Rainwater garden suitable for drainage of upward-convex green land in sponge city

Abstract

The invention relates to a rainwater garden suitable for drainage of an upward-convex greenbelt in a sponge city, the rainwater garden comprises the upward-convex greenbelt, a rainwater retention area and a groove, the rainwater retention area is arranged at the slope toe of the upward-convex greenbelt, the groove is arranged around the upward-convex greenbelt and the rainwater retention area, the rainwater retention area is communicated with a municipal pipeline through an overflow pipe, and the overflow pipe is communicated with the upward-convex greenbelt. The groove is communicated with the rainwater retention area through a drain pipe, and the rainwater retention area is deeper than the groove. Aiming at the upward-convex greenbelt which cannot completely sink due to terrains or other limiting conditions, on the basis of keeping the original structure of the greenbelt, a rainwater retention area is arranged at the slope toe of the upward-convex greenbelt and is used for collecting rainwater and guiding the rainwater to a retention facility. Under the condition of low-intensity rainfall, rainwater can permeate and be naturally absorbed in the rainwater retention area, and the rainwater does not need to be discharged; under the condition of high-intensity rainfall, rainwater exceeding the retention capacity of the rainwater retention area is safely discharged into the municipal pipeline through the overflow pipe, effective control over rainwater runoff can be achieved, and maintenance is easy and convenient.

Description

Technical Field

[0001] The invention relates to the technical field of rainwater management, and in particular to a rainwater garden suitable for drainage of convex green spaces in sponge cities. Background Art

[0002] A rainwater garden is a shallow green space formed naturally or artificially on the roadbed. It is also a rainwater runoff control technology recommended by the Technical Guide for Sponge City Construction. It is derived from rainwater sand filtration and infiltration ditch technology and integrates the functions of the two technologies. As rainwater flows through retention and utilization facilities, it is reduced through infiltration, sedimentation, and interception, and pollutants in the runoff are better removed. Part of the rainwater runoff gradually seeps into the soil to conserve groundwater.

[0003] In the practice of sponge city construction, sunken green space has been widely adopted and applied to various projects as an effective rainwater management measure, such as residential areas, parks, and municipal roads. However, there are many constraints in actual projects, which limit the full implementation of sunken green space. In the existing technology, some green spaces are equipped with municipal infrastructure such as wells, water meters, communication wells, and gas pipelines. The existence of these facilities makes it difficult for green spaces to be sunken. Most of the existing green spaces are convex. If they are forcibly transformed into a sunken type, it will not only cause earthwork treatment problems, but also may cause rainwater to carry sediment back to the road in areas with large slopes, causing environmental pollution. Therefore, there is an urgent need for a rainwater garden suitable for drainage of convex green spaces in sponge cities, and innovative designs for convex green spaces are carried out to meet the technical requirements of sponge city construction for rainwater runoff control, while taking into account cost-effectiveness and ease of maintenance. Summary of the invention

[0004] Based on this, it is necessary to provide a rain garden suitable for drainage of upper convex green spaces in sponge cities, which provides a cost-effective and easy-to-maintain rainwater management method and can achieve effective control of rainwater runoff.

[0005] A rainwater garden suitable for drainage of an upper convex green space in a sponge city comprises an upper convex green space, a rainwater retention area and a groove, wherein the rainwater retention area is arranged at the foot of the slope of the upper convex green space, the groove is arranged around the upper convex green space and the rainwater retention area, the rainwater retention area is connected to a municipal pipeline through an overflow pipe, the groove is connected to the rainwater retention area through a drainage pipe, and the depth of the rainwater retention area is greater than that of the groove.

[0006] The above-mentioned rainwater gardens are suitable for drainage of convex green spaces in sponge cities. For those convex green spaces that cannot be fully sunken due to terrain or other restrictions, the rainwater gardens provided in this application are suitable for drainage of convex green spaces in sponge cities. On the basis of maintaining the original structure of the green space, a rainwater retention area is set at the foot of the slope of the convex green space to collect rainwater and guide it to the retention facilities. The grooves are set around the convex green space and the rainwater retention area. In the case of low-intensity rainfall, rainwater can infiltrate and be naturally absorbed in the rainwater retention area without external discharge; in the case of high-intensity rainfall, rainwater that exceeds the retention capacity of the rainwater retention area will be safely discharged into the municipal pipeline through the overflow pipe. It provides a cost-effective and easy-to-maintain rainwater management method that can achieve effective control of rainwater runoff.

[0007] In one of the embodiments, the area of ​​the rainwater retention zone is greater than or equal to 10% of the upper convex green space.

[0008] In one embodiment, the rainwater retention area includes a retention layer, a plant layer and a soil layer in sequence along the depth direction, the retention layer is used to retain rainwater, the overflow pipe passes through the soil layer, and the water inlet of the overflow pipe is higher than the soil layer.

[0009] In one embodiment, the water inlet of the overflow pipe is at a height of 15 cm to 25 cm relative to the soil layer.

[0010] In one embodiment, the soil layer includes an anti-scour fixing layer, a coarse particle filtration layer and a fine particle filtration layer in sequence along the depth direction.

[0011] In one of the embodiments, the groove is a grass-planted groove or a cover groove, and a gravel layer is provided in the groove.

[0012] In one of the embodiments, a first overflow plate is provided in the groove, and the first overflow plate is arranged around and higher than the drain pipe at one end opening of the groove, and the height of the first overflow plate is higher than the drain pipe.

[0013] In one of the embodiments, a second overflow plate is provided in the rainwater retention area, and the second overflow plate is arranged around and higher than an opening of one end of the drain pipe located in the rainwater retention area.

[0014] In one embodiment, the height of the first overflow plate and the second overflow plate is 5 cm to 10 cm.

[0015] In one embodiment, the groove is annular in structure, and a rainwater retention area is provided on opposite sides of the upper convex green space. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0017] Figure 1 A schematic plan view of a rainwater garden suitable for drainage of convex green spaces in sponge cities according to an embodiment;

[0018] Figure 2 It is a cross-sectional view AA of a rain garden suitable for drainage of an upper convex green space in a sponge city according to an embodiment;

[0019] Figure 3 BB is a cross-sectional view of a rain garden suitable for drainage of an upper convex green space in a sponge city according to an embodiment;

[0020] Figure 4 This is a structural schematic diagram of a rainwater garden with grass-planted trenches or cover trenches connected to a rainwater retention area for drainage of an upper convex green space in a sponge city according to an embodiment;

[0021] Figure 5 This is a schematic diagram of the structure of the soil layer of a rainwater garden suitable for drainage of convex green spaces in sponge cities according to an embodiment.

[0022] Figure numerals: rain garden 10 suitable for drainage of upper convex green space in sponge city; upper convex green space 20; rainwater retention area 30; retention layer 31; plant layer 32; soil layer 33; anti-scour fixed layer 331; coarse particle filter layer 332; fine particle filter layer 333; groove 40; cover groove 42; gravel layer 43; first overflow plate 44; second overflow plate 45; overflow pipe 50; water inlet 51; drainage pipe 60; safety sign 70 DETAILED DESCRIPTION

[0023] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0024] In the description of the present invention, the meaning of "above", "below", "exceed", etc. is not inclusive of the number itself, and the meaning of "above", "below", "within", etc. is inclusive of the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0026] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0027] Sponge city rain garden is an ecologically sustainable rainwater control and rainwater utilization facility, which is mainly used to collect and absorb rainwater from roofs or ground. Through the combined action of plants and sand, rainwater is purified and gradually infiltrated into the soil to conserve groundwater, or used to replenish urban water such as landscape water and toilet water. Rain gardens are also called bioretention areas. They are usually low-lying areas where trees or shrubs are planted in gardens and green spaces. They replenish groundwater and reduce the peak of storm surface runoff by retaining and infiltrating rainwater. It can also reduce pollution through processes such as adsorption, degradation, ion exchange and volatilization. The design of rain gardens needs to fully consider factors such as groundwater and topography to ensure that they are effectively connected with relevant sponge facilities and play the role of rainwater runoff control and pollution reduction. The design should follow the concept of ecological design, use environmentally friendly materials, and reduce construction and maintenance costs.1. During construction, tree roots, stones and debris in the area and slope protection should be removed, existing plants should be retained as much as possible, and a good drainage system should be ensured for the green planting foundation.

[0028] In the practice of sponge city construction, sunken green space has been widely adopted and applied to various projects as an effective rainwater management measure, such as residential areas, parks, and municipal roads. However, there are many constraints in actual projects, which limit the full implementation of sunken green space. In the existing technology, some green spaces are equipped with municipal infrastructure such as wells, water meters, communication wells, and gas pipelines. The existence of these facilities makes it difficult for green spaces to be sunken. Most of the existing green spaces are convex. If they are forcibly transformed into a sunken type, it will not only cause earthwork treatment problems, but also may cause rainwater to carry sediment back to the road in areas with large slopes, causing environmental pollution. Therefore, there is an urgent need for a rainwater garden suitable for drainage of convex green spaces in sponge cities, and innovative designs for convex green spaces are carried out to meet the technical requirements of sponge city construction for rainwater runoff control, while taking into account cost-effectiveness and ease of maintenance.

[0029] See also Figure 1 In order to solve the above problems, the embodiment of the present application provides a rainwater garden 10 suitable for drainage of upper convex green space in sponge city, including an upper convex green space 20, a rainwater retention area 30 and a groove 40. The rainwater retention area 30 is arranged at the foot of the slope of the upper convex green space 20, and the groove 40 is arranged around the upper convex green space 20 and the rainwater retention area 30. The rainwater retention area 30 is connected to the municipal pipeline through an overflow pipe 50, and the groove 40 is connected to the rainwater retention area 30 through a drainage pipe 60. The depth of the rainwater retention area 30 is greater than that of the groove 40.

[0030] See also Figure 1 , Figure 2 and Figure 3In some embodiments, the convex green space 20 refers to a green space that is higher than the road surface, which is usually used in urban landscape design. The main feature of this green space is that it is neat and beautiful, but because it is higher than the road surface, the rainwater collection and water retention function is relatively weak. Most of the existing green spaces are convex green spaces 20. If they are forcibly transformed into sunken green spaces, it will not only cause earthwork processing problems, but also cause rainwater to carry sediment to flow back to the road in areas with large slopes, causing environmental pollution. The rainwater retention area 30 refers to a low-lying area in a garden green space where trees or shrubs are planted, covered with bark or ground cover plants. Its main function is to replenish groundwater, reduce water pollution and reduce storm peaks by retaining rainwater. It is an ecologically sustainable rainwater control and rainwater utilization facility. The rainwater retention area 30 is a naturally formed or artificially excavated shallow concave green space, which is used to collect and absorb rainwater from the roof or the ground. Through the combined effects of plants and sand, rainwater is purified and gradually infiltrates into the soil, conserving groundwater, or used to replenish urban water such as landscape water and toilet water. The rainwater retention area 30 can store and reduce the peak flow, reduce the discharge of rainwater, and protect the downstream pipelines and structures. At the same time, the rainwater retention area 30 can also purify rainwater, conserve groundwater, make full use of runoff rainfall, and alleviate water shortage. In addition, the rainwater retention area 30 can improve the environment. Through reasonable design and maintenance, it can improve the environment, enhance the diversity of biological species, and regulate air humidity and temperature. The rainwater retention area 30 is located at the foot of the slope of the upper convex green space 20, and the rainwater of the upper convex green space 20 can flow into the rainwater retention area 30. The groove 40 refers to the groove 40 excavated to ensure the smooth drainage of the rain garden, to guide the rainwater around the rain garden into the drainage pipe 60, to prevent rainwater accumulation and infiltration, thereby protecting the rain garden from flooding. The specific depth of the groove 40 depends on the soil type, the type of drainage system and relevant standards and specifications. The appropriate depth of the groove 40 can ensure the normal operation of the rain garden 10 suitable for drainage of the upper convex green space in the sponge city, avoid blockage and water accumulation of the rainwater pipe, and thus reduce damage to the rain garden. The groove 40 is arranged around the upper convex green space 20 and the rainwater retention area 30 so that rainwater from the upper convex green space 20 and the rainwater retention area 30 can flow into the groove 40, the rainwater retention area 30 is connected to the municipal pipeline through the overflow pipe 50, and the groove 40 is connected to the rainwater retention area 30 through the drainage pipe 60.

[0031] See also Figure 1 , Figure 2 and Figure 3In some embodiments, the rain garden 10 provided by the present application for drainage of upper convex green space in sponge city can be combined with the characteristics of the surrounding projects of the rain garden, adopt landscape and localized design strategies, and plant shielding facilities such as overflow pipe 50. In some embodiments, the rain garden 10 provided by the present application for drainage of upper convex green space in sponge city is suitable for green space renovation projects such as old residential areas, park green space, municipal roads, etc. In some embodiments, the overall green space area of ​​the rain garden 10 provided by the present application for drainage of upper convex green space in sponge city is not less than 50 square meters. In the case of low-intensity rainfall, rainwater can be infiltrated and naturally absorbed in the rainwater retention area 30 without external discharge; in the case of high-intensity rainfall, rainwater exceeding the retention capacity of the rainwater retention area 30 will be safely discharged into the municipal pipeline through the overflow pipe 50, which is cost-effective and easy to maintain, can achieve effective control of rainwater runoff, and has the effect of optimizing landscape effects.

[0032] Continue reading Figure 1 , Figure 2 and Figure 3 In some embodiments, the area of ​​the rainwater retention area 30 is greater than or equal to 10% of the upper convex green space 20. In one embodiment, the area of ​​the rainwater retention area 30 is equal to 10% of the upper convex green space 20 to ensure the effect of collecting rainwater in the rainwater retention area 30. In other embodiments, the area of ​​the rainwater retention area 30 is greater than 10% of the upper convex green space 20, for example, the area of ​​the rainwater retention area 30 is equal to 15% of the upper convex green space 20. In the case of low-intensity rainfall, rainwater can be infiltrated and naturally absorbed in the rainwater retention area 30 without external discharge.

[0033] See also Figure 1 , Figure 2 , Figure 3 and Figure 4In some embodiments, the rainwater retention area 30 includes a retention layer 31, a plant layer 32 and a soil layer 33 in the depth direction. The retention layer 31 is used to retain rainwater. When it rains, the retention layer 31 can temporarily store a large amount of rainwater, reduce rainwater runoff, and thus reduce the pressure on downstream pipelines and structures. At the same time, the retention layer 31 can precipitate some harmful substances and metal molecules to reduce the pollution of rainwater to the environment. The plants in the plant layer 32 should be selected to be flood-resistant and have strong decontamination capabilities. For example, native plants can be selected. Native plants have good adaptability to local climate conditions, soil conditions and surrounding environment. They can play a good decontamination ability in the rain garden and make the garden landscape have a strong local feature. Common native plants include slash pine, metasequoia, bald cypress, pond cypress, weeping willow, etc. Plants with strong purification ability can be selected. These plants can effectively remove suspended particles, organic pollutants, heavy metal ions, pathogens and other harmful substances in rainwater through photosynthesis, root oxygen transmission and adsorption of pollutants. Common plants with strong purification ability and flood resistance include reed, reed, cattail, fine-leaved sand grass, vetiver, etc. Plants that are both flood-resistant and drought-resistant can also be selected. These plants can survive in the case of alternating full water and dry seasons. Common plants include horsetail, variegated silver grass, fine-leaved silver grass, cattail, and cyperus. In addition, aromatic plants such as canna, ginger flower, arrowhead, yellow iris, etc. can not only purify water quality, but also attract insects such as bees and butterflies to create a good landscape effect. In some embodiments, the overflow pipe 50 passes through the soil layer 33, and the overflow pipe 50 treats rainwater by a natural filtration method, using the natural filtration effect of groundwater and plants to purify the rainwater and discharge it. When the rainwater exceeds the designed water storage capacity, the overflow pipe 50 will discharge the excess rainwater to ensure that the water level in the rain garden will not be too high. The water inlet 51 of the overflow pipe 50 is higher than the soil layer 33, so that the soil layer 33 of the rainwater retention area 30 can be discharged from the overflow pipe 50 to the municipal pipeline. In some embodiments, the water inlet 51 of the overflow pipe 50 is 15 cm to 25 cm high relative to the soil layer 33. The storage depth of the rainwater retention area 30 refers to the maximum depth of water storage in the rainwater retention facility. The specific depth of the storage depth depends on the flood resistance of the plants and the soil permeability. The storage of the rainwater retention area 30 is mainly used to temporarily retain the peak flow of rainwater runoff, and then slowly discharge it after the maximum flow drops, so as to avoid the peak of rainwater, realize the recycling of rainwater, and avoid the pollution of the receiving water body by initial rainwater. In one embodiment, the water inlet 51 of the overflow pipe 50 is 20 cm high relative to the soil layer 33.

[0034] See also Figure 1 , Figure 2 , Figure 3 and Figure 5, the soil layer 33 includes an anti-scour fixed layer 331, a coarse particle filter layer 332 and a fine particle filter layer 333 in the depth direction. The main function of the anti-scour fixed layer 331 is to prevent the soil from being scoured by water flow and protect the soil from erosion. It achieves this goal by reducing the water flow velocity, increasing the stability of the soil and promoting the growth of vegetation. Specifically, the fixed layer can reduce the impact of raindrops and runoff, prevent the soil from being directly exposed to rainwater and runoff, and thus reduce soil erosion. Specifically, the anti-scour fixed layer 331 can be provided with a reinforced Mac pad, which is a reinforced three-dimensional geotextile mat formed by extruding a three-dimensional polyester material on a machine-woven hexagonal double-twisted steel wire mesh surface. It has the characteristics of high strength, convenient construction, and good environmental protection effect. After the reinforced Mac pad is flattened and fixed on the slope surface, grass seeds are sown in the cavity of the net. The grass seeds and organic soil are protected by the hexagonal double-twisted metal mesh and are not easily scoured. At the same time, they can also retain moisture and promote the growth of grass. The anti-scour fixed layer 331 can also be made of vegetation. The roots of the vegetation can reinforce the shallow surface soil of the slope after passing through the reinforced Mike pad, connecting the slope vegetation and the shallow surface soil affected by the roots of the vegetation into a whole, and enhancing the overall stability of the shallow surface soil of the slope. The anti-scour fixed layer 331 should be able to ensure that it will not be washed away within the design flood time. The coarse particle filter layer 332 refers to the water filtration facility between the fine particles and the coarse particles set in the seepage medium, which is mainly used to maintain the anti-seepage stability of the fine particles and prevent penetration damage. The filtering effect is achieved by combining particles of different particle sizes. The fine particle filter layer 333 refers to the water filtration facility between the fine particles and the coarse particles set in the soil, which is mainly used to maintain the anti-seepage stability of the fine particles and prevent penetration damage. For example, the material of the filter layer can mainly adopt gravel backfiltration and geosynthetics backfiltration. The gravel filter layer is generally made of multiple layers of non-cohesive soil with different particle sizes, from fine to coarse. The layer surface is nearly perpendicular to the seepage direction, and the particle size of each layer increases step by step with the seepage direction.

[0035] See also Figure 1 , Figure 2 , Figure 3 and Figure 4In some embodiments, the groove 40 is a grass-planted groove or a cover groove 42. In one embodiment, the groove 40 is a grass-planted groove, which is a sponge facility with controllability and engineering characteristics that is artificially designed and constructed by simulating natural green space. It collects, transfers and purifies rainwater through the synergistic effect of ditches and plants, and can achieve total runoff control, total pollutant reduction, flood peak delay, and groundwater replenishment. In some embodiments, the grass-planted groove can be set to an inverted trapezoidal or inverted parabolic structure. In another embodiment, the groove 40 is a cover groove 42, which refers to a component in the drainage ditch for placing and fixing the cover plate. The main function of the cover groove 42 is to carry and fix the cover plate, ensure the normal operation and safe use of the drainage ditch, and ensure that the drainage ditch is unobstructed. The size of the grass-planted groove or the cover groove 42 meets the flow requirements under the design rainfall intensity. In some embodiments, it can be set according to 1.5 to 2 times the flow under the design rainfall intensity.

[0036] In some embodiments, if the surrounding area of ​​the rain garden 10 suitable for drainage of the upper convex green space in the sponge city is densely populated or there is insufficient space for setting a grass-planting ditch, the cover plate ditch 42 can be preferably used as the ditch 40. In some embodiments, a hollow stainless steel cover plate can be used on the cover plate ditch 42, and the hollow stainless steel cover plate has the advantage of being easy to repair. In some embodiments, a gravel layer 43 is provided in the ditch 40, and the gravel layer 43 is used to reduce the initial rainwater pollution. The gravel layer 43 can be composed of a double layer, wherein the lower layer is gravel and the upper layer is coarse sand. The thickness of the lower layer can be set to 0.3 meters, and the thickness of the upper layer can be set to 0.1 meters, which can prevent the silt from being pumped out during the pumping process. Specifically, during the pumping process, the gravel layer 43 can effectively prevent the silt from being pumped out and maintain the stability of the foundation pit. At the same time, the gravel layer 43 can prevent the bottom soil of the pit from being disturbed. Specifically, by laying the gravel layer 43, the disturbance of the bottom soil of the pit during the pumping process can be reduced to maintain the stability of the foundation pit.

[0037] Continue reading Figure 1 , Figure 2 , Figure 3 and Figure 4In some embodiments, a first overflow plate 44 is provided in the groove 40, and the first overflow plate 44 is arranged around and higher than the drain pipe 60 at one end opening of the groove 40, and the height of the first overflow plate 44 is higher than the drain pipe 60. A second overflow plate 45 is provided in the rainwater retention area 30, and the second overflow plate 45 is arranged around and higher than the drain pipe 60 at one end opening of the rainwater retention area 30. The design of the first overflow plate 44 and the second overflow plate 45 being higher than the drain pipe 60 is to ensure that when the drain pipe 60 is blocked, rainwater can flow out through the first overflow plate 44 and the second overflow plate 45, thereby preventing flooding. In some embodiments, the grass-planted ditch or the cover ditch 42 is preferably connected to the rainwater retention area 30 through a gravity flow pipe or an open channel, and the first overflow plate 44 and the second overflow plate 45 are preferably arranged before and after the interface. In some embodiments, the height of the first overflow plate 44 and the second overflow plate 45 is 5 cm to 10 cm. In some embodiments, the groove 40 is annular in structure, and a rainwater retention area 30 is provided on opposite sides of the upper convex green space 20. In some embodiments, the rain garden 10 suitable for drainage of the upper convex green space in the sponge city also includes a safety sign 70, which can be set on the soil layer 33. The safety sign 70 can be written with words such as "rainy water source, no entry" to remind people passing by that entry is prohibited, which is conducive to the maintenance of the rain garden and improving safety.

[0038] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A rainwater garden suitable for drainage of convex green spaces in sponge cities, characterized in that: It includes an upper convex green space, a rainwater retention area and a ditch. The rainwater retention area is arranged at the foot of the slope of the upper convex green space. The ditch is arranged around the upper convex green space and the rainwater retention area. The rainwater retention area is connected to the municipal pipeline through an overflow pipe. The ditch is connected to the rainwater retention area through a drainage pipe. The depth of the rainwater retention area is greater than that of the ditch.

2. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 1 is characterized in that: The area of ​​the rainwater retention zone is greater than or equal to 10% of the upper convex green space.

3. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 1 is characterized in that: The rainwater retention area includes a retention layer, a plant layer and a soil layer in sequence along the depth direction. The retention layer is used to retain rainwater. The overflow pipe passes through the soil layer, and the water inlet of the overflow pipe is higher than the soil layer.

4. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 3 is characterized in that: The water inlet of the overflow pipe is at a height of 15 cm to 25 cm relative to the soil layer.

5. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 3 is characterized in that: The soil layer includes an anti-scour fixing layer, a coarse particle filtering layer and a fine particle filtering layer in sequence along the depth direction.

6. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 1 is characterized in that: The groove is a grass-planted groove or a cover groove, and a crushed stone layer is arranged in the groove.

7. The rainwater garden suitable for drainage of upper convex green space in sponge city according to claim 1 is characterized in that: A first overflow plate is provided in the groove, and the first overflow plate is arranged around and higher than the drain pipe at one end opening of the groove, and the height of the first overflow plate is higher than the drain pipe.

8. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 7 is characterized in that: A second overflow plate is provided in the rainwater retention area, and the second overflow plate is arranged around and higher than an opening of one end of the drain pipe located in the rainwater retention area.

9. The rainwater garden suitable for drainage of upper convex green space in sponge city according to claim 8 is characterized in that: The height of the first overflow plate and the second overflow plate is 5 cm to 10 cm.

10. The rainwater garden suitable for drainage of convex green space in sponge city according to claim 1, characterized in that: The groove is in an annular structure, and a rainwater retention area is provided on opposite sides of the upper convex green space.

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