A device and method for quickly counting submerged plants in lakes

Abstract

The present invention discloses a device for quickly counting submerged plants in lakes, which includes a display screen, a floating device, a retractable rod, and an underwater high-definition camera; the floating device floats on the surface of the lake, the retractable rod is fixedly connected to the bottom of the floating device, the lower end of the retractable rod is connected to the underwater high-definition camera, the top of the floating device is connected to the display screen via a signal transmission line, and the other end of the signal transmission line is connected to the signal output end of the underwater high-definition camera. The present invention also discloses a method for quickly counting submerged plants in lakes. The present invention can more accurately estimate the biomass and coverage rate of submerged plants in lakes and reservoirs; and more comprehensively understand the community structure and species diversity of submerged plants in lakes and reservoirs.

Description

Technical Field

[0001] The invention belongs to the field of water area metering and counting, and more specifically relates to a device and method for quickly counting submerged plants in lakes. Background Art

[0002] Submerged plants are an important part of the lake ecosystem. They can absorb nutrients such as nitrogen and phosphorus in the water and have important ecological value for controlling lake eutrophication. Submerged plants absorb various nutrients from the bottom sediment by absorbing soluble and suspended nutrients in the water and fixing them in their own bodies, thereby reducing the concentration of nutrient salts in the water and bottom sediment and inhibiting the growth of phytoplankton. Submerged plants can reduce the impact of wind and waves and lake currents on the bottom sediment, reduce the resuspension of bottom sediment and the release of nutrients, promote the sedimentation of suspended matter in the water, increase water transparency, and improve the underwater lighting environment. Submerged plants create a still water environment, provide a large habitat surface area for zooplankton, and create a good environment and conditions for the survival of zooplankton communities. High-density zooplankton can capture phytoplankton, thereby indirectly controlling the biomass of phytoplankton and achieving the purpose of improving water quality.

[0003] The underwater high-definition camera is an underwater camera system that uses high-quality cables as video transmission control lines, plus auxiliary control equipment such as control boxes. It uses high-light wide-angle infrared sensor lights and can be seen in muddy water at night. Its main functions are measurement / monitoring / exploration, etc. It can be used for seabed resource surveys, river and lake bottom biological community observations, etc.

[0004] Based on the functions of the above-mentioned submerged plants and underwater cameras, in order to quickly and intuitively understand the community structure, biomass and biological species of submerged plants in lakes, and provide real-time and effective data to improve the lake water ecological environment, combined with the extended functions of underwater cameras, a fast, intuitive and accurate quantitative counting device and method for submerged plant biomass can be studied.

[0005] Chinese patent document 201810168497.6 discloses a quantitative device and survey method for submerged plants in lakes and reservoirs, which is applied to the quantitative survey method for submerged plants in lakes and reservoirs, including a traction rope, an automatic rope-releasing hook and a grass-grabbing bucket; the automatic rope-releasing hook includes a flat plate and a hook plate, and the traction rope is connected to the flat plate; a hook head is provided at one end of the hook plate, and the hook plate is hinged to the flat plate; the grass-grabbing bucket includes two grabbing buckets, which are used to grab aquatic plants, and the two grabbing buckets are hinged at one end facing each other, and a steel wire rope is provided at the hinge, and the grass-grabbing bucket is connected to the flat plate through the steel wire rope at the hinge; the ends of the two grabbing buckets that are far away from each other are connected together by a steel wire rope. In the sampling area of ​​a lake or reservoir, the device is used to grab submerged vegetation, and the biomass and diversity of the submerged plant community in the sampled water body are calculated. Although the device and method are suitable for biomass estimation research at different water depths, the biomass captured by its grab bucket is random and cannot be effectively measured in real time. It has low efficiency, poor biomass measurement accuracy, complex equipment operation, and cannot intuitively understand its growth environment. Therefore, it is not suitable for rapid and efficient measurement research of complex biological structures in lakes. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned disadvantages and provide a device and method for quickly counting submerged plants in lakes.

[0007] In order to achieve these purposes and other advantages according to the present invention, a rapid counting device for submerged plants in lakes is provided, which includes a display screen, a floating device, a retractable rod and an underwater high-definition camera;

[0008] The floating device floats on the surface of the lake, the retractable rod is fixedly connected to the bottom of the floating device, the lower end of the retractable rod is connected to the underwater high-definition camera, the top of the floating device is connected to the display screen through a signal transmission line, and the other end of the signal transmission line is connected to the signal output end of the underwater high-definition camera.

[0009] Preferably, a hollow structure is provided inside the telescopic rod, and a channel for the signal transmission line to pass through is provided in the hollow structure.

[0010] Preferably, the telescopic rod is arranged perpendicular to the floating body device, and the telescopic rod comprises an upper rod body, a middle rod body and a lower rod body which are telescopically connected, the diameters of the upper rod body, the middle rod body and the lower rod body decrease successively, and a cable channel with a hollow structure is provided on the central axis of the three, a counterweight ring block is fixedly connected to the lower end of the lower rod body and located above the underwater high-definition camera, an underwater ranging laser radar is bonded to the bottom of one side of the counterweight ring block, and the data of the underwater ranging laser radar is connected to the ranging display through the cable channel via a data transmission line; a hand winch is also provided on the floating body device, and the hand winch The base of the disc is fixedly connected to the upper surface of the floating body device, and the wire rope of the hand-cranked winch passes through the cable channels of the upper rod body, the middle rod body and the lower rod body in sequence and is fixedly connected to the bottom end of the lower rod body. A large gear locking part is provided on the lower side of the large gear of the hand-cranked winch, and the large gear locking part includes an arc-shaped locking piece and a cylindrical shaft rotatably connected thereto, and a pair of support seats arranged at both ends of the cylindrical shaft and fixedly connected thereto, and the bottom of the support seat is fixedly connected to the upper surface of the floating body device, and the upper part of the arc-shaped locking piece is provided with a tip portion that can be embedded and stuck with the tooth portion of the large gear, and the lower part of the arc-shaped locking piece is provided with a columnar hole for the cylindrical shaft to pass through;

[0011] The telescopic rod is configured as follows: when underwater, the counterweight ring block and the underwater high-definition camera will stretch the length of the telescopic rod to the maximum under the action of gravity; then the measurement personnel stabilize the floating device, and then use the crank of the hand-cranked winch to drive the wire rope to pull the bottom end of the lower rod body upward, thereby driving the underwater high-definition camera to move upward, and the sample measurement personnel adjust the length of the telescopic rod to an appropriate measurement range according to the display distance of the ranging display.

[0012] Preferably, a sampling work boat is provided beside the floating device, and the sampling work boat drags and moves the floating device, and the display screen and the distance measuring display are placed on the sampling work boat and powered by an external power supply.

[0013] Preferably, the floating device comprises:

[0014] A square floating body part for floating on the water surface, wherein the middle of the square floating body part is provided with a mounting hole for the top of the electric telescopic rod to pass through and be fixed;

[0015] Four vertical counterweight rods are respectively arranged at the four corners of the bottom of the square floating body;

[0016] Four V-shaped counterweight rods, each connecting the upper portion of two adjacent vertical counterweight rods, wherein the bottom end of the V-shaped counterweight rod is at the same horizontal height as the bottom end of the vertical counterweight rod;

[0017] Four flow-stabilizing filter screens, which are bonded between the V-shaped counterweight rod and the bottom of the square floating body;

[0018] The square floating body can be a floating plate or a hollow pontoon, and its length and width are both 50-60cm. The length and width cannot be too large, otherwise it will be inconvenient to control and operate. The bottom ends of the vertical counterweight rod and the V-shaped counterweight rod are both connected to a counterweight ball.

[0019] Preferably, when observing and counting the submerged plants at the bottom of a lake, the length of the retractable rod is adjusted according to the water depth, the camera shooting picture is connected to the display screen through a signal transmission line, on which the growth conditions and biomass of the submerged plants at the bottom of the lake are displayed, and the screen recording and counting are started to achieve the purpose of rapid submerged plant biomass measurement.

[0020] Preferably, the floating device comprises:

[0021] A square floating body part for floating on the water surface, wherein the middle of the square floating body part is provided with a mounting hole for the top of the electric telescopic rod to pass through and be fixed;

[0022] Four vertical counterweight rods are respectively arranged at the four corners of the bottom of the square floating body;

[0023] Four V-shaped counterweight rods, each connecting the upper portion of two adjacent vertical counterweight rods, wherein the bottom end of the V-shaped counterweight rod is at the same horizontal height as the bottom end of the vertical counterweight rod;

[0024] Four flow-stabilizing filter screens, which are bonded between the V-shaped counterweight rod and the bottom of the square floating body;

[0025] The square floating body part can be a floating plate or a hollow buoyancy box, and the bottom ends of the vertical counterweight rod and the V-shaped counterweight rod are both connected with a counterweight ball.

[0026] A method for quickly counting submerged plants in lakes, comprising the following steps:

[0027] S1. Determine the lake area where biomass needs to be measured through field measurements or online maps;

[0028] S2. Measure the water depth of lake water bodies with portable instruments and collect isobath data;

[0029] S3. Based on the measured lake area and depth at different points in the lake, the different areas for measuring biomass are divided;

[0030] S4. Use a lake submerged plant rapid counting device to observe and measure the biomass of submerged plants in the water body; determine the total length of the retractable rod according to the depth of the lake water body, then adjust the measuring length of the retractable rod, test whether the data transmission of the underwater camera and the display screen is normal, fix it on the floating device, move along the measurement area, and record the screen to observe the biomass of submerged plants; the shooting angle of the underwater camera is 220°, then its lake surface interval scanning distance L = 2×tan110×h, where h is the distance between the end of the underwater camera and the bottom of the lake;

[0031] T1. There are two calculation methods according to the size of the measurement area: ① The measurement area of ​​the lake is ≤ 50m 2 , the data are empirical values, using full-area scanning mode to record screen counts; ② Measure lake area>50m 2 The five-point average method is used for measurement, that is, five points are selected at the four corners and the middle of the area graph, and each area is 10m 2 , find the biomass per unit area, and then calculate the biomass of the total lake area.

[0032] T2. Establish the calculation formula I for submerged plant biomass and calculate the submerged plant biomass in the measurement area;

[0033]

[0034] Where: S 0 is the biomass per unit area, in plants / m 2 ; S 1 is the number of plants within the scanning area, in units of plants; A is the area of ​​the underwater camera scanning area, in units of m 2 ;

[0035] If the measured lake area is > 50m 2 , the calculation formula is as follows:

[0036]

[0037] S=S 0 ×A

[0038] Where: S 0 is the biomass per unit area, in plants / m 2 ; S 1 , S 2 , S 3 , S 4 , S 5 A is the number of plants within the scanned area, in units of plants; 1 , A 2 , A 3 , A 4 , A 1is the area of ​​the underwater camera scanning area, in m 2 ; S is the biomass of the measurement area, in plants; A is the lake area of ​​the measurement area, in m 2 .

[0039] If the measured lake area is ≤50m 2 , the calculation formula is as follows:

[0040] S=S 0

[0041] Where: S, S 0 It is the biomass of the measured area, in units of plants.

[0042] Preferably, when the five-point average method is adopted for measurement, the five points of the area graph are selected as the four corners and the middle position of the lake where the biomass needs to be measured.

[0043] The present invention can more accurately estimate the biomass and coverage of submerged plants in lakes and reservoirs; and more comprehensively understand the community structure and species diversity of submerged plants in lakes and reservoirs. The hand-cranked winch and underwater ranging laser radar cooperate with the telescopically connected upper rod body, middle rod body and lower rod body to control the length of the telescopic rod within an appropriate range. The total length of the telescopic rod is set according to the depth range of the water area, and the length of the upper rod body is greater than the length of the middle rod body and the lower rod body. The design of the floating device can effectively improve its stability on the water surface. The vertical counterweight rod, V-shaped counterweight rod and counterweight ball work together to effectively extend the floating device below the water surface, while increasing the counterweight to improve stability. The flow stabilizing filter part is arranged between the V-shaped counterweight rod and the bottom of the square floating part, which can effectively buffer the fluctuation of the water flow through the filter screen. In actual use, the effect of improving the stability of the floating body is particularly obvious.

[0044] Other advantages, objectives and features of the present invention will be embodied in part through the above description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the structure of Example 1.

[0046] Figure 2 This is a schematic diagram of the distribution of the five points of the area graph.

[0047] Figure 3 This is a schematic diagram of the structure of Example 2.

[0048] Figure 4 It is a structural schematic diagram of the floating device.

[0049] Figure 5 It is a schematic diagram of the structure of the large gear and the large gear locking part.

[0050] Figure 6 It is a schematic diagram of the structure of the arc-shaped locking plate.

[0051] Figure 7 It is a schematic diagram of the structure of a cylindrical shaft and a pair of support seats. DETAILED DESCRIPTION

[0052] The present invention is described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention accordingly after reading the description.

[0053] <Example 1>

[0054] A rapid counting device for submerged plants in lakes, comprising a display screen 1, a floating device 2, a retractable rod 3 and an underwater high-definition camera 4;

[0055] The floating device 2 floats on the surface of the lake, the retractable rod 3 is fixedly connected to the bottom of the floating device 2, the lower end of the retractable rod 3 is connected to the underwater high-definition camera 4, the top of the floating device 2 is connected to the display screen 1 through a signal transmission line 5, and the other end of the signal transmission line 5 is connected to the signal output end of the underwater high-definition camera 4.

[0056] When observing and counting the submerged plants at the bottom of a lake, the length of the retractable rod 3 is adjusted according to the water depth. The camera shooting picture is connected to the display screen 1 through the signal transmission line 5, on which the growth status and biomass of the submerged plants at the bottom of the lake are displayed, and the screen recording and counting are started to achieve the purpose of quickly measuring the biomass of submerged plants.

[0057] <Example 2>

[0058] On the basis of Embodiment 1, a hollow structure is provided inside the telescopic rod 3, and a channel for the signal transmission line 5 to pass through is provided in the hollow structure.

[0059] The telescopic rod 3 is arranged perpendicular to the floating body device 2, and the telescopic rod 3 includes an upper rod body 31, a middle rod body 32 and a lower rod body 33 which are telescopically connected. The diameters of the upper rod body 31, the middle rod body 32 and the lower rod body 33 decrease successively, and a cable channel with a hollow structure is provided on the central axis of the three. A counterweight ring block 16 is fixedly connected to the lower end of the lower rod body 33 and located above the underwater high-definition camera. An underwater ranging laser radar 17 is bonded to the bottom of one side of the counterweight ring block 16. The data of the underwater ranging laser radar 17 is connected to the ranging display 18 through the cable channel via a data transmission line 19;

[0060] The floating body 2 is also provided with a hand-cranked winch 34, the base of which is fixedly connected to the upper surface of the floating body 2, and the steel wire rope of the hand-cranked winch 34 passes through the cable channels of the upper rod body 31, the middle rod body 32 and the lower rod body 33 in sequence and is fixedly connected to the bottom end of the lower rod body 33, and a large gear locking portion 41 is provided on the lower side of the large gear 40 of the hand-cranked winch 34, and the large gear locking portion 41 includes an arc-shaped locking piece 42 and a cylindrical shaft 45 rotatably connected thereto, and a pair of support seats 44 arranged at both ends of the cylindrical shaft 45 and fixedly connected thereto, and the bottom of the support seat 44 is fixedly connected to the upper surface of the floating body 2, and the upper part of the arc-shaped locking piece 42 is provided with a tip portion that can be embedded and stuck with the tooth portion of the large gear 40, and the lower part of the arc-shaped locking piece 42 is provided with a columnar hole 43 for the cylindrical shaft 45 to pass through;

[0061] The telescopic rod 3 is configured as follows: when underwater, the counterweight ring block 16 and the underwater high-definition camera will stretch the length of the telescopic rod 3 to the maximum under the action of gravity; then the surveyor stabilizes the floating device 2, and then drives the wire rope to pull the bottom end of the lower rod body 33 upward through the crank of the hand-cranked winch 34, thereby driving the underwater high-definition camera 4 to move upward, and the sample measuring personnel adjust the length of the telescopic rod 3 to a suitable measurement range according to the display distance of the ranging display 18, and then fix the wire rope of the hand-cranked winch 34 through the large gear locking part 41. The hand-cranked winch and the underwater ranging laser radar cooperate with the telescopically connected upper rod body, middle rod body and lower rod body to control the length of the telescopic rod within a suitable range. The total length of the telescopic rod is set according to the actual depth range of the water area, and the length of the upper rod body is greater than the length of the middle rod body and the lower rod body. In actual measurement, multiple floating devices with different measurement depths need to be configured, and the lengths of the telescopic rods of different floating devices are set according to actual measurement requirements.

[0062] A sampling work boat is arranged beside the floating device 2, and the sampling work boat drags and moves the floating device 2. The display screen 1 and the distance measuring display 18 are placed on the sampling work boat and are powered by an external power supply.

[0063] The floating device 2 comprises:

[0064] A square floating body 10 for floating on the water surface, wherein a mounting hole 14 is provided in the middle of the square floating body 10 for the top of the electric telescopic rod 3 to pass through and be fixed;

[0065] Four vertical counterweight rods 11 are respectively arranged at the four corners of the bottom of the square floating body 10;

[0066] Four V-shaped counterweight rods 12, which respectively connect the upper parts of two adjacent vertical counterweight rods 11, and the bottom ends of the V-shaped counterweight rods 12 and the bottom ends of the vertical counterweight rods 11 are located at the same horizontal height;

[0067] Four flow stabilizing screen parts 15, which are bonded between the V-shaped counterweight rod 12 and the bottom of the square floating body part 10;

[0068] The square floating body 10 can be a floating plate or a hollow pontoon, and its length and width are both 50-60cm. The length and width cannot be too large, otherwise it will be inconvenient to control and operate. The bottom ends of the vertical counterweight rod 11 and the V-shaped counterweight rod 12 are connected to a counterweight ball 13. The design of the floating device can effectively improve its stability on the water surface. The vertical counterweight rod, the V-shaped counterweight rod and the counterweight ball work together to effectively extend the floating device below the water surface, while increasing the counterweight to improve stability. The flow stabilizing filter is arranged between the V-shaped counterweight rod and the bottom of the square floating body, which can effectively buffer the fluctuation of the water flow through the filter. In actual use, the effect of improving the stability of the floating body is particularly obvious.

[0069] The method for rapidly counting submerged plants in lakes using Example 1 or Example 2 specifically comprises the following steps:

[0070] S1. Determine the lake area where biomass needs to be measured through field measurements or online maps;

[0071] S2. Measure the water depth of lake water bodies with portable instruments and collect isobath data;

[0072] S3. Based on the measured lake area and depth at different points in the lake, the different areas for measuring biomass are divided;

[0073] S4. Use a lake submerged plant rapid counting device to observe and measure the biomass of submerged plants in the water body; determine the total length of the telescopic rod 3 according to the depth of the lake water body, then adjust the measuring length of the telescopic rod 3, test whether the data transmission of the underwater camera 4 and the display screen 1 is normal, fix it on the floating device 2, move along the measuring area, and record the screen to observe the biomass of submerged plants; the shooting angle of the underwater camera is 220°, then the lake surface interval scanning distance L = 2×tan110×h, where h is the distance between the end of the underwater camera and the bottom of the lake;

[0074] T1. There are two calculation methods according to the size of the measurement area: ① The measurement area of ​​the lake is ≤ 50m 2 , the data are empirical values, using full-area scanning mode to record screen counts; ② Measure lake area>50m 2 The five-point average method is used for measurement, that is, five points are selected at the four corners and the middle of the area graph, and each area is 10m 2 , find the biomass per unit area, and then calculate the biomass of the total lake area.

[0075] T2. According to the above conditions, the calculation formula I of submerged plant biomass is established to calculate the submerged plant biomass in the measurement area;

[0076]

[0077] Where: S 0 is the biomass per unit area, in plants / m 2 ; S 1 is the number of plants within the scanning area, in units of plants; A is the area of ​​the underwater camera scanning area, in units of m 2 ;

[0078] If the measured lake area is > 50m 2 , the calculation formula is as follows:

[0079]

[0080] S=S 0 ×A

[0081] Where: S 0 is the biomass per unit area, in plants / m 2 ; S 1 , S 2 , S 3 , S 4 , S 5 A is the number of plants within the scanned area, in units of plants; 1 , A 2 , A 3 , A 4 , A 1 is the area of ​​the underwater camera scanning area, in m 2 ; S is the biomass of the measurement area, in plants; A is the lake area of ​​the measurement area, in m 2 .

[0082] If the measured lake area is ≤50m 2 , the calculation formula is as follows:

[0083] S=S 0

[0084] Where: S, S 0 It is the biomass of the measured area, in units of plants.

[0085] In another technical solution, when the five-point average method is used for measurement, the five points of the area graph are selected as the four corners and the middle position of the lake where the biomass needs to be measured.

[0086] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A rapid counting device for submerged plants in lakes, characterized in that It comprises a display screen (1), a floating device (2), a telescopic rod (3) and an underwater high-definition camera (4); The floating device (2) floats on the surface of the lake, the retractable rod (3) is fixedly connected to the bottom of the floating device (2), the lower end of the retractable rod (3) is connected to the underwater high-definition camera (4), the top of the floating device (2) is connected to the display screen (1) via a signal transmission line (5), and the other end of the signal transmission line (5) is connected to the signal output end of the underwater high-definition camera (4); The floating device (2) comprises: A square floating body (10) for floating on the water surface, wherein a mounting hole (14) is provided in the middle of the square floating body (10) for the top of the telescopic rod (3) to pass through and be fixed; Four vertical counterweight rods (11) are respectively arranged at the four corners of the bottom of the square floating body (10); Four V-shaped counterweight rods (12), which respectively connect the upper parts of two adjacent vertical counterweight rods (11), and the bottom ends of the V-shaped counterweight rods (12) and the bottom ends of the vertical counterweight rods (11) are located at the same horizontal height; Four flow stabilizing filter screen parts (15) are bonded and arranged between the V-shaped counterweight rod (12) and the bottom of the square floating body part (10); The square floating body (10) can be a floating plate or a hollow buoyancy box, and the bottom ends of the vertical counterweight rod (11) and the V-shaped counterweight rod (12) are both connected to a counterweight ball (13).

2. A rapid counting device for submerged plants in lakes as claimed in claim 1, characterized in that: The telescopic rod (3) is an electric telescopic rod, and a hollow structure is provided inside the telescopic rod (3), and a channel is provided in the hollow structure for the signal transmission line (5) to pass through.

3. A rapid counting device for submerged plants in lakes as claimed in claim 2, characterized in that: The telescopic rod (3) is arranged perpendicular to the floating body device (2); a counterweight ring block (16) is fixedly connected to the lower end of the telescopic rod (3) and located above the underwater high-definition camera; an underwater ranging laser radar (17) is bonded to the bottom of one side of the counterweight ring block (16); data of the underwater ranging laser radar (17) is connected to a ranging display (18) through the inside of the telescopic rod (3) via a data transmission line (19); and a sample measuring person adjusts the length of the telescopic rod (3) according to the display distance of the ranging display (18).

4. A rapid counting device for submerged plants in lakes as claimed in claim 3, characterized in that: A sampling work boat is arranged beside the floating device (2), and the sampling work boat drags and moves the floating device (2). The display screen (1) and the distance measuring display (18) are placed on the sampling work boat and are powered by an external power supply.

5. A rapid counting device for submerged plants in lakes as claimed in claim 1, characterized in that: When observing and counting submerged plants at the bottom of a lake, the length of the telescopic rod (3) is adjusted according to the water depth, the camera shooting picture is connected to the display screen (1) through the signal transmission line (5), the growth status and biomass of the submerged plants at the bottom of the lake are displayed on it, and the screen recording and counting are started, so as to achieve the purpose of rapid submerged plant biomass measurement.

6. A method for rapid counting of submerged plants in lakes, characterized in that: Using a lake submerged plant rapid counting device as described in any one of claims 1 to 5 specifically comprises the following steps: S1. Determine the lake area where biomass needs to be measured through field measurements or online maps; S2. Measure the water depth of lake water bodies using portable instruments and collect isobath data; S3. Based on the measured lake area and depth data at different points in the lake, different areas for measuring biomass are divided; S4. Use a lake submerged plant rapid counting device to observe and measure the biomass of submerged plants in the water body; adjust the length of the retractable rod (3) according to the depth of the lake water body, test whether the data transmission of the underwater camera (4) and the display screen (1) is normal, fix it on the floating device (2), move along the measurement area, and record the screen to observe the biomass of submerged plants; the shooting angle of the underwater camera is 220°, then its lake surface interval scanning distance L = 2×tan110×h, where h is represented by the distance between the end of the underwater camera and the bottom of the lake.

7. A method for rapid counting of submerged plants in lakes as claimed in claim 6, characterized in that: The specific steps of observation and measurement in S4 are: T1. There are two calculation methods according to the size of the measurement area: ① The measurement area of ​​the lake is ≤ 50m 2 , the data are empirical values, using full-area scanning mode to record screen counts; ② Measure lake area>50m 2 The five-point average method is used for measurement, that is, five points are selected at the four corners and the middle of the area graph, and each area is 10m 2 , find the biomass per unit area, and then calculate the biomass of the total lake area; T2. Establish the calculation formula I for submerged plant biomass and calculate the submerged plant biomass in the measurement area; Where: S0 is the biomass per unit area, in units of plants / m 2 ; S1 is the number of plants within the scanning area, in units of plants; A is the area of ​​the underwater camera scanning area, in units of m 2 ; If the measured lake area is > 50m 2 , the calculation formula is as follows: S=S0×A Where: S0 is the biomass per unit area, in units of plants / m 2 ; S1, S2, S3, S4, S5 are the number of plants within the scanning area, in units of plants; A1, A2, A3, A4, A1 are the area of ​​the underwater camera scanning area, in units of m 2 ; S is the biomass of the measurement area, in plants; A is the lake area of ​​the measurement area, in m 2 ; If the measured lake area is ≤50m 2 , the calculation formula is as follows: S=S0 Where: S, S0 are the biomass of the measurement area, in units of plants.

8. A method for rapid counting of submerged plants in lakes as claimed in claim 7, characterized in that: When the five-point average method is used for measurement, the five points selected in the area graph are the four corners and the middle position of the lake where the biomass needs to be measured.

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