Device for rapidly and accurately measuring biological crust soil roughness

Abstract

The utility model discloses a device for rapidly and accurately measuring the roughness of biological crust soil, and belongs to the technical field of field measuring equipment. The device comprises two metal rods, a probe unit and a resistance wire. The bottom of the metal rod can be vertically arranged on the earth surface to be measured, a plurality of probe units which are vertically arranged in parallel at equal intervals are arranged in the middle of the metal rod, and plastic plates are mounted on, in and under the metal rod for fixing; the resistance wire sequentially passes through the upper part of the probe unit, one end is welded with the metal rod, and the other end is connected with the pulley which is arranged on the bottom plastic plate. The device can be arranged on the biological crust earth surface, the resistance values of the resistance wire in the initial stage and the measurement stage are obtained by measuring the voltages at the two ends of the resistance wire, the change of the length of the resistance wire is calculated, and the earth surface roughness of the biological crust soil is finally obtained. The biological crust soil surface roughness measuring device measures the biological crust surface roughness through voltage changes, is rapid and accurate in measurement, easy and convenient to operate and convenient to carry, and is suitable for rapid measurement of the field biological crust soil surface roughness.

Description

Technical Field

[0001] The utility model belongs to the technical field of field measurement equipment and relates to a device for quickly and accurately measuring the roughness of biological crust soil. Background Art

[0002] Soil surface roughness, a key component of field surveys, is a crucial indicator influencing surface runoff and erosion. Surface roughness is typically the result of factors such as crop cultivation and management practices, human activities, and soil erosion. It is a primary physical property of the ground and a key factor controlling land surface processes such as rainfall infiltration, surface runoff, wind erosion, and water erosion. Soil surface roughness reflects the surface microtopography and is an essential parameter for modeling and predicting soil and water loss processes and the migration and transformation of pollutants.

[0003] Currently, commonly used methods for measuring soil surface roughness can be generally categorized into two types: non-contact and contact measurement. Non-contact measurement techniques offer higher accuracy and automation, primarily including image analysis and remote sensing technologies. For example, image analysis involves capturing images of the soil surface, analyzing them using image processing software, and extracting surface contour information, thereby determining soil roughness. Remote sensing, on the other hand, involves acquiring surface images using platforms such as remote sensing satellites or drones, and extracting surface roughness information through remote sensing image processing and analysis. Contact measurement methods, on the other hand, primarily include the chain method and the stylus method, which typically utilize simple, inexpensive instruments. The chain method involves placing a fixed-length chain on the surface and measuring the relationship between the chain's horizontal length and its actual length to measure surface roughness. The stylus method, on the other hand, utilizes a row of equally spaced, movable styluses of equal length. The stylus tips are placed in contact with the surface, and the position of the stylus tips is recorded to map the surface profile and calculate surface roughness.

[0004] Biological crusts are special complexes of a certain thickness formed by the cementation of microorganisms such as microorganisms, cyanobacteria, lichens, and mosses with soil particles. They play an important role in fragile ecosystems. Studies have shown that the algae, bacteria, and other biological components in biological crusts can promote soil nutrient cycling and increase soil formation rates through their physiological metabolism. While changing soil properties (such as microtopography), they also affect surface roughness, thereby profoundly affecting the physical, chemical, and biological processes of the soil. Understanding the changes in surface roughness during the development of biological crust soils and the factors that influence them is of great significance for clarifying their role in changing soil structure, surface eco-hydrological processes, and energy conversion characteristics.

[0005] Although the aforementioned non-contact and contact measurement techniques can be used to measure the roughness of biocrust soils, the non-contact measurement technology requires bulky equipment, cumbersome operation, and high price. Furthermore, it is affected by a variety of factors and requires specialized image processing software and technical support, making it unsuitable for rapid field surveys. Compared to non-contact measurement technology, contact measurement technology has a simpler instrument structure, is inexpensive, and is easy to carry, making it more suitable for rapid measurement of biocrust soil roughness during field surveys. However, existing methods are relatively complex to operate, the measurement process is significantly affected by human experience, and may cause certain damage to the soil. In summary, although there have been studies on the measurement of biocrust soil roughness, there are still deficiencies in the development of equipment that can accurately and rapidly measure the roughness of biocrust soils in the field. Utility Model Content

[0006] The purpose of this utility model is to overcome the shortcomings of the above-mentioned existing technologies and provide a device that can quickly and accurately measure the roughness of biological crust soil, so as to provide a reference for exploring the influence of biological crust on surface erosion, runoff generation process and eco-hydrological process.

[0007] The purpose of this utility model is achieved through the following technical solutions:

[0008] A device for quickly and accurately measuring the roughness of biocrust soil comprises two metal rods of adjustable length, a short top plastic plate, a short middle plastic plate, a long bottom plastic plate, multiple stylus units, a resistance wire serving as a measurement reference, and a pulley. The multiple stylus units are plastic needles of equal length; the short top plastic plate, the short middle plastic plate, and the long bottom plastic plate are horizontally mounted on the two metal rods; the short middle plastic plate and the long bottom plastic plate are provided with holes for the stylus units to pass through, and the stylus units pass through the short middle plastic plate and the long bottom plastic plate and are arranged equidistantly and parallel between the two metal rods; one end of the long bottom plastic plate extends beyond a portion of the metal rod; the stylus units and one metal rod are provided with threading holes for the resistance wire to pass through; the pulley is fixed to the portion of the long bottom plastic plate that extends beyond the metal rod; one end of the resistance wire is fixed to the metal rod, and the other end passes through the stylus unit and the metal rod with the threading holes and is wound around the pulley.

[0009] The height of the metal rod can be adjusted according to the actual surface conditions, and the bottom is preferably a conical needle structure, which is easy to install and fix on the surface to be measured; a preferred size of the metal rod is: 20.0 cm high and 0.5 cm in diameter.

[0010] The materials of the top short plastic plate, the middle short plastic plate, the bottom long plastic plate and the measuring needle unit are preferably polyvinyl chloride; the top short plastic plate is used to support the measuring needle unit to prevent the measuring needle unit from falling out, and serves as a reference for whether the top end of the measuring needle unit is parallel; the middle short plastic plate is used to fix the measuring needle unit, and its interior is punched and the inner wall is smooth, and the number of holes corresponds one to one with the measuring needle unit; the bottom long plastic plate is used to fix the measuring needle unit and the pulley, and the number of internal holes corresponds one to one with the middle plastic plate and the inner wall is smooth; a preferred size of the top short plastic plate, the middle short plastic plate and the bottom long plastic plate is: the top short plastic plate is 25.0 cm long, 2.0 cm wide and 0.5 cm thick, the middle short plastic plate is 25.0 cm long, 2.0 cm wide and 5.0 cm thick, and the bottom long plastic plate is 35.0 cm long, 2.0 cm wide and 0.5 cm thick; a preferred size of the measuring needle unit is: 15.0 cm long, 0.1 cm in diameter, and the distance between needles is 0.1 cm.

[0011] A rubber support is provided at the bottom of the probe unit to prevent the bottom of the probe unit from entering the soil and causing measurement value deviation; a preferred size of the rubber support is: 0.5 cm long and 0.1 cm wide.

[0012] The resistance wire is preferably made of nickel-chromium alloy with a smooth surface, and is preferably fixed to the metal rod by welding. A preferred size of the resistance wire is: 0.05 cm in diameter.

[0013] The pulley is further provided with a screw; the pulley is used to wind the resistance wire, and the screw on the pulley is used to adjust the length of the resistance wire. After all the measuring needle units are fixed in position, the resistance wire can be straightened by rotating the screw on the pulley to restore all the measuring needle units to their original positions.

[0014] The device for measuring the roughness of biological crust soil is used to measure the surface roughness of biological crust soil.

[0015] The method for measuring the surface roughness of biological crust soil using the above-mentioned device for measuring the roughness of biological crust soil includes the following steps: inserting two metal rods into the soil so that the device is horizontal and the highest position of the surface protrusion contacts the probe unit; tightening the pulley screw to straighten the resistance wire so that all the probe units are in the same horizontal position and parallel and equidistant from the short plastic plate on the top, connecting the top ends of the two metal rods to a power supply device and a data collector via wires, and measuring the voltage value V1 across the resistance wire at this time using the data collector; then, loosening the pulley screw to loosen the resistance wire, pressing the probe unit vertically downward until the rubber support at the bottom of each probe unit is in close contact with the soil surface, tightening the pulley screw so that the resistance wire can be consistent with the outline of the connecting line of the top of the probe unit, and measuring the voltage value V2 across the resistance wire at this time using the data collector;

[0016] According to Ohm's law Apply the same current I and calculate the resistance of the resistance wire R1 and R2;

[0017] According to the law of resistance Where ρ is the resistivity, S is the cross-sectional area, and the lengths of the resistance wire L1 and L2 before and after the measurement are calculated;

[0018] The surface roughness Cr of the biological crust soil was determined by the relationship equation Cr = (1-L1 / L2) × 100 between the change in resistance wire length and soil roughness.

[0019] Advantages and benefits of this utility model: By measuring the voltage across a resistance wire, the resistance values ​​of the resistance wire during the initial and measurement phases are obtained, and the change in the resistance wire length is calculated to ultimately determine the surface roughness of the biocrust soil. This utility model utilizes voltage changes to measure the roughness of biocrust soil. The measurement is fast and accurate, simple to operate, and portable, making it suitable for rapid measurement of biocrust soil surface roughness in the field. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of the surface roughness measuring device of the utility model;

[0021] Figure 2 This is a schematic structural diagram of a probe unit of a surface roughness measuring device of the present invention;

[0022] Figure 3 The results of measuring surface roughness using the surface roughness measuring device of the utility model are compared with those using the traditional chain method.

[0023] In the figure: 1-metal rod, 2-metal rod, 3-top short plastic plate, 4-middle short plastic plate, 5-bottom long plastic plate, 6-probe unit, 7-rubber drag, 8-resistance wire, 9-pulley, 10-screw, 11-wire. DETAILED DESCRIPTION

[0024] The structure of the device of the present invention and the principle and method of measuring the roughness of biological crust soil are further described in detail below with reference to the embodiments and drawings.

[0025] Example 1

[0026] The utility model provides a device for quickly and accurately measuring the roughness of biological crust soil. Figure 1-2As shown, the device comprises two adjustable metal rods (metal rod 1 and metal rod 2), a short top plastic plate 3, a short middle plastic plate 4, a long bottom plastic plate 5, multiple stylus units 6, a rubber support 7, a resistance wire 8 serving as a reference for measurement, and a pulley 9. The top, middle, and bottom plastic plates 3, 4, and 5 are mounted horizontally on the two metal rods, with one end of the bottom plastic plate 5 extending slightly beyond the metal rod 2. The bottoms of the metal rods are tapered, needle-like structures, making them easy to attach to the surface being measured. The multiple stylus units 6 are plastic needles of equal length. The short middle plastic plate 4 and the long bottom plastic plate 5 also have holes through which the stylus units 6 pass, allowing them to slide up and down. The stylus units 6 pass through the short middle plastic plate 4 and the long bottom plastic plate 5 and are arranged equidistantly and parallel between the two metal rods. The stylus units 6 have threading holes on their upper portions for the resistance wire 8, and rubber supports 7 are attached to their lower ends. The metal rod 2 also has a hole on its upper portion for the resistance wire 8. The pulley 9 is fixed to the end of the bottom long plastic plate 5 that extends beyond the metal rod 2. One end of the resistance wire 8 is welded to the metal rod 1, and the other end passes through the stylus unit 6 and the metal rod 2 before being wound around the pulley 9. A screw 10 is provided on the pulley 9 to adjust the length of the resistance wire 8. Wires 11 are connected to the tops of the two metal rods, which can be connected to an external power supply and data acquisition device.

[0027] A preferred size specification of the device for quickly and accurately measuring the roughness of biological crust soil is as follows: the adjustable metal rod is 20.0 cm high and 0.5 cm in diameter, and the height of the metal rod can be adjusted according to the actual surface conditions; the top short plastic plate 3, the middle short plastic plate 4, and the bottom long plastic plate 5 are made of polyvinyl chloride plastic plates; the top short plastic plate is 25.0 cm long, 2.0 cm wide, and 0.5 cm thick; the middle short plastic plate is 25.0 cm long, 2.0 cm wide, and 5.0 cm thick; the bottom long plastic plate is 35.0 cm long, 2.0 cm wide, and 0.5 cm thick; the measuring needle unit 6 is a plurality of black polyvinyl chloride plastic needles of equal length, each plastic needle is 15.0 cm long and 0.1 cm in diameter, and the distance between the needles is 0.1 cm; the rubber support 7 is 0.5 cm long and 0.1 cm wide; the resistance wire 8 is made of nickel-chromium alloy, has a smooth surface, and a diameter of 0.05 cm.

[0028] This device calculates the difference in voltage between the resistance wire and the resistance wire before and during measurement, and then calculates the difference in resistance wire length change. The surface roughness of the biocrust soil is then calculated using the equation that relates the change in resistance wire length to the surface roughness. The method for using this device and the process for calculating the biocrust soil roughness are as follows.

[0029] Adjust the lengths of metal rods 1 and 2 based on the actual surface roughness to ensure the measuring device is at an appropriate height. Insert the tapered, needle-shaped metal rod vertically into the surface, ensuring both rods are inserted into the soil and the device is level. The device should not be too high, causing excessive deformation of the resistance wire during the downward movement of the stylus unit 8. It should also not be too low, causing a large amount of the rubber support 7 at the bottom of the stylus unit 6 to contact the surface before measurement, causing errors. Ensure that the highest point of the surface protrusion contacts the stylus unit.

[0030] Next, check that the resistance wire 8 passes through the threading holes on the top of the stylus unit 6 in order. Using a 100-stylus unit setup as an example, the stylus units 6 consist of 100 black plastic needles of equal length, 15.0 cm long and 0.1 cm in diameter, with the distance between adjacent needles being 0.1 cm. Ensure that all 100 stylus units can move vertically between the middle short plastic plate 4 and the bottom long plastic plate 5. Ensure that the upper ends of the stylus units 6 are outside the top of the middle short plastic plate 4 and do not contact the top short plastic plate 3, and that the lower ends pass through the bottom of the bottom long plastic plate 5 and land on the surface to be measured. Once verified, adjust the resistance wire 8 by rotating the screw 10 on the pulley 9. Tighten the screw to straighten the resistance wire 8 and return the 100 stylus units to their original positions, ensuring that all stylus units 6 are in the same horizontal position and parallel to and equidistant from the top short plastic plate 3. The top ends of the two metal rods are connected to the power supply and data acquisition device via wires 11. The data acquisition device then measures the voltage V1 across the resistance wires.

[0031] Afterwards, loosen the pulley screw 10 to release the resistance wire 8, and press the probe units 6 vertically downward until the rubber support 7 at the bottom of each probe unit is close to the soil surface. The force should not be too heavy, causing the rubber support to sink into the soil and cause deviation, nor too light, causing the probe units 6 to be suspended in the air and cause errors. After 100 probe units 6 have fully contacted the surface to be measured, slightly tighten the pulley screw 10 so that the resistance wire 8 can be aligned with the contour line connecting the top of the probe unit 6. The voltage value V2 at both ends of the resistance wire at this time is measured by the data acquisition device. According to Ohm's law (1), when the same current I is applied, the resistance of the resistance wire R1 and R2 can be calculated.

[0032]

[0033] According to the resistance law (2), the lengths of the resistance wire L1 and L2 before and after the measurement are calculated. Finally, the relationship equation (3) between the change in the length of the resistance wire and the soil roughness is used to quickly and accurately measure the surface roughness Cr of the biological crust soil.

[0034]

[0035] Wherein ρ is the resistivity and S is the cross-sectional area, both of which are related to the material of the resistance wire used. The resistance wire used in the present invention is made of nickel-chromium alloy with a smooth surface and a diameter of 0.05 cm.

[0036] Cr = (1-L1 / L2) × 100 (3)

[0037] In summary, the present invention provides a device for quickly and accurately measuring the surface roughness of biocrust soil, which mainly includes metal rods 1 and 2, a probe unit 6, a rubber support 7, a resistance wire 8, three plastic plates 3, 4, 5 and a pulley 9. The metal rods 1 and 2 can be fixed vertically to the surface to be measured to fix the device. A plurality of probe units 6 arranged in parallel and equidistantly are provided between the metal rods 1 and 2. The resistance wire 8 passes through the probe units in sequence to simulate the true shape of the surface contour to be measured. The resistance wire 8 and the probe unit 6 can measure the surface roughness to be measured by the chain method and the probe method. At the same time, by measuring the difference in voltage between the two ends of the resistance wire before and after, the difference in resistance value and length change of the resistance wire can be calculated. Finally, the relationship equation between the resistance wire length difference and the surface roughness is used to achieve a quick and accurate measurement of the surface roughness of the biocrust soil. In addition, the two-dimensional plane surface roughness can also be obtained through multiple measurements.

[0038] Example 2

[0039] In August 2024, three plots (moss crust aeolian sandy soil, algae-moss mixed aeolian sandy soil, and algae crust aeolian sandy soil) were selected from typical biocrust aeolian soils in the northern Loess Plateau of China. Five replicates were used in each plot. The surface roughness of the biocrust soils was measured using both the traditional chain method and the device proposed in this study.

[0040] Preliminary work: Before measurement, check that the resistance wire passes through the threading holes on the top of all stylus units in sequence, and ensure that all stylus units are movably mounted vertically on the middle and bottom plastic plates. After checking that everything is correct, adjust the resistance wire by rotating the pulley screw. Tighten the screw to straighten the resistance wire and return the stylus units to their original position, so that all stylus units are at the same horizontal position and parallel to and equidistant from the top plastic plate. Clear dead branches and leaves from the surface of the selected soil. According to the actual roughness of the surface to be measured, adjust the two adjustable metal rods to the appropriate height so that the main body of the measuring device is at an appropriate height. Insert the tapered needle-shaped metal rod vertically into the surface to be measured, ensuring that both metal rods are inserted into the soil and the device is horizontal.

[0041] Measurement process: First, a CR3000 data logger (Campbell Scientific, Inc., USA) was used to record the voltage across the resistance wire in its initial state. Next, the pulley screw was loosened to release the resistance wire, and the probe units were pressed vertically downward until the rubber drag at the bottom of each probe unit rested firmly on the soil surface. Once the probe units were fully in contact with the surface being measured, the pulley screw was slightly tightened until the resistance wire aligned with the contour of the probe unit top. The voltage across the resistance wire at this point was measured using the data logger.

[0042] Data processing: The data collector obtains the voltage difference between the two ends of the resistance wire before and after the measurement, obtains the resistance difference of the resistance wire before and after the measurement, and then converts it into the change value of the resistance wire length. Finally, the final roughness of the soil surface is calculated.

[0043] In addition, the soil roughness of the biological crust was measured using the traditional chain method (silver, 20 cm long, 0.1 cm in diameter) at the same plot. The results of the traditional chain method and the device of the utility model ( Figure 3 ) shows that for the roughness measurement of the same biocrust soil sample, the traditional chain method may be subject to large human reading errors (up to one decimal place can be estimated), while the device of the present invention can accurately measure the change in resistance based on the resistance wire fitting the surface undulations, thereby obtaining the surface roughness (the measurement result can be accurate to three decimal places). This is reflected in the specific results. For example, in the moss crust measurement, the maximum value measured by the traditional chain method is 5.8, and the minimum value is 4.1, with a difference of 1.7 between the maximum and minimum values; while the maximum value measured by the device of the present invention is 5.323, and the minimum value is 4.213, with a difference of only 1.11 between the maximum and minimum values. In summary, the device of the present invention can obtain the surface roughness of biocrust soil more quickly and accurately.

[0044] The above embodiments are provided for the purpose of illustration and description in order to better illustrate the principles and practical applications of the present invention. They are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the utility model.

Claims

1. A device for quickly and accurately measuring the roughness of biological crust soil, characterized by: It includes two metal rods with adjustable lengths, a short plastic plate at the top, a short plastic plate in the middle, a long plastic plate at the bottom, multiple measuring needle units, a resistance wire, and a pulley; the multiple measuring needle units are multiple plastic needles of equal length; The top short plastic plate, the middle short plastic plate, and the bottom long plastic plate are horizontally mounted on two metal rods; The middle short plastic plate and the bottom long plastic plate are provided with holes for the stylus unit to pass through. The stylus unit passes through the middle short plastic plate and the bottom long plastic plate and is equidistantly and parallelly arranged between the two metal rods; one end of the bottom long plastic plate extends beyond a portion of the metal rod; The measuring needle unit and the upper part of a metal rod are provided with a threading hole for the resistance wire to pass through; the pulley is installed on the part of the bottom long plastic plate that extends beyond the metal rod; one end of the resistance wire is fixed to the metal rod, and the other end passes through the measuring needle unit and the metal rod with the threading hole and is wound around the pulley.

2. The device for quickly and accurately measuring the roughness of biological crust soil according to claim 1, characterized in that: The bottom of the metal rod is a conical needle-shaped structure.

3. The device for rapidly and accurately measuring the roughness of biological crust soil according to claim 1, characterized in that: The top short plastic plate, the middle short plastic plate, the bottom long plastic plate and the measuring needle unit are made of polyvinyl chloride.

4. The device for rapidly and accurately measuring the roughness of biological crust soil according to claim 1, characterized in that: A rubber support is provided at the bottom of the measuring needle unit.

5. The device for rapidly and accurately measuring the roughness of biological crust soil according to claim 1, characterized in that: The resistance wire is made of nickel-chromium alloy.

6. The device for rapidly and accurately measuring the roughness of biological crust soil according to claim 1, characterized in that: The pulley is provided with a screw.

7. The device for rapidly and accurately measuring the roughness of biological crust soil according to any one of claims 1 to 6, characterized in that: The metal rod is 20.0 cm high and 0.5 cm in diameter; the top short plastic plate is 25.0 cm long, 2.0 cm wide and 0.5 cm thick; the middle short plastic plate is 25.0 cm long, 2.0 cm wide and 5.0 cm thick; the bottom long plastic plate is 35.0 cm long, 2.0 cm wide and 0.5 cm thick.

8. The device for rapidly and accurately measuring the roughness of biological crust soil according to any one of claims 1 to 6, characterized in that: The measuring needle unit has a length of 15.0 cm and a diameter of 0.1 cm, and the distance between the needles is 0.1 cm.

9. The device for rapidly and accurately measuring the roughness of biological crust soil according to claim 4, characterized in that: The rubber support is 0.5 cm long and 0.1 cm wide.

10. The device for quickly and accurately measuring the roughness of biological crust soil according to any one of claims 1 to 6, characterized in that: The resistance wire has a diameter of 0.05 cm.

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