CN116908412A - Field soil evaporation limit depth measurement device and measurement method - Google Patents

Abstract

The invention provides a field soil evaporation limit depth measuring device and a measuring method, which relate to the fields of environmental science and hydrology experiments. The measuring device includes a moisture monitoring tube, a waterproof cap and a moisture monitoring component; the bottom of the moisture monitoring tube is closed and the top is provided with an opening and a side wall. There are multiple jacks, and anti-leakage plugs are inserted into the jacks; the waterproof cap is buckled on the top opening; the moisture monitoring component includes a data collector, a power supply device and multiple soil moisture sensors; the probes of each soil moisture sensor are one by one. Correspondingly, it is inserted into the cylinder through each anti-leakage plug; all soil moisture sensors are connected to the data collector, and the data collector is connected to the power supply device; the data collector sends the soil moisture information sensed by each soil moisture sensor to the monitoring platform. The invention has a simple structure and low cost, can be flexibly placed in the field, measures in situ and remotely monitors the evaporation process of soil moisture, and is used to better study the ultimate depth of soil evaporation in this area.

Description

Field soil evaporation limit depth measurement device and measurement method

Technical field

The invention relates to the fields of environmental science and hydrology experiments, and in particular to a field soil evaporation limit depth measuring device and a measuring method.

Background technique

In arid and semi-arid areas, bare soil evaporation accounts for about 50-70% of the average annual total evaporation. With the increase in human production activities, the production and use of regional water resources has increased. At the same time, mining and agricultural production and other activities will also have an impact on the production and use of regional water resources. Water resources in the region have caused certain damage. Therefore, studying the hydrodynamic process of soil evaporation is crucial to the protection of water resources balance and ecological environment in semi-arid areas.

Traditional methods for studying soil evaporation show that the dynamic process of soil evaporation is very complex and can be roughly divided into two stages. When the water in the vadose zone is sufficient or close to saturation, soil evaporation is mainly affected by atmospheric control and belongs to the atmospheric control stage; As evaporation continues, the soil surface gradually dries out. Under the joint influence of soil moisture content, hydraulic properties and temperature gradient, soil evaporation gradually transitions to a stage controlled by the hydraulic properties of porous media. The dynamic process of soil evaporation is affected by many factors, such as soil texture, soil retention capacity, atmospheric demand and groundwater table depth.

At this stage, there are an increasing number of methods for estimating soil evaporation rate, including both measurement estimation methods and modeling methods, which are mainly divided into experimental observation methods, field observation methods, analytical solution methods or fully coupled physical model methods based on the Richards equation. On-site observation methods are considered to be more accurate observation methods, which mainly include lysimeter system observation methods, Bowen ratio system evaporation observation methods (BC), eddy-related system evaporation observation methods (EC) and chamber method system observation methods. Among the observation methods, the Bowen ratio system evaporation observation method (BC) and the eddy-related system evaporation observation method (EC) are relatively expensive, are greatly affected by factors such as meteorology and instrument accuracy, and are expensive; the lysimeter system observation method is One of the most accurate instruments for measuring soil evaporation, because this method does not make any assumptions and has the advantages of in-situ measurement of soil moisture content, temperature and evaporation, and can be carried out under approximately real natural conditions. However, this method is expensive to build and maintain. , once built, it cannot be moved and has poor flexibility.

Contents of the invention

The purpose of the present invention is to provide a field soil evaporation limit depth measuring device and a measuring method, so as to alleviate the existing measurement methods that have inaccurate non-situ measurements, in-situ measuring instruments that are greatly affected by weather factors, and high construction and maintenance costs. high problem.

In order to achieve the above objects, the embodiments of the present invention adopt the following technical solutions:

In a first aspect, embodiments of the present invention provide a field soil evaporation limit depth measuring device, which includes a moisture monitoring tube, a waterproof cap and a moisture monitoring component.

The bottom of the moisture monitoring tube is closed and an opening is provided at the top. A plurality of jacks are provided at intervals along the length of the moisture monitoring tube on the side wall of the moisture monitoring tube. Each of the jacks is inserted with an anti-protection device inside. Water leakage plug; the waterproof cap is buckled on the opening at the top of the moisture monitoring tube; the moisture monitoring component includes a soil moisture sensor, a data collector and a power supply device; the soil moisture sensor has multiple, each of which is The probes of the soil moisture sensors pass through each of the anti-leakage plugs and are inserted into the interior of the moisture monitoring tube in one-to-one correspondence; all the soil moisture sensors are connected to the data collector, and the data collector is connected to the data collector. The power supply device is connected; the data collector can receive the soil moisture information sensed by each of the soil moisture sensors and send the soil moisture information to the monitoring platform.

In an optional implementation of this embodiment, preferably, the waterproof cap includes a bracket and a cap connected to the top of the bracket, and the cap is in a shape with a high middle and a low periphery.

Further preferably, the cap is made of light-transmitting material.

Preferably, the cross-sectional surface of the cap is in an imbricated shape in which a plurality of water-blocking tile structures are overlapped and arranged downwards from the center to the symmetrical two sides.

Further preferably, the cap includes a central conical tile structure and a plurality of frustum-shaped tile structures arranged in sequence from top to bottom. The top of the uppermost frustum-shaped tile structure is inserted into the bottom of the central cone-shaped tile structure, and the outer surface of the top of the uppermost frustum-shaped tile structure is attached to the center The inner side of the bottom of the conical tile structure; among the two adjacent truncated cone-shaped tile structures, the top of the conical cone-shaped tile structure located below is inserted into the bottom of the conical cone-shaped tile structure located above. inside, and the top outer surface of the frustum-shaped tile structure located below is in contact with the bottom inner surface of the frustum-shaped tile structure located above, and the top of the frustum-shaped tile structure located below The diameter is larger than the top diameter of the upper frustum-shaped tile structure, and the bottom diameter of the lower frustum-shaped tile structure is larger than the bottom diameter of the upper frustum-shaped tile structure.

In an optional implementation of this embodiment, preferably, the anti-leakage plug is made of gel material, and a pin channel is provided inside the anti-leakage plug. The pin channel is in a free state. In the closed state, when a probe is inserted, it is squeezed open to allow the probe to pass.

Further preferably, a lead opening connected to the pin channel is provided on the side of the anti-leakage plug facing the outside of the moisture monitoring tube.

In an optional implementation of this embodiment, preferably, the moisture monitoring tube is made of a steel pipe and a steel plate welded and sealed.

In an optional implementation of this embodiment, preferably, the power supply device of the moisture monitoring component includes a solar panel and a battery, and the solar panel, the data collector and the soil moisture sensor are connected to each other through wires respectively. Describe the battery connections.

In a second aspect, embodiments of the present invention provide a field soil evaporation limit depth measurement method, using the field soil evaporation limit depth measurement device described in any one of the preceding embodiments.

The field soil evaporation limit depth measurement method includes the following steps:

Drill a hole in the selected soil area in the field that can accommodate the entire moisture monitoring tube and has a depth deeper than the height of the moisture monitoring tube, and during the process of drilling downward, arrange the soil in the order in which it was taken out. good;

Put the moisture monitoring tube with the anti-leakage plug and the soil moisture sensor inserted into the drill hole vertically, so that the upper edge of the moisture monitoring tube is a certain distance away from the ground;

Backfill soil into the gap between the inner wall of the borehole and the outer wall of the moisture monitoring tube, and fill the soil that was arranged in the order of removal when drilling into the inside of the moisture monitoring tube in the original upper and lower order. All backfill soil inside and outside the moisture monitoring cylinder shall be backfilled to a height equal to the ground;

Inject water into the moisture monitoring tube until the soil in the moisture monitoring tube reaches a water saturated state, and then buckle the waterproof cap on the opening at the top of the moisture monitoring tube;

Connect all the soil moisture sensors to the data collector, connect the data collector to the power supply device, and detect through the monitoring platform that the soil moisture sensors arranged from top to bottom in the moisture monitoring tube sense The soil moisture content gradually decreases, and the installation depth corresponding to the soil moisture sensor when it no longer decreases is used as the maximum evaporation depth of soil moisture in the selected area.

The beneficial effects that the field soil evaporation limit depth measurement device and measurement method provided by this embodiment can achieve include:

(1) The device has a simple structure and low cost. Once installed, the device can achieve long-term, remote, intelligent and high-precision monitoring, saving a lot of manpower and material resources;

(2) It can be flexibly placed in the field, and the maximum evaporation depth of soil moisture for a specific soil structure in a certain area can be obtained in situ, which is effective and realistic;

(3) The device has high monitoring accuracy and can effectively isolate the confounding effect of atmospheric precipitation on soil moisture, and can be used to better study the ultimate depth of soil evaporation in this area.

Description of the drawings

In order to more clearly explain the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings that need to be used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description The drawings illustrate some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting any creative effort.

Figure 1 is a schematic diagram of the overall structure of a field soil evaporation limit depth measuring device provided by an embodiment of the present invention;

Figure 2 is an enlarged view of the partial structure of part A in Figure 1;

Figure 3 is a front view of the waterproof cap in the field soil evaporation limit depth measuring device provided by the embodiment of the present invention, with Figure 1 as the front perspective;

Figure 4 is a top view of the waterproof cap in the field soil evaporation limit depth measuring device provided by the embodiment of the present invention, with Figure 1 as the front view;

Figure 5 is a front view of the anti-leakage plug in the field soil evaporation limit depth measuring device provided by the embodiment of the present invention, taking Figure 1 as a front view;

Figure 6 is a side view of the anti-leakage plug in the outdoor soil evaporation limit depth measuring device provided by the embodiment of the present invention, with Figure 1 as a front view;

Figure 7 is a front view of the soil moisture sensor in the field soil evaporation limit depth measuring device provided by the embodiment of the present invention, with Figure 1 as the front perspective;

Figure 8 is a side view of the soil moisture sensor in the field soil evaporation limit depth measuring device provided by the embodiment of the present invention, taking Figure 1 as a front view.

Icon: 1-moisture monitoring tube; 2-waterproof cap; 21-bracket; 22-cap; 221-central conical tile structure; 222-truncated cone-shaped tile structure; 3-moisture monitoring component; 31-soil moisture sensor; 311-probe; 32-data collector; 33-power supply device; 4-leakage-proof plug; 41-pin channel; 42-lead opening.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Therefore, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters represent similar items in the drawings, therefore, once an item is defined in one drawing, it does not need further definition or explanation in subsequent drawings.

In the description of the present invention, it should be noted that the terms “upper”, “lower”, “vertical”, “horizontal”, “inner”, “outer”, etc. indicate the orientation or positional relationship based on those shown in the accompanying drawings. The orientation or positional relationship, or the orientation or positional relationship in which the invention product is customarily placed when used, is only for the convenience of describing the invention and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific orientation, Constructed and operated in specific orientations and therefore not to be construed as limitations of the invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions and shall not be understood as indicating or implying relative importance.

In addition, the terms "horizontal" and "vertical" do not mean that the component is required to be absolutely horizontal or overhanging, but may be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical". It does not mean that the structure must be completely horizontal, but can be slightly tilted.

In the description of the present invention, it should also be noted that, unless otherwise clearly stated and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. Detachable connection, or integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments and features in the embodiments may be combined with each other without conflict.

The first aspect of this embodiment provides a field soil evaporation limit depth measuring device. Referring to Figures 1 and 2, the field soil evaporation limit depth measuring device includes a moisture monitoring tube 1, a waterproof cap 2 and a moisture monitoring component 3.

Specifically, the bottom of the moisture monitoring tube 1 is closed and an opening is provided at the top. The side wall of the moisture monitoring tube 1 is provided with a plurality of jacks spaced along the length direction of the moisture monitoring tube 1, and an anti-leakage plug is inserted inside each jack. Head 4; the waterproof cap 2 is buckled on the opening at the top of the moisture monitoring tube 1; the moisture monitoring component 3 includes a soil moisture sensor 31, a data collector 32 and a power supply device 33; there are multiple soil moisture sensors 31, each soil moisture sensor 31 The probes 311 pass through each anti-leakage plug 4 and are inserted into the interior of the moisture monitoring tube 1 in one-to-one correspondence; all soil moisture sensors 31 are connected to the data collector 32, and the data collector 32 is connected to the power supply device 33; data collection The sensor 32 can receive the soil moisture information sensed by each soil moisture sensor 31 and send the soil moisture information to the monitoring platform.

In view of the field soil evaporation limit depth measuring device provided in the first aspect of this embodiment, the second aspect of this embodiment also provides a field soil evaporation limit depth measuring method. The field soil evaporation limit depth measuring method needs to apply any of the methods in the first embodiment. An optional embodiment provides a field soil evaporation limit depth measurement device.

Specifically, the field soil evaporation limit depth measurement method includes the following steps:

Drill a hole in the selected soil area in the field that can accommodate the entire moisture monitoring tube 1 and has a depth slightly deeper than the height of the moisture monitoring tube 1. During the process of drilling downward, arrange the soil in the order in which it was taken out. ;

Place the moisture monitoring tube 1 with the anti-leakage plug 4 and the soil moisture sensor 31 inserted into the hole vertically, so that the upper edge of the moisture monitoring tube 1 is 4cm-6cm away from the ground, preferably a small distance of 5cm;

Backfill the soil into the gap between the inner wall of the borehole and the outer wall of the moisture monitoring tube 1, and fill the soil arranged in the order taken out during drilling into the interior of the moisture monitoring tube 1 in the original upper and lower order. All backfill soil inside and outside the cylinder shall be backfilled to a height equal to the ground;

Inject water into the moisture monitoring tube 1 until the soil in the moisture monitoring tube 1 reaches a water saturated state. After that, fasten the waterproof cap 2 to the opening at the top of the moisture monitoring tube 1;

Connect all soil moisture sensors 31 to the data collector 32, connect the data collector 32 to the power supply device 33, and let it sit for a long time. During this period, the monitoring platform monitors each soil moisture sensor 31 arranged from top to bottom in the moisture monitoring cylinder 1. The soil moisture content sensed by these soil moisture sensors 31 can be monitored. The soil moisture content sensed by these soil moisture sensors 31 gradually decreases from top to bottom. The installation depth corresponding to the soil moisture sensor 31 when it no longer decreases is used as the soil in the selected area. Maximum evaporation depth of water. This depth represents the maximum evaporation depth of soil water in the soil structure of the monitoring point in the area under the local climate conditions. It is important for studying the loss of soil moisture in the area, the transformation of groundwater-soil water-atmospheric water, and specifying intensive and efficient irrigation schemes in the area. Guiding significance.

Among them, it is better to bury the data collector 32 shallowly in the soil layer at a depth of 10cm to ensure the stability of data collection; in addition, trial monitoring can also be carried out before actual monitoring, and the actual monitoring can be carried out after testing that all structural functions are normal. , and can also be monitored multiple times to obtain an average value to improve the accuracy of monitoring data.

The field soil evaporation limit depth measurement device and measurement method provided by this embodiment have at least the following advantages:

(1) The device has a simple structure and low cost. Once installed, the device can achieve long-term, remote, intelligent and high-precision monitoring, saving a lot of manpower and material resources;

(2) It can be flexibly placed in the field, and the maximum evaporation depth of soil moisture for a specific soil structure in a certain area can be obtained in situ, which is effective and realistic;

(3) The device has high monitoring accuracy and can effectively isolate the confounding effect of atmospheric precipitation on soil moisture, and can be used to better study the ultimate depth of soil evaporation in this area.

In an optional implementation of this embodiment, preferably, as shown in Figures 3 and 4, the waterproof cap 2 includes a bracket 21 and a cap 22 connected to the top of the bracket 21. The cap 22 is in a shape with a high middle and a low periphery. In order to quickly guide the rainwater, the rainwater flows away from the lower edge of the cap 22. In the buckled state, the lower edge of the cap 22 is lower than the upper edge of the top opening of the moisture monitoring tube 1. Therefore, it can ensure that the rainwater and Atmospheric condensation water will not enter the moisture monitoring tube 1 at the bottom of the waterproof cap 2.

In order to make the lighting conditions of the soil inside the tube as much as possible the same as outside the tube, it is further preferred that the cap 22 is made of light-transmitting organic glass or other light-transmitting materials, so that the waterproof cap 2 will not block the sunlight for the soil inside the moisture monitoring tube 1 of exposure.

Furthermore, in order to avoid that when the evaporation effect is strong, a large amount of water vapor evaporated in the moisture monitoring tube 1 accumulates in the waterproof cap 2 to form a high-humidity area and affects the evaporation of soil moisture. This embodiment ensures that the waterproof cap 2 has a rapid diversion effect. While preventing rainwater from pouring back into the tube, the waterproof cap 2 is designed to be ventilated. Specifically, continue to refer to Figures 3 and 4, so that in the waterproof cap 2, the cross-section of the cover 22 is in the form of multiple water-retaining tiles. The structures overlap and are arranged sequentially downward from the center to the symmetrical two sides to form an imbricated shape. More preferably, the cap 22 includes a central conical tile structure 221 and a plurality of frustum-shaped tiles arranged sequentially from top to bottom. Slice structure 222. The top of the uppermost frustum-shaped tile structure 222 is inserted into the bottom of the central cone-shaped tile structure 221 , and the top outer surface of the uppermost frustum-shaped tile structure 222 is attached to the central cone-shaped tile structure 221 The inner side of the bottom of the two adjacent frustum-shaped tile structures 222, the top of the lower frustum-shaped tile structure 222 is inserted into the bottom of the upper frustum-shaped tile structure 222, and the lower cone-shaped tile structure 222 is inserted into the bottom of the upper frustum-shaped tile structure 222. The outer surface of the top of the frustum-shaped tile structure 222 is in contact with the inner surface of the bottom of the frustum-shaped tile structure 222 located above, and the top diameter of the frustum-shaped tile structure 222 located below is larger than the diameter of the top of the frustum-shaped tile structure 222 located above. The top diameter of the structure 222 and the bottom diameter of the lower frustum-shaped tile structure 222 are larger than the bottom diameter of the upper frustum-shaped tile structure 222 .

In an optional implementation of this embodiment, preferably, as shown in Figures 5 to 8, the anti-leakage plug 4 is made of rubber, silicone or other gel material, and an insert is provided inside the anti-leakage plug 4. The pin channel 41 is in a closed state in a free state, and is squeezed open when the probe 311 is inserted to allow the probe 311 to pass through, so as to ensure that the anti-leakage plug 4 allows the detection of the soil moisture sensor 31 When the needle 311 enters, at the same time, the water and soil in the cylinder will not flow out due to the entry of the probe 311.

Further preferably, a lead opening 42 connected with the pin channel 41 is provided on the side of the anti-leakage plug 4 facing the outside of the moisture monitoring tube 1 to guide the insertion of the probe 311 .

In an optional implementation of this embodiment, preferably, the moisture monitoring tube 1 is made of a steel pipe and a steel plate welded and sealed, which is easy to manufacture, but good welding sealing performance must be ensured to prevent water leakage.

In an optional implementation of this embodiment, preferably, the power supply device 33 of the moisture monitoring component 3 includes a solar panel and a battery. The solar panel, data collector 32 and soil moisture sensor 31 are respectively connected to the battery through wires. In the solar energy A support rod can be set between the plate and the battery, and the electric wires are arranged in the inner cavity of the support rod or around the support rod, preferably in the inner cavity of the support rod to protect the electric wires. The solar panel provides electric energy for the soil moisture sensor 31 and the data collector 32, and the battery can be directly integrated on the data collector 32 to keep the soil moisture sensor 31 and the data collector 32 working normally at night and on rainy days.

Finally, it should be noted that each embodiment in this specification is described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. That’s it; the above embodiments in this specification are only used to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions recorded in the foregoing embodiments, or to equivalently replace some or all of the technical features; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention. range.

Claims (10)

1. A field soil evaporation limit depth measuring device which is characterized in that: comprises a moisture monitoring cylinder (1), a waterproof cap (2) and a moisture monitoring component (3);

the water monitoring device is characterized in that an opening is formed in the closed top of the bottom of the water monitoring cylinder (1), a plurality of jacks are formed in the side wall of the water monitoring cylinder (1) at intervals along the length direction of the water monitoring cylinder (1), and water leakage prevention plugs (4) are inserted into the jacks;

the waterproof cap (2) is buckled on an opening at the top of the water monitoring cylinder (1);

the moisture monitoring assembly (3) comprises a soil moisture sensor (31), a data collector (32) and a power supply device (33); the soil moisture sensors (31) are provided with a plurality of probes (311) of the soil moisture sensors (31) are inserted into the moisture monitoring cylinder (1) through the water leakage prevention plugs (4) in a one-to-one correspondence manner; all the soil moisture sensors (31) are connected with the data acquisition device (32), and the data acquisition device (32) is connected with the power supply device (33);

the data collector (32) can receive the soil moisture information sensed by each soil moisture sensor (31) and send the soil moisture information to the monitoring platform.

2. The field soil evaporation limiting depth measurement apparatus according to claim 1, wherein: the waterproof cap (2) comprises a bracket (21) and a cap (22) connected to the top of the bracket (21), wherein the cap (22) is in a shape with a high middle and a low periphery.

3. The field soil evaporation limiting depth measurement apparatus according to claim 2, wherein: the cap (22) is made of a light-transmitting material.

4. The field soil evaporation limiting depth measurement apparatus according to claim 2, wherein: the section of the cap (22) is in a folded tile shape formed by overlapping and downward arranging a plurality of water retaining tile structures from the center to the symmetrical two side directions in sequence.

5. A field soil evaporation limiting depth measurement apparatus according to claim 3, wherein: the cap (22) comprises a central conical tile structure (221) and a plurality of truncated cone tile structures (222) which are sequentially arranged from top to bottom;

the top of the uppermost cone-shaped tile structure (222) is inserted into the bottom of the central cone tile structure (221), and the top outer side surface of the uppermost cone-shaped tile structure (222) is attached to the bottom inner side surface of the central cone tile structure (221);

in the adjacent two truncated cone-shaped tile structures (222), the top of the truncated cone-shaped tile structure (222) positioned below is inserted into the bottom of the truncated cone-shaped tile structure (222) positioned above, and the outer side surface of the top of the truncated cone-shaped tile structure (222) positioned below is attached to the inner side surface of the bottom of the truncated cone-shaped tile structure (222) positioned above, the top diameter of the truncated cone-shaped tile structure (222) positioned below is larger than the top diameter of the truncated cone-shaped tile structure (222) positioned above, and the bottom diameter of the truncated cone-shaped tile structure (222) positioned below is larger than the bottom diameter of the truncated cone-shaped tile structure (222) positioned above.

6. The field soil evaporation limiting depth measurement apparatus according to claim 1, wherein: the anti-leakage plugging head (4) is made of a colloid material, a contact pin channel (41) is arranged in the anti-leakage plugging head (4), the contact pin channel (41) is in a closed state in a free state, and the contact pin channel is extruded and opened in a state that a probe (311) is inserted so that the probe (311) passes through.

7. The field soil evaporation limiting depth measurement apparatus according to claim 6, wherein: and a connecting opening (42) communicated with the contact pin channel (41) is arranged on one side of the water-proof plug (4) facing the outside of the water monitoring cylinder (1).

8. The field soil evaporation limiting depth measurement apparatus according to claim 1, wherein: the water content monitoring cylinder (1) is formed by welding and sealing a steel pipe and a steel plate.

9. The field soil evaporation limiting depth measurement apparatus according to claim 1, wherein: the power supply device (33) of the moisture monitoring assembly (3) comprises a solar panel and a storage battery, and the solar panel, the data collector (32) and the soil moisture sensor (31) are connected with the storage battery through electric wires respectively.

10. A field soil evaporation limit depth measuring method is characterized in that: use of the field soil evaporation limiting depth measurement apparatus according to any one of claims 1 to 9, the field soil evaporation limiting depth measurement method comprising the steps of:

drilling down a borehole in a selected soil area in the field, the borehole being capable of accommodating the entire moisture monitoring cylinder (1) and having a depth deeper than the height of the moisture monitoring cylinder (1), and arranging the soil in order of removal during the down borehole;

the water monitoring cylinder (1) inserted with the water leakage prevention plug (4) and the soil moisture sensor (31) is vertically placed in the drill hole, so that the upper edge of the water monitoring cylinder (1) is at a distance from the ground;

backfilling soil in a gap between the inner wall of the drill hole and the outer barrel wall of the water monitoring barrel (1), and filling the soil which is well discharged in the order of taking out during the drill hole into the water monitoring barrel (1) according to the original upper and lower layer order, wherein all backfilled soil in the water monitoring barrel (1) and outside the barrel is backfilled to be level with the ground;

injecting water into the water monitoring cylinder (1) until the soil in the water monitoring cylinder (1) reaches a water saturation state, and then buckling the waterproof cap (2) on an opening at the top of the water monitoring cylinder (1);

all soil moisture sensors (31) are connected with a data acquisition device (32), the data acquisition device (32) is connected with a power supply device (33), the fact that the soil moisture content sensed by the soil moisture sensors (31) arranged from top to bottom in the moisture monitoring cylinder (1) is gradually reduced through monitoring platforms is monitored, and the installation depth corresponding to the soil moisture sensors (31) when the soil moisture content is not reduced is used as the maximum evaporation depth of the soil moisture in a selected area.