Experimental device for monitoring hydrodynamic shear stress of mangrove forest

Abstract

The utility model belongs to the field of marine ecological environment engineering. The experimental device for monitoring the hydrodynamic shear stress of the mangrove forest comprises a water tank and a display, seawater is contained in the water tank, a simulated mud flat is arranged on one side in the water tank, mangrove seedlings are planted on the simulated mud flat, a force sensor is installed beside a mangrove seedling model, and the force sensor is connected with the display. A wave simulation mechanism is arranged on the other side, opposite to the simulation mud flat, of the water tank; the wave simulation mechanism comprises a mounting plate arranged at the top of the water tank, a driving motor is arranged on the mounting plate, an output shaft of the driving motor is connected with a telescopic rod, the end part of the telescopic rod is connected with a wave shifting plate, and the wave shifting plate is used for driving the wave shifting plate to move in the water tank along the length direction of the water tank so as to simulate waves; an adjusting switch is arranged on the driving motor; the display is mounted on one side of the exterior of the water tank; and the display is electrically connected with the force sensor. The device can repeatedly simulate the situation that tidal water scours the mud flat in a laboratory and record the shear stress generated on the mangrove seedlings.

Description

Technical Field

[0001] The utility model belongs to the field of marine ecological environment engineering, and particularly relates to an experimental device for monitoring the hydrodynamic shear stress of mangroves. Background Art

[0002] Mangroves are special forests that grow in the transition zone between land and sea. They are known as "coastal guards, bird paradise, and fish and shrimp granaries". Mangroves are not only one of the most important blue carbon ecosystems, but also play an extremely important role in purifying seawater, preventing wind and waves, maintaining biodiversity, and fixing and storing carbon. They are also an integral part of ecological civilization construction and are of great significance to achieving the goal of carbon neutrality. However, due to the rapid development of economic construction, changes in the global climate and marine environment, and the fact that some people are not aware of the important value of mangroves, mangrove degradation occurs from time to time in some areas. Although a large number of protection and restoration projects have been implemented in mangrove growth areas in recent years, restoration work has not been successful in every place. The growth environment of mangroves is very special. They are rooted in mudflats and are not only eroded by seawater, but also face the impact of harsh environments such as typhoons on the sea surface. Therefore, whether it is artificially planted seedlings or transplanted seedlings, in the short period before successful planting, due to weak root systems, low anchoring force, and greater influence of tidal waves, they often fall over, which ultimately affects their survival rate.

[0003] The restoration of mangroves is generally carried out in areas suitable for the growth of mangroves. That is, mangrove seedlings are planted on the original mudflats according to the suitable elevation, and protection is applied to make them grow into forests. In fact, the restoration work cannot be carried out smoothly in every place, and failures in mangrove planting also occur from time to time. This is because mangroves have a special growth environment and take root in mudflats. They are affected by seawater erosion and tidal waves. The root system of mangrove seedlings is not strong, and the anchoring force on the mudbed is small. The frequent erosion of tidal waves will lead to failure of planting when the bearing capacity of mangrove seedlings is exceeded. Among them, when eroded by tidal waves, the force that mangrove seedlings use to overcome the water flow is "bottom bed shear stress". Shear stress is one of the main stress factors in the growth process of mangrove seedlings, and it is also an important parameter for predicting the effect of mangrove ecological reconstruction and establishing numerical simulation models. Therefore, it is very important to be able to quantitatively measure the "bottom bed shear stress" of mangroves at high tide and low tide for mangrove planting and ecological modeling. In the current research on mangroves planted on mudflats, there is a lack of experimental equipment for simulating the hydrodynamic shear stress of mangroves. Through simulation, the shear stress data of mangroves can be mastered in advance.

[0004] Therefore, it is necessary to provide an experimental device for monitoring the hydrodynamic shear stress of mangroves to solve the above technical problems. Utility Model Content

[0005] The present utility model aims to solve at least one of the technical problems raised in the above-mentioned background art, and provides an experimental device for monitoring the hydrodynamic shear stress of mangroves. Its structure is reasonable, which can solve the problem that it is difficult to collect and monitor in-situ shear stress data, so as to facilitate researchers to repeatedly experiment on the influence of shear stress magnitude on the growth state of mangrove seedlings in the laboratory, more intuitively observe and record the experimental results, and apply the experimental conclusions to the actual mangrove restoration work.

[0006] To achieve the above object, the technical solution adopted by the present utility model is:

[0007] An experimental device for monitoring the hydrodynamic shear stress of mangroves, including a water tank and a display. The water tank is filled with seawater. On one side of the water tank, there is a simulated tidal flat, and mangrove seedlings are planted on the simulated tidal flat. A force-sensitive sensor is installed beside the mangrove seedling model. On the other side of the water tank opposite to the simulated tidal flat, there is a wave simulation mechanism. The wave simulation mechanism includes a mounting plate arranged on the top of the water tank. A driving motor is arranged on the mounting plate. The output shaft of the driving motor is connected with a telescopic rod, and the end of the telescopic rod is connected with a wave paddle for driving the wave paddle to move along the length direction of the water tank in the water tank, so as to simulate waves. An adjustment switch is arranged on the driving motor. The display is installed on one side outside the water tank. The display is electrically connected with the force-sensitive sensor.

[0008] As a further improvement of the present utility model, the simulated tidal flat is made of intertidal zone soil, and the force-sensitive sensor is arranged in the front or rear position of the mangrove seedling.

[0009] As a further improvement of the present utility model, the water tank is made of transparent acrylic material, and height scale marks are arranged on the water tank.

[0010] As a further improvement of the present utility model, the top surface of the simulated tidal flat is an inclined surface, and the lower end of the inclined surface faces the wave simulation mechanism. The bottom surface and three side surfaces of the simulated tidal flat are attached to the inner wall of the water tank.

[0011] As a further improvement of the present utility model, the wave paddle is perpendicular to the bottom of the water tank.

[0012] As a further improvement of the present utility model, the driving motor is a variable-frequency driving motor with a speed-changing mechanism.

[0013] Due to adopting the above technical solution, the present utility model has the following beneficial effects:

[0014] An experimental device for monitoring the hydrodynamic shear stress of mangroves of the present utility model has a reasonable structure and can solve the problem of difficulty in obtaining the shear stress data of mangrove seedlings in the field. By using this experimental device, the scenario of tidal water scouring the tidal flat can be repeatedly simulated in the laboratory, and the magnitude of the shear stress generated on the mangrove seedlings can be recorded. At the same time, according to the scale, the shear stress generated by the hydrodynamic force on the tidal flats at different elevations can be observed and compared, solving the problem of difficulty in field monitoring of the shear stress data of mangrove seedlings. According to the experimental data, the magnitude of the shear stress generated by the hydrodynamic force during the growth of mangrove seedlings can be better understood, facilitating the establishment of a hydrodynamic prediction model for mangrove growth and providing a better plan for mangrove restoration and planting.

[0015] The present utility model simplifies the complex and changeable tidal flat environment by setting a simulated tidal flat inside the water tank and matching seawater and a wave simulation mechanism for simulating the water environment and generating hydrodynamic forces, and simulating the ebb and flow of waves, which is convenient for observing and understanding the phenomenon of tidal water scouring the tidal flat. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a three-dimensional view of an experimental device for monitoring the hydrodynamic shear stress of mangroves of the present utility model;

[0017] Figure 2 is a top view structural schematic diagram of an experimental device for monitoring the hydrodynamic shear stress of mangroves of the present utility model;

[0018] Figure 3 is a structural schematic diagram of the display of the present utility model;

[0019] Figure 4 is a schematic diagram when the wave plate of the present utility model starts at a relatively low speed;

[0020] Figure 5 is a schematic diagram when the wave plate of the present utility model starts at a relatively high speed;

[0021] Among them, the labels in the drawings are: 1. water tank; 2. seawater; 3. simulated tidal flat; 4. mangrove seedlings; 5. force-sensitive sensor; 6. mounting plate; 7. drive motor; 8. telescopic rod; 9. wave plate; 10. adjustment switch; 11. display; 12. height scale mark; 13. power switch; 14. zero key; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0023] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and defined, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0024] Please refer to Figures 1 - 5 , an experimental device for monitoring the hydrodynamic shear stress of mangroves, including a water tank 1 and a display 11. The water tank 1 is filled with seawater 2 used to simulate the water environment and generate hydrodynamic forces. On one side of the water tank 1, there is a simulated tidal flat 3. Red mangrove seedlings 4 are planted on the simulated tidal flat 3. A force-sensitive sensor 5 for sensing the shear stress of the red mangrove seedlings 4 is installed beside the model of the red mangrove seedlings 4. On the other side of the water tank 1 opposite to the simulated tidal flat 3, there is a wave simulation mechanism; the wave simulation mechanism includes a mounting plate 6 arranged on the top of the water tank 1. A driving motor 7 is provided on the mounting plate 6. The output shaft of the driving motor 7 is connected to a telescopic rod 8. The end of the telescopic rod 8 is connected to a wave paddle 9 for stirring the seawater 2 to create hydrodynamic factors. The telescopic rod 8 is fixedly connected to the wave paddle 9 and drives the wave paddle 9 to move along the length direction of the water tank 1 in the water tank 1, thereby simulating waves; an adjustment switch 10 is provided on the driving motor 7; the display 11 is installed on one side outside the water tank 1; the display 11 is electrically connected to the force-sensitive sensor 5. The circuit connection between the force-sensitive sensor 5 and the display 11 is prior art and will not be elaborated here to save space.

[0025] Among them, the simulated tidal flat 3 is made of intertidal zone soil. In this embodiment, the simulated tidal flat 3 is made of soil retrieved from the tidal flat near the planting area of the red mangrove seedlings 4. The force-sensitive sensor 5 is arranged in front of or behind the red mangrove seedlings 4. The display 11 has a power switch 13 and a zeroing key 14, which respectively control the switch of the display 11 and the zeroing of the displayed data.

[0026] The water tank 1 is made of transparent acrylic material. Compared with traditional glass material, acrylic material is lighter in weight, making it easier to carry and place. It has higher strength, is not easily broken, has higher transparency, is corrosion-resistant, and has good insulation performance. The size of the water tank 1 is determined according to the experimental needs. The reference size in this embodiment is 2.3 m in length, 0.6 m in width, and 0.5 m in height. The water tank 1 is provided with height scale marks 12 for observing the elevation of the tidal flat.

[0027] The wave plate 9 and the mounting plate 6 are made of wood or plastic board, which have the advantages of being light, easily obtainable, and corrosion-resistant. The wave plate 9 is fixed on the telescopic rod 8 in front of the driving motor 7. The speed of the telescopic rod 8 is controlled by the adjustment switch 10 of the driving motor 7, thereby controlling the speed of the wave plate 9 to generate "waves" of different degrees. It is recommended that the outer shell of the driving motor 7 and the telescopic rod 8 be made of stainless steel or painted with an anti-corrosion coating because there is seawater 2 in this experimental device, which may rust the driving motor 7 and the telescopic rod 8. The driving motor 7 is connected to the power supply through an external connecting wire. The connecting wire can be an ordinary rubber-coated wire, which can prevent corrosion and is used to supply power to the driving motor 7.

[0028] It is recommended that the seawater 2 be seawater 2 retrieved from the field or a liquid with the same density as the seawater 2, which can more accurately simulate the hydrodynamic conditions of the seawater 2 and reduce experimental errors.

[0029] The force sensor 5 is placed in front of or behind the mangrove seedlings 4 to sense the shear stress generated by the hydrodynamic force on the mangrove seedlings 4 and transmit the data to the display screen. The variety of the mangrove seedlings 4 can be selected according to the research needs and actual situations. The zero scale line of the height scale marks 12 should indicate the lowest point inside the water tank 1, and its range and graduation value can be set according to the specific box body and actual observation needs.

[0030] Among them, the top surface of the simulated tidal flat 3 is an inclined plane, and the angle between the inclined plane and the horizontal plane is 15° - 20°. The lower end of the inclined plane faces the wave simulation mechanism; the bottom surface and three side surfaces of the simulated tidal flat 3 are attached to the inner wall of the water tank 1.

[0031] As a further improvement of the present utility model, the wave plate 9 is perpendicular to the bottom of the water tank 1.

[0032] Among them, the driving motor 7 is a variable-frequency driving motor 7 with a speed-changing mechanism, and this motor has the functions of variable speed and adjustable speed.

[0033] The usage method of an experimental device for monitoring the hydrodynamic shear stress of mangroves in the present utility model is as follows: On one side inside the water tank 1, lay a simulated tidal flat 3 at a certain elevation obliquely according to the height scale line, and inject an appropriate amount of seawater 2. When the power supply, the display 11, and the battery power supply of the force-sensitive sensor 5 are connected by the connecting wire and the battery power is sufficient, turn on the power switch 13 of the display 11. After the reading is stable, press the zero key 14 to zero the reading of the display 11. Control the driving motor 7 to work by adjusting the switch 10, so that the telescopic rod 8 drives the wave plate 9 to move back and forth at different speeds, observe the state of the mangrove seedlings 4 respectively, and record the magnitude of the shear stress displayed by the force-sensitive sensor 5 on the display screen.

[0034] The above description is a detailed description of the preferred feasible embodiment of the present utility model, but the embodiment is not used to limit the scope of the patent application of the present utility model. Any equivalent changes or modifications completed under the technical spirit prompted by the present utility model shall fall within the scope of the patent covered by the present utility model.

Claims

1. An experimental device for monitoring the hydrodynamic shear stress of mangroves, characterized by: The invention comprises a water tank (1) and a display (11), wherein the water tank (1) contains seawater (2), a simulated beach (3) is arranged on one side of the water tank (1), a mangrove seedling (4) is planted on the simulated beach (3), a force-sensitive sensor (5) is installed next to the model of the mangrove seedling (4), and a wave simulation mechanism is arranged on the other side of the water tank (1) relative to the simulated beach (3); the wave simulation mechanism comprises a mounting plate (6) arranged on the top of the water tank (1), a driving motor (7) is arranged on the mounting plate (6), an output shaft of the driving motor (7) is connected to a telescopic rod (8), an end of the telescopic rod (8) is connected to a wave-rattle board (9) for driving the wave-rattle board (9) to move in the water tank (1) along the length direction of the water tank (1), thereby simulating waves; an adjusting switch (10) is arranged on the driving motor (7); the display (11) is installed on one side outside the water tank (1); and the display (11) is electrically connected to the force-sensitive sensor (5).

2. The experimental device for monitoring the hydrodynamic shear stress of mangroves according to claim 1, characterized in that: The simulated tidal flat (3) is made of shaped intertidal zone soil, and the force-sensitive sensor (5) is arranged at the front side or the rear side of the mangrove seedling (4).

3. The experimental device for monitoring the hydrodynamic shear stress of mangroves according to claim 1, characterized in that: The water tank (1) is made of a transparent acrylic material, and a height scale mark (12) is provided on the water tank (1).

4. The experimental device for monitoring the hydrodynamic shear stress of mangroves according to claim 1, characterized in that: The top surface of the simulated tidal flat (3) is an inclined surface, and the lower end of the inclined surface faces the wave simulation mechanism; the bottom surface and three side surfaces of the simulated tidal flat (3) are arranged in contact with the inner wall of the water tank (1).

5. The experimental device for monitoring the hydrodynamic shear stress of mangroves according to claim 1, characterized in that: The wave-rattle board (9) is arranged vertically at the bottom of the water tank (1).

6. The experimental device for monitoring the hydrodynamic shear stress of mangroves according to claim 1, characterized in that: The drive motor (7) is a variable frequency drive motor (7) with a speed change mechanism.

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