A method for self-growth construction of a mangrove ecological island and an artificial island siltation device

Abstract

This invention relates to a method for constructing a biodegradable mangrove ecological island based on dynamic tidal energy regulation, and an artificial island siltation device. The artificial island siltation device includes a bamboo gate system, a hemp rope net system, a fixed pile system, and a limiting system. A dynamic filtration structure is formed by the liftable bamboo gate and the hemp rope net. Utilizing the buoyancy difference and water flow velocity changes generated by tidal rise and fall, a synergistic effect is achieved: accelerating the passage of sediment-laden water during high tide and promoting siltation during low tide. A fully biodegradable material is used to construct a growing silt body. The buoyancy balance is regulated by the bamboo joint holes, ensuring the device remains suspended on the surface layer of the silt body. This allows for continuous siltation and elevation of the tidal flat, forming an artificial island that provides a site for mangrove seedling planting and meets the required daily sunrise duration for mangrove growth. The method and device of this invention have technical advantages such as low construction cost, dynamic adaptation to tidal changes, and avoidance of secondary pollution.

Description

Technical Field

[0001] This invention belongs to the field of coastal engineering technology and involves the cross-technology of tidal energy utilization, artificial siltation and land reclamation, and mangrove ecological restoration. Specifically, it is a method for the self-growth construction of mangrove ecological islands and an artificial island siltation device. Background Technology

[0002] Mangrove seedlings require 4-6 hours of root exposure above sea level daily for optimal growth. When planting mangroves on low-lying tidal flats, artificial islands need to be constructed to raise the elevation. Traditional mangrove artificial island construction often uses reinforced concrete dikes or plastic breakwaters, which suffers from high construction costs (cost per meter > 2000 yuan), hinders natural water and sediment exchange, and generates construction waste pollution. Furthermore, in some coastal areas with excessively low tidal flats, mangroves remain submerged and cannot survive, affecting not only the survival rate of individual mangroves but also the overall growth needs of the mangrove forest.

[0003] Existing siltation technologies generally use plastic mesh or fiber bags, which have the drawback of non-degradable materials; many siltation systems use fixed riprap or concrete piles, which are difficult to adapt to changes in tidal levels, resulting in the inability to dynamically adjust the elevation of the silt deposits. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method for the self-growth construction of mangrove ecological islands and an artificial island siltation device. This invention and its dedicated device are designed to enable the self-construction of ecological islands on tidal flats planted with mangroves using tidal kinetic energy, meeting the requirement of mangrove seedlings having their roots exposed above the sea surface for 4-6 hours daily, and are suitable for the rapid construction of biodegradable mangrove ecological islands on silty tidal flats.

[0005] To achieve the above-mentioned objectives, the technical solution provided by this invention patent is as follows:

[0006] This invention first provides a method for the self-growth construction of mangrove ecological islands, which specifically includes the following steps:

[0007] S1. An artificial island siltation device is deployed on a tidal flat where mangrove seedlings are to be planted but the mangroves cannot be exposed to the sea surface for 4-6 hours per day. The artificial island siltation device includes a bamboo tube gate system, a hemp rope net system, a fixed pile system, and a limiting system. The fixed pile system includes multiple wooden piles inserted into the tidal flat. The bamboo tube gate system is installed on one side of the fixed pile system. One end of the hemp rope net system is connected to the bamboo tube gate system, and the other end is connected to the fixed pile system. The limiting system is set on the fixed pile system to limit the vertical sliding height of the bamboo tube gate system and the hemp rope net system.

[0008] S2, the initial elevation of the limiting system is set by tidal observation data to ensure that the bamboo gate system is in a semi-floating state at the average tide level;

[0009] S3, during the spring tide, the artificial island siltation device is put into operation, and the water and sand separation effect generated by the hemp rope net system is used to achieve an average daily siltation rise of 0.5 to 1 cm;

[0010] S4. After several days of siltation and elevation, when the height of the silt reaches the elevation required for mangrove root growth, the rope netting system is removed, and mangrove seedlings are planted on the formed mangrove ecological island.

[0011] Furthermore, in the aforementioned artificial island sedimentation device:

[0012] The bamboo tube gate system is composed of bamboo tubes forming a horizontal gate body. Vertical through holes are pre-drilled at both ends of the bamboo tubes, and a horizontal through hole is opened in the center of each bamboo tube segment.

[0013] The hemp rope net system includes a hemp rope net with square holes. The hemp rope net is square with the same length and width. One end of the hemp rope net is tied to the bamboo in the bamboo tube gate system, and the other end is horizontally opened in the opposite direction of the main wave and connected to the fixed pile system.

[0014] The fixed pile system consists of four wooden piles, divided into two groups of two. One group penetrates vertically through the vertical through holes reserved at both ends of the bamboo tube in the bamboo tube gate system to form a sliding joint; the other group penetrates vertically through the outside of the open hemp rope net. The wooden piles are vertically inserted into the depth of the tidal flat for fixation.

[0015] The limiting system consists of wooden nails driven into the top of the wooden stakes. These nails limit the vertical sliding height of the bamboo tube gate system and the hemp rope net system. Calculated from the beach surface, the upward displacement of the bamboo tube gate system is ≤1.0m, and the upward displacement of the hemp rope net system facing away from the main wave direction is ≤0.2m.

[0016] Furthermore, the biodegradation cycles of the bamboo tube gate system, hemp rope net system, fixed pile system, and limiting system are matched with the artificial island forming cycle, wherein the degradation time of bamboo is 24-36 months, the degradation time of hemp rope net is 18-24 months, and the degradation time of wooden pile is 36-48 months.

[0017] Furthermore, in S3,

[0018] When the tide rises at the tidal flat location, the tide causes the bamboo tube gate system to float up. The hemp rope net at the front end of the fixed pile system floats up with the height adjustment body, so that the hemp rope net at the front end of the fixed pile system and the hemp rope net at the rear end of the fixed pile system form an angle of up to 30°. At the same time, the holes of the hemp rope net are stretched open, and seawater flows through the hemp rope net to realize the transport of suspended sand.

[0019] When the tide recedes at the tidal flat, the bamboo gate system at the front of the fixed pile system falls with the tide, and the hemp rope net at the front of the fixed pile system falls with the bamboo gate system, so that the hemp rope net at the front and rear of the fixed pile system form a sand-blocking angle. At the same time, the holes of the hemp rope net droop and close, and the flow velocity of seawater decreases when it passes through the mesh, which promotes the sedimentation of suspended sand and the formation of silt.

[0020] After the tide recedes completely from the tidal flat, the bamboo sluice gate system is pressed tightly against the surface of the tidal flat, and the hemp rope net is covered on the silt, generating surface pressure to prevent the silt from cracking and flowing away.

[0021] Furthermore, when the bamboo gate system is arranged on the tidal flat, the angle between the length direction of the bamboo gate system and the direction of the main tidal wave is 75-90°.

[0022] Furthermore, at high tide in the tidal flat area, the maximum angle between the hemp rope net and the sea surface is 30°, while at high tide in the tidal flat area, the angle between the hemp rope net and the sea surface is no greater than 20°.

[0023] Furthermore, during the installation of the fixed pile system, the wooden piles are carbonized, the depth of the wooden piles inserted into the tidal flat is not less than 0.5m, the height of the exposed wooden piles on the tidal flat is higher than the height of the tidal flat at high tide, and the height of the exposed wooden piles on the tidal flat is not less than 1m.

[0024] Furthermore, in S4, after the thickness of the silt body increases by 30cm, the position of the limiting system is adjusted so that the bamboo tube gate system is in a floating state, while the inclination angle between the hemp rope net and the beach surface is in the range of 0-30°.

[0025] This invention also relates to a mangrove artificial island siltation device, which includes a bamboo gate system, a hemp rope net system, a fixed pile system, and a limiting system. The fixed pile system comprises multiple wooden stakes inserted into the tidal flat. The bamboo gate system is installed on one side of the fixed pile system. One end of the hemp rope net system is connected to the bamboo gate system, and the other end is connected to the fixed pile system. The limiting system is set on the fixed pile system to limit the vertical sliding height of the bamboo gate system and the hemp rope net system. The bamboo gate system floats on the tidal flat when the tide reaches it.

[0026] Furthermore, the bamboo tube gate system is composed of bamboo tubes forming a horizontal gate body, with vertical through holes pre-drilled at both ends of the bamboo tubes, and a horizontal through hole opened in the center of each bamboo tube segment.

[0027] The hemp rope net system includes a hemp rope net with square holes. The hemp rope net is square with the same length and width. One end of the hemp rope net is tied to the bamboo in the bamboo tube gate system, and the other end is horizontally opened in the opposite direction of the main wave and connected to the fixed pile system.

[0028] The fixed pile system consists of four wooden piles, divided into two groups of two. One group penetrates vertically through the vertical through holes reserved at both ends of the bamboo tube in the bamboo tube gate system to form a sliding joint; the other group penetrates vertically through the outside of the open hemp rope net. The wooden piles are vertically inserted into the depth of the tidal flat for fixation.

[0029] The limiting system consists of wooden nails driven into the top of the wooden stakes. These nails limit the vertical sliding height of the bamboo tube gate system and the hemp rope net system. Calculated from the beach surface, the upward displacement of the bamboo tube gate system is ≤1.0m, and the upward displacement of the hemp rope net system facing away from the main wave direction is ≤0.2m.

[0030] Based on the above technical solutions, the present invention patent's method for self-growth construction of mangrove ecological islands and artificial island siltation device have achieved the following technical advantages through practical application:

[0031] 1. The self-growth construction method of mangrove ecological islands of the present invention uses a specialized artificial island siltation device. The artificial island siltation device includes a bamboo tube gate system, a hemp rope net system, a fixed pile system, and a limiting system. The lifting bamboo tube gate (15cm in diameter × 1.5m) and the hemp rope net with a 10×10cm aperture form a dynamic filtration structure. By utilizing the buoyancy difference and water flow velocity changes generated by the ebb and flow of tides, the device achieves a synergistic effect of accelerating the passage of sand-carrying water during high tide and promoting siltation by blocking sand during low tide.

[0032] 2. In the process of forming the mangrove ecological island, the bamboo tube gate system of the present invention adopts a dual adjustment mechanism of bamboo joint holes. Horizontal through holes are opened in each bamboo tube segment to allow seawater to enter. This not only controls the buoyancy of the bamboo tube and keeps the bamboo tube suspended at about 10cm below the water surface, but also forms local turbulence to enhance fine particle flocculation.

[0033] 3. In the formation process of the mangrove ecological island of this invention, the hemp rope net siltation system forms a dynamic filtration structure. During high tide, the mesh opens, not affecting the transport of suspended sediment; during low tide, the mesh closes, blocking seawater and promoting sediment settling. The porosity of the hemp rope net changes non-linearly with the tide level (80% at high tide → 40% at low tide). Combined with the bamboo-joint holes regulating buoyancy balance, the device remains suspended on the surface layer of the sediment mass, achieving continuous siltation and elevation of the tidal flat to form an artificial ecological island. Once mangrove seedlings are planted on the artificial ecological island, it ensures that the mangrove roots are exposed above the sea surface for a sufficient amount of time each day.

[0034] 4. The mangrove artificial island sedimentation device of the present invention innovatively uses fully biodegradable materials to construct a growing sedimentation body. Moreover, the degradation cycle of the device (2-3 years) is precisely matched with the artificial island forming cycle (24-30 months). The bamboo tube gate, hemp rope net, fixed pile and limiter are all eco-friendly biodegradable materials that can be completely degraded, avoiding pollution to the ocean.

[0035] 5. Experiments have shown that the self-growth construction method and artificial island siltation device of the present invention can achieve rapid siltation of artificial islands, improve the siltation efficiency by more than 40% compared with traditional technology (the measured monthly average siltation thickness reaches 20cm), reduce the construction cost by about 75%, and achieve a structural integrity rate of >95% under typhoon conditions. After the materials are completely degraded, the natural stability coefficient of the artificial island still remains above 0.85. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating a method for constructing a self-growing mangrove ecological island according to the present invention.

[0037] Figure 2 This is a perspective view of the installation of the artificial island sedimentation device used in the self-growth construction method of a mangrove ecological island according to the present invention.

[0038] Figure 3 This is a diagram showing the usage status of the tidal flat fixing pile system and hemp rope net system in the self-growth construction method of mangrove ecological islands and artificial island siltation device of the present invention.

[0039] Figure 4 This is a diagram showing the usage status of the tidal flat fixing pile system and hemp rope net system in the self-growth construction method of mangrove ecological islands and artificial island siltation device of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific examples shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment belongs to a method for the self-growth construction of mangrove ecological islands, which specifically includes the following steps:

[0043] S1. An artificial island siltation device is set up on the tidal flat where mangrove seedlings are to be planted but the mangroves cannot be exposed to the sea surface for 4-6 hours per day. The artificial island siltation device includes a bamboo tube gate system 1, a hemp rope net system 2, a fixed pile system 3, and a limiting system 4. The fixed pile system 3 includes multiple wooden piles to be inserted into the tidal flat. The bamboo tube gate system 1 is installed on one side of the fixed pile system 3. One end of the hemp rope net system 2 is connected to the bamboo tube gate system 1, and the other end is connected to the fixed pile system 3. The limiting system 4 is set on the fixed pile system 3 to limit the vertical sliding height of the bamboo tube gate system 1 and the hemp rope net system 2.

[0044] S2, the initial elevation of the limiting system 4 is set by tidal observation data to ensure that the bamboo gate system 1 is in a semi-floating state at the average tide level;

[0045] S3, the artificial island siltation device is activated during the spring tide, and the water and sand separation effect generated by the hemp rope net system 2 is used to achieve an average daily siltation rise of 0.5 to 1 cm;

[0046] S4. After several days of siltation and elevation, when the height of the silt reached the elevation required for mangrove root growth, the hemp rope net system 2 was removed, and the silt formed a special ecological artificial island. Mangrove seedlings were planted on the formed mangrove ecological island to meet the requirement of mangroves being exposed to the sea surface for 4-6 hours a day, providing a good growth environment for subsequent mangrove growth.

[0047] In the aforementioned artificial island sedimentation device:

[0048] The bamboo tube gate system 1 is composed of bamboo tubes forming a horizontal gate body. Vertical through holes are pre-drilled at both ends of the bamboo tubes, and a horizontal through hole is opened in the center of each bamboo tube segment. When the bamboo tube gate system 1 is arranged on the tidal flat, the angle between the length direction of the bamboo tube gate system 1 and the direction of the main wave of the tide is 75-90°.

[0049] The hemp rope net system 2 includes a hemp rope net with square holes. The hemp rope net is square with the same length and width. One end of the hemp rope net is tied to the bamboo in the bamboo tube gate system, and the other end is horizontally opened in the opposite direction of the main wave and connected to the fixed pile system.

[0050] The fixed pile system 3 includes four wooden piles, two piles per group, forming two groups. One group penetrates vertically through the vertical through holes reserved at both ends of the bamboo tube in the bamboo tube gate system to form a sliding joint; the other group penetrates vertically through the outside of the open hemp rope net. The wooden piles are vertically inserted into the depth of the tidal flat for fixation.

[0051] The limiting system 4 is composed of wooden nails driven into the top of the wooden stakes. These wooden nails limit the vertical sliding height of the bamboo tube gate system and the hemp rope net system. Calculated from the beach surface, the upward displacement of the bamboo tube gate system is ≤1.0m, and the upward displacement of the hemp rope net system facing away from the main wave direction is ≤0.2m.

[0052] The bamboo tube gate system 1, hemp rope net system 2, fixed pile system 3, and limiting system 4 are all eco-friendly biodegradable materials. The biodegradation cycle of these materials matches the formation cycle of the artificial island. The degradation time of bamboo is 24-36 months, that of hemp rope net is 18-24 months, and that of wooden pile is 36-48 months. They can be completely degraded to avoid pollution to the ocean.

[0053] In S3, when the tide rises at the tidal flat location, the tide causes the bamboo tube gate system 1 to float up, and the hemp rope net at the front end of the fixed pile system 3 floats up with the limiting system 4, so that the hemp rope net at the front end of the fixed pile system 3 and the hemp rope net at the rear end of the fixed pile system 3 form an angle of up to 30°. At the same time, the holes of the hemp rope net are stretched open, and seawater carrying sediment rushes quickly to the shore from below the bamboo tube gate and through the holes of the hemp rope net, realizing the transport of suspended sediment.

[0054] As the tide recedes at the beach, the bamboo gate system 1 at the front end of the fixed pile system 3 sinks with the tide, as does the hemp rope net at the front end of the fixed pile system 3. This creates a sand-blocking angle between the hemp rope net at the front and rear ends of the fixed pile system 3. Simultaneously, the holes in the hemp rope net droop and close, reducing the flow velocity of seawater passing through the mesh and promoting the sedimentation of suspended sand into silt. During the low tide, the bamboo gate system 1 descends, and the hemp rope net droops and closes close to the beach surface. As seawater carrying sediment passes through the hemp rope net, it is slowed down, promoting gravity sedimentation and causing water-sand separation. Meanwhile, seawater flows back from above the bamboo gate, and the sediment is blocked by the hemp rope net and the bamboo gate, quickly settling and silting up. Furthermore, the reduced seawater flow velocity minimizes erosion and damage to the already accumulated sediment.

[0055] After the tide completely recedes from the tidal flat, the bamboo gate system 1 lies close to the surface of the tidal flat, and the hemp rope net covers the surface of the sediment, creating surface pressure to prevent the sediment from cracking and flowing away. The hemp rope net, falling and covering the sediment pile that forms the sediment pile, improves the crack resistance and wind resistance of the sediment pile. Through the bamboo gate and hemp rope net, which rely on the buoyancy of the tide to remain above the sediment pile, the sediment pile can continuously accumulate and rise to form an artificial island, ensuring the daily submersion and exposure of mangroves for their growth.

[0056] At high tide in the tidal flat area, the angle between the hemp rope net and the sea surface is a maximum of 30°, while at high tide in the tidal flat area, the angle between the hemp rope net and the sea surface is no greater than 20°.

[0057] During installation, the fixed pile system 3 involves carbonizing the wooden piles, inserting them into the tidal flat to a depth of at least 0.5m, and ensuring that the height of the exposed wooden piles on the tidal flat is higher than the high tide level of the tidal flat, with a height of at least 1m.

[0058] In S4, after the thickness of the silt increases by 30cm, the position of the limiting system 4 is adjusted so that the bamboo tube gate system is in a floating state, and at the same time the inclination angle between the hemp rope net and the beach surface is in the range of 0-30°.

[0059] Example 2

[0060] like Figures 2-4As shown, this embodiment is a mangrove artificial island siltation device. The artificial island siltation device includes a bamboo tube gate system 1, a hemp rope net system 2, a fixed pile system 3, and a limiting system 4. The fixed pile system 3 includes multiple wooden piles inserted into the tidal flat. The bamboo tube gate system 1 is installed on one side of the fixed pile system 3. One end of the hemp rope net system 2 is connected to the bamboo tube gate system 1, and the other end is connected to the fixed pile system 3. The limiting system 4 is set on the fixed pile system 3 to limit the vertical sliding height of the bamboo tube gate system 1 and the hemp rope net system 2. The bamboo tube gate system 1 floats on the tidal flat when the tide reaches the tidal flat.

[0061] Furthermore, the bamboo tube gate system 1 is composed of bamboo tubes forming a horizontal gate body, with vertical through holes pre-drilled at both ends of the bamboo tubes, and a horizontal through hole opened in the center of each bamboo tube segment.

[0062] The hemp rope net system 2 includes a hemp rope net with square holes. The hemp rope net is square with the same length and width. One end of the hemp rope net is tied to the bamboo in the bamboo tube gate system, and the other end is horizontally opened in the opposite direction of the main wave and connected to the fixed pile system.

[0063] The fixed pile system 3 includes four wooden piles, two piles per group, forming two groups. One group penetrates vertically through the vertical through holes reserved at both ends of the bamboo tube in the bamboo tube gate system to form a sliding joint; the other group penetrates vertically through the outside of the open hemp rope net. The wooden piles are vertically inserted into the depth of the tidal flat for fixation.

[0064] The limiting system 4 is composed of wooden nails driven into the top of the wooden stakes. These wooden nails limit the vertical sliding height of the bamboo tube gate system and the hemp rope net system. Calculated from the beach surface, the upward displacement of the bamboo tube gate system is ≤1.0m, and the upward displacement of the hemp rope net system facing away from the main wave direction is ≤0.2m.

[0065] The artificial island siltation device of the present invention comprises a bamboo tube gate system 1, a hemp rope net system 2, a fixed pile system 3, and a limiting system 4. During high tide, the bamboo tube gate floats up, and the hemp rope net tauts away from the beach surface, allowing seawater carrying sediment to rush onto the shore rapidly from below the bamboo tube gate and through the holes in the hemp rope net. During low tide, the bamboo tube gate descends, and the hemp rope net hangs close to the beach surface, causing the seawater carrying sediment to be slowed down as it passes through the hemp rope net, thus promoting gravity settling and resulting in water-sediment separation. Seawater flows back from above the bamboo sluice gate, and the silt is blocked and quickly sinks and accumulates due to the combined effect of the hemp rope net and the bamboo sluice gate. At the same time, reducing the seawater flow velocity reduces erosion damage to the accumulated silt. After the tide recedes completely, the hemp rope net covers the surface of the accumulated silt, improving the crack resistance and wind resistance of the silt. The bamboo sluice gate and hemp rope net remain above the silt by the buoyancy of the tide, allowing the silt to continuously accumulate and rise to form an artificial island, ensuring the daily submersion and exposure of mangroves for growth. The bamboo sluice gate, hemp rope net, anchor piles, and limiters are all environmentally friendly biodegradable materials that can completely degrade and avoid pollution to the ocean.

[0066] This invention utilizes the buoyancy difference and water flow velocity changes generated by tidal fluctuations to achieve a synergistic effect of accelerating the passage of sediment-laden water during high tide and simultaneously hindering sedimentation and promoting siltation during low tide. It innovatively employs fully biodegradable materials to construct a growing sedimentary body, and uses bamboo-joint holes to regulate buoyancy balance, ensuring the device remains suspended on the surface of the sedimentary body. This allows for continuous sedimentation and elevation of the tidal flats, facilitating the early formation of an artificial ecological island. Specifically, the bamboo gate and hemp rope net rely on tidal buoyancy to remain above the sediment pile, allowing the sediment pile to continuously accumulate and rise, forming an artificial island and ensuring the daily submersion and exposure of mangroves for growth. The device of this invention has technical advantages such as low construction cost, dynamic adaptation to tidal changes, and avoidance of secondary pollution.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for constructing a self-growing mangrove ecological island, characterized in that, The method specifically includes the following steps: S1. A special artificial island siltation device is set up on the tidal flat where mangrove seedlings are to be planted and the mangroves cannot be exposed to the sea surface for 4-6 hours a day. The artificial island siltation device includes a bamboo tube gate system (3), a hemp rope net system, a fixed pile system (1) and a limiting system (4). The fixed pile system (1) includes multiple wooden piles to be inserted into the tidal flat. The bamboo tube gate system (3) is installed on one side of the fixed pile system (1). One end of the hemp rope net system is connected to the bamboo tube gate system (3) and the other end is connected to the fixed pile system (1). The limiting system (4) is set on the fixed pile system (1) to limit the vertical sliding height of the bamboo tube gate system (3) and the hemp rope net system. In the aforementioned artificial island sedimentation device: The bamboo tube gate system (3) is composed of bamboo tubes of moso bamboo forming a horizontal gate body. Vertical through holes are pre-drilled at both ends of the bamboo tubes, and horizontal through holes are opened in the center of each bamboo tube segment. The hemp rope net system (2) includes a hemp rope net with square holes. The hemp rope net is square with the same length and width. One end of the hemp rope net is bound to the bamboo in the bamboo tube gate system (3), and the other end is horizontally opened in the opposite direction of the main wave and connected to the fixed pile system (1). The fixed pile system (1) includes four wooden piles, two piles per group, forming two groups. One group penetrates vertically through the vertical through holes reserved at both ends of the bamboo tube in the bamboo tube gate system (3) to form a sliding joint; the other group penetrates vertically through the outside of the open hemp rope net. The wooden piles are vertically inserted into the depth of the tidal flat for fixation. The limiting system (4) is made of wooden nails driven into the top of the wooden stakes. The wooden nails limit the vertical sliding height of the bamboo tube gate system (3) and the hemp rope net system. Calculated from the beach surface, the upward displacement of the bamboo tube gate system (3) is ≤1.0m, and the upward displacement of the hemp rope net system facing away from the main wave direction is ≤0.2m. S2, the initial elevation of the limiting system (4) is set by tidal observation data to ensure that the bamboo gate system (3) is in a semi-floating state at the average tide level; S3, during the spring tide, the artificial island siltation device is put into operation, and the water and sand separation effect generated by the hemp rope net system is used to achieve an average daily siltation rise of 0.5 to 1 cm; S4. After several days of siltation and elevation, when the height of the silt reaches the elevation required for mangrove root growth, the rope net system is removed, and mangrove seedlings are planted on the formed mangrove ecological island. In S4, after the thickness of the silt increases by 30cm, the position of the limiting system (4) is adjusted so that the bamboo tube gate system (3) is in a floating state, and the inclination angle between the hemp rope net and the beach surface is 0-30°. When the bamboo tube gate system (3) is arranged on the tidal flat, the angle between the length direction of the bamboo tube gate system (3) and the direction of the main wave of the tide is 75-90°. At high tide in the tidal flat area, the angle between the hemp rope net and the sea surface is up to 30°.

2. The method for constructing a self-growing mangrove ecological island according to claim 1, characterized in that, The biodegradation cycles of the bamboo tube gate system (3), hemp rope net system (2), fixed pile system (1) and limiting system (4) are matched with the artificial island forming cycle. The degradation time of bamboo is 24-36 months, the degradation time of hemp rope net is 18-24 months, and the degradation time of wooden pile is 36-48 months.

3. The method for constructing a self-growing mangrove ecological island according to claim 1, characterized in that, In S3, When the tide rises at the tidal flat location, the tide causes the bamboo tube gate system (3) to float up, and the hemp rope net at the front end of the fixed pile system (1) floats up with the bamboo tube gate system (3), so that the hemp rope net at the front end of the fixed pile system (1) and the hemp rope net at the rear end of the fixed pile system (1) form an angle of up to 30°. At the same time, the holes of the hemp rope net are stretched open, and seawater flows through the hemp rope net to realize the transport of suspended sand. When the tide recedes at the tidal flat location, the bamboo tube gate system (3) at the front end of the fixed pile system (1) falls with the tide, and the hemp rope net at the front end of the fixed pile system (1) falls with the bamboo tube gate system (3), so that the hemp rope net at the front end of the fixed pile system (1) and the hemp rope net at the rear end of the fixed pile system (1) form a sand-blocking angle. At the same time, the holes of the hemp rope net hang down and close, and the flow velocity of seawater decreases when passing through the mesh, which promotes the sedimentation of suspended sand to form silt. After the tide recedes completely from the tidal flat, the bamboo gate system (3) is pressed against the surface of the tidal flat, and the hemp rope net is covered on the silt to generate surface pressure and inhibit the drying and loss of mud and sand.

4. The method for constructing a self-growing mangrove ecological island according to claim 1, characterized in that, At high tide in the tidal flat area, the angle between the hemp rope net and the sea surface should not exceed 20°.

5. The method for self-growth construction of mangrove ecological islands based on dynamic regulation of tidal energy according to claim 1, characterized in that, When the fixed pile system (1) is installed, the wooden piles are carbonized, the depth of the wooden piles inserted into the tidal flat is not less than 0.5m, the height of the exposed wooden piles on the tidal flat is higher than the height of the tidal flat at high tide, and the height of the exposed wooden piles on the tidal flat is not less than 1m.

6. A mangrove artificial island siltation device, applied to the mangrove ecological island self-growth construction method based on dynamic tidal energy control as described in any one of claims 1-5, characterized in that, The artificial island siltation device includes a bamboo gate system (3), a hemp rope net system (2), a fixed pile system (1), and a limiting system (4). The fixed pile system (1) contains multiple wooden stakes inserted into the tidal flat. The bamboo gate system (3) is installed on one side of the fixed pile system (1). One end of the hemp rope net system (2) is connected to the bamboo gate system (3), and the other end is connected to the fixed pile system (1). The limiting system (4) is set on the fixed pile system (1) to limit the vertical sliding height of the bamboo gate system (3) and the hemp rope net system (2). The bamboo gate system (3) floats on the tidal flat when the tide reaches it. The bamboo tube gate system (3) is composed of bamboo tubes of moso bamboo forming a horizontal gate body. Vertical through holes are pre-drilled at both ends of the bamboo tubes, and horizontal through holes are opened in the center of each bamboo tube segment. The hemp rope net system (2) includes a hemp rope net with square holes. The hemp rope net is square with the same length and width. One end of the hemp rope net is bound to the bamboo in the bamboo tube gate system (3), and the other end is horizontally opened in the opposite direction of the main wave and connected to the fixed pile system (1). The fixed pile system (1) includes four wooden piles, two piles per group, forming two groups. One group penetrates vertically through the vertical through holes reserved at both ends of the bamboo tube in the bamboo tube gate system (3) to form a sliding joint; the other group penetrates vertically through the outside of the open hemp rope net. The wooden piles are vertically inserted into the depth of the tidal flat for fixation. The limiting system (4) is made of wooden nails driven into the top of the wooden stakes. The wooden nails limit the vertical sliding height of the bamboo tube gate system (3) and the hemp rope net system. Calculated from the beach surface, the upward displacement of the bamboo tube gate system (3) is ≤1.0m, and the upward displacement of the hemp rope net system facing away from the main wave direction is ≤0.2m.

Images