Ecological restoration method for marsh wetland water system based on water retaining weir
By building a water barrier weir in the river channel, using mortar block stone structure and geotextile anti-seepage layer to slow down the flow rate and raise the water level, the problem of wetland habitat degradation caused by river water system erosion is solved, and a low-interference and efficient wetland restoration effect is achieved.
Patent Information
- Application Number
- CN202510810167.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-17
- Publication Date
- 2025-07-18
AI Technical Summary
The existing wetland restoration technology in the river water system erodes the riverbed and leads to accelerated flow rate, decreased water level, and reduced water distribution, leading to wetland habitat degradation. The existing methods have problems such as large habitat interference, insufficient hydrological regulation, high costs, long cycles and insufficient ecological protection.
Water blocking weirs are built in the river channel, and the water storage flow is blocked to slow down the flow rate, raise the water level, and increase the amount of water holding. The mortar block stone structure and geotextile anti-seepage layer are used to design fish migration channels. The construction is carried out during the dry season and is regularly maintained to form a stable wetland habitat.
It effectively solved the problems of water level drop and accelerated flow rate caused by downsliding of river channels. After repair, the water level was raised by 25-75cm, the flow rate was reduced by 20%-40%, the water holding volume increased by 30%-50%, the groundwater level increased by 10-50cm, and the vegetation coverage rate increased by 20%-35%, reducing soil erosion and forming a long-term and stable wetland habitat.
Smart Images
Figure CN120331204A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of wetland ecological restoration, and particularly to a method for ecological restoration of the water system in a swamp wetland based on a water retaining weir. By building water retaining weirs in the river channel, reducing the flow velocity, raising the water level, and increasing the water holding capacity, the water system of the swamp wetland is restored, which is applicable to swamp wetland areas where the river water system scours the riverbed and causes the riverbed to lower, resulting in an increase in flow velocity, a decrease in water level, and a reduction in water volume distribution. Background Art
[0002] Swamp wetlands are important ecosystems with important functions of regulating hydrology, protecting biodiversity, and maintaining ecological balance. However, due to long-term water flow scouring, riverbed incision, and riverbed lowering, many swamp wetlands have problems such as increased flow velocity, decreased water level, and reduced water volume distribution, resulting in the degradation of wetland habitats, difficulty in maintaining wetland vegetation communities, a decrease in the groundwater level, and insufficient water volume during the dry season, seriously affecting the ecological functions of the wetland.
[0003] Existing wetland restoration technologies mainly include methods such as large-area vegetation planting, external water diversion for replenishment, and large-scale river channel transformation. However, these methods have the following deficiencies: (1) Great habitat interference: Large-scale construction or water diversion projects often cause great disturbance to the habitats around the wetland, and may damage the existing ecosystem; (2) Insufficient hydrological regulation: Existing methods are difficult to accurately regulate the flow velocity and water level of the river channel, and the restoration effect is unstable, especially difficult to maintain the water volume during the dry season; (3) High cost and long cycle: Large-scale engineering construction has high costs and a long cycle, and lacks pertinence to local water system problems; (4) Insufficient ecological protection: Some restoration methods do not fully consider ecological needs such as fish migration, affecting the integrity of the wetland ecosystem.
[0004] Therefore, there is an urgent need for a low-interference, high-efficiency, and sustainable method for restoring the water system of swamp wetlands, which can accurately regulate hydrological conditions, extend the water holding time, slow down soil erosion, promote the natural restoration of wetland vegetation, and form a long-term stable wetland habitat without damaging the surrounding habitats. Summary of the Invention
[0005] The object of the present invention is to solve the difficult problem of restoring swamp wetlands in the prior art where the river water system scours the riverbed and causes the riverbed to lower, resulting in an increase in flow velocity, a decrease in water level, and a reduction in water volume distribution. A method for ecological restoration of the water system in a swamp wetland based on a water retaining weir is proposed. By building several water retaining weirs in the river channel, the water flow velocity is reduced, the water level is raised, the water holding capacity and the water holding time are increased, the groundwater level is promoted to rise, the water volume during the dry season is improved, so as to improve the hydrological conditions, extend the water holding time, slow down soil erosion, promote the natural restoration of wetland vegetation, and form a long-term stable wetland habitat.
[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A method for ecological restoration of the water system in a marsh wetland based on a water retaining weir, comprising the following steps: S1: Site selection of the water retaining weir: For a marsh wetland where the river water system scours the riverbed and causes the riverbed to downcut, resulting in an increase in flow velocity and a decrease in water level, select a river section with severe riverbed downcut and gentle terrain around to ensure the impounding effect and reduce the interference to the surrounding habitats. Priority is given to a river section where the riverbed downcut depth is greater than 50 cm, the river channel slope is less than 5%, and the terrain around is gentle; S2: Preliminary preparation: Obtain hydrological change data for at least 1 year (covering all four seasons), including the flow rate, water level, and flow velocity changes during the dry season and the wet season, for flood discharge and impounding design. Determine the elevation difference between the upstream and downstream of the restoration area, and calculate the number of water retaining weirs through the formula "Number of water retaining weirs = Elevation difference between the upstream and downstream of the restoration area / 100 cm"; S3: Design of the water retaining weir: Width: The width of the weir body is the same as the width of the river channel to ensure the impounding effect; Height: The height of the weir is 25 cm lower than the river bank and does not exceed 100 cm to ensure the flood discharge capacity during the rainy season; Structure: The weir body adopts a structure of grouted rubble masonry. The layered structure of the weir body from top to bottom includes energy dissipation stones with a height of 140 - 150 mm, a river beach stone masonry layer with a thickness of 280 - 300 mm, a geotextile anti-seepage layer with a thickness of 2 - 3 mm, a clay tamping layer with a thickness of 400 mm, a river beach stone structure layer with a thickness of 100 mm, and the natural riverbed layer; S4: Construction and maintenance: Build several designed water retaining weirs in the river section. Select the dry season (usually from October of each year to February of the next year), avoid construction during the wet season and strong rainfall weather, and conduct regular inspections and maintenance after construction until a stable wetland habitat is formed.
[0007] As a further technical solution of the present invention, in the S3, the top width of the water retaining weir is 500 mm, and a ramp is provided on the back water surface of the weir body, the width of which is not less than 3 times the height of the weir body, with a trapezoidal cross-section and a slope less than 1:3.
[0008] As a further technical solution of the present invention, in the S3, the energy dissipation stones are located at the top of the weir body and the back water surface ramp, and are arranged in a staggered manner, with a stone spacing of 300 mm to ensure the fish migration channel.
[0009] As a further technical solution of the present invention, in the S3, the river beach stone masonry layer adopts natural river beach stones, and the stones are arranged naturally, and the exposed part does not leak mortar, taking into account ecological beauty.
[0010] As a further technical solution of the present invention, in the S3, the geotextile anti-seepage layer is an optional setting for reducing water leakage, and the compaction coefficient of the clay tamping layer is not less than 0.90.
[0011] As a further technical solution of the present invention, in the S4, the construction steps specifically include: S41: Clear the silt and debris in the river channel to ensure a flat foundation; S42: Lay a 100 - mm - thick river beach stone structural layer as the foundation of the weir body; S43: Lay a 400 - mm - thick clay layer and compact it, with a compaction coefficient not less than 0.90; S44: Optionally, lay a 2 - 3 - mm - thick geotextile anti - seepage layer on the clay layer; S45: Use 280 - 300 - mm - thick river beach stones for mortar masonry to build the main body of the weir; S46: Build a ramp on the backwater side of the weir body, with a slope less than 1:3, and stagger - set energy - dissipating stones with a height of 140 - 150 mm on the surface of the ramp.
[0012] As a further technical solution of the present invention, in S4, regular inspections and maintenance are carried out once a month to check the stability of the weir body, the integrity of the ramp, the position of the energy - dissipating stones, and the scouring and leakage conditions. If it is found that the weir body is loose or the foundation sinks due to water flow scouring, stones or sand and gravel are replenished in time, and the water level, flow velocity, and vegetation recovery are continuously monitored until a stable water environment and vegetation community are formed (the vegetation coverage rate increases by 20% - 35%), which usually takes 1 - 2 years.
[0013] The beneficial effects of the present invention are as follows: Building a water - retaining weir in the river channel effectively solves the problems of water level decline and flow velocity increase caused by river channel incision. After restoration, the river water level rises by 25 - 75 cm, and the flow velocity decreases by 20% - 40%; the construction is only carried out in the river channel, with the minimum ecological interference, protecting the habitats around the wetland; the water - holding capacity increases by 30% - 50%, and the water - holding time is extended to the end of the dry season, and the groundwater level in the adjacent area rises by 10 - 50 cm, improving the water volume in the dry season; the soil erosion rate is reduced by more than 50%, and the vegetation coverage rate increases by 20% - 35%, forming a long - term stable marsh wetland habitat; using local materials (river beach stones) and natural design, the construction cost is low and the ecological aesthetics is strong. Description of the Drawings
[0014] Figure 1 It is a cross - section and construction schematic diagram of the weir dam; Figure 2 It is a flow chart of a marsh wetland water system ecological restoration method based on a water - retaining weir proposed by the present invention. Detailed Embodiments
[0015] To make the technical means, creative features, achieved purposes, and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.
[0016] Please refer to the attached Figure 2 , a marsh wetland water system ecological restoration method based on a water - retaining weir, comprising the following steps: S1: Selection of the water retaining weir site: For marsh wetlands where the river water system scours the riverbed and causes the riverbed to incise, resulting in increased flow velocity and decreased water level, select a river section with severe riverbed incision and gentle surrounding terrain to ensure the water retaining effect and reduce interference with the surrounding habitats. Priority should be given to river sections where the riverbed incision depth is greater than 50 cm, the riverbed slope is less than 5%, and the surrounding terrain is gentle. S2: Preliminary preparation: Obtain hydrological change data for at least 1 year (covering all four seasons), including the flow rate, water level, and velocity changes during the dry season and the wet season, for flood discharge and water retaining design. Determine the elevation difference between the upstream and downstream of the restoration area, and calculate the number of water retaining weirs using the formula "Number of water retaining weirs = Elevation difference between the upstream and downstream of the restoration area / 100 cm". S3: Design of the water retaining weir: Width: The width of the weir body is the same as the width of the river channel to ensure the water retaining effect. Height: The height of the weir is 25 cm lower than the riverbank and does not exceed 100 cm to ensure the flood discharge capacity during the rainy season. Structure: The weir body is made of mortar-laid block stones. The layered structure of the weir body from top to bottom includes energy dissipation stones with a height of 140 - 150 mm, a river beach stone masonry layer with a thickness of 280 - 300 mm, a geotextile anti-seepage layer with a thickness of 2 - 3 mm, a clay tamping layer with a thickness of 400 mm, a river beach stone structure layer with a thickness of 100 mm, and the natural riverbed layer. S4: Construction and maintenance: Build several designed water retaining weirs in the river section. Select the dry season (usually from October of each year to February of the following year), avoid construction during the wet season and heavy rainfall weather, and conduct regular inspections and maintenance after construction until a stable wetland habitat is formed.
[0017] In a preferred embodiment, in S3, the top width of the water retaining weir is 500 mm. A ramp is provided on the backwater side of the weir body, with a width not less than 3 times the height of the weir body, having a trapezoidal cross-section and a slope less than 1:3. The energy dissipation stones are located at the top of the weir body and on the backwater side ramp, arranged in a staggered manner with a spacing of 300 mm between the stones to ensure the fish migration channel. The river beach stone masonry layer uses natural river beach stones, with the stones arranged naturally and no mortar leakage on the exposed part, taking into account both ecology and aesthetics. The geotextile anti-seepage layer is an optional setting to reduce water leakage, and the compaction coefficient of the clay tamping layer is not less than 0.90.
[0018] In a preferred embodiment, in S4, the construction steps specifically include: S41: Clean the silt and debris in the river channel to ensure a flat foundation. S42: Lay a river beach stone structure layer with a thickness of 100 mm as the foundation of the weir body. S43: Lay a 400 - mm thick clay layer and tamp it, with a compaction coefficient not less than 0.90. S44: Lay a geotextile anti-seepage layer with a thickness of 2 - 3 mm (optional) on the clay layer. S45: Use 280-300mm thick river beach stones for mortar masonry to build the main body of the weir; S46: Build a ramp on the back water side of the weir with a slope less than 1:3, and set energy dissipation stones 140-150mm high at different locations on the ramp surface.
[0019] In a preferred embodiment, in S4, regular inspections and maintenance are carried out once a month to check the stability of the weir, the integrity of the slope, the position of the energy dissipation stone, and the scouring and leakage. If it is found that the weir is loose or the foundation is sinking due to scouring by water, stones or sand and gravel are replenished in time, and the water level, flow rate and vegetation recovery are continuously monitored until a stable water environment and vegetation community are formed (the vegetation coverage rate increases by 20%-35%), which usually takes 1-2 years.
[0020] Example 1 Restoration of the alpine swamp wetland in Wangdongwan, Jingning Take the Jingning Wangdongyan Alpine Swamp Wetland Nature Reserve as an example. Due to the downcutting of the "丰"-shaped river system, the water level in the area has dropped and the flow rate has increased. The water holding time in the dry season has shortened and the wetland habitat has degraded. Before the restoration, the depth of the river downcut reached 60-120cm, the flow rate was 1.2m / s, the water level was less than 10cm in the dry season, there was no visible water in some areas, the groundwater level was 100mm below the riverbed, and the vegetation coverage rate of the surrounding wetlands was less than 20%.
[0021] S1: Preliminary preparation: Obtain the hydrological data for the whole year of 2022-2024, the flow rate in the dry season is 0.05m³ / s, the flow rate in the flood season is 1.5m³ / s, the length of the repaired river section is 500m, the width of the river channel is 2-5.5m, and the height difference between upstream and downstream is 600cm; S2: Weir design and site selection: According to the formula "height difference / 100cm=number of weirs", 7 weirs need to be built, located in the river section where the river channel cut depth is greater than 50cm and the surrounding terrain is gentle (slope less than 5%), the weir height is 350-950mm, the top width is 500mm, the width of the back water surface ramp of the weir body is 3 times the height of the weir body, and the width of the weir body is consistent with the width of the river channel (2-5.5m); the layered structure of the weir body is: 150mm high energy dissipation stones are set on the top and back water surface ramps, with a spacing of 300mm; the main part is built with 280-300mm thick river beach stones; a geotextile anti-seepage layer is set in the middle (optional); the lower part is a 400mm thick clay ramming layer; the foundation is a 100mm thick river beach stone structure layer, and the bottom is a natural layer; S3: Construction: Construction will be carried out in November 2024 (dry season). After clearing the silt in the river channel, a 100mm thick riverbed stone structure layer will be laid, a 400mm thick clay layer will be laid and compacted (compaction coefficient 0.90), a geotextile anti-seepage layer (thickness 2mm) will be laid, the weir body will be built with riverbed stone mortar, and a ramp with a slope of 1:3 will be built on the back of the water. Energy dissipation stones with a height of 150mm will be set at different positions on the surface of the ramp. S4: Maintenance and Monitoring: After the construction is completed, conduct inspections once a month to monitor water level, flow velocity, leakage, and vegetation restoration. The data in May 2025 showed that the water level rose by 40 cm, the flow velocity decreased to 0.8 m / s, the groundwater level rose by 15 cm, and the vegetation coverage rate in the surrounding area increased to 40%, initially forming a stable marsh wetland habitat.
[0022] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: Low interference: The construction is only carried out within the river channel without disturbing the surrounding habitat.
[0023] Hydrological improvement: Raise the river water level by 25 - 75 cm through the water retaining weir, increase the water holding capacity in the surrounding area (increase by 30% - 50%), and extend the water holding time until the end of the dry season.
[0024] Flow velocity control: Reduce the flow velocity by 20% - 40% and reduce the soil erosion rate by more than 50%.
[0025] Ecological protection: Set up fish migration channels to ensure the integrity of the ecosystem.
[0026] Natural restoration: Promote the rise of the groundwater level in the adjacent area (10 - 50 cm), supplement the water volume during the dry season, and increase the wetland vegetation coverage rate by 20% - 35%.
[0027] Those of ordinary skill in the art should understand that the discussion of any above embodiment is only exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.
[0028] The present invention aims to cover all such substitutions, modifications, and variations that fall within the broad scope of the claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.
Claims
1. A method for ecological restoration of the water system in a marsh wetland based on a water retaining weir, characterized in that, It includes the following steps: S1: Selection of water retaining weir site: For marsh wetlands where the river water system scours the riverbed and causes the riverbed to downcut, resulting in increased flow velocity and decreased water level, select a river section with severe riverbed downcut and gentle surrounding terrain. Priority is given to river sections with a riverbed downcut depth greater than 50 cm, a river channel slope less than 5%, and gentle surrounding terrain; S2: Preliminary preparation: Obtain hydrological change data for at least 1 year, determine the elevation difference between the upstream and downstream of the restoration area, and calculate the number of water retaining weirs through a formula; S3: Design of water retaining weir: Width: The width of the weir body is the same as the width of the river channel; Height: The height of the weir is 25 cm lower than the river bank and does not exceed 100 cm; Structure: The weir body adopts a structure of mortar - laid stones. The layered structure of the weir body from top to bottom includes energy - dissipating stones with a height of 140 - 150 mm, a river beach stone masonry layer with a thickness of 280 - 300 mm, a geotextile anti - seepage layer with a thickness of 2 - 3 mm, a clay tamping layer with a thickness of 400 mm, a river beach stone structure layer with a thickness of 100 mm, and the natural riverbed layer; S4: Construction and maintenance: Build several designed water retaining weirs in the river section. Select the dry season to construct, avoiding the flood season and heavy rainfall weather. Conduct regular inspections and maintenance after construction until a stable wetland habitat is formed.
2. The ecological restoration method of the marsh wetland water system based on the water retaining weir according to claim 1, wherein, In S3, the top width of the water retaining weir is 500 mm. A ramp is set on the back water surface of the weir body, with a width not less than 3 times the height of the weir body and a slope less than 1:
3.
3. The method for ecological restoration of marsh wetland water systems based on a water retaining weir according to claim 2, wherein In S3, the energy - dissipating stones are located at the top of the weir body and on the back - water - surface ramp, arranged in a staggered pattern with a spacing of 300 mm between the stones.
4. A method for ecological restoration of the water system in a swamp wetland based on a water retaining weir according to claim 3, characterized in that, In S3, the river beach stone masonry layer uses natural river beach stones, with the stones arranged naturally and no leakage of mortar in the exposed part, taking into account ecological beauty.
5. A method for ecological restoration of the water system in a marsh wetland based on a water retaining weir, characterized in that, In S3, the geotextile anti - seepage layer is an optional setting, and the compaction coefficient of the clay tamping layer is not less than 0.
90.
6. The ecological restoration method of the marsh wetland water system based on a weir according to claim 1, characterized in that, In S4, the construction steps specifically include: S41: Clear the silt and debris in the river channel to ensure a flat foundation; S42: Lay a 100 - mm - thick river beach stone structure layer as the foundation of the weir body; S43: Lay a 400 - mm - thick clay layer and tamp it, with a compaction coefficient not less than 0.90; S44: Lay a 2 - 3 - mm - thick geotextile anti - seepage layer on the clay layer; S45: Use 280 - 300 - mm - thick river beach stones for mortar masonry to build the main body of the weir; S46: Build a ramp on the back - water surface of the weir body with a slope less than 1:3, and stagger - set energy - dissipating stones with a height of 140 - 150 mm on the surface of the ramp.
7. A method for ecological restoration of marsh wetland water systems based on a water retaining weir according to claim 1, characterized in that, In S4, the regular inspection and maintenance are carried out once a month. Check the stability of the weir body, the integrity of the ramp, the position of the energy - dissipating stones, and the scouring and leakage conditions. If it is found that the weir body is loose or the foundation sinks due to water flow scouring, replenish stones or sand in time, and continuously monitor the water level, flow velocity, and vegetation restoration situation until a stable water environment and vegetation community are formed.