A system and method for promoting siltation and land reclamation on sandy coasts or islands with one-way sand transport

Abstract

The present invention discloses a system and method for promoting siltation and land reclamation on sandy coasts or islands with one-way sand transport. The system for promoting siltation and land reclamation includes underwater one-way sand transport dikes, one-way sand transport fences on the shore, semicircular grass grids and enclosure barrel planting devices arranged in sequence from the ocean direction to the land direction, and the underwater one-way sand transport dikes and one-way sand transport fences on the shore are respectively parallel to the coastline and arranged in multiple lanes. The system for promoting siltation and land reclamation on sandy coasts or islands provided by the present invention includes four measures with different functions, with distribution areas ranging from the nearshore seabed to the land beach, and complementing each other. With the help of natural forces such as waves, tides, and wind, it can promote the transportation of water, sand, and wind-blown sand sediments to the shore, and block the return flow of sediments to the sea, so that the supply of sediments to the shore is greater than the loss to the sea, promote the siltation of the seabed and the beach, and has the effect of promoting siltation and land reclamation and inhibiting coastal erosion. It is very suitable for the protection of sandy coasts and islands where sediments are lost year by year.

Description

Technical Field

[0001] The invention belongs to the technical field of coastal erosion control, and in particular relates to a system and method for promoting siltation and land formation on sandy coasts or islands with one-way sand transport. Background Art

[0002] Among marine disasters, coastal erosion, which has a global trend, has attracted widespread attention. Coastal erosion refers to the destructive process of coastal retreat caused by the fact that the coastal sand supply is less than the coastal sand loss under the action of ocean dynamics. This causes environmental hazards such as beach retreat, reduction of island and land area, flooding of coastal low-lying areas, backflow of seawater, and destruction of near-shore buildings and facilities. Therefore, it is very necessary to develop methods to promote the siltation of sandy coasts and islands and prevent coastal erosion.

[0003] In order to mitigate the damage caused by coastal erosion, the current method is to change the migration pattern of nearshore sediment through engineering measures in local coastal sections, so that the sediment accumulates. The main protective projects are as follows:

[0004] First, seawalls are a traditional method of coastal protection for human beings. They are built in areas with higher beaches and are used to separate coastal land and sea areas. They are generally parallel to the coastline. Although they play a great role in fixing the coast and preventing moisture and waves, they are generally not used for beach protection and are not suitable as a long-term wave protection method, unless they are used as an auxiliary or emergency measure under other engineering measures. Therefore, this type of engineering structure is generally only suitable for coasts with small waves or silted coasts to prevent abnormal sea subsidence.

[0005] Second, spur dikes and spur dike groups are coastal structures that are nearly perpendicular to the coastline. Their function is to intercept the silt transported from the upstream coast to form a wide beach and protect the coast. Spur dikes have a relatively mature application on muddy coasts and can be used in muddy coastal areas. Spur dikes and spur dike groups rely on intercepted silt to achieve the purpose of protecting the coast. Therefore, for rivers with decreasing sediment transport volume year by year, such as the Yellow River, it is not conducive for spur dikes to intercept a large amount of silt to form a beach. Therefore, this protection method has shortcomings, especially for sandy coasts.

[0006] Third, offshore breakwaters are breakwaters built in the sea area at a certain distance from the coastline and roughly parallel to the coastline. They are called offshore breakwaters, or offshore breakwaters for short. They function similarly to groins and can cause siltation on the upstream side of the offshore breakwater. Large stones or various concrete blocks can be used as protective surfaces. However, the opening of the offshore breakwater is small, and pollution is easy to accumulate in the bay and difficult to discharge. Therefore, environmental pollution issues should be considered when choosing an offshore breakwater as a coastal protection project.

[0007] Fourth, artificial river beach sand replenishment, collecting suitable sand from the sea or land to replenish the eroded beach is the most natural countermeasure to solve coastal erosion. Beach sand replenishment has been proven to be an economical and effective measure, and its impact on downstream beaches is less than other protective facilities. Since the sand artificially filled on the beach will still be washed away under various marine environmental conditions, especially sandy islands under the action of waves, the beach must be replenished every few years.

[0008] Fifth, in the existing relevant patent CN 115217063A, the seabed sand-retaining and silting-promoting embankment and the inclined one-way sand barrier are respectively set in the sea water and on the coastal beach, which can promote the transport of sediments to the shore and inhibit their retreat to the sea, playing a role in promoting siltation and land formation.

[0009] Although there are many forms of coastal protection projects, they all have their own shortcomings. From the above analysis, we can see that, first of all, except for the fourth and fifth measures, the rest of the measures are set up in the sea water, which does not protect the beaches above the high tide line, and the sand will still be eroded into the sea water by wind; secondly, various dams have played a role in reducing waves and silt accumulation on the shore, but at the same time a large amount of sea sand is still washed back into the sea. Both sides of the dam play a role in blocking silt, reducing the supply of silt to the shore and the siltation effect.

[0010] In order to solve the deficiencies in the above-mentioned prior art, the present invention applies the Tesla valve structure for the first time to the field of promoting siltation and land reclamation on coasts and islands. The underwater one-way sand transport dyke and onshore one-way sand transport fence established are very different from the siltation dyke and sand barrier in the above-mentioned patents in terms of principle and structure. The present invention can make the resistance of water and air flow to the sea much greater than the resistance to flow to the shore. It uses the unique spatial physical structure and natural forces to accelerate the flow of fluid to the shore, hinder the retreat process to the sea, and promote beach siltation; and the channel-type structural design has a stronger effect on accelerating the fluid to the shore and decelerating it to the sea, and has a better effect on promoting siltation; the one-way valve structure without movable components does not require maintenance and has the advantages of low cost and long life. Summary of the invention

[0011] The main purpose of the present invention is to provide a system and method for promoting siltation and land reclamation on sandy coasts or islands with one-way sand transport, so as to overcome the shortcomings of the prior art.

[0012] In order to achieve the above-mentioned invention object, the technical solution provided by the present invention includes:

[0013] The present invention provides a unidirectional sand transport system for promoting siltation and land reclamation on sandy coasts or islands, comprising an underwater unidirectional sand transport dike, an onshore unidirectional sand transport fence, a semicircular grass grid and a protective barrel planting device which are arranged in sequence from the ocean direction to the land direction, and the underwater unidirectional sand transport dike and the onshore unidirectional sand transport fence are respectively parallel to the coastline and are arranged in multiple lanes.

[0014] Furthermore, the underwater one-way sand transport dike is arranged on the intertidal zone between the lowest tide line and the highest tide line, and the top of the underwater one-way sand transport dike is lower than the lowest tide line;

[0015] The underwater one-way sand transport dike includes a plurality of first channel side plates, a first guide plate and a first connecting rod, and the bottom of the first channel side plate is connected and fixed to a base buried under the seabed surface; the plurality of first channel side plates are perpendicular to the coastline direction and are arranged in multiple rows in parallel; between two adjacent first channel side plates, 2-4 pairs of first guide plates are arranged in pairs through the first connecting rod, each pair of first guide plates is opposite to each other at an acute angle of 20-40 degrees, and maintains an opening of 30-50 cm at one end close to each other, and the narrow opening direction of each pair of first guide plates faces the land, and the wide opening direction faces the ocean.

[0016] Furthermore, the first channel side panels are provided with embedded bolt fixing holes, the four corners of the first guide plate are provided with embedded steel bar fixing rings, the first connecting rod is a steel rod with threads on both ends processed from solid steel bars, the two ends of the first connecting rod are respectively fixed in the bolt fixing holes of two adjacent first channel side panels, and the middle passes through the embedded steel bar fixing rings of the paired first guide plates, so as to fix the multiple first channel side panels and the first guide plates therebetween to each other.

[0017] Furthermore, the onshore one-way sand transport fence is arranged above the highest tide line and in a dry beach area with strong wind and sand transmission, and includes a plurality of second channel side panels, a second guide plate and a second connecting rod, and both ends of the second channel side panels and the second guide plate are tied and fixed on the vertical poles inserted into the ground; the plurality of second channel side panels are perpendicular to the coastline direction and are arranged in parallel in multiple rows; between two adjacent second channel side panels, 2-4 pairs of second guide plates are arranged in pairs through the second connecting rod, each pair of second guide plates is opposite to each other at an acute angle of 20-40 degrees, and at one end close to each other, an opening of 30-50 cm is maintained, and the narrow opening direction of each pair of second guide plates faces the land, and the wide opening direction faces the sea;

[0018] The second channel side plates and the second guide plates are both rectangular frame structures welded from round steel, on which a HDPE net with a porosity of 30-45% is bound and fixed.

[0019] Furthermore, the semicircular grass grid is used to fix the mobile sand dunes in the coastal foredune belt, and includes a grass rope and a plurality of plant straw bundles, wherein the plurality of plant straw bundles are distributed in sequence along the length direction of the grass rope, wherein the plant straw bundle has a semicircular structure formed by wrapping a plurality of plant straws in the middle with the grass rope.

[0020] Furthermore, the enclosure barrel planting device is used for planting seedlings and afforestation at the beach location, and comprises an enclosure barrel, a water-collecting membrane with a circular or square ring structure, and a membrane edge sealing and fixing wedge. The enclosure barrel comprises a barrel structure formed by curling straw mats, at least the lower part of the barrel structure is arranged underground, and the rest is located above the ground surface, and planting holes and seedlings are distributed in the barrel structure; the water-collecting membrane is sleeved on the enclosure barrel, and the inner ring is tightly attached to the outer wall of the enclosure barrel, and the edges of the four sides of the outer ring are respectively attached to the membrane edge sealing and fixing wedges, and the membrane edge sealing and fixing wedges are vertically inserted into the ground surface, so that the water-collecting membrane is laid flat on the ground surface, and the surrounding of the water-collecting membrane is kept sealed and fixed;

[0021] Wherein, the straw mat is soaked in a hydrophilic adhesive, the hydrophilic adhesive comprises a hydrophilic high molecular organic substance and water, and the hydrophilic high molecular organic substance comprises epoxy resin, polyurethane or acrylic resin.

[0022] The present invention also provides a method for promoting siltation and land reclamation on a sandy coast or island with one-way sand transport, the method for promoting siltation and land reclamation is implemented based on the above-mentioned system for promoting siltation and land reclamation on a sandy coast or island with one-way sand transport, and the method for promoting siltation and land reclamation comprises:

[0023] An underwater one-way sand transport dike is set up in the intertidal zone between the lowest tide line and the highest tide line to gradually accumulate water and sand on the nearshore seabed;

[0024] In dry beach areas above the highest tidal level and with strong wind-blown sand transport, one-way sand transport fences are installed on the shore to promote the onshore transport of wind-blown sand in the beach area, inhibit the retreat of wind-blown sand sediments to the sea, and promote the accumulation of beach quicksand;

[0025] A semicircular grass grid is arranged in the coastal forehill belt to fix the mobile sand dunes in the coastal forehill belt;

[0026] Seedlings are planted on the beach using a protective barrel planting device to form a planting belt to fix quicksand and restore the ecology.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The one-way sand transport system for promoting siltation and land formation on sandy coasts or islands of the present invention, in seawater, the underwater one-way sand transport dam can promote the onshore transport of sediments in the nearshore seabed area and inhibit the transport of sediments to the sea; on land, the one-way sand transport fence on the shore can promote the onshore transport of sediments in the beach area and inhibit the transport of sediments to the sea; in addition, the semi-circular grass grids arranged in the coastal foredune belt and the protective barrel planting device arranged in the beach area can effectively fix the silted quicksand and restore the ecology; four measures with different functions are arranged in multiple channels parallel to the coastline according to the beach terrain conditions, and the siltation and land formation system formed by combining with each other, from the nearshore seabed to the land beach, makes the onshore supply of water, sand and wind-blown sand sediments greater than the loss to the sea, promotes the siltation of the seabed and the beach, and continuously improves the seabed surface and beach elevation. For sandy coastlines and islands, it is an effective measure for promoting siltation and land formation and comprehensive management of nearshore water, sand and wind-blown sand.

[0029] (2) The underwater one-way sand transport dam and the one-way sand transport fence on the shore of the present invention apply the Tesla valve structure for the first time in the field of promoting siltation and land reclamation on coasts and islands. The resistance of water and air flow to the sea is much greater than the resistance to flow to the shore. The unique spatial physical structure and natural forces are used to accelerate the flow of fluids to the shore and hinder the retreat process to the sea. The sediment accumulation on sandy coastlines and islands can be effectively promoted, achieving the purpose of continuous surface uplift and promoting siltation and land reclamation.

[0030] (3) The underwater one-way sand transport dam and the one-way sand transport fence on the shore in the present invention do not need to rely on controlling any movable components to achieve the open and closed state. It is a one-way valve structure without movable components and has no moving parts. Therefore, it does not require any maintenance, which has the advantages of cost saving and long service life of the project. In addition, the one-way sand transport fence on the shore is liftable. When quicksand accumulates in the fence, the fence can be lifted without affecting the function of the one-way valve.

[0031] (4) The semicircular grass grid in the present invention simulates the radial branching structure of the above-ground straw of the traditional grass grid, which can sway with the wind to reduce wind energy. There is no need to bury straw underground. It has the advantages of large wind-blocking surface, high sand-fixing efficiency, straw saving, convenient construction, natural degradation, and promotion of crusting and native vegetation growth. The addition of branches with leaves improves the wind-blocking and sand-fixing efficiency of the grass grid and makes the structure more stable. This technology also overcomes the problem of the traditional grass grid's straw lodging that reduces the sand-fixing efficiency.

[0032] (5) The enclosure barrel planting device of the present invention can promote the rapid penetration of rainwater or artificial irrigation into the deep soil layer; provide shade and moisture to protect seedlings from high temperature, reduce the temperature of the sand surface where the seedlings are grounded, and prevent the phloem of the seedlings from being scalded or scalded to death; compared with the protective shading method of PVC pipes, the enclosure barrel has a larger water contact area and vertical gap, and is added with a hydrophilic adhesive, which has a better water infiltration effect, while only the outer wall and the inner wall of the PVC pipe can guide water downward, and the hydrophilic adhesive can increase the toughness of the straw material and reduce its brittleness; in addition, the easily buried water-collecting membrane can prevent the evaporation of soil moisture, and directly guide rainfall and artificial irrigation to the edge of the enclosure barrel, so that it can quickly infiltrate into the deep soil layer, promoting root development and plant growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a schematic structural diagram of a sandy coast or island siltation and land formation system with one-way sand transport in one embodiment of the present application.

[0035] Figure 2 yes Figure 1 Schematic diagram of the structure of the underwater one-way sand transport dike.

[0036] Figure 3 yes Figure 1 Schematic diagram of the structure of the one-way sand transport fence on the middle shore.

[0037] Figure 4 yes Figure 1 Schematic diagram of the cross section of a medium semicircular grass grid.

[0038] Figure 5 yes Figure 1 Schematic diagram of the structure of the medium-enclosing barrel planting device.

[0039] Figure 6 It is a schematic diagram of the flow field of the underwater one-way sand transport dike and the one-way sand transport fence on the shore.

[0040] Explanation of reference numerals: 1. Underwater one-way sand transport embankment, 11. First channel side plate and base, 12. First guide plate, 13. First connecting rod, 2. Onshore one-way sand transport fence, 21. Second channel side plate, 22. Second guide plate, 23. Second connecting rod, 24. Vertical pole, 3. Semicircular grass grid, 31. Plant straw bundle, 32. Grass rope, 33. Branch, 4. Enclosure barrel planting device, 41. Enclosure barrel, 42. Water collection membrane, 43. Membrane edge Sealing fixed wedge, 44. Seedlings, 51. Lowest tide line, 52. Highest tide line, 53. Onshore current, 54. Onshore wind, 55. Nearshore seabed, 56. Sand dunes, 57. Intertidal zone, 58. Beach, 59. Coastal foredune zone, 60. Sandy beach, 7. Schematic diagram of the flow field of sand transport dikes and sand transport fences, 71. Schematic diagram of the flow field of sand transport dikes and sand transport fences under the action of onshore wind, 72. Schematic diagram of the flow field of sand transport dikes and sand transport fences under the action of onshore wind. DETAILED DESCRIPTION

[0041] The present invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are only exemplary of the present invention, which can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be interpreted as limiting, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in different ways in virtually any appropriate detailed embodiment.

[0042] In order to solve the deficiencies in the prior art, the present invention utilizes the Tesla valve principle and adds an obstacle with a specific angle inside the channel ( Figure 6 ), from the sea to the shore (i.e., the flow field diagram of the sand transport dike and sand transport fence under the action of the sea breeze 71), the fluid is in a "convergent" state, while from the shore to the sea (i.e., the flow field diagram of the sand transport dike and sand transport fence under the action of the onshore wind 72), the fluid is in a "dispersed" state. The convergence and dispersion of fluids have completely different physical properties. In the convergent state, as the contact area decreases, the flow velocity of the fluid increases. This acceleration means that the pressure in the flow direction decreases; in the dispersed state, it is completely the opposite. The pressure will increase along the flow direction. This pressure increase is also called adverse pressure gradient. As the pressure increases along the flow direction, the flow velocity of the fluid particles decreases, and then a backflow is formed after continuing to move forward for a certain distance, which will lead to the appearance of vortices and energy loss. Simply put, dispersed flow is difficult to sustain, and it encounters much greater resistance than convergent flow.

[0043] Using the Tesla valve principle mentioned above, we have designed underwater one-way sand transport dikes and onshore one-way sand transport fences that can promote one-way flow of water, sand and wind. It allows fluid to flow in one direction, but there is huge resistance in the opposite direction. With its unique structural design and natural power, it effectively realizes passive flow control in the channel, which can have a pressure drop characteristic related to the direction, forming a "fluid diode" effect, that is, the flow resistance in one direction is higher than that in the other direction. By using natural water power and wind power, sea sand is continuously accumulated toward the shore. At the same time, semi-circular grass grids and enclosure barrel planting devices are used to fix quicksand and build vegetation. In the long run, this system can effectively increase the elevation and area of ​​the coastline and islands, and achieve the purpose of promoting siltation and land reclamation.

[0044] One aspect of an embodiment of the present invention provides a one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands, comprising an underwater one-way sand transport embankment, an onshore one-way sand transport fence, a semicircular grass grid and a protective barrel planting device arranged in sequence from the ocean direction to the land direction, and the underwater one-way sand transport embankment and the onshore one-way sand transport fence are respectively parallel to the coastline and are arranged in multiple lanes.

[0045] In some preferred embodiments, the underwater one-way sand transport dike is arranged on the intertidal zone between the lowest tide line and the highest tide line, and the top of the underwater one-way sand transport dike is lower than the lowest tide line;

[0046] The underwater one-way sand transport dike includes a plurality of first channel side plates, a first guide plate and a first connecting rod, and the bottom of the first channel side plate is connected and fixed to a base buried under the seabed surface; the plurality of first channel side plates are perpendicular to the coastline direction and are arranged in multiple rows in parallel; between two adjacent first channel side plates, 2-4 pairs of first guide plates are arranged in pairs through the first connecting rod, each pair of first guide plates is opposite to each other at an acute angle of 20-40 degrees, and maintains an opening of 30-50 cm at one end close to each other, and the narrow opening direction of each pair of first guide plates faces the land, and the wide opening direction faces the ocean.

[0047] In some preferred embodiments, the first channel side panels are provided with pre-embedded bolt fixing holes, the four corners of the first guide plate are provided with pre-embedded steel bar fixing rings, the first connecting rod is a steel rod with threads on both ends processed from solid steel bars, the two ends of the first connecting rod are respectively fixed in the bolt fixing holes of two adjacent first channel side panels, and the middle passes through the pre-embedded steel bar fixing rings of the paired first guide plates, so as to fix the multiple first channel side panels and the first guide plates therebetween to each other.

[0048] In some more preferred embodiments, the height of the first channel side plate is 1-1.5m, the thickness is 15-40cm, the length perpendicular to the shoreline is 3-6m, and the spacing between two adjacent first channel side plates is 1.5-2.5m.

[0049] In some more preferred embodiments, the first guide plate is a rectangular plate structure cast with cement, with a height of 1-1.5m, a length of 1-2m, and a thickness of 15-30cm.

[0050] In some more preferred embodiments, the diameter of the first connecting rod is 2-4 cm, and the length is the distance between two adjacent first channel side plates.

[0051] In some more preferred embodiments, the base is an integrally molded structure cast in cement, and the cross-section of the base is trapezoidal, with a height of 0.8-1.5m, a length of the bottom side of the cross-section of 0.6-1m, a length of the top side of the cross-section of 15-40cm, and a length perpendicular to the shoreline of 3-6m.

[0052] In some preferred embodiments, the onshore one-way sand transport fence is arranged above the highest tidal line and in a dry beach area with strong wind and sand transmission, and includes a plurality of second channel side panels, a second guide plate and a second connecting rod, and both ends of the second channel side panels and the second guide plates are tied and fixed on the vertical poles inserted into the ground; the plurality of second channel side panels are perpendicular to the coastline direction and are arranged in parallel in multiple rows; between two adjacent second channel side panels, 2-4 pairs of second guide plates are arranged in pairs through the second connecting rod, each pair of second guide plates is opposite to each other at an acute angle of 20-40 degrees, and maintains an opening of 30-50 cm at one end close to each other, and the narrow opening direction of each pair of second guide plates faces the land, and the wide opening direction faces the sea;

[0053] The second channel side plates and the second guide plates are both rectangular frame structures welded from round steel, on which a HDPE net with a porosity of 30-45% is bound and fixed.

[0054] In some more preferred embodiments, the length of the second channel side plate in the direction perpendicular to the coastline is 3-6 m, the height is 1-1.5 m, and the spacing between two adjacent second channel side plates is 1.5-2.5 m.

[0055] In some more preferred embodiments, the second guide plate has a length of 1-2 m and a height of 1-1.5 m.

[0056] In some more preferred embodiments, the second connecting rod is a round steel with a diameter of 2-4 cm, and the two ends of the second connecting rod are respectively welded and fixed to the top and bottom round steel frames of the second channel side plates and the second guide plates, so as to fix the plurality of second channel side plates and the second guide plates therebetween to each other.

[0057] In some more preferred embodiments, the vertical pole is a round steel with a diameter of 3-4 cm, which is inserted into the ground, wherein the underground burial depth is 50-100 cm and the above-ground leakage height is 2.0-2.5 m.

[0058] In some more preferred embodiments, a plurality of vertical poles are bundled with the sides of the second channel side plates and the second guide plate to fix the second channel side plates and the second guide plate; when the second channel side plates and the second guide plate are buried in sand, the bundles between the vertical poles and the second channel side plates and the second guide plate can be untied to lift the second channel side plates and the second guide plate.

[0059] The underwater one-way sand transport dyke and the one-way sand transport fence on the shore in the embodiment of the present invention apply the Tesla valve structure to the field of promoting siltation and land formation on coasts and islands for the first time, which can make the resistance of water and air flow to the sea much greater than the resistance to flow to the shore. The unique spatial physical structure and natural force are used to accelerate the flow of fluid to the shore and hinder the retreat process to the sea, which can effectively promote the accumulation of sediments on sandy coastlines and islands, and achieve the purpose of continuous surface uplift and promoting siltation and land formation. It does not need to rely on controlling any active components to achieve the opening and closing state. It is a one-way valve structure without active components and has no moving parts. Therefore, it does not require any maintenance and has the advantages of cost saving and long engineering service life. In addition, the one-way sand transport fence on the shore is liftable. When quicksand accumulates in the fence, the fence can be lifted without affecting the function of the one-way valve.

[0060] In some preferred embodiments, the semicircular grass grid is used to fix the mobile sand dunes in the coastal foredune belt, and includes a grass rope and a plurality of plant straw bundles, wherein the plurality of plant straw bundles are distributed in sequence along the length direction of the grass rope, wherein the plant straw bundle has a semicircular structure formed by wrapping a plurality of plant straws in the middle with the grass rope.

[0061] In some more preferred embodiments, the semicircular grass grids are arranged in a size of 1-2m×1-2m.

[0062] In some more preferred embodiments, the plant straw bundle is fixed on the shifting sand dunes of the coastal forehill belt via branches with leaves, and the semicircular surface of the plant straw bundle is arranged perpendicular to the shifting sand dunes.

[0063] The semicircular grass grid in the embodiment of the present invention simulates the radial branching structure of the above-ground straw of the traditional grass grid, which can sway with the wind to reduce wind energy. There is no need to bury straw underground. It has the advantages of large wind-blocking surface, high sand-fixing efficiency, straw saving, convenient construction, natural degradation, promotion of crusting and native vegetation growth, etc. The addition of branches with leaves improves the wind-blocking and sand-fixing efficiency of the grass grid and makes the structure more stable. This technology also overcomes the problem of reduced sand-fixing efficiency due to lodging of straw in traditional grass grids.

[0064] In some preferred embodiments, the enclosure barrel planting device is used for planting seedlings and afforestation at the beach location, and includes an enclosure barrel, a water-collecting membrane with a circular or square ring structure, and a membrane edge sealing and fixing wedge. The enclosure barrel includes a barrel structure formed by curling straw curtains, at least the lower part of the barrel structure is arranged underground, and the rest is located above the ground surface, and planting holes and seedlings are distributed in the barrel structure; the water-collecting membrane is sleeved on the enclosure barrel, and the inner ring is tightly attached to the outer wall of the enclosure barrel, and the edges of the four sides of the outer ring are respectively attached to the membrane edge sealing and fixing wedges, and the membrane edge sealing and fixing wedges are vertically inserted into the ground surface, so that the water-collecting membrane is laid flat on the ground surface and the surrounding of the water-collecting membrane is kept sealed and fixed;

[0065] Wherein, the straw mat is soaked in a hydrophilic adhesive, the hydrophilic adhesive comprises a hydrophilic high molecular organic substance and water, and the hydrophilic high molecular organic substance comprises epoxy resin, polyurethane or acrylic resin.

[0066] The enclosure barrel planting device in the embodiment of the present invention can promote rainwater or artificial irrigation to quickly penetrate deep into the soil layer; provide shade and moisture to protect seedlings from high temperature, reduce the sand surface temperature at the grounding part of the seedlings, and prevent the phloem of the seedlings from being scalded or scalded to death; compared with the protective shading method of PVC pipes, the enclosure barrel has a larger water contact area and vertical gap, and is added with a hydrophilic adhesive, and its water infiltration effect is better, while only the outer wall and the inner wall of the PVC pipe can conduct water downward, and the hydrophilic adhesive can increase the toughness of the straw material and reduce its brittleness; in addition, the easily buried water-collecting membrane can prevent the evaporation of soil moisture, and directly guide rainfall and artificial irrigation to the edge of the enclosure barrel, so that it can quickly infiltrate into the deep soil layer, promoting root development and plant growth.

[0067] In summary, the one-way sand transport system for promoting siltation and land formation in sandy coasts or islands provided by the embodiments of the present invention is as follows: in seawater, the underwater one-way sand transport embankment can promote the onshore transport of sediments in the nearshore seabed area and inhibit the transport of sediments to the sea; on land, the one-way sand transport fence on the shore can promote the onshore transport of sediments in the beach area and inhibit the transport of sediments to the sea; in addition, the semi-circular grass grids arranged in the coastal foredune belt and the protective barrel planting devices arranged in the beach area can effectively fix the silted quicksand and restore the ecology; four measures with different functions are arranged in multiple channels parallel to the coastline according to the beach terrain conditions, and the siltation and land formation system formed by combining with each other makes the onshore supply of water, sand and wind-blown sand sediments greater than the loss to the sea from the nearshore seabed to the land beach, promotes the siltation of the seabed and the beach, and continuously improves the seabed surface and the beach elevation. For sandy coastlines and islands, it is an effective measure for promoting siltation and land formation and comprehensive management of nearshore water, sand and wind-blown sand.

[0068] Another aspect of the embodiments of the present invention provides a method for promoting siltation and land reclamation on a sandy coast or island with one-way sand transport, the method for promoting siltation and land reclamation is implemented based on the above-mentioned system for promoting siltation and land reclamation on a sandy coast or island with one-way sand transport, and the method for promoting siltation and land reclamation comprises:

[0069] An underwater one-way sand transport dike is set up in the intertidal zone between the lowest tide line and the highest tide line to gradually accumulate water and sand on the nearshore seabed;

[0070] In dry beach areas above the highest tidal level and with strong wind-blown sand transport, one-way sand transport fences are installed on the shore to promote the onshore transport of wind-blown sand in the beach area, inhibit the retreat of wind-blown sand sediments to the sea, and promote the accumulation of beach quicksand;

[0071] A semicircular grass grid is arranged in the coastal forehill belt to fix the mobile sand dunes in the coastal forehill belt;

[0072] Seedlings are planted on the beach using a protective barrel planting device to form a planting belt to fix quicksand and restore the ecology.

[0073] The embodiments of the present invention utilize the system and method to promote the transport of water sand and wind-blown sand to the shore, while inhibiting the process of sediment retreating to the sea, ultimately forming a sandy coast and island siltation and land formation system that takes into account both underwater and onshore.

[0074] The following will describe the technical solutions in the embodiments of the present invention in detail in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] Example 1

[0076] This embodiment provides a unidirectional sand transport system for promoting siltation and land reclamation on sandy coasts or islands, such as Figure 1 As shown, it includes an underwater one-way sand transport dike 1, an onshore one-way sand transport fence 2, a semicircular grass grid 3, and a protective barrel planting device 4 which are arranged in sequence from the ocean direction to the land direction, and the underwater one-way sand transport dike 1 and the onshore one-way sand transport fence 2 are respectively parallel to the coastline and are arranged in multiple lanes.

[0077] like Figure 1 and 2As shown, the underwater one-way sand transport dike 1 is arranged on the intertidal zone 57 between the lowest tide line 51 and the highest tide line 52, and the top of the underwater one-way sand transport dike 1 is lower than the lowest tide line 51; wherein, the underwater one-way sand transport dike 1 includes a plurality of first channel side panels and a base 11, a first guide plate 12 and a first connecting rod 13, specifically, a base is provided at the bottom of the first channel side panel, which is an integrally molded structure cast by cement.

[0078] Multiple first channel side panels are perpendicular to the coastline and arranged in parallel, and the spacing between two adjacent first channel side panels is 1.5-2.5m; the base is buried under the seabed surface, with a trapezoidal cross-section, a height of 0.8-1.5m, a length of the bottom side of the cross-section of 0.6-1m, a length of the top side of the cross-section of 15-40cm, and a length perpendicular to the coastline of 3-6m; the height of the first channel side panel is 1-1.5m, the thickness of the first channel side panel is 15-40cm, and the length perpendicular to the coastline is 3-6m, and the first channel side panel is provided with pre-embedded bolt fixing holes.

[0079] The first guide plate 12 is a rectangular plate structure cast with cement, with a height of 1-1.5m, a length of 1-2m, and a thickness of 15-30cm. Between two adjacent first channel side plates, 2-4 pairs of first guide plates 12 are arranged in pairs, each pair of first guide plates 12 is opposite to each other at an acute angle of 20-40 degrees, and maintains an opening of 30-50cm at one end close to each other, and the end close to each other faces the land direction, that is, the narrow opening direction of each pair of first guide plates 12 faces the land, and the wide opening direction faces the sea, and the four corners of each rectangular guide plate are provided with pre-buried steel bar fixing rings.

[0080] The first connecting rod 13 is a steel rod with threads on both ends processed from solid steel bars. The two ends of the first connecting rod 13 are respectively fixed in the bolt fixing holes of the two adjacent first channel side plates, and the middle passes through the steel bar fixing ring pre-embedded in the pair of first guide plates 12, so as to fix and connect multiple first channel side plates and the first guide plates 12 therebetween; wherein, the diameter of the first connecting rod 13 is 2-4cm, and the length is the spacing between the two adjacent first channel side plates, 1.5-2.5m.

[0081] like Figure 1 and 3As shown, the onshore one-way sand transport fence 2 is set above the highest tidal line 52 and in a dry beach 58 area with strong wind sand transmission, and includes a plurality of second channel side panels 21, a second guide plate 22 and a second connecting rod 23, and both ends of the second channel side panels 21 and the second guide plate 22 are tied and fixed on the vertical pole 24 inserted into the ground; the plurality of second channel side panels 21 are perpendicular to the coastline direction and are arranged in multiple rows in parallel; between two adjacent second channel side panels 21, 2-4 pairs of second connecting rods 23 are arranged in pairs. The second guide plates 22, each pair of the second guide plates 22 are opposite to each other at an acute angle of 20-40 degrees, and at one end close to each other, an opening of 30-50 cm is maintained, and the narrow opening direction of each pair of the second guide plates 22 faces the land, and the wide opening direction faces the sea; wherein the second channel side plate 21 and the second guide plate 22 are both rectangular frame structures welded from round steel, and a HDPE net with a porosity of 30-45% is tied and fixed thereon, and the length of the second channel side plate 21 perpendicular to the coastline direction is 3-6 m, and the height The length of the second guide plate 22 is 1-2m, the height is 1-1.5m, the second connecting rod 23 is a round steel with a diameter of 2-4cm, and the two ends of the second connecting rod 23 are respectively welded and fixed on the top and bottom round steel frames of the second channel side plates 21 and the second guide plates 22, so as to fix the plurality of second channel side plates 21 and the second guide plates 22 therebetween to each other. In specific implementation, the plurality of vertical rods 24 and the first The sides of the second channel side plate 21 and the second guide plate 22 are bound together to fix the second channel side plate 21 and the second guide plate 22; when the second channel side plate 21 and the second guide plate 22 are buried in sand, the binding between the vertical pole 24 and the second channel side plate 21 and the second guide plate 22 can be untied, and the second channel side plate 21 and the second guide plate 22 can be lifted, and the vertical pole 24 is a round steel with a diameter of 3-4 cm, which is inserted into the ground, wherein the underground burial depth is 50-100 cm, and the above-ground leakage height is 2.0-2.5 m.

[0082] like Figure 1 and 4 As shown, the semicircular grass grid 3 is used to fix the moving sand dunes 56 of the coastal forehill belt 59, and includes a grass rope 32 and a plurality of plant straw bundles 31, and the plurality of plant straw bundles 31 are distributed in sequence along the length direction of the grass rope 32, wherein the plant straw bundle 31 has a semicircular structure formed by wrapping a plurality of plant straws in the middle with the grass rope 32, and the semicircular grass grid 3 is arranged according to the specification of 1-2m×1-2m, and the plant straw bundle 31 is fixed on the moving sand dunes 56 of the coastal forehill belt 59 through branches 33 with leaves, and the semicircular surface of the plant straw bundle 31 is arranged perpendicular to the moving sand dunes 56.

[0083] like Figure 1 and 5As shown, the enclosure barrel planting device 4 is used for planting seedlings and afforestation at the location 60 of the beach on the shore, and includes an enclosure barrel 41, a water-collecting membrane 42 with a circular or square ring structure, and a membrane edge sealing and fixing wedge 43. The enclosure barrel 41 includes a barrel structure formed by curling straw mats, at least the lower part of the barrel structure is located underground, and the rest is located above the ground surface, and planting holes and seedlings 44 are distributed in the barrel structure; the water-collecting membrane 42 is sleeved on the enclosure barrel 41, and the inner circle is tightly attached to the outer wall of the enclosure barrel 41, and the edges of the four sides of the outer circle are respectively attached to the membrane edge sealing and fixing wedge 43, and the membrane edge sealing and fixing wedge 43 is vertically inserted into the ground surface, so that the water-collecting membrane 42 is laid flat on the ground surface and keeps the water-collecting membrane 42 sealed and fixed on all sides; wherein, the straw mat is treated by soaking in a hydrophilic adhesive, the hydrophilic adhesive includes a hydrophilic macromolecular organic matter and water, and the hydrophilic macromolecular organic matter is selected from epoxy resin, polyurethane or acrylic resin.

[0084] The one-way sand transport system for promoting siltation and land formation on sandy coasts or islands provided in this embodiment is as follows: in seawater, the underwater one-way sand transport dam 1 can promote the onshore transport of sediments in the nearshore seabed area and inhibit the transport of sediments to the sea; on land, the onshore one-way sand transport fence 2 can promote the onshore transport of sediments in the beach area and inhibit the transport of sediments to the sea; in addition, the semicircular grass grids 3 arranged in the coastal forehill belt 59 and the protective barrel planting device 4 arranged in the beach area 60 can effectively fix the silted quicksand and restore the ecology; four measures with different functions are arranged in multiple channels parallel to the coastline according to the beach terrain conditions, and the siltation and land formation system formed by combining with each other makes the onshore supply of water, sand and wind-blown sand sediments greater than the loss to the sea from the nearshore seabed to the land beach, promotes the siltation of the seabed and the beach, and continuously improves the seabed surface and the beach elevation. For sandy coastlines and islands, it is an effective measure for promoting siltation and land formation and comprehensive management of nearshore water, sand and wind-blown sand.

[0085] Example 2

[0086] This embodiment provides a method for promoting siltation and land reclamation on a sandy coast or island with one-way sand transport. The method is implemented based on the system for promoting siltation and land reclamation on a sandy coast or island with one-way sand transport in Example 1, and the method comprises:

[0087] An underwater one-way sand transport dam 1 is provided on the intertidal zone 57 between the lowest tide line 51 and the highest tide line 52, so that water and sand gradually accumulate on the nearshore seabed 55;

[0088] A one-way sand transport fence 2 is set on the dry beach 58 area above the highest tidal line 52 and with strong wind sand transport, so as to promote the onshore transport of wind sand in the beach area, inhibit the retreat of wind sand sediments to the sea, and promote the accumulation of beach quicksand;

[0089] A semicircular grass grid 3 is provided in the coastal forehill belt 59 to fix the mobile sand dunes 56 in the coastal forehill belt 59;

[0090] The enclosing barrel planting device 4 is used to plant seedlings and trees at the location of the beach 60 to form a planting belt for fixing the quicksand and restoring the ecology.

[0091] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0092] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present invention and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, it is not intended herein to limit the present invention to the disclosed specific embodiments for performing the present invention, but it is intended that the present invention will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another.

Claims

1. A unidirectional sand transport system for promoting siltation and land reclamation on sandy coasts or islands, characterized in that: It includes an underwater one-way sand transport dam, an onshore one-way sand transport fence, a semicircular grass grid and a protective barrel planting device which are arranged in sequence from the ocean direction to the land direction, and the underwater one-way sand transport dam and the onshore one-way sand transport fence are respectively parallel to the coastline and arranged in multiple lanes; The underwater one-way sand transport dam is arranged on the intertidal zone between the lowest tide line and the highest tide line, and the underwater one-way sand transport dam includes a plurality of first channel side panels, a first guide plate and a first connecting rod, and the bottom of the first channel side panels is connected and fixed to a base buried under the seabed surface; the plurality of first channel side panels are perpendicular to the coastline direction and are arranged in parallel in multiple rows; between two adjacent first channel side panels, 2-4 pairs of first guide plates are arranged in pairs through the first connecting rods, and each pair of first guide plates are opposite to each other at an acute angle of 20-40 degrees, and maintain an opening of 30-50 cm at one end close to each other, and the narrow opening direction of each pair of first guide plates faces the land, and the wide opening direction faces the ocean.

2. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 1, characterized in that: The first channel side panels are provided with embedded bolt fixing holes, and the four corners of the first guide plate are provided with embedded steel bar fixing rings. The first connecting rod is a steel rod with threads on both ends processed from solid steel bars. The two ends of the first connecting rod are respectively fixed in the bolt fixing holes of the two adjacent first channel side panels, and the middle passes through the embedded steel bar fixing rings of the paired first guide plates, so as to fix the multiple first channel side panels and the first guide plates therebetween to each other.

3. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 2, characterized in that: The first channel side plates have a height of 1-1.5 m, a thickness of 15-40 cm, a length perpendicular to the shoreline of 3-6 m, and a spacing between two adjacent first channel side plates of 1.5-2.5 m.

4. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 2, characterized in that: The first guide plate is a rectangular plate structure cast with cement, with a height of 1-1.5m, a length of 1-2m, and a thickness of 15-30cm.

5. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 2, characterized in that: The diameter of the first connecting rod is 2-4 cm, and the length is the distance between two adjacent first channel side plates.

6. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 2, characterized in that: The base is an integrally formed structure cast in cement, and the cross-section of the base is trapezoidal, with a height of 0.8-1.5m, a length of the bottom side of the cross-section of 0.6-1m, a length of the top side of the cross-section of 15-40cm, and a length perpendicular to the shoreline of 3-6m.

7. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 1, characterized in that: The onshore one-way sand transport fence is arranged above the highest tide line and in a dry beach area with strong wind and sand transmission, and includes a plurality of second channel side panels, a second guide plate and a second connecting rod, and both ends of the second channel side panels and the second guide plates are tied and fixed on the vertical poles inserted into the ground; the plurality of second channel side panels are perpendicular to the coastline direction and are arranged in parallel in multiple rows; between two adjacent second channel side panels, 2-4 pairs of second guide plates are arranged in pairs through the second connecting rod, each pair of second guide plates is opposite to each other at an acute angle of 20-40 degrees, and maintains an opening of 30-50 cm at one end close to each other, and the narrow opening direction of each pair of second guide plates faces the land, and the wide opening direction faces the sea; The second channel side plates and the second guide plates are both rectangular frame structures welded from round steel, on which a HDPE mesh with a porosity of 30-45% is bound and fixed.

8. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 7, characterized in that: The length of the second channel side plate in a direction perpendicular to the coastline is 3-6 m, the height is 1-1.5 m, and the spacing between two adjacent second channel side plates is 1.5-2.5 m.

9. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 7, characterized in that: The second guide plate has a length of 1-2 m and a height of 1-1.5 m.

10. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 7, characterized in that: The second connecting rod is a round steel with a diameter of 2-4 cm. Both ends of the second connecting rod are welded and fixed to the top and bottom round steel frames of the second channel side plates and the second guide plates, respectively, to fix multiple second channel side plates and the second guide plates therebetween.

11. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 7, characterized in that: The vertical pole is a round steel with a diameter of 3-4 cm, which is inserted into the ground, wherein the underground burial depth is 50-100 cm and the above-ground leakage height is 2.0-2.5 m.

12. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 7, characterized in that: A plurality of vertical rods are bound together with the second channel side plate and the side edge of the second guide plate to fix the second channel side plate and the second guide plate.

13. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 1, characterized in that: The semicircular grass grid is used to fix the mobile sand dunes in the coastal foredune belt, and includes a grass rope and a plurality of plant straw bundles, wherein the plurality of plant straw bundles are sequentially distributed along the length direction of the grass rope, wherein the plant straw bundle has a semicircular structure formed by wrapping a plurality of plant straws in the middle with the grass rope.

14. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 13, characterized in that: The semicircular grass grids are arranged according to the specifications of 1-2m×1-2m.

15. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 13, characterized in that: The plant straw bundle is fixed on the mobile sand dunes of the coastal forehill belt via branches with leaves, and the semicircular surface of the plant straw bundle is arranged perpendicular to the mobile sand dunes.

16. The one-way sand transport system for promoting siltation and land reclamation on sandy coasts or islands according to claim 1, characterized in that: The enclosure barrel planting device is used for planting seedlings and afforestation at the beach location, and includes an enclosure barrel, a water-collecting membrane with a circular or square ring structure, and a membrane edge sealing and fixing wedge. The enclosure barrel includes a barrel structure formed by curling straw mats, at least the lower part of the barrel structure is arranged underground, and the rest is located above the ground surface. Planting holes and seedlings are distributed in the barrel structure; the water-collecting membrane is sleeved on the enclosure barrel, and the inner ring is tightly attached to the outer wall of the enclosure barrel, and the edges of the four sides of the outer ring are respectively attached to the membrane edge sealing and fixing wedges, and the membrane edge sealing and fixing wedges are vertically inserted into the ground surface, so that the water-collecting membrane is laid flat on the ground surface, and the surrounding of the water-collecting membrane is kept sealed and fixed; Wherein, the straw mat is soaked in a hydrophilic adhesive, the hydrophilic adhesive comprises a hydrophilic high molecular organic substance and water, and the hydrophilic high molecular organic substance comprises epoxy resin, polyurethane or acrylic resin.

17. A method for promoting siltation and land reclamation on sandy coasts or islands with one-way sand transport, characterized in that: The method for promoting siltation and land reclamation is implemented based on the siltation and land reclamation system for sandy coasts or islands with one-way sand transport according to any one of claims 1 to 16, and the method for promoting siltation and land reclamation comprises: An underwater one-way sand transport dike is set up in the intertidal zone between the lowest tide line and the highest tide line to gradually accumulate water and sand on the nearshore seabed; In dry beach areas above the highest tidal level and with strong wind-blown sand transport, one-way sand transport fences are installed on the shore to promote the onshore transport of wind-blown sand in the beach area, inhibit the retreat of wind-blown sand sediments to the sea, and promote the accumulation of beach quicksand; Set up semicircular grass grids in the coastal forehill belt to fix the mobile sand dunes in the coastal forehill belt; Seedlings are planted on the beach using a protective barrel planting device to form a planting belt to fix quicksand and restore the ecology.

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