Upright riverbed ecological transformation structure

Abstract

The present invention relates to an upright riverbed ecological reconstruction structure, in which a revetment embankment structure similar to the natural riverbed shape is installed in the river channel in response to the current upright riverbed, and a gentle slope is formed between the current upright riverbed and the corresponding revetment embankment structure, which slopes from the upright riverbed to the revetment embankment structure, and plants are planted on the gentle slope. The present invention uses a revetment embankment structure made by gluing and stacking block stones to create a shape similar to the natural river channel in the river channel, and restores plant colonies in the closed shallow water area formed by the revetment embankment and the current upright riverbed, thereby improving the current situation in which biodiversity is lost in urban river channels and the ecosystem is deteriorated. The present invention increases the complexity of the river channel structure by reconstructing the topography in the river channel, increases the diversity of hydraulic conditions, and at the same time provides a good place for aquatic animals to take refuge and rest, and the restoration of plants can purify the river channel water quality and improve the biodiversity of the river channel, which is helpful in building a healthy river water ecosystem. The present invention is applicable to the technical field of river channel ecological restoration.

Description

[Technical Field]

[0001] The priority information of this invention is priority number CN202210371207.4, priority date April 1, 2022, and title of the invention is "Upright Riverbed Ecological Renovation Structure," the disclosure of which is incorporated herein by reference. The present invention relates to the technical field of river channel ecological restoration, and in particular to an upright riverbed ecological renovation structure. [Background technology]

[0002] Meandering is a natural tendency in the dynamic change process of rivers. There are several reasons why meandering river channels are formed, the main one being that when water flows through the convex banks of a slightly curved river section, centrifugal force causes the water to erode the concave banks, forming deep pools and shallow areas on the other side.

[0003] For historical reasons, as China's urbanization process continues to intensify, previous river channel improvement projects, due to a lack of awareness and limited coastal water space, have often focused on water conservancy construction while ignoring ecology. Under this philosophy, river channels in many Chinese cities have been straightened, with bends cut off, drainage channels formed, and hardened, destroying the ecological integrity of the river channels and leaving the landscape uniform. In particular, meandering river berms, which are common in plain river channels, are becoming increasingly severe because current improvement measures meandering water flows more strongly in bends than in straight berms of the same length. Furthermore, bends with too small a radius of curvature result in uneven water flow during flood periods, often creating large basins and steep valley sections, threatening the safety of the levees and making it difficult to ensure the stability and service life of the improvement and reconstruction projects. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem to be solved by the present invention is to provide an upright riverbed ecological renovation structure to address the above-mentioned problems. [Means for solving the problem]

[0005] The technical plan adopted in this invention is an upright riverbed ecological modification structure in which a revetment embankment structure resembling the natural river channel shape is installed in the river channel in correspondence with the existing upright riverbed, and a gentle slope is formed between the existing upright riverbed and the corresponding revetment embankment structure, sloping from the upright riverbed toward the revetment embankment structure, and plants are planted on this gentle slope.

[0006] Furthermore, the revetment structure will adopt a flushing-resistant structure in areas prone to flushing and erosion by water currents, while the remaining areas will adopt a gravel beach structure.

[0007] Furthermore, flashing-resistant structures are built up with large blocks of stone or large stone slabs.

[0008] Furthermore, the top of the flashing-resistant structure is slightly higher than the normal water level of the river channel.

[0009] Furthermore, the egg pebble beach will be created by dumping chunky stones and high-end boulders, and the beach will adopt a gentle slope entry method.

[0010] Furthermore, the average particle size of the egg gravel beach is approximately D50 = 20 mm, of which the content of 10 to 50 mm particle size group accounts for approximately 80%.

[0011] In addition, an ecological low weir will be installed across the river channel.

[0012] Furthermore, ecological weirs can be I-, J-, V-, U- or W-shaped, made of logs or blocks of stone, and their height usually does not exceed 30cm. The lowest part of the ecological weir should be located in the center of the river channel, and the blocks of stone should extend to the top of the river channel.

[0013] Furthermore, the plants planted on the gentle slope include submerged plants and the recovery of emerged plants, with the emerged plants being one or more species selected from Iris pseudacorus, Monochoria korsakowii, Cyperus persica, lotus flower, cornflower, cattail, reed and dandelion, and the submerged plants being one or more species selected from Eelgrass, Shrimp grass and Malayan menthaea.

[0014] Furthermore, an appropriate area that can meet the demand for gentle slope water access will be set up as a water access platform, and stairs will be installed extending from the top of the current upright riverbed to the water access platform.

[0015] Furthermore, the upright riverbed ecological modification structure is used for meandering river section governance, which includes a number of bends. Along the water flow direction, each bend includes an upwater side and a backwater side. A flushing-resistant structure is installed on the upwater side, a pebble beach is installed on the backwater side, and an ecological low weir spanning the river channel is installed at the junction of each bend.

[0016] Furthermore, the ecological low weir is used in turbid water flushing conditions, and its structural type is a submerged low weir structure.

[0017] Furthermore, the submerged low dam structure is preferably a submerged three-dimensional low dam structure.

[0018] Furthermore, the weir crest of an ecological low weir has a zigzag waveform in the direction crossing the river channel, and the main factors to be considered in designing the shape of the receiving surface of the weir body of an ecological low weir are the average annual discharge and average gradient of the meandering river section.

[0019] Specifically, when the meandering river step has a high average annual outflow and average gradient, the shape of the receiving surface of the weir body is an arc-shaped surface concave toward the weir body, and the angle α between the arc-shaped surface and the bottom surface of the weir body is 30° to 60°.

[0020] When the meandering river section has a medium average annual discharge and average gradient, the weir body receiving surface includes a lower slope and an upper arc surface connected to the lower slope, the upper arc surface protrudes in a direction away from the weir body crest, and the angle β between the lower slope and the weir body bottom surface is 40° to 80°.

[0021] When the meandering river section has a low average annual discharge and low average gradient, the weir body receiving surface is a slope, and the angle γ between the slope and the weir body bottom is 40° to 80°. [Effects of the Invention]

[0022] The beneficial effects of this invention are that it creates a natural river channel shape within the river channel using a revetment structure made of block stones, and restores plant colonies in the enclosed shallow water area formed by the revetment and the existing upright riverbed, thereby improving the current lack of biodiversity, ecosystem degradation, and monotonous landscape of urban river channels. By restructuring the topography within the river channel, the invention increases the complexity of the river channel structure and the diversity of hydraulic conditions, while providing good shelter and resting places for aquatic animals. The restoration of plants also purifies the river channel water quality, improves the biodiversity of the river channel, and contributes to the creation of a healthy river water ecology.

[0023] In addition, by installing the anti-flushing structure on the upwater side of the bend and the pebble beach on the backwater side of the bend, combined with the specific structural layout of the ecological low weir at the junction of each bend, the water flow rate of the next bend can be effectively alleviated, further reducing the flushing force on the revetment embankment structure, greatly improving the overall stability and service life of the ecologically modified structure, and achieving the beneficial effects of simple structure, convenient construction, and reduced overall modification costs. [Brief explanation of the drawings]

[0024] The following drawings are included to provide a further understanding of the present application and constitute a part of this application and are intended only as an illustrative illustration and description of the invention, not as a limitation on the scope of the invention. [Figure 1] 1 is a schematic plan view of an embodiment of the present application; [Figure 2] 1 is a typical cross-sectional view of an embodiment of the present application; [Figure 3] FIG. 1 is a schematic plan view of another embodiment of the present application. [Figure 4] FIG. 10 is a front view of an ecological low weir according to another embodiment of the present application, taken along the river channel width direction. [Figure 5] 5 is a cross-sectional view AA taken along line AA of FIG. 4 in another embodiment of the present application. [Figure 6] FIG. 5 is a cross-sectional view (AA)' taken along line AA in FIG. 4 in another embodiment of the present application. [Figure 7] FIG. 5 is a cross-sectional view (AA)″ taken along line AA in FIG. 4 in another embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following drawings clarify some embodiments of the present application and clearly and completely describe the technical solution of the present invention. The drawings in the specification, which form a part of this application, are used to provide a further understanding of the present invention. The exemplary embodiments and explanations of the present invention are for the purpose of interpreting the present invention and do not constitute undue limitations on the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative efforts fall within the scope of protection of the present invention.

[0026] In addition to the directions defined individually, directions such as up, down, left, and right in this specification all correspond to the directions such as up, down, left, and right shown in FIG. 1 of the embodiments of this application, and when the specific posture changes, the directional indications also change accordingly. The terms "first," "second," "third," "fourth," and similar terms used in this application do not indicate any order, number, or importance, but are only used to distinguish different components. In each embodiment of this disclosure, the same or similar reference symbols represent the same or similar components.

[0027] In the present invention, unless otherwise expressly specified or limited, the terms "connection," "fixed," etc. should be understood in a broad sense. For example, unless otherwise expressly limited, "connection" may be a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0028] In addition, the technical solutions between the embodiments of the present invention may be combined with each other, but this must be based on what a person skilled in the art can achieve. If the combination of the technical solutions contradicts each other or cannot be realized, it should be considered that such combination of the technical solutions does not exist and is not within the scope of protection of the claimed invention.

[0029] Example 1 This example is an upright riverbed ecological renovation structure, in which a revetment embankment structure with a shape similar to a natural river channel (for example, an S-shaped river channel shape) is installed within the river channel to correspond to the existing upright riverbed, and the revetment embankment elevation must meet both the ecological and landscape beautification needs while satisfying the river channel's flow requirements. In the closed shallow water area between the existing upright riverbed and the corresponding revetment embankment structure, a gentle slope is formed from the upright riverbed toward the revetment embankment structure, and plants are planted on this gentle slope to restore plant colonies.

[0030] In this example, the revetment structure uses a flushing-resistant structure in areas prone to flushing and erosion by water currents, and a gravel beach in the remaining areas. The flushing-resistant structure is made of large blocks or large stone slabs (large blocks range in size from 40mm to 200mm, and can be shaped like round pebbles or boulders, or even larger, flat blocks). The top of the flushing-resistant structure is approximately 30cm higher than the normal water level of the river channel. The gravel beach is made by adding blocks and high-end boulders. The average particle size of the gravel beach is approximately D50 = 20mm, of which 10-50mm particles account for approximately 80%. The beach uses a gentle slope inlet method. Gravel is mixed in the middle area to simulate the natural sorting of the riverbed substrate.

[0031] In this example, depending on the river channel topography, ecological low weirs are installed within the river channel to span the river, or continuous gradient structures are installed. Ecological low weirs are installed in different structural forms, such as I-, J-, V-, U-, or W-type, depending on different geological conditions. The materials used are logs or blocks of stone, and the height usually does not exceed 30 cm so as not to affect fish migration. The lowest part of the ecological low weir should be located in the center of the river channel, and the blocks extend to the top of the channel to protect the bank slope.

[0032] In this example, the recovery of plant colonies includes the recovery of submerged plants and emerged plants. The emerged plants include iris (30 plants / m 2 ), reeds (4 plants / m 2 ), Konagi (20 plants / m 2 ), Purple loosestrife (10 plants / m 2 ), cattail (16 plants / m 2 ) and the submerged plants were eelgrass (4-5 stems / bundle, 25 bundles / m 2 ), Asagra (5-10 stems / bundle, 9 bundles / m 2 ), Ebimo (10-15 stems / bundle, 9 bundles / m 2 ) and other plants will be selected and cultivated in combination to purify water quality and improve the appearance of the river channel landscape.

[0033] In this embodiment, a hydrophilic platform is installed in the closed shallow water area between the existing upright riverbed and the corresponding revetment embankment structure, where appropriate, in the corresponding urban area or where there is a need for hydrophilic activities. Bluestone steps are installed from the top of the existing upright riverbed to the hydrophilic platform, allowing people to enter the hydrophilic platform. The hydrophilic platform is approximately 40 cm higher than the normal water level, and within the open protective fence, grass clippers can be cultivated to create a hydrophilic space, satisfying the hydrophilic needs of surrounding residents.

[0034] Example 2 The upright riverbed ecological modification structure in this embodiment is used for meandering river section governance, which includes a number of bends. Along the water flow direction, each bend includes an upwater side and a backwater side. A flushing-resistant structure is installed on the upwater side, a pebble beach is installed on the backwater side, and an ecological low weir spanning the river channel is installed at the junction of each bend.

[0035] An ecological low weir is a river engineering structure constructed on a river channel, connected to both sides of the riverbed, to prevent undercutting of the riverbed and reduce local flow velocities. As shown in Figure 3, this embodiment installs ecological low weirs spanning the river channel at the junctions of each bend (i.e., between bends a and b, between bends b and c, and between bends c and d), which effectively reduces the water flow velocity of the next bend and reduces the flushing force on the revetment embankment structure, contributing to the stable use and extended lifespan of the revetment embankment structure. It also has the beneficial effects of being simple in structure, easy to install, and reducing overall costs.

[0036] Furthermore, by installing the anti-flushing structure on the upstream side of the bend, and the pebble beach on the backwater side of the bend, combined with the specific structural layout of the ecological low weir at the junction of each bend, the installation of the ecological low weir at the junction of the bend can effectively reduce the water flow velocity and change the direction of the water flow from rushing straight towards the anti-flushing structure, further reducing the impact force on the anti-flushing structure, playing a better role in maintaining the revetment embankment structure and greatly improving the stability and service life of the revetment embankment structure, which is of great significance in the groundbreaking renovation in the field of meandering river section governance.

[0037] The flashing-resistant structure and the structure of the pebble beach in the revetment structure of this embodiment may be constructed by using a cement-hardened structure that artificially resembles natural attributes.

[0038] Furthermore, in practical applications, the water flow intensity is relatively strong under turbid water flushing conditions. Therefore, how to better ensure the operational stability and service life of revetment structures in riverbed ecological restoration and renovation has long been a technical challenge that has not been overcome by those skilled in the art. In response to this technical challenge, the applicant's research and development team conducted N turbid water flushing experiments based on the technical solution of the present invention. For example, in one experiment, a sand-filled self-circulating tank was constructed with a length of 15 m, a width of 1.54 m, and a depth of 0.48 m, three serpentine bends, each with a flushing-resistant structure on the upstream side of the bends and a pebble beach on the backwater side. A first submerged low weir structure and a second submerged low weir structure were installed at the junctions of two adjacent bends, respectively. A flushing experiment was conducted under turbid water conditions with sand being fed. The flushing data upstream and downstream of the first submerged low weir structure and the location data of large lumps and high-end boulders in the upstream and downstream revetment structures were measured. By setting different flow rates and discharge rates and corresponding to different structural shapes of ecological low weirs with different weir body receiving surfaces, the measurement results of the position data of the embankment structure remain almost unchanged, which further effectively demonstrates the specific layout of the riverbed ecological transformation structure in this embodiment, greatly improving the beneficial effects of the service stability and service life of the embankment structure, and further guaranteeing the overall stability and service life of the riverbed ecological transformation structure.

[0039] Example 3 Based on Example 2, the preferred embodiment is a submerged low weir structure suitable for turbid water flushing environments. As shown in Figure 4, the weir crest 51 of the ecological low weir 5 in this example has a zigzag waveform along the direction crossing the river channel, which is convenient for fish migration. However, it is not limited to a zigzag waveform and can be configured with other irregular shapes, such as a perforated frame, depending on the actual situation. This example focuses on the clever design of the weir body's receiving surface structure. The shape of the weir body receiving surface 53 of this ecological low weir is designed mainly taking into account factors such as the average annual discharge and average gradient of the meandering river section.

[0040] The average annual runoff of a meandering river step is the average flow rate through a cross section of the river, and is the arithmetic mean value of the annual runoff over a long period of time. The average gradient of a meandering river step is the ratio of the total head of the meandering river step to the length of the river step.

[0041] As shown in Figure 5, in one embodiment, when the meandering river step has a high annual average discharge and average gradient, the shape of the weir body receiving surface 53 is a circular arc concave toward the weir body, and the radius of curvature of the circular arc is reasonably designed according to the height and thickness of the weir body. The angle α between the circular arc and the weir body bottom surface 52 is 30° to 60°, preferably 40° to 50°, and more preferably 45°. The sediment flow upstream of the ecological low weir (the mark in Figure 5 indicates the direction of the sediment flow) is circular. It is easy to rotate along the arc surface, and during rotation, it finally rotates and falls away from the weir body 50 along the upper arc surface 531 of the arc surface, which is advantageous for reducing the water flow speed and changing the water flow direction, thereby better playing the role of protecting the revetment embankment structure, improving the stability and service life of the revetment embankment structure, and further ensuring the overall stability and service life of the riverbed ecological renovation structure, and has the beneficial effects of being simple in structure, easy to install, and reducing the overall renovation costs.

[0042] In this embodiment, the so-called "high stage" is specifically defined as a meandering river section with an average annual runoff of 2 to 4 billion cubic meters and an average gradient of 6 to 8%, such as the Renhe River and the Jinhe River, which are main tributaries of the Han River in China. The reason why the receiving surface 53 of the weir body is shaped as a concave arc and has an appropriate angle α is because high-stage meandering rivers have relatively large runoff volumes and radial flow velocities and are accompanied by relatively large amounts of sediment flow. This sediment flow can have a relatively large spatial swirl within the concave arc, which is beneficial to reducing the water flow velocity and changing the water flow direction, thereby better ensuring the overall stability and service life of the riverbed ecological renovation structure.

[0043] As shown in Figure 6, in one embodiment, when the meandering river section has a medium average annual discharge and average gradient, the weir body receiving surface includes a lower slope 532 and an upper arcuate surface 531 connected to the lower slope. The upper arcuate surface 531 protrudes away from the weir body crest, and the radius of curvature of the upper arcuate surface is reasonably designed according to the height and thickness of the weir body. The angle β between the lower slope 532 and the weir body bottom surface 52 is 40° to 80°, preferably 50° to 70°, and more preferably 60°. This technical solution allows the sediment flow upstream of the ecological low weir (the markers in Figure 6 indicate the direction of the sediment flow) to rotate along the lower slope 532 and the upper arcuate surface 531, and finally rotate and fall away from the weir body 50 along the upper arcuate surface 531.

[0044] In this embodiment, the so-called intermediate stage is specifically defined as a meandering river section with an average annual outflow of 1 to 2 billion cubic meters and an average gradient of 3% to 6%, such as the Danjiang River and Ziwu River, which are main tributaries of the Han River in China.

[0045] As shown in Figure 7, in one embodiment, when the meandering river section has a low average annual discharge and average gradient, the weir body receiving surface 53 is a slope, and the angle γ between the slope and the weir body bottom surface 52 is 40° to 80°, more preferably 50° to 70°, and even more preferably 60°. Because the discharge and radial flow velocity of a low-stage meandering river are relatively small and accompanied by a relatively small amount of sediment flow, making the weir body receiving surface 53 a slope can reduce the water flow velocity and change the water flow direction, thereby ensuring the overall stability and service life of the riverbed ecological renovation structure.

[0046] In this embodiment, the so-called low stage is specifically defined as a meandering river section with an average annual outflow of 0.1 to 1 billion cubic meters and an average gradient of 0.2% to 3%, such as the Yudai River, Muma River, and Huangyang River, which are main tributaries of the Han River in China.

[0047] The above description clearly illustrates and describes the preferred embodiments of the present application, but it should be understood that the present application is not limited to the forms disclosed herein and should not be considered exclusive of other embodiments, but may be used in various other combinations, modifications, and environments, and may be modified by the above teachings or the skill or knowledge of the relevant art within the scope of the subject concept of the present application. However, modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present application, and should all be included in the scope of protection of the claims appended hereto. [Explanation of symbols]

[0048] 1. Current upright riverbed; 2. Plants; 3. Large blocks of stone; 4. Hydrophilic platform; 5. Ecological low weir; 50, weir body; 51, weir crest; 52, weir body base; 53, weir body receiving surface; 531, upper arc surface; 532, lower slope; 54, weir body backwater surface; 6, pebble beach.

Claims

1. This is an upright riverbed ecological reconstruction structure, in which a new bank protection structure resembling the natural river channel form is installed in the river channel in correspondence with the existing upright riverbed, and a gentle slope is formed between the existing upright riverbed and the corresponding bank protection structure, sloping from the upright riverbed to the bank protection structure. A closed shallow water area is formed between the existing upright riverbed and the revetment embankment structure, and plant colonies are restored in the closed shallow water area. The gentle slope is planted with plants, The upright riverbed ecological modification structure is applicable to meandering river sections, and the meandering river sections include a plurality of bends, each of which has an anti-flushing structure on the upstream side, a pebble beach on the backwater side, and an ecological low weir spanning the river channel at the junction of adjacent bends.

2. The upright riverbed ecological transformation structure according to claim 1, characterized in that the revetment embankment structure adopts a flushing-resistant structure in the corresponding area that is easily flushed and eroded by the water flow, and adopts a pebble beach in the remaining area.

3. The upright riverbed ecological transformation structure according to claim 2, characterized in that the anti-flush structure is made of large blocks of stone or large stone slabs.

4. The upright riverbed ecological transformation structure according to claim 2, wherein the top of the anti-flushing structure is slightly higher than the normal water level of the river channel.

5. The upright riverbed ecological transformation structure according to claim 2, characterized in that the pebble beach is made by throwing in chunk stones and high-end boulders, and the beach adopts a gentle slope water entry method.

6. The upright riverbed ecological transformation structure of claim 5, characterized in that the average particle size of the egg pebble beach is about D50 = 20 mm, of which the content of 10-50 mm particle size group accounts for about 80%.

7. 2. The upright riverbed ecological transformation structure according to claim 1, wherein an ecological low weir spanning the river channel is installed within the river channel.

8. The ecological weir is I-, J-, V-, U- or W-shaped, made of logs or blocks of stone, and its height is usually not more than 30 cm. The lowest part of the ecological weir should be located in the center of the river channel, and the blocks of stone extend to the top of the river channel.

9. 2. The upright riverbed ecological modification structure according to claim 1, wherein the plants planted on the gentle slope include submerged plants and emerged plants, the emerged plants being one or more of Iris pseudorasbora, Monochoria korsakowii, Cyperus persica, lotus flower, cornflower, cattail, reed and Chinese lantern plant, and the submerged plants being one or more of Zostera marina, Ebimosa and Malayan menthaea.

10. The upright riverbed ecological transformation structure according to claim 1, characterized in that an appropriate area that can meet the water access needs of the gentle slope is set up as a water access platform, and stairs extending from the top of the existing upright riverbed to the water access platform are installed.

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