An ecological protection system for eroded coasts

Abstract

An erosion coast ecological protection system comprises: ecological submerged dikes, tidal flat habitats, vegetation habitats and ecological breeding areas arranged in sequence from sea to land on the erosion coast; the ecological submerged dikes are arranged in the subtidal zone parallel to the coast, the overall structure is composed of multiple sections of submerged dikes and gates, and the length of a single section of submerged dikes is not less than 8 times the wavelength; the tidal flat habitat is connected with the ecological submerged dike and is properly decorated according to the tidal flat terrain to form a multiple habitat consisting of shallow water areas and deep water areas; the vegetation habitat area is located in the intertidal zone, and its outer edge is arranged with riprap to avoid tidal channels, the slope is about 1:2-1:3, and a vegetation belt of not less than 50m wide is planted on the land side; the ecological breeding area is provided with a plurality of breeding ponds with field-shaped channels, the top width of the channel is about 4-6m, and several rows of tamarisks are planted to form a wind-resistant buffer zone.

Description

Technical Field

[0001] The utility model relates to the field of marine ecological engineering and coastal zone protection, and in particular to an eroded coastal ecological protection system. Background Art

[0002] The coastal zone is located at the junction of land and sea. Under the influence of natural factors and human activities, it is very easy to cause an imbalance in sediment income and expenditure, leading to a series of coastal erosion phenomena such as coastline retreat and beach erosion, causing coastal ecosystem degradation and coastal economic losses. Taking Yancheng City, Jiangsu Province as an example, due to the significant reduction in sediment sources after the diversion of the Yellow River, the coast is currently in a dynamic change process of "erosion in the north and siltation in the south". The average erosion rate from 2009 to 2018 was 2.0km2·a-1, resulting in further shrinkage of tidal flat aquaculture and bird habitats.

[0003] At present, coastal erosion protection mainly adopts hard protection such as building seawalls and wave-breaking piles or flexible protection such as oyster reefs and coastal plants. Both types of protection have their specific advantages and disadvantages. On the one hand, the landscape quality and ecological benefits of hard protection are low, and on the other hand, flexible protection has the problem of being unable to stand in a strong erosion environment and having low survival rate. Therefore, it is urgent to explore an ecological protection system for coastal erosion based on the concept of natural solutions. Utility Model Content

[0004] In order to solve the above problems existing in the prior art, the purpose of the utility model is to provide an erosion coastal ecological protection system, which is generally applicable to coasts severely eroded by tidal action, so as to overcome the above shortcomings and deficiencies existing in the prior art.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An erosion coast ecological protection system, comprising: ecological submerged dikes, tidal flat habitats, vegetation habitats and ecological breeding areas arranged in sequence from sea to land on the erosion coast;

[0007] The ecological submerged dike is parallel to the existing shoreline and arranged at intervals, and is composed of a plurality of single-end submerged dikes connected together, and the length of the single-end submerged dike is not less than 8 times the wavelength;

[0008] The tidal flat habitat is connected with the ecological submerged dike, and the tidal flat habitat is micro-topographically modified according to the existing topography to have a plurality of habitats consisting of a light beach area, a tidal ditch area, a shallow water area and a deep water area;

[0009] The vegetation habitat area includes a planting area and a riprap bank. The outer edge of the riprap bank avoids the tidal ditch and is arranged parallel to the coastline, with a slope of about 1:2 to 1:3. The rear side of the riprap bank is backfilled with excess earth from the tidal flat habitat as a planting area. The ecological breeding area is located at the rear side of the planting area and is equipped with a number of breeding ponds with field-shaped channels. The top of the embankment of the channel of the breeding pond is widened to 4 to 6 meters, and 1 to 2 rows of Tamarix chinensis are planted at intervals of 2 meters on both sides of the embankment to form a wind-resistant buffer zone.

[0010] Optionally, the single-ended submerged dike adopts a riprap slope structure with a certain roughness, a top width of 4 to 6 m, an inner and outer slope of 1:2 to 1:3, and a riprap foot guard of 5 to 10 m width. Oyster shells are thrown and filled in the gaps between the stones to create an oyster reef habitat.

[0011] Optionally, the bottom elevation of the tidal gully area is lower than the average low tide level and forms a base profile with a varied slope, with a slope ratio of 1:10 to 1:20.

[0012] Optionally, the water depths in the shallow water area and the deep water area are 0.3-0.4 m and 0.5-1.0 m respectively.

[0013] Optionally, the riprap embankment uses non-woven geotextile and bagged crushed stone cushion as anti-filtration structure.

[0014] Optionally, the slope of the beach surface after backfilling in the planting area is not higher than 3° and meets the vegetation growth elevation. A reed belt of not less than 50m wide or other vegetation with rapid growth, well-developed root system and strong branches is planted on the side of the planting area close to the current coastline of the subtidal zone, and low herbs are sown in the area away from the current coastline of the subtidal zone.

[0015] Optionally, 20-30% of the light beach is reserved inside the planting area of ​​the vegetation habitat area, which reserves space for natural succession and provides a habitat for birds.

[0016] Optionally, two single-end submerged dikes are connected through a gate, a soft drainage bottom protection is arranged at the gate, and two layers of pressed drainage stones are laid on top.

[0017] Due to the adoption of the above technical solution, the utility model has the following beneficial effects:

[0018] (1) The utility model is based on a natural solution, combining ecological hard protection and flexible protection, restoring the coastal ecosystem and creating a comprehensive coastal protection system that coordinates ecological disaster reduction.

[0019] (2) The utility model follows the principle of earthwork balance and forms a multiple habitat consisting of light beaches, tidal gullies, shallow water, deep water and vegetation through micro-topography transformation within the system without involving external earthwork, thereby improving the friction and slowing effect of the tidal flat and providing habitats for benthic organisms, birds and other organisms.

[0020] (3) The vegetation belt of the utility model plays a key role in stabilizing the coast and absorbing sediment. It can not only reduce the negative impact of sea level rise, but also has the ability to self-recover after being damaged by extreme conditions such as storm surges, thereby improving the resilience of coastal protection and reducing subsequent maintenance costs.

[0021] (4) On the one hand, the ecological breeding area of ​​the utility model forms a "planting-breeding" coupling system, which improves the aquaculture water quality and increases the aquaculture output while feeding back the vegetation growth. On the other hand, measures such as drainage and drying of ponds in autumn and winter can provide a food source for migratory birds, improve the utilization efficiency of material resources, and increase the ecological and economic benefits of coastal aquaculture. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the plan layout of the utility model's coastal ecological protection system.

[0023] Figure 2 This is a cross-sectional diagram of the coastal ecological protection system.

[0024] Description of Figure Numbers:

[0025] 1-ecological submerged dike; 2-tidal flat habitat; 3-riprap protection bank; 4-vegetation habitat; 5-ecological breeding area; 6-mouth; 7-tidal ditch; 11-riprap and oyster shells; 12-soft-bodied row; 22-shallow water habitat; 23-deep water habitat; 24-beach habitat; 41-earth backfill; 42-reed belt; 43-salt-marsh salsa; 51-Tamarisk; 52-Chuankelophora; 53-pond bank. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] See also Figure 1-2 For example, an erosion coast ecological protection system includes: an ecological submerged dike 1, a tidal flat habitat 2, a vegetation habitat 4 and an ecological breeding area 5 in order from sea to land on the erosion coast.

[0028] The ecological submerged dike 1 is arranged parallel to the existing shoreline, and the length of a single-end submerged dike is not less than 8 times the wavelength. The single-end submerged dike adopts a riprap slope structure with a certain degree of roughness, with a top width of 4 to 6m, an inner and outer slope of 1:2 to 1:3, and a riprap footing of 5 to 10m wide. Oyster shells 11 are thrown and filled in the gaps between the stones to create an oyster reef habitat. The dike body is paved with sand-ribbed soft-shell rows + bagged gravel, and the inside and outside are laid with concrete interlocking block soft-shell rows. Soft-shell rows 12 are laid at the 6 openings in the middle of the submerged dike (between the two single-end submerged dikes) to protect the bottom, and two layers of pressed stone rows are laid on top.

[0029] The tidal flat habitat is connected to the ecological submerged dike and is located at the rear. The tidal flat habitat is micro-topographically modified according to the existing topography to create a multiple habitat consisting of a light beach 24, a tidal ditch 7, shallow water 22 and deep water 23, thereby improving the heterogeneity of the habitat. The proportion of the light beach, shallow water and deep water habitats is about 10:3:1 to 5:2:1. After low tide, the water depths in the shallow water 22 and deep water 23 habitats are maintained at 0.3 to 0.4m and 0.5 to 1.0m, respectively. In addition, the existing tidal ditch is properly dredged and sorted, the bottom elevation is lower than the average low tide level, and a base profile with a varied slope is formed, with a slope ratio of about 1:10 to 1:20.

[0030] The outer edge of the vegetation habitat area avoids the tidal ditch and is arranged parallel to the coastline, with a slope of about 1:2 to 1:3. The riprap 3 uses non-woven geotextiles and bagged gravel cushions as anti-filtration structures. The interior (the back side of the riprap) uses the excess earthwork from the tidal flat habitat to backfill as a planting area. After backfilling, the beach slope is not higher than 3° and meets the vegetation growth elevation. In April-May of the same year or the following year after the completion of the ecological submerged dike, a reed belt 42 or other fast-growing, well-developed root systems, and strong branches and trunks are planted on the side of the planting area of ​​the earth backfill 41 close to the coastline to slow down the scouring effect of the water flow and improve the anti-erosion ability of the beach. Low herbs such as Salicornia salsa 43 and Salicornia herbacea are sown on the side of the planting area of ​​the earth backfill 41 away from the coastline to enhance vegetation diversity and improve the stability of the ecosystem. A 20-30% light beach is reserved inside the planting area, which not only leaves space for natural succession but also provides a habitat for birds.

[0031] The ecological breeding area carries out ecological transformation of the rear breeding pond. The top of the pond bank 53 is widened to 4-6m and 1-2 rows of Tamarix 51 are planted at intervals of 2m along the inner side of the pond bank to form a wind-resistant buffer zone. Shellfish, crabs, fish and other organisms are raised in the ecological breeding area, and natural tidal channels are used as drainage channels. The normal water level is maintained at 1.0-2.0m. Salt-tolerant submerged plants such as Sichuan creeping algae 52 are planted at the bottom of the pond, covering an area of ​​about 5-10%.

[0032] Ecological submerged dike, tidal flat habitat, vegetation habitat and ecological breeding area; the ecological submerged dike is arranged at the subtidal mudflat, and the gaps in its riprap structure are filled with oyster shells to create an artificial oyster reef belt; the tidal flat habitat is connected with the ecological submerged dike, and a multi-habitat consisting of light beach, tidal ditch, shallow water and deep water is formed through micro-topography transformation; the outer edge of the vegetation habitat is a riprap embankment, and the inner side is divided into a vegetation wave-breaking area and a bird habitat area; the pond embankment of the ecological breeding area naturally extends to the vegetation habitat, and shrubs are planted on the inner side; submerged plants are planted at the bottom of the pond. This utility model is based on a natural solution, giving full play to the specific advantages of ecological hard protection and flexible protection, restoring the coastal ecosystem, creating a comprehensive coastal protection system that coordinates ecological disaster reduction, and further improving the comprehensive benefits of coastal breeding.

[0033] The specific implementation modes of the present invention are described above, but the present invention is not limited thereto. The present invention can also have various changes without departing from the purpose of the present invention.

Claims

1. An erosion coastal ecological protection system, characterized in that: include: Ecological submerged dikes, tidal flat habitats, vegetation habitats and ecological aquaculture areas are arranged from sea to land on the eroded coast; The ecological submerged dike is parallel to the existing shoreline and arranged at intervals, and is composed of a plurality of single-end submerged dikes connected together, and the length of the single-end submerged dike is not less than 8 times the wavelength; The tidal flat habitat is connected with the ecological submerged dike, and the tidal flat habitat is micro-topographically modified according to the existing topography to have a plurality of habitats consisting of a light beach area, a tidal ditch area, a shallow water area and a deep water area; The vegetation habitat area includes a planting area and a riprap bank as an outer edge. The riprap bank avoids the tidal gully and is arranged parallel to the coastline. The slope is about 1:2 to 1:

3. The rear side of the riprap bank is backfilled with excess earth from the tidal flat habitat to form a planting area. The ecological breeding area is located at the rear of the planting area and is provided with a plurality of breeding ponds with field-shaped passages. The top of the pond bank of the breeding pond passage is widened to 4-6m and 1-2 rows of Tamarix chinensis are planted at intervals of 2m on both sides of the pond bank to form a wind-resistant buffer zone.

2. The coastal erosion ecological protection system according to claim 1 is characterized in that: The single-end submerged dike adopts a riprap slope structure, with a top width of 4 to 6 m, inner and outer slopes of 1:2 to 1:3, and a riprap foot guard of 5 to 10 m width. Oyster shells are thrown and filled in the gaps between the stones to create an oyster reef habitat.

3. The coastal erosion ecological protection system according to claim 1 is characterized in that: The bottom elevation of the tidal gully area is lower than the average low tide level and forms a base profile with a varied slope, with a slope ratio of 1:10 to 1:

20.

4. The coastal erosion ecological protection system according to claim 1 is characterized in that: The water depths in the shallow water area and the deep water area are 0.3-0.4m and 0.5-1.0m respectively.

5. The coastal erosion ecological protection system according to claim 1 is characterized in that: The riprap embankment adopts non-woven geotextile and bagged crushed stone cushion as anti-filtration structure.

6. The coastal erosion ecological protection system according to claim 1, characterized in that: After backfilling, the beach surface slope of the planting area shall not be higher than 3° and shall meet the vegetation growth elevation. A reed belt of not less than 50m wide or other vegetation with rapid growth, developed root system and strong branches shall be planted on the side of the planting area close to the existing coastline of the subtidal zone, and low herbs shall be sown in the area away from the existing coastline of the subtidal zone.

7. The coastal erosion ecological protection system according to claim 1 is characterized in that: A light beach with an area of ​​20 to 30% is reserved inside the planting area of ​​the vegetation habitat, which not only reserves space for natural succession but also provides a habitat for birds.

8. The coastal erosion ecological protection system according to claim 1 is characterized in that: The two single-end submerged dikes are connected by a gate, where a soft drainage bottom protection is laid and two layers of pressed drainage stones are laid on top.

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