[0111] Specifically, when the first water supply device is used to supply water to the surface of the test soil, the second preset condition is specifically the water supply flow and water supply time of the first water supply device, and the first water supply device can select at least one of the first water supply component and the second water supply component.

[0112] When a rainfall device is used to supply water to the surface layer of the test soil, the second preset condition is specifically the rainfall intensity and rainfall time of the artificial simulated rainfall performed by the rainfall device.

[0113] At the same time, the third preset condition is specifically the water supply flow rate and water supply time of the second water supply device supplying water to the pipeline channel.

[0114] It should be pointed out here that the soil erosion rate of the test soil after the pipeline channel collapse can be obtained based on the fourth runoff sediment sample. By combining the soil erosion rate with the volume (or area) of the pipeline channel collapse, the contribution rate of the pipeline channel collapse to the test soil erosion can be obtained.

[0115] In practical applications, the second water supply device can be controlled to supply water to the pipeline channel at a variety of different water flow rates while ensuring that the water supply parameters for the surface layer of the test soil remain constant, so as to study the erosion of the test soil by the pipeline channel.

[0116] As shown in the following Table 2, in this embodiment, artificial rainfall can be simulated on the test soil at two rainfall intensities while keeping the upper water supply flow rate (using a steady flow trough to supply water to the surface of the test soil) constant. The soil erosion rate of the test soil at each rainfall intensity can be studied, and the erosion of the test soil by the pipeline channel can be studied based on the pipeline flow contribution rate.

[0117] Table 2: Comparative data of slope soil erosion

[0118]

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test method, characterized in that: The test method is implemented based on a soil erosion test system with superposition of surface runoff and pipeline flow, and can quantify the erosion of test soil by separate surface runoff and pipeline flow and the contribution of pipeline collapse to soil erosion. The soil erosion test system with superposition of surface runoff and pipeline flow includes: A test soil trough, a rainfall device, a first water supply device, a second water supply device and an embedded part; the test soil trough is filled with test soil; the embedded part is used to construct a pipeline channel in the test soil, and the pipeline channel extends along the runoff direction in the test soil trough; the first water supply device is used to supply water to the surface layer of the test soil, and the second water supply device is used to supply water to the pipeline channel; the rainfall device is arranged above the test soil trough to perform artificial simulated rainfall on the test soil in the test soil trough; The test method includes: Control the rainfall device to artificially simulate rainfall on the test soil so that the water content of the test soil reaches saturation, and then let the test soil stand for a preset time so that the water in the test soil is evenly distributed; In the case where no pipeline channel is constructed in the test soil, controlling at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to the first preset condition, and after surface runoff occurs in the test soil, collecting a first runoff sediment sample flowing out of the test soil; In the case where a pipeline channel is constructed in the test soil, at least one of the first water supply device and the rainfall device is controlled to supply water to the surface layer of the test soil according to the first preset condition, and after surface runoff occurs in the test soil, a second runoff sediment sample flowing out of the test soil is collected; The soil erosion rate of the test soil is obtained according to the first runoff sediment sample and the second runoff sediment sample, respectively, and then the erosion of the test soil by surface runoff under the two conditions of having a pipe channel inside the soil but no pipe flow outflow and having no pipe channel inside the soil is analyzed, so as to verify the difference in the influence of surface runoff on the erosion of the test soil under the two conditions of having a soil pipe but no pipe flow outflow and having no pipe inside the soil; The test method also includes: In the case where a pipeline channel is constructed in the test soil, controlling at least one of the first water supply device and the rainfall device to supply water to the surface layer of the test soil according to the second preset condition, and controlling the second water supply device to supply water to the pipeline channel according to the third preset condition; After the test soil has surface runoff and pipeline flow, collect the third runoff sediment sample flowing out of the test soil and collect the pipeline flow sediment sample at the same time; and after the pipeline channel collapses, collect the fourth runoff sediment sample flowing out of the test soil; Based on the third runoff sediment sample, pipeline flow sediment sample and the fourth runoff sediment sample, the surface runoff erosion rate and pipeline flow erosion rate of the test soil and the erosion rate after pipeline collapse were obtained respectively, and then the erosion of the test soil by surface runoff and pipeline flow, as well as the contribution rate of pipeline channel collapse to the erosion of the test soil were analyzed.

2. The test method according to claim 1, characterized in that The first water supply device includes a first water supply assembly; the first water supply assembly is arranged at one end of the test soil trough along the runoff direction to achieve water supply for the surface layer of the test soil along the runoff direction.

3. The test method according to claim 2, characterized in that: The first water supply component includes a flow stabilizing trough, which is connected to a test soil trough and forms an overflow surface between the flow stabilizing trough and the test soil trough, and the overflow surface is flush with the surface of the test soil.

4. The test method according to claim 1, characterized in that: The first water supply device includes a second water supply component, which is used to be arranged on at least one side of the test soil trough along a direction perpendicular to the runoff direction to supply water to the surface layer of the test soil along a direction perpendicular to the runoff direction.

5. The test method according to claim 4, characterized in that The second water supply assembly includes a water supply main pipe and multiple water supply branches; the water supply main pipe is connected to the multiple water supply branches respectively, the water supply main pipe extends along the runoff direction, the multiple water supply branches are arranged in sequence along the runoff direction, and the water supply branches extend to the inner side of the test soil trough perpendicular to the runoff direction.

6. The test method according to claim 5, characterized in that The second water supply assembly is provided with two sets, and the two sets of the second water supply assembly are arranged at opposite sides of the test soil trough, and the water supply branch pipes of the two sets of the second water supply assembly are arranged opposite to each other.

7. The test method according to any one of claims 1 to 6, characterized in that: The test soil forms a test soil layer in the test soil trough, and a gauze layer and a sand layer are laid in sequence on the lower side of the test soil layer; the pipeline channel is constructed in the test soil layer.

8. The test method according to any one of claims 1 to 6, characterized in that: Also includes: A slope adjusting device is connected to the test soil trough to adjust the inclination angle of the test soil trough relative to the ground.

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