Sediment-water interface methane bubbling flux automatic observation device

Abstract

The utility model relates to a sediment-water interface methane bubbling flux automatic observation device. The sediment-water interface methane bubbling flux automatic observation device comprises a bottom frame, a door-shaped frame, a gas collecting hopper and a blocking piece, the door-shaped frame is vertically arranged on the bottom frame which is horizontally arranged, and the bucket-shaped gas collecting bucket formed by closing two right triangle side plates and rectangular plates is hinged to the lower portion of a cross beam of the door-shaped frame through a rectangular plate intersection line; the length ratio of two right-angle plates of a right triangle is 1: (2-2.5), the downward opening plane of the gas collecting hopper is parallel to the bottom frame by overlapping one side of a short right-angle side through a blocking piece, and when one side of a long right-angle side is overturned upwards, a magnetic sheet on the side enters an induction area of the magnetic induction counter and counts overturning events and records the occurrence time; compared with the prior art, the device has the advantages that continuous data of turnover event counting and occurrence time are obtained by means of multiple times of turnover and resetting of the turnover gas collecting hopper with a downward opening and a closed upper part, and the methane bubbling flux of the sediment-water interface is continuously and accurately observed according to the critical volume for inducing the turnover of the gas collecting hopper.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of methane automatic observation, especially to a sediment-water interface methane bubble flux automatic observation device. BACKGROUND

[0002] Methane, as the second largest greenhouse gas, contributes 20% to the global greenhouse effect, of which the methane emission of inland water bodies (lakes, reservoirs and other water bodies) accounts for 40-50% of the total global methane emission; Bubble is considered to be one of the main ways of methane release in inland water bodies. For example, the methane bubble emission of lakes is 8-48Tg / yr, accounting for 6-16% of the total global release; When a large amount of methane is produced in the sediment, most of it is released into the atmosphere through bubbles, except for a small part in the form of molecular diffusion; The methane released in the form of molecular diffusion is easily oxidized and consumed during diffusion in the overlying water body, and has less impact on the environment; The solubility of methane bubbles in water is extremely low, and when the water temperature is 20℃, the solubility is only 3nmol L -3 ; Therefore, when methane is released in the form of bubbles, it can be quickly transported to the atmosphere; Therefore, the monitoring of underwater methane bubble flux is of great significance.

[0003] In the prior art, the traditional water body methane bubble flux is usually determined by the inverted funnel method, which is to invert the funnel under the water surface, collect the methane bubbles released from the sediment through the bucket part, and introduce them into the gas storage bag through the pipe part; The methane bubble volume collected is measured periodically, and the methane bubble flux is calculated according to the setting time; It is found in application that due to the capacity limitation of the gas storage bag, it needs to be replaced regularly, in order to accurately determine the cut-off time of collecting methane bubbles, the gas storage bag can only be recovered before it is full; Due to the timing of recovering the gas storage bag, combined with the time-consuming operation process, not only the obtained data cannot be continuous in time, but also the single collection amount or interval time cannot be consistent; In application, a larger capacity gas storage bag can be selected, such as a gas storage bag that can accommodate more than a week of emission, although it can reduce the number of gas storage bag replacements and prolong the single monitoring time, but due to the high randomness of the methane bubble amount in the water body (i.e. the methane bubble amount may change at any time), the change of the methane bubble amount during the long-time collection process cannot be distinguished; If a small-capacity gas storage bag is used, although the methane bubble data in a short time can be obtained, which is beneficial to distinguish the change process of the methane bubble amount during the collection process, but based on the timing requirements of recovering the gas storage bag and the time-consuming replacement process, it is still impossible to obtain continuous data in time, and a person needs to be on duty at all times during the monitoring process, which seriously limits its application; Therefore, it can be seen that the inverted funnel method in the prior art cannot obtain continuous data of the methane bubble amount in the water body no matter how it is applied, and it cannot reliably distinguish the change process of the bubble amount during the collection process; Therefore, there is an urgent need for a new type of automatic observation device for sediment-water interface methane bubble flux to solve the above problems. UTILITY MODEL CONTENT

[0004] In order to overcome the defects of the prior art, the utility model discloses a sediment-water interface methane bubble flux automatic observation device to overcome the problem of inverted funnel method.

[0005] The utility model discloses a sediment-water interface methane bubble flux automatic observation device including bottom frame, door type frame, gas collecting hopper, blocking piece, the both sides door column of door type frame is vertically arranged on the horizontally arranged bottom frame frame, and the bottom surface of surrounding frame extends outward and sets up the anti -trapping flat plate, the gas collecting hopper includes two parallelly arranged, same shape and setting direction, right triangle's side board, and the rectangular area is formed respectively based on interval and two right angle edges between two side boards, and the rectangular area is closed by the rectangular plate A, rectangular plate B of corresponding size respectively and closes into intersection line C at right angle point, thereby forming the hopper structure, and the length ratio of the right angle edge corresponding with rectangular plate A, rectangular plate B is 1:2 ~ 2.5, and the intersection line C is parallel with the axis of door type frame crossbeam, and the gas collecting hopper is hinged below crossbeam through intersection line C, and the gas collecting hopper opening is downward corresponding bottom frame hollow area, and the rectangular plate B on the back side of gas collecting hopper is provided with magnetic sheet, the vertical section of blocking piece is set up on the bottom frame frame of rectangular plate A side, and the end of its horizontal extension section can overlap rectangular plate A from the back side of gas collecting hopper, so that the downward opening plane of gas collecting hopper is parallel with bottom frame, the magnetic induction counter is horizontally extended and is set up to the rectangular plate B side perpendicularly to the crossbeam of door type frame, and the data storage component is electrically connected above the magnetic induction counter, the data storage component includes data storage device, data reading interface and power supply that maintains data storage and magnetic induction work, when the rectangular plate B side of gas collecting hopper is turned up, the magnetic sheet enters the induction area of magnetic induction counter and can complete the turnover event count and turnover event occurrence time record, and the lowest point of rectangular plate A side of gas collecting hopper is close to the bottom surface of bottom frame and is accurate to not influence turnover, when applying, the bottom surface of bottom frame is placed on the underwater ground, and the gas collecting hopper is located underwater, and the critical gas volume of inducing the rectangular plate B side of gas collecting hopper to turn up is 10ml ~ 100ml.

[0006] Compared with the prior art, the utility model has the following beneficial effects:

[0007] (1) the inverted funnel of prior art is replaced by the open downward, upward closed turnover gas collecting hopper, and the critical gas volume of inducing the gas collecting hopper to turn up is used as the single collection methane bubble volume by the help of the gravity center of gas collecting hopper offset when hanging and cooperating with blocking piece and magnetic induction counter, then the magnetic sheet enters the induction area of magnetic induction counter when the gas collecting hopper turns up, so as to complete the turnover event count and turnover event occurrence time record, and the time sequence data of methane bubble collection is obtained through the multiple turnover and reset of gas collecting hopper, so as to calculate the sediment-water interface methane bubble flux, especially suitable for the continuous automatic observation of shallow water body without water grass or other impurities on the ground,

[0008] (2) By the gas collecting head size control to form the critical gas volume of induced gas collecting head upward turning is different gas collecting head, such as the critical gas volume is 10 mL~100 mL;Based on the critical gas volume and the relationship between the methane bubble floating speed, quantity can control the interval time of the turning event, not only can keep the same single collection volume when continuous observation, but also according to the time difference of forming the turning event to distinguish the change of methane bubble quantity in the collection process, the smaller the critical gas volume, the more accurate the change of methane bubble quantity in the collection process can be distinguished;

[0009] (3) Relative to the time to reach the critical gas volume of gas collecting head upward turning, the gas collecting head turning and resetting time can be ignored, which usually does not affect the calculation result of sediment-water interface methane bubble flux;Even if the turning and resetting time is considered, since the time is fixed, the calculation result can be corrected by mathematical algorithm during calculation, so that the calculation result is more accurate;

[0010] (4) By designing the counterweight structure of the bottom frame or setting the drill rod, the bottom frame can be stably arranged underwater, and the lifting ring is convenient for underwater arrangement and recovery of the utility model;

[0011] (5) By the cooperation of the sliding sleeve arranged on the bottom frame and the positioning slide rod which can be inserted into the underwater ground, not only is the underwater arrangement of the utility model convenient, but also the positioning slide rod can be left in the original position to observe the change of methane bubble quantity in different time periods;At the same time, by the cooperation of the sliding sleeve and the positioning slide rod or the anti-sinking flat plate, no matter how the inclination of the underwater ground is, the bottom frame can be maintained in a horizontal state, the gas collecting head opening is vertically downward to collect methane bubbles, and the utility model is convenient to be arranged above the water grass or other impurities.

[0012] At the same time, the utility model also has the characteristics of simple structure and convenient application. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a lateral structure schematic view of the utility model, and an anti-sinking flat plate and a lifting ring are arranged;

[0014] Figure 2 It is a three-dimensional structure schematic view of the gas collecting head in the utility model, and the opening is downward;

[0015] Figure 3 It is Figure 1 It is a lateral structure schematic view of the further setting drill rod;

[0016] Figure 4 It is Figure 3 It is a lateral structure schematic view of the further setting sliding sleeve, and the sliding sleeve cooperates with the positioning slide rod;

[0017] Figure 5 It is Figure 4The side structure schematic diagram of setting data storage assembly through floating body does not set drill rod;

[0018] In the figure: 1-bottom frame, 2-door frame, 3-data storage assembly, 4-magnetic induction counter, 5-gas collector, 6-magnetic sheet, 7-block, 8-lifting ring, 9-drill rod, 10-sliding sleeve, 11-positioning sliding rod, 12-rectangular plate A, 13-rectangular plate B, 14-side plate, 15-meeting line C, 16-anti-trapping flat plate, 17-floating body. DETAILED DESCRIPTION

[0019] The utility model makes further explanation in combination with the drawings, but does not in any way add the utility model, based on the utility model teaching makes any change or replacement, all belong to the protection scope of the utility model.

[0020] As Figure 1 The sediment-water interface methane bubble flux automatic observation device includes bottom frame 1, door frame 2, gas collector 5, block 7 as shown in the figure, the two side door columns of door frame 2 are vertically arranged on the horizontal arrangement bottom frame 1 frame, and the bottom surface of the frame is outwardly extended to be provided with anti-trapping flat plate 16, the gas collector 5 includes two parallelly arranged, same shape and setting direction, right-angled triangle side plates 14, the rectangular area is formed between the two side plates 14 based on the interval and two right-angled edges respectively, the rectangular area is closed by the rectangular plate A 12 and rectangular plate B 13 of corresponding size respectively and is closed into meeting line C 15 at right-angled point, to form the structure of the bucket, the length ratio of the right-angled edge corresponding to the rectangular plate A 12 and rectangular plate B 13 is 1:2~2.5, the meeting line C 15 is parallel with the axis of the crossbeam of door frame 2, the gas collector 5 is hinged below the crossbeam by the meeting line C 15, the opening of the gas collector 5 is downward corresponding to the hollow area of bottom frame 1, the magnetic sheet 6 is arranged on the rectangular plate B 13 of the back side of the gas collector 5, the vertical section of block 7 is arranged on the frame of bottom frame 1 on one side of rectangular plate A 12, and the end of the transverse extension section can be overlapped with rectangular plate A 12 from the back side of gas collector 5, so that the downward opening plane of gas collector 5 is parallel to bottom frame 1, the magnetic induction counter 4 is vertically arranged to the crossbeam of door frame 2 and is horizontally extended to one side of rectangular plate B 13, and the data storage assembly 3 is electrically connected above the magnetic induction counter 4, the data storage assembly 3 includes data storage device, data reading interface and power supply for maintaining data storage and magnetic induction work, when one side of the rectangular plate B 13 of the gas collector 5 is upwardly overturned, the magnetic sheet 6 enters the induction area of the magnetic induction counter 4 and can complete the overturning event counting and overturning event time recording, the lowest point of one side of the rectangular plate A 12 of the gas collector 5 is close to the bottom surface of bottom frame 1 and is not affected by overturning, in application, the bottom surface of bottom frame 1 is placed on the underwater ground, the gas collector 5 is located underwater, and the critical gas volume of inducing one side of the rectangular plate B 13 of the gas collector 5 to be upwardly overturned is 10ml~100ml.

[0021] The working principle of the methane bubble flux automatic observation device of the sediment-water interface is as follows:

[0022] In combination Figure 1 It is understood that, compared with the inverted funnel in the prior art, the utility model adopts the upper closed gas collecting funnel 5 as the core structure for collecting methane bubbles, the bottom frame 1 is arranged underwater as the foundation, the door-shaped frame 2 is used for suspending the gas collecting funnel 5 and making the opening downward correspond to the hollow area of the bottom frame 1, and the methane bubbles from the sediment-water interface are collected into the gas collecting funnel 5; since the side plate 14 of the gas collecting funnel 5 is a right triangle with a length ratio of 1:2~2.5, the gravity center of the gas collecting funnel 5 is offset to one side of the rectangular plate B13 by being hinged to the gas collecting funnel 5 below the crossbeam of the door-shaped frame 2 through the intersection line C15, if one side of the rectangular plate A12 is not limited, one side of the rectangular plate B13 of the gas collecting funnel 5 is inclined downward; since the blocking piece 7 is arranged, the end of the horizontal extension section of the blocking piece 7 overlaps the rectangular plate A12 from the back side of the gas collecting funnel 5, so that the opening plane of the gas collecting funnel 5 is parallel to the bottom frame 1 and is in the best gas collecting state.

[0023] In application, the gas collecting funnel 5 of the utility model is below the water surface, the lower surface of the bottom frame 1 falls on the underwater ground, the data storage assembly 3 and the magnetic induction counter 4 are in the working state before entering the water (the data storage assembly 3 and the magnetic induction counter 4 are waterproofed), when the methane bubbles are not collected initially, the blocking piece 7 makes the plane of the downward opening of the gas collecting funnel 5 parallel to the bottom frame 1 and correspond to the hollow area of the bottom frame 1; the methane bubbles from the sediment-water interface and gradually collect into the gas collecting funnel 5, when the volume of the collected methane bubbles reaches the critical gas volume for turning over of the gas collecting funnel 5, one side of the rectangular plate B13 of the gas collecting funnel 5 turns over upward and makes the magnetic sheet 6 enter the induction area of the magnetic induction counter 4, the magnetic induction counter 4 completes one counting for the turning over event and records the time of the turning over event, and stores in the data storage assembly 3; the methane bubbles are discharged in the turning over process, after turning over to the highest point, the gas collecting funnel 5 makes one side of the rectangular plate B13 descend by the weight, and returns to the initial collecting state through the blocking piece 7, and re-collects the methane bubbles until the next turning over; through the repeated turning over and resetting of the gas collecting funnel 5, the counting of the methane bubble volume collected in a single time and the time sequence record of the occurrence time can be obtained; since the critical gas volume for turning over of the gas collecting funnel 5 can be known through calibration before application and the value is fixed, the methane bubble flux of the sediment-water interface can be calculated in combination with the counting and time record.

[0024] According to common knowledge, the water body capable of generating methane is usually below 10m, most of which is below 5m (generally, the water body with a depth of 10m or less is referred to as a shallow water body), and the underwater ground is usually soft, mostly in a silt state; in order to make the downward opening of the gas collector 5 closer to the underwater ground, and the plane of the bottom frame 1 perpendicular to the vertical upward path of the methane bubbles, the utility model sets the lowest point of the one side of the rectangular plate A12 of the gas collector 5 to be close to the bottom surface of the bottom frame 1 and not to affect the overturning, and the irregular sinking of the bottom frame 1 can be prevented by setting the anti-trapping flat plate 16, which not only can avoid the bottom frame 1 from being unable to be placed due to sinking, but also can prevent the silt from entering the bottom frame 1 to affect the overturning of the gas collector 5, and the utility model can be arranged on the ground without water grass or impurities, so that the continuous automatic observation of the methane bubble flux of the shallow water body can be realized; at the same time:

[0025] Firstly, due to the unstable state of the water body during the first overturning event counting after the arrangement of the utility model, the data during the first counting may not be reliable; therefore, the first overturning event can not be considered during the calculation, and only the occurrence time of the counting is taken as the initial recording time, and the subsequent counting and time recording can be combined to more accurately calculate the methane bubble flux of the sediment-water interface.

[0026] Secondly, the critical gas volume inducing the overturning of the gas collector 5 is taken as the single collection amount of the methane bubbles, and different gas collectors 5 with the critical gas volume in the range of 10mL-100mL are obtained by controlling the size of the gas collector 5; in theory, when the discharge speed and discharge amount of the methane bubbles are constant, the smaller the critical gas volume, the shorter the interval time of the overturning; that is, when the critical gas volume is the same, if the discharge speed and discharge amount of the methane bubbles change, the interval time of the overturning event changes; based on this, the interval time of the overturning event can be controlled by selecting the gas collector 5 with a suitable critical gas volume, which not only can keep the volume of the single collected gas the same during the continuous observation, but also can distinguish the change of the methane bubble amount in the collection process according to the interval time difference of the overturning event, and the smaller the critical gas volume, the more accurate the change of the methane bubble amount in the collection process can be distinguished.

[0027] Thirdly, the time of the continuous observation arranged underwater depends on the self-working time length of the data storage assembly 3, and it is found during application that the power consumption of the data storage assembly 3 mainly occurs during the magnetic induction counting, and the power consumption is very small, so that the appropriate power supply can make the utility model continuously and automatically observe for a long time, and even can be applied for 1 year.

[0028] Fourth, although the gas collector 5 overturning, resetting process will affect the data in time on the continuity, but the turnover, reset time is short, 1~2s can be completed, and limited to the amount of methane production, the time to collect and reach the gas collector 5 overturning critical gas volume will be very long (often need dozens of minutes or even hours), so the turnover, reset time can be ignored, generally will not affect the accuracy of the methane bubble flux; even considering the turnover, reset time, due to the gas collector 5 itself weight, the position of the center of gravity and induced gas collector 5 overturning critical gas volume is fixed, the time of each turnover, reset is the same, in the calculation can be corrected by mathematical algorithm on the calculation results, so as to obtain more accurate sediment-water interface methane bubble flux.

[0029] Preferably, the edge frame of the bottom frame 1 is surrounded by a rectangle, a circle or an ellipse, which is mainly to form a stable support structure; of course, other edge frame shapes of the bottom frame 1 which are convenient for the door-shaped frame 2 and the blocking piece 7 to be arranged and can meet the working principle described above can also be applied.

[0030] Preferably, the edge frame of the bottom frame 1 is a hollow pipe with a through hole, and the through hole is provided with a closing plug; this arrangement can provide a counterweight for the bottom of the utility model, and before entering the water, the high-density flowing medium such as fine sand, lead pellets, etc. can be injected from the through hole, and the stability of the water arrangement can be improved after being closed by the closing plug; the flowing medium can be discharged during recovery, which is convenient for storage and transportation.

[0031] Preferably, as shown in Figure 1 , 3 , 4, 5, a plurality of lifting rings 8 are arranged above the edge frame of the bottom frame 1, and a plurality of lifting rings 8 are arranged above the crossbeam of the door-shaped frame 2; the lifting ring 8 is convenient for underwater arrangement and recovery of the utility model, and is especially suitable for relatively deep water.

[0032] Preferably, as shown in Figure 3 , 4 , one or more downward vertical drill rods 9 are fixedly arranged below the edge frame of the bottom frame 1; this arrangement is a kind of underwater stability preferred structure, for relatively stable water flow or shallow water area, such as Figure 1 The structure shown can be stabilized underwater by the weight of the structure itself or the hollow tubular structure of the edge frame of the bottom frame 1; if the water flow fluctuates greatly or there is an underwater current, the drill rod 9 can be inserted into the ground during underwater arrangement by means of its own weight, so as to ensure the stability of the arrangement.

[0033] Preferably, as shown in Figure 4 , 5As shown, the side of the bottom frame 1 frame is provided with two or more than two sliding sleeve 10, sliding sleeve 10 and the corresponding number of insertable underwater ground positioning slide rod 11 sliding fit, the anti-sink plate 16 is provided with a through hole corresponding to the positioning slide rod 11; preferably three or more than three sliding sleeve 10 and the corresponding number of positioning slide rod 11; the setting is another kind of underwater stability preferred structure, when used, the positioning slide rod 11 can be sleeved in the sliding sleeve 10, and then the positioning slide rod 11 is inserted into the underwater ground, and the bottom frame 1 is slid along the positioning slide rod 11 into the underwater and can be completed; or according to the position and number of sliding sleeve 10, the positioning slide rod 11 is inserted into the underwater ground, and then the sliding sleeve 10 is sleeved on the positioning slide rod 11 and slid into the underwater; the setting is suitable for various water flow state of deep water or shallow water, as long as the positioning slide rod 11 is inserted into the underwater bottom surface and is stable enough, the stability can be guaranteed; when the monitoring task is completed, the positioning slide rod 11 can be recycled, or the positioning slide rod 11 can be left in place, and the next observation can be arranged in situ, and the change of methane emission at different time stages can be found; if the data is obtained in the middle stage of the monitoring plan time, the position of the positioning slide rod 11 is kept unchanged when recycling, and the data is obtained and arranged in situ again, which can affect the underwater environment state to a smaller extent; especially, since the methane bubbles vertically float upward, the horizontal arrangement of the bottom frame 1 is beneficial to the collection of the gas collector 5; in actual application, the underwater ground may be inclined, if the bottom frame 1 (or cooperated with the drill rod 9) is directly arranged, the bottom frame 1 can only be inclined with the ground; when the bottom frame 1 is arranged by means of the sliding sleeve 10 along the positioning slide rod 11, due to the limiting relationship of the sliding sleeve 10 and the positioning slide rod 11 and / or the anti-sink plate 16, no matter how the ground is inclined, the bottom frame 1 can maintain the horizontal state, so that the opening of the gas collector 5 can collect the methane bubbles vertically downward; moreover, if there are waterweeds or other impurities on the ground, according to the height of the waterweeds or other impurities, the limiting piece of the positioning slide rod 11 is provided with the sliding sleeve 10, so that the utility model can be arranged above the waterweeds or other impurities, and the original state of the ground in the methane generating area can be maintained, and the observation result will not be affected.

[0034] Preferably, as shown in the figure, Figure 5 The data storage assembly 3 is arranged on the floating body 17 floating on the water surface, and the floating body 17 is connected with the bottom frame 1 or the door-shaped frame 2 through a cable, and the data storage assembly 3 is electrically connected with the underwater magnetic induction counter 4; as shown in the structure of the figure, Figure 1 、 3 , 4, the data obtained by the structure needs to recycle the utility model, and the observation time is very long under normal circumstances, and the operation of recycling and obtaining data is not complicated, however, recycling and rearrangement will affect the time continuity and the observation area needs a certain time to recover; the data storage assembly 3 is arranged above the water surface by using the floating body 17, not only the data can be obtained at any time through the data reading interface, but also the working state of the underwater device will not be changed during the data obtaining period, which is more conducive to the stability of continuous data.

[0035] Preferably, the bottom frame 1, the door-shaped frame 2 and the blocking piece 7 are integrated components or combined components.

[0036] Preferably, the gas collector 5 is a stainless steel gas collector.

[0037] Compared with the prior art, the utility model is characterized in that the upper closed gas collector 5 that can be turned over and reset is matched with the magnetic induction counter 4, the critical gas volume that induces the turning over of the gas collector 5 is ingeniously utilized as the single collection methane bubble volume, the continuous observation of the methane bubble flux is realized through the counting of the turning over events and the time of the turning over event; the critical gas volume that induces the turning over of the gas collector 5 can be selected, so that the methane collection data can be acquired with smaller turning over event interval time, and the change of the methane bubble volume can be more conveniently distinguished from the change of the turning over event interval time; with the limiting relationship of the sliding sleeve 10, the positioning sliding rod 11 and / or the anti-trapping flat plate 16, no matter how the ground inclination is, the bottom frame 1 can be maintained in a horizontal state, so that the gas collector 5 can always be open downward to collect the methane bubble; if the floating body 17 is used to set the data storage assembly 3 above the water surface, not only can the data be acquired at any time through the data reading interface, but also the working state of the underwater device will not be changed during the data acquisition, so that the continuous data stability is more favorable.

Claims

1. An automatic observation device for methane bubbling flux at the sediment-water interface, characterized in that, The system includes a base frame (1), a portal frame (2), an air collection hopper (5), and a blocking component (7). The portal frame (2) has two vertically positioned pillars on the horizontally arranged frame of the base frame (1), with an anti-sinking plate (16) extending outwards around the bottom surface of the frame. The air collection hopper (5) includes two parallel, right-angled triangular side plates (14) of the same shape and orientation. The two side plates (14) form rectangular areas based on their spacing and the two right-angled sides. These rectangular areas are formed by rectangular plates A (12) and B (14) of corresponding dimensions. 3) Close the intersection line C (15) at the right angle point to form a bucket-shaped structure; the length ratio of the right angle side corresponding to the rectangular plate A (12) and the rectangular plate B (13) is 1:2~2.

5. The intersection line C (15) is parallel to the axis of the crossbeam of the portal frame (2). The air collecting bucket (5) is hinged to the bottom of the crossbeam through the intersection line C (15) so that the opening of the air collecting bucket (5) faces downward to the hollow area of ​​the bottom frame (1). A magnetic sheet (6) is set on the rectangular plate B (13) on the back side of the air collecting bucket (5); the vertical section of the blocking member (7) is set on the rectangular plate B (13). On the side of the bottom frame (1) of plate A (12), the end of its horizontal extension section can overlap the rectangular plate A (12) from the back of the gas collecting hopper (5), so that the downward opening plane of the gas collecting hopper (5) is parallel to the bottom frame (1); a magnetic induction counter (4) is set on the beam perpendicular to the portal frame (2) and extending horizontally towards the side of the rectangular plate B (13), and a data storage component (3) is electrically connected above the magnetic induction counter (4); the data storage component (3) includes a data storage device, a data reading interface, and a power supply to maintain data storage and magnetic induction operation. When the rectangular plate B (13) of the gas collecting bucket (5) flips upward, the magnetic sheet (6) enters the sensing area of ​​the magnetic induction counter (4) and can complete the counting of the flipping event and the recording of the flipping event occurrence time. The lowest point of the rectangular plate A (12) of the gas collecting bucket (5) flips downward is close to the bottom surface of the bottom frame (1) and is based on not affecting the flipping. When in use, the bottom surface of the bottom frame (1) is placed on the underwater ground and the gas collecting bucket (5) is located underwater. The critical gas volume that induces the rectangular plate B (13) of the gas collecting bucket (5) to flip upward is 10mL~100mL.

2. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1, characterized in that, The border of the bottom frame (1) is enclosed in a rectangle, circle or ellipse.

3. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1 or 2, characterized in that, The bottom frame (1) has a hollow tube with through holes, and the through holes are fitted with sealing plugs.

4. The automatic observation device for methane bubbling flux at the sediment-water interface according to claim 1 or 2, characterized in that, Multiple hanging rings (8) are evenly arranged above the frame of the bottom frame (1).

5. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1, characterized in that, Multiple lifting rings (8) are evenly arranged above the crossbeam of the portal frame (2).

6. The automatic observation device for methane bubbling flux at the sediment-water interface according to claim 1 or 2, characterized in that, One or more vertically downward-pointing rods (9) are fixedly installed below the bottom frame (1).

7. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1 or 2, characterized in that, Two or more sliding sleeves (10) are provided on the side of the bottom frame (1). The sliding sleeves (10) are slidably engaged with a corresponding number of positioning sliding rods (11) that can be inserted into the underwater ground. The anti-sinking plate (16) is provided with a through hole through which the positioning sliding rods (11) pass.

8. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1, characterized in that, The data storage component (3) is set on a floating body (17) floating on the water surface. The floating body (17) is connected to the bottom frame (1) or the gantry frame (2) by a cable. The data storage component (3) is electrically connected to the underwater magnetic induction counter (4).

9. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1, characterized in that, The bottom frame (1), the portal frame (2), and the blocking component (7) are integral or combined components.

10. The automatic methane bubbling flux monitoring device at the sediment-water interface according to claim 1, characterized in that, The gas collecting hopper (5) is a stainless steel gas collecting hopper.

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