(2) Jiahe River Comprehensive Improvement Project-Construction of Ecological Wetland Park
According to the development and construction planning of Jiahe River in Yantai City, combined with the environmental protection planning of drinking water sources in Yantai City, and on the basis of in-depth study and analysis of the existing work results of Jiahe Wetland, the green island area on the west side of Gongjia Island and Jiahe Estuary are initially selected as wetland engineering construction areas for wetland restoration and water quality purification, and Dongjiang rock wet area, green island wet area and Jiahe Estuary wet area are built along Jiahe River. The total construction area of the project is 9,799 mu, of which the Jiahe Corridor Wetland System is 22.83km long, with an area of about 6,845 mu, the Dongzhuyan Wetland Area is 760 mu, the Green Island Wetland Area is 994 mu, and the Jiahe Estuary Wetland Area is 1.200 mu.
The wetland project includes four parts: Jiahe Corridor Wet Area, Dongzhuyan Wet Area, Green Island Wet Area and Jiahe Estuary Wet Area (Figure 9-4):
(1) Jiahe Corridor Wetland Project
Jiahe corridor wetland is constructed by ecological restoration technology scheme of dike+rubber dam+ecological flood detention pond. The Jiahe river channel from Motang rubber dam (pile number 22+830) to the estuary is reconstructed, with a length of 22.83km. Because the dams in some river sections are solidified by concrete or masonry, which blocks the connection between the river and the terrestrial ecosystem, it is necessary to carry out ecological slope protection reconstruction in combination with flood control planning and the current situation of the river. Use the existing Zhu Yan River Sluice (No.20+580), Jia Zhu Rubber Dam (No.0/6+800), Yushuzhuang Rubber Dam (No.0/2+790), Dashabu Rubber Dam (No.9+228) and Gongjiadao Rubber Dam (No.4+070). The project area covers an area of about 6845 mu.
(2) Dongzhuyan Wetland Project
Implement the project of returning farmland to wetlands, wasteland and some farmland on the east side of Jiahe River in the east side of Dongzhuyan Village. Through earthwork adjustment, local dredging, restoration of wetland vegetation and other measures, the communication between Dongzhuyan wetland and Jiahe river system can be realized, the area of Jiahe wetland can be expanded, and the ecological stability of Jiahe wetland system and the function of river flood storage and water conservation can be improved. The area is about 760 mu.
Figure 9-4 Layout of Ecological Wetland Construction Project in Jiahe River Basin
(3) Green Island Wetland
Green Island Wetland is located in the upper reaches of Jiahe Bridge, covering an area of 994 mu. Including area A on the west side of Jiahe River and area B on the east side, area A covers an area of 788 mu and area B covers an area of 206 mu. Hydraulic dredging will be carried out in some areas of Green Island Area A, and scattered ponds will be opened to realize river water system connection. Allocate aquatic plants according to the water depth and flood discharge requirements, repair the wetland vegetation on the bank slope and improve the ecological stability of Jiahe wetland system. At the same time, a diversion culvert will be built on the dam between Zone B and Jiahe in Lvdao to realize the connection between Zone B and Jiahe, and plant restoration and ecological slope protection will be carried out on the beach in Zone B. ..
(4) Jiahekou Wetland
Jiahekou Wetland is located in the east of Jiahekou, with an area of1200mu. This area is mainly swamps and wet depressions, with reeds growing, and large swamps are exposed at low tide. The transition zone between swamp and land is wide, with various halophytes and semi-halophytes growing, and many psammophytes can be seen on sand ridges and dunes. Protect the existing wetland, remove the coal ash yard on the east side of the wetland and restore the wetland. On the premise of protecting the existing wetland resources, we should partially dredge wetlands, restore wetland vegetation, strengthen the construction of protection facilities, and improve the ecological stability of Jiahekou wetland system.
2. Ecological restoration measures of Dongzhuyan Wetland Park
Dongzhuyan wet area is located in the upstream of Jiahe Waterfront Development Zone in Yantai City, adjacent to Laishan Airport in the southeast and Dongzhuyan section in the southwest. There are two tributaries in the project area, Qinhe River in the west and Zhuyan River in the south. The specific planning scope of the wetland project is: Jiahe River as the boundary in the south, new municipal roads in the east and north, and the intersection with the airport expressway in the west. The planned area is 760 mu (excluding the water surface of Jiahe River), which is triangular, with the longest from east to west1260m and the widest from north to south/966m. The project area is flat, the ground elevation is within the range of11.2 ~14.90m, and the water level of Zhu Yan River sluice is/kloc. ..
The ecological restoration project of Dongzhuyan wetland firstly dredges and connects the water area, and leads the water from Jiahe River to the wetland to increase the water area and water storage capacity of the wetland. Secondly, ecological slope protection and wetland plant planting engineering are carried out for soil revetment in water areas, mainly for ecological slope protection, wetland plant planting and landscape development. The specific contents of Jiahe East Zhu Yan Wetland Restoration Project are as follows.
(1) water dredging
Following the existing flood control plan of Jiahe River, the existing waterlogged depressions and cultivated land in the project area will be excavated without disturbing the flood control levee of Jiahe River, and the flood detention pond will be excavated in the center of the wet area, which has comprehensive functions such as flood detention, storage regulation and landscape. The flood detention pond covers an area of about 190 mu, with the designed bottom elevation of 10.00 m and the water surface elevation of 12.00 m. Diversion culverts are respectively built in Qinhe River and Zhu Yan River estuary near the wet area to control the water diversion and drainage in the wet area. Design and build a waterway that runs through the outside of the whole wetland, with a width of10.0m and a water depth of 2.0m, connecting the diversion gate and the detention basin. This project needs to cross the waterway1500m ... 567,000m3 of earthwork needs to be excavated for river dredging. At the same time, it is necessary to carry out earthwork adjustment on some terraces and wasteland, restore the original appearance of wetlands, dig diversion ditches along waterways, and design landscape types such as ponds, streams, ponds and wetlands. The area to be adjusted in this project is about 220 mu, and the excavated earthwork is about 300,000m3. After excavation, it can be used to build wetland cofferdams, walkways and habitat islands.
The new culvert runs vertically through the existing dam. The single-hole breast wall culvert of the sluice includes four parts: entrance section, sluice chamber section, tunnel body and exit section. The downstream length of the inlet section is 10.0m, and the splayed wing wall and bottom plate are adopted to form an integral structure, which is a reinforced concrete structure; The downstream length of the lock chamber is 5.0m, the gate is a down-the-hole flat steel gate, the orifice size is 2.0m×2.0m, and the top elevation of the gate floor is10.50m.: : The tunnel is a reinforced concrete box culvert with a section of 2.0m×2.0m, the elevation of the entrance tunnel bottom is 10.50m, the bottom slope I = 0, and the length of the tunnel body is14.0m.: : The downstream length of the outlet is 5.0m, which is connected by the splayed wing wall and the reinforced concrete structure. The outlet energy dissipation adopts mortar masonry to protect the bottom.
(2) Phytoremediation Project
According to the improved topography of the project area, different aquatic plants are planted according to different water depths; At the same time, rewetting the farmland outside the wetland and planting Arundo donax, Salix psammophila and moisture-tolerant trees; In addition, greening projects are carried out on roads in wet areas, such as Amorpha fruticosa, Fraxinus mandshurica and weeping willows, and lawns are planted on slope protection. By taking the above measures, the ecological environment of Dongzhuyan wetland has been protected.
1) emergent and floating plants. Implement the project of returning farmland to humidity in the project area and plant economic plants such as Arundo donax and Salix psammophila; In beaches and shallow waters (0 ~ 1.2m), plants with strong purification ability can be selected: wet plants (onion, cress, Melaleuca, etc. ) and emergent plants (cattail, reed and water bamboo); The water depth is relatively deep (1.0 ~ 1.5m). Choose floating-leaf plants (lotus, wild water chestnut, water lily, Euryale ferox) with purification ability and ornamental ability. Through the construction and restoration of beach vegetation, the water purification capacity and ecological stability of wetland system can be improved
Planting area: 300 mu.
2) Submerged plants. In the deep water area of the wetland system (in the detention pond), Ceratophyllum demersum, Sophora alopecuroides, black algae, red grass and POTAMOGETON crispus with strong purification ability are selected and planted in blocks.
Design parameters: the coverage rate is 50%.
Planting area: 230 mu.
3) Remediation of waterlogged forest land. Some existing waterlogged depressions in Dongzhuyan wet area are now planted by local farmers, with little economic and landscape benefits. Moreover, the non-point source pollution of peripheral farmland is easy to enter humid areas, thus polluting the water quality of drinking water source protection areas. Based on the above situation, ecological forestry is carried out in waterlogged forest land, and the main tree species in forest land are wet poplar, willow, slash pine, Taxodium ascendens, Metasequoia glyptostroboides and Taxodium distichum. So as to establish a stable ecosystem in the reservoir area and reduce non-point source pollution in the upstream farmland. Turf is planted on natural soil slopes, and grass species are common in the local area. Common species are drought-tolerant and moisture-tolerant shrubs and herbs: Chinese rose, Zoysia Ophiopogon japonicus, Bermuda grass, alfalfa and so on. This area covers an area of 230 mu.
3. Ecological restoration measures of Green Island Wetland Park
Green Island Wet Zone is located in the middle and lower reaches of Jiahe Waterfront Development Zone in Yantai City, starting from Tongshan Expressway in the north, reaching Yongfuyuan Road in the west, Gongjiadao Village in the east and Hongqi West Road in the south. Jiahe River runs through the wetland from south to north, in which Green Island Area A is located in the west of Jiahe River and Area B is located in the east of Jiahe River. The planned area of this area is 994 mu (excluding the water surface of Jiahe River), with 788 mu in Area A and 206 mu in Area B.
At present, the wetland of the proposed Green Island is mainly composed of terraced fields, reed fields, water systems and woodlands. The land layout of Green Island Project Area is shown in Figure 9-4. Among them, only one end of the water surface in Area A (the west bank of Jiahe River) is connected with the main stream of Jiahe River, and there is a peninsula dam in the middle, so the water system circulation is not smooth; Area B (east bank of Jiahe River) is mainly composed of fish ponds, ponds and tidal flats. It is separated from Jiahe River by Jiahe East Dike, and the water body cannot be exchanged. The dumping of garbage along the river is repeatedly prohibited, which seriously damages the resources of Jiahe Wetland, worsens the water situation of Jiahe Wetland and directly reduces the flood storage. The original drainage channels and rivers are seriously silted, forming a small area of stagnant water, which is not conducive to the stability of the wetland system and needs to be rectified. The elevation of pond bottom in Green Island Area A is in the range of 0 ~ 1.5~4.50m, the elevation of highland is in the range of 1.5~4.50m, and the elevation of the top of the original Jiahe levee is 8.0 ~ 8.5m: the elevation of reservoir bottom in Green Island B is in the range of 0 ~ 1.5m ... Gongjiadao rubber dam.
The ecological restoration project of Green Island Wetland is to dredge the connecting waters, increase the wetland water area and increase the wetland water storage capacity. Secondly, ecological slope protection and wetland plant planting projects are implemented for soil revetment in waters, which are mainly used for ecological slope protection, wetland plant planting and landscape development. The specific contents of the Green Island Wetland Restoration Project are as follows:
(1) water dredging
1) According to the existing flood control plan of Jiahe River, the existing waterlogged depressions and soil ridges near the south side of Tongsan Expressway in Lvdao Area A on the west side of Jiahe River are excavated to dredge the waterway, and the ponds in Wetland Area A are connected with the Jiahe River system, so as to design and build a waterway that runs through the whole wetland, with a width of12.0mm and a bottom elevation of 0. This project needs to cross the waterway 950 meters and excavate 23,000 cubic meters of earth and stone, which can be used to build biological islands and walkways after excavation.
Due to the disturbance of disorderly human activities such as reclamation, some natural wetlands have been developed into terraces and fish ponds, and the aquatic plants in the existing wetland ecosystem have also been seriously degraded. It is necessary to adjust some terraced fields and wasteland to restore the original appearance of wetlands. Excavate diversion ditch along the waterway, the water system covers the whole wetland, and design landscape types such as ponds, streams, ponds and wetlands. This project needs to adjust the area by about 500 mu, and the excavated earthwork is about 500,000 m3. After excavation, it can be used to build new flood levees, sidewalks and wetland habitat islands.
New flood control dikes will be built in the south and west of Green Island Area A, which will be connected with the existing Jiahe levee. The newly-built dike is 1338m long, the designed dike top elevation is 7.70m, the dike width is 6.0m and the slope coefficient is 1: 3. A wide slope revetment is built on the water-facing slope near the wetland side, and the revetment technology of wooden stakes and plant vegetation bundles is adopted at the bank slope angle.
2) green island b area. According to the existing flood control plan of Jiahe, under the condition of not interfering with the flood control levee of Jiahe, water diversion culverts are built at the south and north ends of Jiahe East dike near wetland area B, connecting Green Island area B with Jiahe main stream to realize water exchange. The reservoir pool in Zone B of Green Island Wetland has comprehensive functions such as flood detention, storage regulation and landscape. Green Island Area B covers an area of 206 mu, and the water surface area of Kutang is about 1.65 mu. The designed bottom elevation is 0.00 meters, the water surface elevation is 2.50 meters, and the water storage capacity is 275,000 cubic meters.
In Area B, a diversion ditch is excavated along the reservoir pond, and the water system covers the whole wetland, and the landscape types such as ponds, streams, ponds and wetlands are designed. The area to be adjusted in this project is about 4 1 mu, and the excavated earthwork is about 55,000 m3. After excavation, it can be used to build wetland cofferdams, walkways and habitat islands.
(2) Phytoremediation Project
According to the improved topography of the project area, different aquatic plants are planted according to different water depths; At the same time, the roads and bank slopes in wet areas are afforested, and plants such as Amorpha fruticosa, Fraxinus mandshurica and weeping willows are planted, and lawns are planted on slope protection. Take the above measures to protect the ecological environment of Jiahe wetland.
1) emergent and floating plants. In the beach and shallow water area (0 ~ 1.2m), plants with strong purification ability can be selected: wet plants (Acorus calamus, Acorus calamus, Oenanthe javanica, green bamboo) and emergent plants (onion, cattail, reed and Zizania latifolia); The water depth is relatively deep (1.0~2.0m ~ 2.0m). Choose floating-leaf plants (lotus, wild water chestnut, water lily and Euryale ferox) with purification ability and ornamental ability. Through the construction and restoration of aquatic vegetation, the water purification capacity and ecological stability of wetland system can be improved.
Planting area: 300 mu.
2) Submerged plants. In the deep water area of wetland system, Ceratophyllum demersum, Sophora alopecuroides, black algae, red grass and POTAMOGETON crispus, which like temperature and have strong purification ability, are selected and planted in blocks.
Design parameters: the coverage rate is 50%.
Planting area: 300 mu.
3) Greening plants. Turf is planted on natural soil slopes, and grass species are common in the local area. Common species are drought-tolerant and moisture-tolerant shrubs and herbs: Chinese rose, Zoysia Ophiopogon japonicus, Bermuda grass, alfalfa and so on. Weeping willows, Amorpha fruticosa, Fraxinus mandshurica, Metasequoia glyptostroboides and Taxodium ascendens are planted on both sides of the production road.
Planting area: 394 mu.
4. Ecological restoration measures of Jiahekou Wetland Park
Jiahekou Wetland is located in the east of Jiahekou and north of Xingfu South Road, with an area of 1.200 mu. It is triangular, with an average width of 520m from east to west and a length of 1 540 m from north to south. The project area is flat, the ground elevation is 0 ~ 0 ~ 2.0m, and the Jiahe East Dike runs through the wet area from south to north.
The land layout of Jiahekou Wetland Project Area is shown in Figure 9-4. This area is mainly swamps and wet depressions, with reeds growing, and large swamps are exposed at low tide. The transition zone between swamp and land is wide, with all kinds of halophytes and semi-halophytes growing, and many psammophytes can be seen on sand ridges and dunes.
In the planned Jiahe Wetland Project Area, there is a 1 fly ash sedimentation tank on the east side of Jiahe East Dike and 590m north of Xingfu South Road, covering an area of about 205 mu. The long-term accumulation of coal ash will cover the vegetation around the machine in this area and cause serious damage to the wetland in Jiahekou.
Jiahekou wetland is mainly protected by ecology, and the engineering restoration measures are as follows: first, comprehensively investigate the wetland resource background and environmental conditions in the project area, focus on protecting the existing wetland resources and environment, partially dredge the silted wetland, restore the wetland vegetation, and relocate the fly ash sedimentation tank for wetland restoration. Strengthen the construction of protection facilities and improve the ecological stability of Jiahekou wetland system.
(1) Investigation results of wetland vegetation
This wet area belongs to intertidal wetland type, which is influenced by river water and tide. The vegetation types in the humid area of Jiahe Estuary are mostly halophytes and psammophytes in temperate coastal areas, among which there are many halophytes and vegetation with good sand fixation. The halophytes and psammophytes visible in Jiahekou are as follows:
Orchidaceae (Zhangdan). Limonium bicolor is a perennial herb with basal leaves, oblanceolate stems and terminal cymes. It is an indicator plant of alkaline earth, adapted to soil pH value of 8.0 ~ 9.5, and widely grows in floodplain wetlands.
Tamarix ramosissicaceae is a small deciduous tree or shrub with dense drooping branches and alternate leaves. Widely distributed in coastal areas, born in grass beaches, coastal sandy land and roadsides in saline-alkali land.
Umbelliferae. Radix Glehniae, also known as Radix Glehniae. Panicum miliaceum, the taproot is slender and cylindrical, 70cm long. The leaves are long-stalked, sheath-shaped, purple-red, and the leaves split 2-3 times. The compound umbel is erect, and the flower stems, pedicels and flower widths are all white or grayish brown fluff. Wild ones are mainly distributed in coastal beaches.
Convolvulaceae. Malva, also known as seedlings and sweet potatoes, is a creeping perennial herb with long underground stems and creeping aboveground stems. Single leaf kidney-shaped, thick, heart-shaped at the base and long stalk. Flowers are solitary in leaf axils, and the corolla is funnel-shaped. Distributed in coastal areas, mostly in coastal sandy land.
Passionflower of Verbenaceae, also known as Vitex negundo. Deciduous shrub, the whole plant is gray and puberulent, the main stem is creeping, the roots are uncertain, the leaves are opposite, the leaves are obovate to oval, the whole plant is entire, and the panicle is terminal. I like being born in coastal beaches and places where the sea often hits.
Lithocarpus sibiricus is a perennial herb with slender rhizome, height of 10 ~ 20 cm, white villous leaves, sessile or subsessile leaves, narrow oblong to strip, densely covered with white villous on both sides, and cymes are planted in one room. It is distributed on the grassland of alkaline soil in plains or hills.
Leguminosae Lathyrus sativus is a perennial herb with alternate pinnate leaves, tendrils at the top, large stipules, leaflike, heart-shaped base and axillary racemes. Indicator plants in coastal saline sandy soil. Glycyrrhiza pallidiflora is a perennial herb with woody base, totally covered with flaky yellow glands, odd pinnate compound leaves alternate, leaflets 5 ~ 13, lanceolate stipules, pilose, axillary racemes. Widely distributed in Shandong coastal areas, it is an indicator plant of saline-alkali land. Robinia pseudoacacia, deciduous tree, brown bark, grayish brown branchlets, smooth and hairless, odd pinnate compound leaves alternate, stipules prickly, axillary racemes, developed root system, barren tolerance, and is a sand-fixing plant. Amorpha fruticosa, also known as Amorpha fruticosa, is a tufted shrub, with a height of 1.5 ~ 4m, odd pinnate compound leaves alternate, and small leaves 1 1 ~ 25 pieces. Amorpha fruticosa is resistant to cold and alkali, and drought is not barren. More rivers, beaches and sunny beaches.
Polygonum aviculare of Polygonaceae, also known as Polygonum aviculare, is panicum miliaceum, with a height of 65,438+00 ~ 40 cm, reddish-brown roots, developed lateral roots, creeping or erect stems, green branches, obvious nodes, alternate leaves, oblong or lanceolate, gray-green smooth and hairless, and 65,438+0 ~ in leaf axils. Born on roadsides, watersides, beaches and saline-alkali land.
Atriplex sibirica of Chenopodiaceae, panicum miliaceum, is 20 ~ 50 cm high, with erect stems and silver-gray powder particles on its branches. Leaves alternate, rhombic, oval, usually wavy and obtuse, with two obtuse lobes above the middle, wedge-shaped at the base, green on the surface, silvery gray on the back, and densely covered with powder. Flowers unisexual, yellow-green monoecious, clustered in leaf axils. Mainly distributed in saline-alkali land, but also grown in fields and roadsides. Kochia scoparia, also known as broom grass, is the panicum miliaceum, and its height exceeds1m. Its stems are erect, leaves are dense and alternate, and the leaves are linear or lanceolate, usually with three longitudinal veins. Flowers are bisexual or female, with single flowers or two peanuts in the veins, which are mostly distributed near houses, fields and coastal wasteland. Salicornia bigelovii Torr, also known as Salicornia bigelovii Torr, is panicum miliaceum, with erect stems, many branches, opposite branches and knotty meat. The leaves stretch into opposite sheets. Inflorescence spike-shaped, terminal, short-stalked, small flowers, bisexual, with every three flowers clustered into a fleshy inflorescence axis. Distributed in coastal wet areas. Salsola glauca, also known as Salsola glauca, is located in panicum miliaceum, with an altitude of1m. Its stem branches from the base, and its branchlets are hard, green and striped. The leaves are linear endoplasm, the base is enlarged, extending down to the stem, and there are small thorns at the top. Flowers bisexual, usually arranged in slender spikes at the ends of branches. Widely distributed, Suaeda salsa, also known as Suaeda salsa, is panicum miliaceum, with a height of 30 ~ 150 cm, upright stems, light green stripes, multi-branched upper parts, alternate leaves, dense arrangement, linear or semi-cylindrical, fleshy, unisexual flowers, short stems 1 to several flowers. Widely distributed, it is an indicator plant of saline-alkali land, often mixed with Suaeda salsa and Tamarix chinensis. Suaed heteroptera, panicum miliaceum, is 20 ~ 80 cm high, green, and turns red and purple in late autumn. The stems are erect, with red and purple stripes, and the simple leaves are alternate, linear, semi-cylindrical, fleshy and green. Flowers are clustered sessile, with 3 ~ 5 peanuts in the axils of upper branches, and flowers are unisexual. Widely distributed in Shandong coastal areas, it is an indicator plant of saline-alkali land, because it is often mixed with Tamarix chinensis, Suaeda salsa, reed and so on to produce wetlands.
Ash tree of Compositae, also known as nest-eating grass, is a perennial herb with creeping rhizomes. It is an indicator plant of coastal sandy soil in temperate climate zone of China, and it is a halophyte, often associated with kidney leaves and bowl flowers. Mongolian crow onion variety. Bodhi tree is a perennial herb with grayish brown, hairless, upright, cylindrical, clothed, brown or milky yellow roots and thick or thin woolly hairs inside. The stems are mostly erect or spread from the base, the leaves are fleshy, grayish brown and rough, and 3 to 5 veins are not obvious; Basal leaves lanceolate, leaves sessile, strip lanceolate. A solitary stem tip or branch tip of a flower head. Crotalaria pigmentosa is an indicator plant of saline soil in temperate climate zone of China, and it does not grow on alkaline soil. Shandong province is distributed in saline soil with high salt content.
Liliaceae. Aspsnagus sp. is an erect or climbing herb, with a height of 20 ~ 70 cm, fleshy roots and buds, and leafy branches are clustered every 1 ~ 6 branches, often dioecious at an acute angle with the branches. Mostly distributed in sand dunes, sandy hillsides or dry mounds.
Erythrina gramineae, also known as Erythrina equisetifolia, Tripterygium wilfordii and Phragmites australis. Perennial herb with erect or inclined stems, with a height of 15 ~ 25 cm, sometimes crawling on the ground as long as 80 cm. The base is covered with scaly leaf sheaths, and the nodes are densely hairy, hard, lanceolate and often folded into needles. Panicle is often spike-shaped, distributed in Shandong coastal areas, born in salt flats, and is an excellent sand-fixing plant. Imperative cogongrass var. Major, also known as thatch, is a sweet root. Herbs, with creeping and elongated rhizomes under the ground and fibrous roots and scales on them, are straight and hairless, 50 ~ 80 cm high, and some are as high as1m. Leaf blade is linear or linear-lanceolate, with rough edges and prominent main veins on the back. Panicle is long, narrow and cylindrical. Imperata is a common weed, which can tolerate mild alkaline soil and grow on saline-alkali wasteland with light salt. Reed is a tall perennial herb with a height of 3 meters. Its underground stems have thick creeping rhizomes, thick and straight stems, often with white powder, linear leaves and large panicles at the top. Often distributed in mild saline-alkali soil.
Carex, a perennial herb of Cyperaceae, has long and horizontal stolons, which are stout all year round, erect stems with triangular nodes, purple and black, Ye Guang linear, strong, shiny surface, sharp teeth at the edge and large and terminal flower spikes. Widely distributed in coastal beaches of Shandong.
Equisetum equisetum, a perennial herb of Equisetum family, is 18 ~ 100 cm tall, with hollow stems, many branches, longitudinal ridges, rough surface, single-row stomata in the ditch, loose sheath, short triangular sheath teeth, and gradually brown tips, which are easy to fall off.
The above halophytes and psammophytes form different communities, which are distributed in the soil with different salt content in Jiahekou. The soil salt content gradually increases from less to more, and the plant communities that can be seen in turn are as follows:
1) reed-cogongrass community is distributed in the soil with low salt content (below 0.3%). Under the background of reed growth, imperata also grows more, accompanied by kidney leaves and bowl flowers.
2) Crotalaria hybrida-Carex psammophila community is distributed in slightly saline soil with a soil salt content of about 0.3%. In addition to pig excrement beans and Carex psammophila, a small amount of Suaeda heteroptera (yellow mustard) can be seen.
3) Limonium bicolor-Elaeagnus angustifolia community is distributed in saline soil with soil salt content above 1. 1%, and the salt tolerance of Limonium bicolor and Elaeagnus angustifolia is higher than that of the former community.
4) Suaeda heteroptera (Saussurea involucrata) community is the most salt-tolerant community, and the soil salt content is above 65438 0.5%. In addition to pure snow lotus, sometimes you can see Sedum.
(2) Water dredging
First of all, the fly ash sedimentation tank in the wetland project area was relocated and dismantled, and all the fly ash was transported abroad, with an engineering quantity of about 683,000m3. Terrain adjustment is made to the existing ponds and waterlogged depressions in the project area, and the landscape lake is excavated at the raw coal ash sedimentation tank in the humid area, which has the functions of flood detention, storage regulation and landscape integration. The landscape lake covers an area of about 205 mu, the designed lake bottom elevation is -0.50 ~- 1.00 m, the water surface elevation is 0.00 m, and the excavated earthwork is about 10.9 million cubic meters. At the same time, the diversion ditch is excavated along the landscape lake, which colludes with the reservoir in the project area. The water system covers the whole wetland, and the landscape types such as ponds, streams, ponds and wetlands are designed. The area to be adjusted in this project is about 480 mu, and the excavated earthwork is about 320,000 m3. After excavation, it can be used to build wetland cofferdams, walkways and habitat islands.
According to the existing flood control plan of Jiahe River, a diversion gate is designed to be built on the north side of Xingfu South Road and the tidal dike of Jiahe River without disturbing the tidal dike of Jiahe River, and a waterway running through the whole wetland is excavated. The waterway is 25.0m wide and 1.5m deep, connecting the intake gate with the landscape lake and seashore. This project needs to cross the 2000m waterway, and the dredging of water system needs to excavate earthwork100000 cubic meters.
At the same time, the ecological slope protection of the existing tidal dike on the east bank of Jiahe River was reformed, and the slope protection technology of wooden stakes and riprap was adopted at the bank slope angle, and the length of the slope protection section was1285 m.
(3) Phytoremediation Project
Under the premise of protecting the existing vegetation resources, plant different aquatic plants according to the different water depths of the terrain in the project area; At the same time, shelter forest projects will be carried out on the beaches outside the Jiahe river dampproof dike and on the roads in humid areas, and moisture-tolerant and salt-tolerant tree species such as Amorpha fruticosa, Fraxinus mandshurica, Robinia pseudoacacia and Tamarix chinensis will be planted; Plant salt-tolerant biological species such as Suaeda salsa, Phragmites australis and imperata on the slope protection. By taking the above measures, the ecological environment of Jiahekou wetland has been protected.
1) emergent and floating plants. In the beach and shallow water area (0 ~ 1.2m), plants with strong purification ability can be selected: wet plants (Acorus calamus, Acorus calamus, Oenanthe javanica, green bamboo) and emergent plants (onion, cattail, reed and Zizania latifolia); The water depth is relatively deep (1.0~2.0m ~ 2.0m). Choose floating-leaf plants (lotus, wild water chestnut, water lily and Euryale ferox) with purification ability and ornamental ability. Through the construction and restoration of aquatic vegetation, the water purification capacity and ecological stability of wetland system can be improved.
Planting area: 400 mu.
2) Submerged plants. In the deep water area of wetland system, Ceratophyllum demersum, Sophora alopecuroides, black algae, red grass and POTAMOGETON crispus, which like temperature and have strong purification ability, are selected and planted in blocks.
Design parameters: the coverage rate is 50%.
Planting area: 150 mu.
3) Moisten salt-tolerant plants. Turf is planted on natural soil slopes, and grass species are common in the local area. Common species are drought-tolerant and moisture-tolerant shrubs and herbs: Chinese rose, Zoysia Ophiopogon japonicus, Bermuda grass, alfalfa and so on. And salt-tolerant biological species such as Suaeda salsa, Phragmites australis and imperata. Weeping willows, Amorpha fruticosa, ash trees and Taxodium ascendens are planted on both sides of the production road.
Planting area: 404 mu.
4) Shelterbelt transformation. Eco-forestry should be carried out in the shelter forest land in the humid area of Jiahekou. Use salt-tolerant and moisture-tolerant seedlings such as Pinus densiflora, Robinia pseudoacacia, Amorpha fruticosa, Tamarix ramosissima, Pinus elliottii, Taxodium ascendens, Metasequoia glyptostroboides and Taxodium ascendens to construct estuarine and tidal flat ecological forest.
Planting area: 246 mu.
Jiahe Ecological Park is located in the middle of Yantai City, southwest of Zhifu District, facing Laishan Airport in the south and Fushan District and Development Zone across the river in the west. The scope includes Waijia River, Dagujia River and its east bank, specifically, it starts from Yanjia River in Dongzhu in the south, reaches the estuary in the north, starts from the railway line, Qingnian South Road and the east boundary of Zhifu District in the east, and reaches Jiahe River in the west, with an area of about 35.89km2. The ecological wetland park in the lower reaches of Jiahe River is a "one corridor and three areas" wetland system, with Jiahe River as the main trunk and Zhuyan wetland and green wetland in the east. The construction scale is 1 1438 mu. The main task is to restore and protect Jiahe natural wetland, gradually restore the ecological function of Jiahe wetland, ensure the ecological integrity and safety of river ecosystem, maximize the landscape and ecological service benefits of wetland, realize the ecological restoration and water quality guarantee of drinking water sources, and achieve the purposes of increasing biodiversity, preventing soil erosion, improving climate and conserving water sources.