Device for measuring field hydrological function of litter

Abstract

The utility model discloses a litter field hydrological function measuring device which comprises an experimental tank, a supporting mechanism and a measuring mechanism, and the top, the front side and the bottom of the experimental tank are open; the supporting mechanism comprises four supporting legs, and the supporting legs are connected to the two sides of the experiment groove respectively; the measuring mechanism comprises a vertical collecting hopper butted at the opening of the bottom of the experimental tank, a lateral collecting hopper butted at the opening of the front side of the experimental tank, a vertical runoff monitoring assembly and a lateral runoff monitoring assembly; a first filter screen is mounted at the joint of the vertical collecting hopper and the bottom of the experimental tank, and the bottom of the vertical collecting hopper is communicated with the vertical runoff monitoring assembly through a flow guide assembly I; a second filter screen is installed at the butt joint position of the lateral collecting hopper and the front side of the experiment groove, and the bottom of the lateral collecting hopper is communicated with the lateral runoff monitoring assembly through a second flow guide assembly. The slope litter hydrological regulation device is high in stability, suitable for respective complex terrains, convenient to carry, capable of objectively reflecting the slope litter hydrological regulation process and small in deviation.

Description

Technical Field

[0001] The utility model relates to the field of research on the hydrological characteristics of litter, and particularly relates to a device for measuring the field hydrological function of litter. Background Technique

[0002] As an important layer for redistributing precipitation resources in the vertical structure of forest stands, forest litter has a large specific surface area, is loose and porous, has a strong ability to absorb and retain water, can absorb part of the kinetic energy of raindrops during rainfall, effectively delay the formation and scouring of surface runoff, has obvious functions of intercepting rainfall, promoting infiltration, regulating surface runoff, reducing soil erosion and improving soil physical and chemical properties, is an important body for exerting the function of water conservation, and plays a certain positive role in improving the replenishment effect of rainwater on soil and the water absorption and utilization effect of plants during rainfall.

[0003] After retrieval, a Chinese utility model patent with the publication number of CN214703179U discloses an observation device for the dynamic interception process of litter, including a litter collector placed on a first weighing device. A litter bearing net is arranged in the litter collector, and a water baffle is inclined below the litter bearing net in the litter collector. A water outlet hole is arranged in the water baffle, and a drain pipe is connected and installed at the water outlet hole. The water outlet of the drain pipe is connected to a collector, and the collector is placed on a second weighing device. For this patent, although using the litter water balance principle is the most reliable and commonly used means for monitoring hydrological functions such as rainfall interception of field understory litter, the observation device of this patent has the following problems:

[0004] ① The overall device lacks functions such as telescoping or folding, and it is difficult to adjust the height, inclination angle, etc. It has high requirements for the surface flatness, cannot adapt to complex terrains, and has poor portability;

[0005] ② The component for bearing litter lacks the slope adjustment function, is difficult to adapt to the actual slope of the mountain research area slope, and cannot reflect the specific influence of slope on the hydrological function of litter;

[0006] ③ The runoff collection is often limited to vertical runoff, lacks records of lateral runoff, and cannot realize the real-time splitting of runoff components, which is not conducive to exploring the development mechanism of "biological cushion flow" under the influence of slope;

[0007] ④ Generally, the water volume recording component mostly uses weighing and other methods for measurement and recording, and it is difficult to avoid the fluctuation of weighing results caused by runoff input or raindrop impact. Therefore, a new device for measuring the hydrological function of litter is needed.

[0008] In addition, two Chinese patents with publication numbers CN209417010U and CN103018795A were also retrieved. By analyzing these two patents, there are still certain defects. In patent CN209417010U, the height and inclination angle of the overall framework are difficult to adjust, making it unable to adapt to the complex terrain of the hillside. At the same time, the overall structure cannot be folded, resulting in low portability. In patent CN103018795A, the slope of the litter catch net is not easy to adjust, making it difficult to adapt to the actual slope of the slope in the mountain research area and unable to reflect the specific impact of the slope on hydrological processes such as litter interception and runoff generation. Utility Model Content

[0009] To solve the above problems, the purpose of the present utility model is to provide a litter field hydrological function measuring device with high stability, capable of adapting to various complex terrains, convenient to carry, capable of objectively reflecting the hydrological regulation process of slope litter and having a small deviation.

[0010] The purpose of the present utility model is achieved through the following technical solutions:

[0011] A litter field hydrological function measuring device includes an experimental tank and a support mechanism. The top, front side, and bottom of the experimental tank are all open. The support mechanism includes at least four support feet for supporting the experimental tank, and the support feet are respectively connected to both sides of the experimental tank. It also includes a measurement mechanism. The measurement mechanism includes a vertical collection hopper docked at the bottom opening of the experimental tank, a lateral collection hopper docked at the front side opening of the experimental tank, a vertical runoff monitoring component for measuring vertical runoff, and a lateral runoff monitoring component for measuring lateral runoff. A first filter screen is installed at the docking position of the vertical collection hopper and the bottom opening of the experimental tank, and the bottom of the vertical collection hopper is connected to the vertical runoff monitoring component through a first diversion component. A second filter screen is installed at the docking position of the lateral collection hopper and the front side opening of the experimental tank, and the bottom of the lateral collection hopper is connected to the lateral runoff monitoring component through a second diversion component.

[0012] Further, in order to adapt to slopes with different gradients and meet the actual terrain requirements, each support foot includes a horizontal bracket and a vertical bracket. Both the horizontal bracket and the vertical bracket are telescopic rods with built-in expansion valves. The two ends of the horizontal bracket are respectively connected to the outside of the experimental tank and the upper end of the vertical bracket through spherical universal joints. The lower end of the vertical bracket is provided with a pointed support foot for inserting into the soil layer.

[0013] Further, to ensure that the support feet can still maintain stability under slight interference and do not shake left and right, a stabilizing plate is fixed to the vertical bracket above the pointed support foot.

[0014] Further, the stabilizing plate is circular.

[0015] Further, the number of support feet is four and they are symmetrically arranged on both sides of the experimental tank.

[0016] Further, both the first diversion component and the second diversion component are hollow conduits.

[0017] Further, both the vertical runoff monitoring component and the lateral runoff monitoring component are self - recording tipping bucket flow meters.

[0018] The beneficial effects of the present utility model compared with the prior art are as follows:

[0019] ① High stability. In the prior art, most of the supporting feet are set to be pointed so as to be inserted into the soil, but the buried part may still be skewed or displaced. However, the present utility model adds circular stabilizing plates to improve the stability of the grounding part, avoiding the skew and displacement of the pointed supporting feet in the soil, so as to keep the experimental tank fixed all the time when receiving rainfall input. It is found in the study of the Quercus variabilis forest on the mountain slope in Beijing that due to the action of gravity, the devices of other types lacking surface stabilizing components in the past would be skewed downward along the slope surface, and even overturned under the action of slope runoff, wind force, etc. The circular stabilizing plates of the present utility model compact the soil near the pointed supporting feet, increasing the friction between the two, so that the litter in the experimental tank remains stable all the time during the rainfall input process, and the interception and runoff processes are not disturbed.

[0020] ② It can adapt to their respective complex terrains and is convenient to carry. In the prior art, the brackets used to fix the experimental tank or the receiving net lack functions such as telescoping or folding, and it is difficult to adjust the height, inclination angle, etc., and it cannot adapt to the complex terrain of the slope surface, and the portability is poor. However, the present utility model selects a telescopic bracket and uses a spherical universal joint to connect at the connection between the bracket and the experimental tank. In this way, the slope of the experimental tank can be set and adjusted according to the actual slope terrain, making the slope of the tested litter closer to the natural condition. At the same time, when not in use, it can be telescoped or folded for planting, which is convenient to carry. Adding a spherical universal joint and a diversion component maximally simulates the actual slope of the litter, realizes the separate monitoring of lateral runoff and vertical runoff, and completes the detailed splitting of the ecological hydrological process of the litter. If the influence of the slope is not considered and the litter is always kept horizontal, only vertical infiltration runoff will be generated when receiving rainfall input, which cannot reflect the influence of the slope on the water redistribution process of the litter. This not only does not conform to the natural rainfall receiving condition of the litter on the forest slope surface, but also cannot accurately judge the spatio - temporal distribution pattern of rainwater after entering the litter layer. Therefore, on the basis of considering the slope where the litter is located, the present utility model uses a diversion component with a diversion function to separately collect the lateral runoff and the vertical runoff into the corresponding runoff monitoring components for separate measurement, achieving the purpose of quantitatively expressing the sub - item hydrological process of the litter.

[0021] ③ It can objectively reflect the hydrological regulation process of slope litter with relatively small deviation. Most of the existing technologies only consider the process of vertical infiltration of rainfall and ignore the lateral migration characteristics of water in the slope litter layer, making it difficult to objectively reflect the specific role of slope in the self-regulation of water distribution by litter. The utility model sets filters on both the bottom and the front side of the experimental tank, and connects them to the self-recording tipping bucket flowmeter through the diversion components respectively, so as to realize the refined splitting of lateral and vertical runoff generation of litter under natural rainfall conditions in the wild. Setting the runoff generation monitoring component as a self-recording tipping bucket flowmeter can effectively eliminate the deviation caused by the impact force of water flow on the runoff generation record. In the study of Quercus variabilis forest in the Beijing mountainous area, it is found that the weighing type water volume recording component is extremely vulnerable to the interference of the gravity impact of water droplets when water flows in, resulting in fluctuations in the recorded values and making it difficult to complete experiments with high precision. When the instantaneous rainfall intensity is less than 20 mm / h, the short-term deviation range of the weighing type water volume recording component is about 12.68 - 31.29 g, while the deviation of the utility model is only about 5.97 - 15.63 g; when the instantaneous rainfall intensity is between 20 - 60 mm / h, the short-term deviation range of the weighing type water volume recording component is about 12.68 - 133.24 g, while the deviation of the utility model is only about 5.97 - 24.35 g. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The structure of the utility model will be further described below with reference to the drawings.

[0023] Figure 1 It is a schematic structural diagram of the device for measuring the field hydrological function of litter described in the utility model.

[0024] Figure 2 It is a top view of the device for measuring the field hydrological function of litter described in the utility model.

[0025] Figure 3 It is a side view of the device for measuring the field hydrological function of litter described in the utility model.

[0026] As shown in the figure: 1 - experimental tank, 2 - horizontal bracket, 3 - vertical bracket, 4 - spherical universal joint, 5 - expansion valve, 6 - stabilizing plate, 7 - pointed support foot, 8 - vertical collecting hopper, 9 - first filter, 10 - first diversion component, 11 - vertical runoff generation monitoring component, 12 - lateral collecting hopper, 13 - first filter, 14 - second diversion component, 15 - lateral runoff generation monitoring component. SPECIFIC EMBODIMENTS

[0027] The following specific embodiments illustrate the implementation manners of the present utility model. Those skilled in this technology can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present utility model without making creative efforts belong to the scope protected by the present utility model.

[0028] It should be noted that the structures, ratios, sizes, etc. depicted in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of narration and are not used to limit the scope for the implementation of the present utility model. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope for the implementation of the present utility model.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations. It should be noted that the terms "including", "comprising", or any other variant are intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article, or device. Embodiment

[0030] As Figures 1-3 shown, this embodiment provides a device for measuring the field hydrological function of litter, including an experimental tank, a support mechanism, and a measurement mechanism.

[0031] The experimental tank 1 is a rectangular box-shaped body with openings at the top, front, and bottom, and is filled with litter inside.

[0032] The support mechanism includes four support feet for supporting the experimental tank 1. The four support feet are symmetrically connected to both sides of the experimental tank 1, with two on each side. Each support foot consists of a horizontal bracket 2 and a vertical bracket 3. Both the horizontal bracket 2 and the vertical bracket 3 are telescopic rods with built-in expansion valves 5 (secondary telescopic rods, and the expansion valve 5 is a locking screw). One end of the horizontal bracket 2 is connected to the outside of the experimental tank 1 through a spherical universal joint 4, and the other end is connected to the upper end of the vertical bracket 3 through another spherical universal joint 4. A pointed support foot 7 for inserting into the soil layer is provided at the lower end of the vertical bracket 3. This setting can adapt to slopes with different gradients to meet the actual terrain requirements. In addition, to ensure that the support feet can remain stable under slight interference and do not sway left and right, a circular stabilizing plate 6 is fixed on the vertical bracket 3 above the pointed support foot 7.

[0033] The measurement mechanism includes a vertical collection hopper 8 docked at the bottom opening of the experimental tank 1, a lateral collection hopper 12 docked at the front opening of the experimental tank 1, a vertical runoff monitoring component 11 for measuring vertical runoff, and a lateral runoff monitoring component 15 for measuring lateral runoff.

[0034] A first filter screen 9 is installed at the docking position between the vertical collection hopper 8 and the bottom opening of the experimental tank 1 (the first filter screen 9 separates the vertical collection hopper 8 from the experimental tank 1, and water flows into the vertical collection hopper 8 through the filter holes of the first filter screen 9). The bottom of the vertical collection hopper 8 is connected to the vertical runoff monitoring component 11 through a first diversion component 10.

[0035] A second filter screen 13 is installed at the docking position between the lateral collection hopper 12 and the front opening of the experimental tank 1 (the second filter screen 13 separates the lateral collection hopper 12 from the experimental tank 1, and water flows into the lateral collection hopper 12 through the filter holes of the second filter screen 13). The bottom of the lateral collection hopper 12 is connected to the lateral runoff monitoring component 15 through a second diversion component 14. Both the first diversion component 10 and the second diversion component 14 are hollow conduits. Both the vertical runoff monitoring component 11 and the lateral runoff monitoring component 15 are self-recording tipping bucket flow meters. The first filter screen 9 and the second filter screen 13 are mainly used to carry litter and welcome the input of water. During and after rainfall, rainwater passes through the first filter screen 9 and the second filter screen 13 and enters the corresponding diversion components, while the litter is blocked in the experimental tank 1, enabling the lateral runoff and vertical runoff of the litter in the tank to enter the corresponding runoff monitoring components respectively to complete real-time recording and measurement.

[0036] Working principle:

[0037] During transportation, the device for measuring the field hydrological functions of litter can fold the four support feet through the spherical universal joints 4 and contract them through the expansion valves 5, thereby reducing the occupation of transportation space. When installing at the sample plot after arrival, it can be unfolded again.

[0038] Before use, first unfold the four support feet. Adjust the horizontal length of the support feet by controlling the screws of the expansion valve 5 on the horizontal bracket 2, adjust the height of the support feet by controlling the screws of the expansion valve 5 on the vertical bracket 3, and adjust the angle of the support feet by controlling the spherical universal shaft 4 to make it meet the actual terrain. Insert the pointed support feet 7 into the ground until the circular stabilizing piece 6 touches the ground surface, so that the whole device can still maintain stability under slight interference and will not sway left and right.

[0039] When rainfall enters the experimental tank 1, due to the certain interception effect of the litter in the experimental tank 1, some or even all raindrops will be adsorbed and retained by the litter. However, when the rainfall is large, the excess water beyond the interception capacity of the litter will form runoff. Among them, vertical runoff refers to the runoff in which water moves downward along the pores between the litter under the action of gravity and leaves the litter layer from the lower surface. Lateral runoff is the lateral water flow moving along the slope surface between the surface of the litter layer and the internal materials. It is mainly because when rainfall enters the litter layer, part of the water volume is continuously blocked by the litter when moving downward under the action of gravity and cannot vertically seep, forming a certain accumulation and confluence on the surface of materials such as leaves, and then transferring and flowing between the surface and the inside of the litter layer under the action of the component force of gravity along the slope direction, thus forming a certain stable flow path. The device in this utility model splits and monitors the lateral runoff and vertical runoff through two groups of diversion and collection components at different positions below, and calculates using the water balance principle to complete the quantitative expression of sub-item hydrological processes such as interception, lateral runoff, and vertical runoff. Among them, the vertical runoff passes through the first filter screen 9 and enters the vertical collection hopper 8, and then is introduced into the vertical runoff monitoring component 11 through the first diversion component 10 for collection and measurement; the lateral runoff passes through the second filter screen 13 and enters the lateral collection hopper 12, and then is introduced into the lateral runoff monitoring component 15 through the second diversion component 14 for collection and measurement.

[0040] When the device described in this utility model is used in a typical Quercus variabilis forest in the Beijing mountain area, according to the average slope of the forest land of 15° and the average tree height of 9.88 m, the inclination angle of the experimental tank is also selected as 15°, and the height from the ground is 1 m, which is mainly achieved through the support feet provided with the spherical universal shaft 4 and the expansion valve 5; when the length of the pointed support feet 7 at the lower side of the circular stabilizing piece 6 located inside the soil body is 20 cm, the overall device can be kept stable; according to the average leaf width of Quercus variabilis of 3.73 cm, the average leaf length of 11.19 cm, and the average unit area mass of 8.27 t / hm2, the aperture of the first filter screen 9 and the second filter screen 13 is selected as 1.0 cm × 1.0 cm; to match the data of the meteorological station in the study area, the recording time step of the data acquisition of the vertical runoff monitoring component 11 and the lateral runoff monitoring component 15 (self-recording tipping bucket flowmeter) is set to 1 min, and the acquisition accuracy is set to 0.1 g; after monitoring the eco-hydrological processes of the litter in the device during different rainfall events in the growing season, it is found that when there is no rainfall event for more than 6 consecutive days:

[0041] ① If light rain occurs (rainfall within 24 hours is less than 10 mm), the average proportion of litter interception is 17.71%, the average proportion of vertical runoff is 70.71%, and the average proportion of lateral runoff is 11.58%;

[0042] ② If moderate rain occurs (rainfall within 24 hours ranges from 10 to 25 mm), the average proportion of litter interception is 6.83%, the average proportion of vertical runoff is 79.82%, and the average proportion of lateral runoff is 13.35%;

[0043] ③ If heavy rain occurs (rainfall within 24 hours ranges from 25 to 50 mm), the average proportion of litter interception is 3.96%, the average proportion of vertical runoff is 80.97%, and the average proportion of lateral runoff is 15.07%;

[0044] ④ If rainstorm occurs (rainfall within 24 hours ranges from 50 to 100 mm), the average proportion of litter interception is 3.02%, the average proportion of vertical runoff is 81.66%, and the average proportion of lateral runoff is 15.32%.

[0045] Other details not elaborated in this utility model are all well-known conventional technologies in the art.

[0046] It should be noted that the term "including", "comprising" or any other variant is intended to cover non-exclusive inclusion, so that a process, method, article or device containing a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0047] The protection scope of this utility model is not limited to the technical solutions disclosed in the specific implementation manners. Any modification, equivalent replacement, improvement, etc. made to the above embodiments based on the technical essence of this utility model shall fall within the protection scope of this utility model.

Claims

1. A device for measuring the field hydrological function of litter, comprising an experimental tank and a support mechanism. The top, front side, and bottom of the experimental tank are all open. The support mechanism includes at least four support feet for supporting the experimental tank, and the support feet are respectively connected to both sides of the experimental tank. It is characterized in that: It further includes a measuring mechanism; the measuring mechanism includes a vertical collecting hopper docked at the bottom opening of the experimental tank, a lateral collecting hopper docked at the front-side opening of the experimental tank, a vertical runoff monitoring component for measuring vertical runoff, and a lateral runoff monitoring component for measuring lateral runoff; a first filter screen is installed at the docking position between the vertical collecting hopper and the bottom opening of the experimental tank, and the bottom of the vertical collecting hopper is communicated with the vertical runoff monitoring component through a first guiding component; a second filter screen is installed at the docking position between the lateral collecting hopper and the front-side opening of the experimental tank, and the bottom of the lateral collecting hopper is communicated with the lateral runoff monitoring component through a second guiding component.

2. The litter field hydrological function measurement device according to claim 1, characterized in that: Each support leg includes a horizontal bracket and a vertical bracket. Both the horizontal bracket and the vertical bracket are telescopic rods with built-in expansion valves. The two ends of the horizontal bracket are respectively connected to the outside of the experimental tank and the upper end of the vertical bracket through spherical universal joints; a pointed support foot for inserting into the soil layer is provided at the lower end of the vertical bracket.

3. The litter field hydrological function measurement device according to claim 2, characterized in that: A stabilizing plate is fixed to the vertical bracket above the pointed support foot.

4. The litter field hydrological function measuring device according to claim 3, wherein: The stabilizing plate is circular.

5. The litter field hydrological function measurement device according to claim 4, characterized in that: The number of the support legs is four and they are symmetrically arranged on both sides of the experimental tank.

6. The litter field hydrological function measuring device according to claim 1, characterized in that: Both the first guiding component and the second guiding component are hollow conduits.

7. The litter field hydrological function measurement device according to claim 1, characterized in that: Both the vertical runoff monitoring component and the lateral runoff monitoring component are self-recording tipping bucket flow meters.

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