A field soil pore network structure dynamic change observation system and observation method

Abstract

The present invention relates to the technical field of testing the permeability, pore volume or pore surface area of ​​porous materials, and discloses a field soil pore network structure dynamic change observation system and observation method, which uses a transparent shielding system that can simulate the interaction that occurs on a cross section of the soil to separate a camera buried in the soil from the soil, so that the camera can capture the dynamic change process of the soil while ensuring that the captured results are not distorted by the wall effect. The transparent imitation soil with the same mechanical properties as the soil does not change the stress on the soil, and the anti-mixing semipermeable membrane ensures that the transparent imitation soil does not mix with the soil to affect the observation, while the migration of organisms and water in the soil is not affected, and the transparent isolation plate allows the camera to shoot without interference. Both the transparent shielding system and the camera can be used in the field, and in conjunction with a wireless transmitter and a solar panel, it can ensure that the results captured by the camera are transmitted to the observer in real time, thereby realizing the field soil pore network structure dynamic change observation.

Description

Technical Field

[0001] The invention relates to the technical field of testing the permeability, pore volume or pore surface area of ​​porous materials, and in particular to a field soil pore network structure dynamic change observation system and observation method. Background Art

[0002] Soil pores are channels and gaps in the soil. They are where plant roots extend, soil animals, and microorganisms are active. Soil pores are interconnected to form a complex network that affects water flow and material transfer processes. The structural characteristics of the pores determine the soil's ability to supply and retain water. Pores with good connectivity can increase soil water penetration. Soils rich in pores will increase the connectivity of precipitation infiltration paths, reduce the resistance to water infiltration, and promote faster water flow to deeper areas. In terms of time and space, precipitation, soil plant and animal life activities, and the distribution of gravel will affect the soil pore network structure, and thus affect the hydraulic properties of soil pores.

[0003] The research methods of soil pore structure are divided into direct method and indirect method. At present, CT technology and MRI technology can be used to directly observe the original pore structure, but this technology is difficult to achieve in-situ observation of the dynamic evolution process of the same location and the same pore. What is more fatal is that the equipment required for these two technologies is not suitable for use in the field, and can only observe the collected samples. The two scientific research projects involved in this invention (Simulation of sand production and optimization configuration technology of control measures for Fengshui composite erosion 2022YFF1300804, Research on the influence of soil macropores on preferential flow 41877154) both include field observations of dynamic changes in soil pore network structure.

[0004] There are methods for observing the dynamic changes of cultivation substrates in the prior art. A typical example is the dynamic observation of the nutrient solution around the root system during soilless cultivation, which uses a surveillance camera to continuously record the nutrient solution. However, the soil is opaque, and if a glass plate is used to separate a section of soil for observation, the inventors found that what is seen is not the real soil pore network, but a soil pore network that is severely deformed under the action of the wall effect. At the same time, the observed root growth and wormhole conditions are also severely distorted under the influence of the glass plate. Summary of the invention

[0005] The invention provides a field soil pore network structure dynamic change observation system and observation method.

[0006] The technical problem to be solved is that the existing soil pore research methods are difficult to achieve in-situ observation of the dynamic evolution process of the same location and the same pore.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: a field soil pore network structure dynamic change observation system, comprising a camera set in the soil, a transparent shielding system shielded between the camera and the soil and used to prevent the soil from interfering with the camera, a wireless transmitter electrically connected to the camera and used to transmit the captured video to the observer along the wireless network, and a solar panel electrically connected to the camera and the wireless transmitter and used to supply power;

[0008] The camera lens extends from a waterproof mounting base, and the transparent shielding system includes a transparent isolation plate attached to the camera, a transparent imitation soil arranged on a side of the transparent isolation plate away from the camera, and an anti-mixing semi-permeable membrane arranged between the transparent imitation soil and the soil to prevent the soil and the transparent imitation soil from mixing and affecting observation;

[0009] The transparent imitation soil is made of transparent plastic material, and the shear modulus of the transparent imitation soil in the horizontal direction is consistent with that of the soil to be tested;

[0010] The anti-mixing semipermeable membrane is a water-permeable transparent semipermeable membrane.

[0011] Furthermore, the edge of the anti-mixing semipermeable membrane is pasted on a transparent isolation board, and together with the transparent isolation board, forms a closed container that wraps the transparent imitation soil; the lens of the camera is placed on the transparent isolation board, and the part of the camera outside the base is wrapped with sealant.

[0012] Furthermore, the anti-mixing semipermeable membrane is a polyvinylidene fluoride microporous membrane, and the transparent isolation plate is a glass plate sprayed with a bactericide for preventing biofilm from forming on the surface.

[0013] Furthermore, the transparent imitation soil is formed by mixing two gels that are insoluble in each other, one of the two gels is in granular form and is uniformly mixed in the other gel.

[0014] Furthermore, the camera is provided with a visible light camera and an infrared camera, and is provided with a lighting lamp for illuminating the soil to be observed, and the lighting lamp includes a white light LED lamp and an infrared lamp.

[0015] Furthermore, the mounting base is a stainless steel box filled with rock wool, and the positions where the camera lens, data cable, and power supply cable pass through the stainless steel box are all sealed with sealant.

[0016] Furthermore, the camera is a network camera, the wireless transmitter is a cellular mobile Internet access device, the wireless transmitter and the battery and transformer matching the solar panel are all arranged in a louvered box close to the soil to be observed; the solar panel is attached to the top of the louvered box.

[0017] A field soil pore network structure dynamic change observation system adopts the above field soil pore network structure dynamic change observation system for observation, and comprises the following steps:

[0018] Step 1: Dig trenches on the soil sample to be observed;

[0019] Step 2: Place a transparent shielding system, a camera, a lighting lamp, and a mounting base in the trench, lead out the data line and power line of the camera, and then backfill the trench; wherein the anti-mixing semi-permeable membrane is placed against the side wall of the trench;

[0020] Step 3: Build a shutter box near the trench, then install the wireless transmitter, the battery and the transformer that match the solar panel in the shutter box, and attach the solar panel on the top of the shutter box;

[0021] Step 4: Arrange the cables and debug the network, turn on the camera on the software that comes with the camera, and start observing.

[0022] Compared with the prior art, the field soil pore network structure dynamic change observation system and observation method of the present invention have the following beneficial effects:

[0023] In the present invention, a transparent shielding system that can simulate the interaction that occurs on a cross section of the soil is used to separate the camera buried in the soil from the soil, so that the camera can capture the dynamic change process of the soil while ensuring that the captured results are not distorted by the wall effect. Among them, a transparent imitation soil whose mechanical properties are consistent with the soil to be observed is used to ensure that the stress condition of the soil does not change, and an anti-mixing semipermeable membrane is used to ensure that the biological migration and water migration in the soil are not affected on the premise that the transparent imitation soil does not mix with the soil to affect the observation, and a transparent isolation plate is used to ensure that the camera can shoot without interference. At the same time, the transparent shielding system and the camera can be used in the wild, and the addition of a wireless transmitter and a solar panel can ensure that the results of the camera shooting are transmitted to the observer in real time. The combination of the above points realizes the observation of the dynamic changes of the soil pore network structure in the wild. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a field soil pore network structure dynamic change observation system in use according to the present invention;

[0025] In the figure, 11-transparent isolation plate, 12-transparent imitation soil, 13-anti-mixing semi-permeable membrane, 2-camera, 3-mounting base, 4-wireless transmitter, 5-solar panel. DETAILED DESCRIPTION

[0026] Take the experimental device to be used in the National Natural Science Foundation project Research on the influence of soil macropores on preferential flow (code 41877154) as an example. Figure 1 As shown, a field soil pore network structure dynamic change observation system includes a camera 2 set in the soil, a transparent shielding system shielded between the camera 2 and the soil to prevent the soil from interfering with the camera, a wireless transmitter 4 electrically connected to the camera 2 and used to transmit the captured video to the observer along the wireless network, and a solar panel 5 electrically connected to the camera 2 and the wireless transmitter 4 and used for power supply;

[0027] The lens of the camera 2 extends out from the waterproof mounting base 3, and the transparent shielding system includes a transparent isolation plate 11 close to the camera 2, a transparent imitation soil 12 arranged on the side of the transparent isolation plate 11 away from the camera 2, and an anti-mixing semi-permeable membrane 13 arranged between the transparent imitation soil 12 and the soil to prevent the soil and the transparent imitation soil 12 from mixing and affecting observation;

[0028] The soil observed here is the soil in contact with the anti-mixing semipermeable membrane 13. Since the mechanical properties of the transparent imitation soil 12 are consistent with those of the soil, and the anti-mixing semipermeable membrane 13 will not block the migration of water and organisms, the interaction between the soil to be observed and the surrounding is consistent with that in the land, so it can be ensured that the observation result is not distorted. Since the field of view of the camera 2 here is relatively small, it is necessary to set up multiple cameras 2. In this embodiment, three cameras 2 are installed in the mounting base 3 with a side length of 20 cm and a thickness of 4.5 cm. The thickness of the transparent anti-soil layer set between the soil and the transparent isolation plate 11 is generally 3 to 5 cm. If it is too thin, it will cause distortion, and if it is too thick, the transparency will be poor.

[0029] The transparent imitation soil 12 is made of a transparent plastic material, and the shear modulus of the transparent imitation soil 12 in the horizontal direction is consistent with that of the soil to be tested;

[0030] The workload of simulating all mechanical properties of soil is relatively large, but for soil, the shear modulus in the horizontal direction has the greatest impact. As long as this value is consistent, it can ensure that various activities in the soil, such as the movement of soil particles, are not affected by the transparent shielding system. Therefore, the transparent soil protection only needs to simulate the shear modulus in the horizontal direction.

[0031] The anti-mixing semipermeable membrane 13 is a water-permeable transparent semipermeable membrane. In this way, the soil and the transparent anti-soil mixing will not affect the observation, and the water migration and biological migration in the soil will not be affected, especially the growth of the root system will not be blocked by the anti-mixing semipermeable membrane 13 (the membrane is very soft and has micropores, which can be easily penetrated by the root system).

[0032] The edge of the anti-mixing semipermeable membrane 13 is pasted on the transparent isolation plate 11, and together with the transparent isolation plate 11, it forms a closed container that wraps the transparent imitation soil 12; this ensures that during installation and use, the soil and the transparent anti-mixing semipermeable membrane 13 will not be mixed.

[0033] The lens of the camera 2 is placed on the transparent isolation plate 11, and the portion of the camera 2 outside the base is wrapped with sealant, so as to ensure that after being buried in the soil, the lens of the camera 2 will not be affected by the soil and will not be infiltrated by water.

[0034] The anti-mixing semipermeable membrane 13 is a polyvinylidene fluoride microporous membrane, which is used to prevent mold and other microorganisms from growing on the surface of the anti-mixing semipermeable membrane 13 to form a biofilm that affects observation. Similarly, the transparent isolation plate 11 is a glass plate sprayed with a bactericide for preventing the formation of a biofilm on the surface.

[0035] In the anti-mixing semipermeable membrane 13 of this embodiment, the micropore diameter is 0.45㎛, the membrane thickness is 100㎛, the width is 254mm, and the transparency is 60~90%;

[0036] The transparent imitation soil 12 is formed by mixing two gels that are insoluble in each other. One of the two gels is granular and uniformly mixed in the other gel, thereby imitating the structure of soil. The granular gel in this embodiment is calcium alginate gel particles formed by dropping sodium alginate solution into calcium chloride solution, and the calcium alginate gel particles are then mixed into plant gels such as agar. The mechanical properties of the transparent imitation soil 12 are adjusted by adjusting the ratio of the two gels. Of course, other gel combinations can also be used in actual use, but care should be taken to avoid using gels that absorb water and swell, such as "water elves"; gels that are corruptible, such as gelatin, should also be avoided.

[0037] The camera 2 is provided with a visible light camera and an infrared camera, and is provided with a lighting lamp for illuminating the soil to be observed, and the lighting lamp includes a white light LED lamp and an infrared lamp.

[0038] The mounting base 3 is a stainless steel box filled with rock wool. The positions where the lens, data cable, and power supply cable of the camera 2 pass through the stainless steel box are sealed with sealant to prevent water from entering and ensure stability.

[0039] The camera 2 is a network camera. The camera 2 selected in this embodiment is an IPC2270 pinhole high-definition network camera 2, with an operating temperature range of -10°C to 50°C. The camera can operate in visible light and infrared modes, supports 128G TF card local storage and 3D digital noise reduction, and the camera 2 uploads the shooting to the cloud platform directly through the wireless transmitter 4. Of course, if there is no professional camera 2, you can also use a surveillance camera on the market instead, such as Xiaomi's surveillance camera (you can remotely control and observe the picture on the Mijia app, and support playback function).

[0040] The wireless transmitter 4 is a cellular mobile Internet access device. The wireless transmitter 4 and the battery and transformer matched with the solar panel 5 are all arranged in a louvered box close to the soil to be observed; the solar panel 5 is attached to the top of the louvered box.

[0041] The cellular mobile Internet access device here refers to mobile phones, portable WiFi routers (devices that insert SIM cards and use cellular mobile networks to provide wired networks and WiFi), and other devices that can connect the camera 2 to the Internet in the wild. If the observation is in a remote area where there is no cellular mobile signal, Starlink terminals, Iridium terminals, and other devices can be used as wireless transmitters 4.

[0042] A field soil pore network structure dynamic change observation system adopts the above field soil pore network structure dynamic change observation system for observation, and comprises the following steps:

[0043] Step 1: Dig trenches on the soil sample to be observed;

[0044] Step 2: Place the transparent shielding system, the camera 2, the lighting, and the mounting base 3 in the trench, lead out the data line and the power line of the camera 2, and then backfill the trench; wherein the anti-mixing semipermeable membrane 13 is arranged close to the side wall of the trench, not in contact with the backfill soil but with the soil in its original state;

[0045] Step 3: Build a venetian blind box near the trench, then install the wireless transmitter 4 and the battery and transformer matching the solar panel 5 in the venetian blind box, and attach the solar panel 5 on the top of the venetian blind box;

[0046] Step 4: Arrange the cables and debug the network, turn on camera 2 on the software that comes with it, and start observing.

[0047] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A field soil pore network structure dynamic change observation system, characterized by: The invention comprises a camera (2) arranged in the soil, a transparent shielding system shielded between the camera (2) and the soil and used to prevent the soil from interfering with the camera, a wireless transmitter (4) electrically connected to the camera (2) and used to transmit the captured video to an observer along a wireless network, and a solar panel (5) electrically connected to the camera (2) and the wireless transmitter (4) and used to supply power; The lens of the camera (2) extends out from a waterproof mounting base (3), and the transparent shielding system comprises a transparent isolation plate (11) abutting against the camera (2), a transparent imitation soil (12) arranged on a side of the transparent isolation plate (11) away from the camera (2), and an anti-mixing semi-permeable membrane (13) arranged between the transparent imitation soil (12) and the soil and used to prevent the soil and the transparent imitation soil (12) from mixing and affecting observation; The transparent imitation soil (12) is made of a transparent plastic material, and the shear modulus of the transparent imitation soil (12) in the horizontal direction is consistent with that of the soil to be tested; The anti-mixing semipermeable membrane (13) is a water-permeable transparent semipermeable membrane.

2. A field soil pore network structure dynamic change observation system according to claim 1, characterized in that: The edge of the anti-mixing semi-permeable membrane (13) is adhered to the transparent isolation plate (11), and the membrane and the transparent isolation plate (11) are enclosed to form a sealed container that encloses the transparent imitation soil (12); the lens of the camera (2) is placed on the transparent isolation plate (11), and the portion of the camera (2) located outside the base is wrapped with a sealant.

3. A field soil pore network structure dynamic change observation system according to claim 1, characterized in that: The anti-mixing semipermeable membrane (13) is a polyvinylidene fluoride microporous membrane, and the transparent isolation plate (11) is a glass plate sprayed with a bactericide for preventing biofilm from forming on the surface.

4. A field soil pore network structure dynamic change observation system according to claim 1, characterized in that: The transparent imitation soil (12) is formed by mixing two gels that are insoluble in each other, one of the two gels being in granular form and uniformly mixed in the other gel.

5. A field soil pore network structure dynamic change observation system according to claim 1, characterized in that: The camera (2) is provided with a visible light camera and an infrared camera, and is provided with a lighting lamp for illuminating the soil to be observed, wherein the lighting lamp comprises a white light LED lamp and an infrared lamp.

6. A field soil pore network structure dynamic change observation system according to claim 1, characterized in that: The mounting base (3) is a stainless steel box filled with rock wool, and the positions where the lens, data cable, and power supply cable of the camera (2) pass through the stainless steel box are all sealed with sealant.

7. A field soil pore network structure dynamic change observation system according to claim 1, characterized in that: The camera (2) is a network camera, the wireless transmitter (4) is a cellular mobile Internet access device, the wireless transmitter (4) and a storage battery and a power conversion device matched with the solar panel (5) are all arranged in a louvered box close to the soil to be observed; the solar panel (5) is attached to the top of the louvered box.

8. A field soil pore network structure dynamic change observation system, characterized by: The observation is performed using a field soil pore network structure dynamic change observation system as claimed in claim 7, and includes the following steps: Step 1: Dig trenches on the soil sample to be observed; Step 2: placing a transparent shielding system, a camera (2), a lighting lamp, and a mounting base (3) in the groove, leading out the data line and power line of the camera (2), and then backfilling the groove; wherein the anti-mixing semi-permeable membrane (13) is arranged close to the side wall of the groove; Step 3: Build a shutter box near the trench, then install the wireless transmitter (4) and the battery and transformer matching the solar panel (5) in the shutter box, and attach the solar panel (5) on the top of the shutter box; Step 4: Arrange the cables and debug the network, open the camera (2) on the software that comes with the camera (2), and start observing.

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