AU2019101161A4

AU2019101161A4 - Multifunctional sunken green space

Info

Publication number: AU2019101161A4
Application number: AU2019101161A
Authority: AU
Inventors: Jiazhen Chen; Xiulei Fan; Jiaqiang Liu; Hongye Nan; Jianhua Wang; Zhipeng XU; Chengfang Yang
Original assignee: Xuzhou University of Technology
Current assignee: Xuzhou University of Technology
Priority date: 2019-02-13
Filing date: 2019-09-30
Publication date: 2019-11-28
Anticipated expiration: 2027-09-30
Also published as: CN109853703A

Abstract

The present disclosure pertains to the technical field of landscape greening and more particularly to a multifunctional sunken green space, including a planting soil pit with a cylindrical structure, and a circumferential side wall of the planting soil pit is 5 piled with a water permeable brick I; a planting soil layer, a coarse sand layer I and a fine sand layer I are successively laid in the planting soil pit from top to bottom, a non-woven geotextile is arranged between the planting soil layer and the coarse sand layer I and between the coarse sand layer I and the fine sand layer I. A middle part of the planting soil layer is recessed to form a circular reservoir, and the circular 10 reservoir is planted with aquatic plants; a middle part of the planting soil layer is provided with a rainwater recycling system; a rainwater utilization device is arranged in the rainwater recycling system for car washing, and water resource for car washing is returned to the planting soil layer from the rainwater recycling system. The excess rainwater flows from the green space into the rainwater recycling system, the 15 rainwater utilization device is arranged in the rainwater recycling system for self-service car washing, which has functions of water storage and water purification, and also has the function of water utilization, thereby providing a variety of functions, and the water for car washing is returned for an irrigation of plants. 6-1 6-2 1

Description

MULTIFUNCTIONAL SUNKEN GREEN SPACE

TECHNICAL FIELD [0001] The present disclosure pertains to the technology field of landscape greening and more particularly to a multifunctional sunken green space.

BACKGROUND [0002] In recent years, with the continuous advancement of urbanization in China, the area of impermeable water is sharply increasing. When the rainfall increases, the rainwater cannot be drained in time, thereby resulting in the disaster of urban inland inundation and severely endangering people’s property security. At the same time, due to the severe pollution problem in the urban roads, the runoff is generated after the rainfall scours the road surface, especially the initial rainwater containing a large amount of pollutants, which is drained into the river without any treatment, resulting in water body pollution, a waste of rainwater resources, and intensifying the urban heat island effect. The sponge city, is a concept with reference to rainfall flood management of the new generation of cities, which refers to a city has a good flexibility in adapting to an environmental change and dealing with a natural disaster caused by the rainwater.

[0003] The rainwater scours the ground, resulting in runoff pollution. However, owing to a slighter degree of the pollution, the rainwater can be served as a water source for urban greening, scouring roads or supplementing underground water after a treatment. Currently, the primary techniques for collecting and purifying rainwater in the construction of the sponge cities are as follows: purification and collection of rainwater from roofs, collection of rainwater from urban roads, recycling of rainwater from urban green parks. The sunken green space is a typical representative of urban green spaces and plays an important part of the sponge city. The sunken green space,

2019101161 30 Sep 2019 refers to a public green space with an elevation lower than the road surface, also known as a low elevation green space, is the simplest application technology with reference to the rainwater utilization of the sponge city, simple and practicable, less investment in the construction and effective rainwater utilization. The idea thereof is to utilize an open space to collect and store the rainwater, thereby reducing the efflux of the runoff, cutting down the runoff pollutants, increasing the underground water resources, mitigating the urban non-point source pollution, regulating the regional climate, curbing the urban heat island effect, economizing the water consumption of the green space, which is of great significance to the construction of the sponge cities.

[0004] The existing sunken green space has the defects of a low water storage capacity, a low infiltration efficiency and a low water purification capacity, a single plant species, a single function; the surface is readily being hardened; a poor purification effect of the runoff; a weak retention ability of the rainwater, etc. ZL20753815U discloses a sunken green space, although a rainwater device is employed, the design of the irrigation sprinkler is unreasonable, which is easily causing nonuniform sprinkling, resulting a waste of the rainwater resources, the removal rate of nitrogen and phosphorus in the runoff is not high, and the green space is severely scoured by the rainwater.

SUMMARY [0005] In order to overcome the deficiencies of the prior art, the present disclosure provides a multifunctional sunken green space.

[0006] The present disclosure is realized by the following technical solutions. A multifunctional sunken green space, including a planting soil pit with a cylindrical structure, a circumferential side wall of the planting soil pit is piled with a water permeable brick I; a planting soil layer, a coarse sand layer I and a fine sand layer I are successively laid in the planting soil pit from top to bottom, a non-woven

2019101161 30 Sep 2019 geotextile is arranged between the planting soil layer and the coarse sand layer I and between the coarse sand layer I and the fine sand layer I. A middle part of the planting soil layer is recessed to form a circular reservoir, and the circular reservoir is planted with aquatic plants; a middle part of the planting soil layer is provided with an overflow well, and one end of the overflow well is erected in the circular reservoir, and the other end of the overflow well leads to a water tank I outside the planting soil pit, one end of the overflow well located in the circular reservoir is provided with a water permeable manhole cover. A periphery of the planting soil layer close to the water permeable brick I is planted with a protective shrub, and an annular irrigation sprinkler is arranged along the water permeable brick I of the planting soil pit. A submersible pump I is arranged in the water tank I, the submersible pump I is connected to a conveying pipeline, the other end of the conveying pipeline is connected to a water tank II, and a submersible pump II is arranged in the water tank II, and the submersible pump II is connected to a sprinkler nozzle through a water pipe; a water permeable brick II is arranged uprightly below the sprinkler nozzle, and a coarse sand layer II, a fine sand layer II and a water collecting tank are successively followed below the water permeable brick II, one end of the water collecting tank is connected to a return pipeline, and the other end of the return pipeline is connected to a water inlet of the annular irrigation sprinkler, the return pipeline is inclined from one end of the water collecting tank to one end of the annular irrigation sprinkler so that water in the return pipeline flows into the annular irrigation sprinkler owing to gravity.

[0007] Further, the manhole cover includes a coarse sand and a fine sand, and a non-woven geotextile is arranged between the coarse sand and the fine sand; the coarse sand and the fine sand are wrapped as a whole by a steel wire mesh.

[0008] Further, the circular reservoir includes a trapezoidal reservoir having a trapezoidal cross section and a rectangular reservoir having a rectangular cross section, and the rectangular reservoir is formed by a lower base of the trapezoidal reservoir annularly recessed.

2019101161 30 Sep 2019 [0009] Further, a trapezoidal waist of the trapezoidal reservoir is planted with zoysia matrella, the trapezoidal lower base of the trapezoidal reservoir is planted with emergent plants, and the trapezoidal reservoir is planted with floating plants.

[0010] Further, the trapezoidal lower base of the trapezoidal reservoir is provided with 5 a plurality of upper bumps composed of cobblestones.

[0011] Further, the planting soil layer is laid with a river sand.

[0012] Further, the overflow well is a pvc (polyvinyl chloride) pipe.

[0013] The multifunctional sunken green space of the present disclosure includes a shrub for protecting the sunken green space, a river sand, a reservoir (the reservoir includes a rectangular reservoir and a trapezoidal reservoir, the rectangular reservoir is planted with floating plants, and the trapezoidal reservoir is planted with emergent plants and zoysia matrella), a planting soil layer (the planting soil layer is formed by mixing an equal part of soil and an equal part of sand with some humus), and further includes a water permeable brick, an annular irrigation sprinkler (the annular irrigation sprinkler includes a annular main pipe with a diameter of 5 cm and 12 branch pipes with a diameter of 3 cm and a length of approximately 5 cm, the annular main pipe is provided with a branch pipe every 30°, and the branch pipe is horizontally placed and is connected to an inner side of the main pipe), upper bumps, (the upper bumps is formed by stacking a number of cobblestones, a guiding infiltration column (the guiding infiltration column is an annular circle with a thickness of approximately 10 cm from a top view and is arranged outside the overflow well, is composed of coarse sand and fine sand; when a rainfall is small, the rainwater can completely infiltrate into the coarse sand layer I and the fine sand layer I through the guiding infiltration column and return to supplement the underground water after purified by the coarse sand layer I and the fine sand layer I; when the rainfall is heavy, a small part of the rainwater enters under the ground through the guiding infiltration column, and most of the rainwater enters the water tank I through the overflow well), an overflow well and a manhole cover, and the

2019101161 30 Sep 2019 overflow well is connected to the water tank.

[0014] The rainwater is stored in the water tank I after purified by the vegetation and soil, and is lifted by the submersible pump I to the rainwater recycling system. After a rainwater utilization, the rainwater is filtered by the coarse sand layer II and the fine sand layer II and is recycled by the water collecting tank (the water collecting tank is a cuboid with a length, width and height of 400 cm x 200 cm x 5 cm made of the pvc plate with a thickness of approximately 1cm, a side surface of the water collecting tank is provided with a connecting hole used for an installation and a connection of the return pipeline of the rainwater recycling system, the upper pvc plate is dotted with holes, a diameter of the hole is approximately 2 cm, and a space between adjacent holes is approximately 1 cm, and the water source flows from the holes into the water collecting tank 22 after filtered by the coarse sand layer II 27 and the fine sand layer II 28), the rainwater enters the rainwater recycling system and irrigates the vegetation by the annular irrigation sprinkler, realizing recycling use. In order to realize a landscape effect and a maximum water storage capacity of the green space, the reservoir is provided with a rectangular reservoir and a trapezoidal reservoir, the rectangular reservoir is stored with water for a long time, and the trapezoidal reservoir is generally free of water or has a small amount of water, under the situation of a large amount of water, the trapezoidal reservoir can be filled with water but cannot last long.

The two combined reservoirs have the characteristics of a recessed depth and a large water storage space, which enhances the water storage capacity. There are various kinds of plants, including both terrestrial plants and aquatic plants, three layers of annular upper bumps are arranged on the surface of the green space, which is able to slow down the flow velocity of the runoff and lengthen the retention time of the runoff in the vegetation, thereby improving the water purification effect. The rainwater recycling system is provided with a rainwater utilization device for self-service car washing, which has the functions of water storage and water purification, and also has the function of water utilization, thereby providing a variety

2019101161 30 Sep 2019 of functions. A layer of river sand is laid on the planting soil layer, and the river sand prevents soil from hardening. Overlooking the multifunctional sunken green space is a circle shape, and a variety of plant types, creating a scenic landscape.

[0015] The advantages of the present disclosure are as follows. 1. Preventing 5 rainwater scouring, soil loss and human trampling of the green space. 2. Improving the infiltration efficiency and effectively preventing the evaporation of soil moisture.

3. Lengthening the retention time of the runoff and enhancing the degree of purification. 4. Efficiently removing pollutants such as nitrogen and phosphorus (an absorption of microorganisms and plants especially aquatic plants, and an adsorption of the coarse sand layer and the fine sand layer). 5. Rapidly draining the rainwater so as to prevent plants from being flooded for a long time (when the rainfall is small, the rainwater returns to supplement the underground water through the guiding infiltration column after filtered by the coarse sand layer and the fine sand layer; when the rainfall is heavy, the rainwater enters the water tank I from the overflow well and is used as the water source for car washing). 6. Preventing secondary pollution of the water body and preventing the wellhole from being blocked (the manhole cover of the overflow well can prevent suspended solids, fine particles and other pollutants in the rainwater from entering the overflow well so as to prevent them from blocking the wellhole and affecting the drainage efficiency, and preventing the rainwater from being polluted once more in the water tank I). 7. Sufficiently utilizing the rainwater resource to create a certain economic benefit. 8. The soil is not readily being hardened and has a long service life.

BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 is a cross-sectional view of a reservoir of the present disclosure;

FIG. 2 is a top plan view of the reservoir of the present disclosure;

FIG. 3 is a cross-sectional view of a manhole cover of an overflow well of the present

2019101161 30 Sep 2019 disclosure;

FIG. 4 is a top plan view of the manhole cover of the overflow well of the present disclosure;

FIG. 5 is a cross-sectional view of a rainwater utilization device of the present 5 disclosure;

FIG. 6 is a top plan view of FIG. 5; and

FIG. 7 is a top plan view of a multifunctional sunken green space with integrated functions of storage, purification and utilization.

In the drawings, 1, water permeable brick I, 2, annular irrigation sprinkler, 3, shrub, 4, upper bump, 5, zoysia matrella, 6, reservoir, 6-1, trapezoidal reservoir, 6-2, rectangular reservoir, 7, guiding infiltration column, 8, coarse sand, 9, fine sand, 10, overflow well, 11, coarse sand layer I, 12, fine sand layer I, 13, submersible pump I, 14, water tank I, 15, non-woven geotextile, 16, river sand, 17, planting soil layer, 18, emergent plant, 19, steel wire mesh, 20, sprinkler nozzle, 21, water tank II, 22, water collecting tank, 23, return pipeline, 24, conveying pipeline, 25, submersible pump II, 26, water permeable brick II, 27, coarse sand layer II, 28, fine sand layer II, 29, floating plant.

DETAILED DESCRIPTION OF THE EMBODIMENTS [0017] The present disclosure will be further described hereinafter according to the drawings and embodiments.

[0018] As shown in FIG. 1 to FIG. 7 , a multifunctional sunken green space, the overall structure is a circular green space with a diameter of approximately 350 cm to 400 cm, and the elevation of the green space is lower than the road surface approximately 5 cm to 10 cm, specifically, including the planting soil pit with a cylindrical structure, and the circumferential side wall of the planting soil pit is piled

2019101161 30 Sep 2019 with the water permeable brick I 1; the planting soil layer 17, the coarse sand layer I 11 and the fine sand layer I 12 are successively laid in the planting soil pit from top to bottom, the non-woven geotextile 15 is arranged between the planting soil layer 17 and the coarse sand layer Ill and between the coarse sand layer Ill and the fine sand layer I 12, the height of the planting soil layer 17 is 90 cm to 100 cm, the height of the coarse sand layer I 11 is 30 cm, and the height of the fine sand layer I 12 is 20 cm. The middle part of the planting soil layer 17 is recessed to form the circular reservoir 6, and the circular reservoir 6 is planted with aquatic plants; the middle part of the planting soil layer 17 is provided with the overflow well 10, and one end of the overflow well 10 is erected in the circular reservoir 6, and the other end of the overflow well 10 leads to the water tank 114 outside the planting soil pit, one end of the overflow well 10 located in the circular reservoir 6 is provided with the water permeable manhole cover; the periphery of the planting soil layer 17 close to the water permeable brick I 1 is planted with the protective shrubs 3, and the annular irrigation sprinkler 2 is arranged along the water permeable brick I 1 of the planting soil pit. The submersible pump 113 is arranged in the water tank I 14, the submersible pump I 13 is connected to the conveying pipeline 24, the other end of the conveying pipeline 24 is connected to the water tank II 21 of the rainwater recycling system, as shown in FIG. 7, the water tank I 14 of the plurality of sunken green spaces is connected to the conveying pipe 24 through the water pipe, so as to assure a sufficient water source in the rainwater recycling system; the submersible pump II 25 is arranged in the water tank II 21, and the submersible pump II 25 is connected to the sprinkler nozzle 20 of the rainwater utilization device through the water pipe, the rainwater utilization device is provided with the three sprinkler nozzles 20; the water permeable brick II 26 is arranged uprightly below the sprinkler nozzle 20; the car travels to the water permeable brick II 26, and then the submersible pump II 25 is activated so that the water source in the water tank II 21 flows to the sprinkler nozzle 20 through the water pipe and is sprayed from the sprinkler nozzle 20 for car washing, the water source in the water tank II 21 can also be sprayed by using an artificial irrigation sprinkler of the fountain through the

2019101161 30 Sep 2019 sprinkler nozzle, so that the water is sprayed with a certain pressure for washing the car more cleanly. The coarse sand layer II 27, the fine sand layer II 28 and the water collecting tank 22 are successively followed below the water permeable brick II 26, the water for car washing infiltrates from the water permeable brick II 26 into the water collecting tank 22, the water collecting tank 22 is a cuboid with the length, width and height of 400 cm><200 cm><5 cm, and is made of the pvc plate with a thickness of approximately 1cm, the side surface of the water collecting tank 22 is provided with the connecting holes used for the installation and the connection of the return pipeline 23 of the rainwater recycling system, the upper pvc plate is dotted with holes, the diameter of the hole is approximately 2 cm, and the space between the adjacent holes is approximately 1 cm, the water source flows from the holes into the water collecting tank 22 after filtered by the coarse sand layer II 27 and the fine sand layer II 28. As shown in FIG. 7, one end of the water collecting tank 22 is connected to the return pipeline 23, and the other end of the return pipeline 23 is connected to the water inlet of the annular irrigation sprinkler 2 of the each sunken green space, and the return pipeline is inclined from one end of the water collecting tank 22 to one end of the annular irrigation sprinkler 2 so that the water in the return pipeline 23 flows into the annular irrigation sprinkler 2 owing to gravity, and the annular irrigation sprinkler 2 irrigates the shrubs 3.

[0019] Further, the manhole cover includes the coarse sand 8 and the fine sand 9, and the non-woven geotextile is arranged between the coarse sand 8 and the fine sand 9, the coarse sand 8 and the fine sand 9 are wrapped as a whole by the steel wire mesh 19. The manhole cover is covered at the open end of the overflow well 10, and the overflow well 10 is located in the reservoir 6, the water permeable manhole cover allows the water in the reservoir 6 to flow into the overflow well 10 and finally flow into the water tank I 14, and the manhole cover prevents silts from entering the overflow well 10.

[0020] Further, the circular reservoir 6 includes the trapezoidal reservoir 6-1 having a trapezoidal cross section and the rectangular reservoir 6-2 having a rectangular cross

2019101161 30 Sep 2019 section, the rectangular reservoir 6-2 is formed by the lower base of the trapezoidal reservoir 6-1 annularly recessed. The height of the trapezoidal reservoir 6-1 is 15 cm, the width of the lower base is 300 cm, the width of the upper base is 340 cm, and the slope ratio is 1:2, the trapezoidal waist of the trapezoidal reservoir 6-1 is planted with zoysia matrella 5, and the trapezoidal lower base of the trapezoidal reservoir 6-1 is planted with emergent plants 18, and the emergent plants 18 that can be planted include acorus calamus, canna, and cattail etc.; the height of the rectangular reservoir 6-2 is 40 cm to 50 cm and the width of the rectangular reservoir 6-2 is 50 cm to 60 cm. The trapezoidal reservoir 6-1 is planted with floating plants 29, and the floating plants 29 that can be planted include water lilies, water hyacinths and pistia stratiotes etc.

[0021] Further, the trapezoidal lower base of the trapezoidal reservoir 6-1 is provided with the plurality of upper bumps 4 composed of a number of cobblestones.

[0022] As a modification of the present embodiment, the river sand 16 is laid on the planting soil layer 17, and the river sand 16 is filtered by a sieve to remove stones before laying, the laying height of the river sand 16 is 1 cm to 2 cm.

[0023] Further, the main body of the overflow well 10 is made of the pvc pipe, and the overflow well 10 is used for guiding the water source in the circular reservoir 6 into the water tank 114.

[0024] The multifunctional sunken green space of the present disclosure includes the 20 shrubs for protecting the sunken green space, the river sand, the reservoir, the planting soil layer, and further includes the water permeable brick, the annular irrigation sprinkler, the upper bumps, the guiding infiltration column, the overflow well and the manhole cover, the overflow well is connected to the water tank. The circular reservoir includes the rectangular reservoir and the trapezoidal reservoir, the rectangular reservoir is planted with floating plants, and the trapezoidal reservoir is planted with emergent plants and Zoysia matrella, the planting soil layer is formed by mixing an equal part of soil and an equal part of sand with some humus, the annular irrigation io

2019101161 30 Sep 2019 sprinkler includes the annular main pipe with the diameter of 5 cm and 12 branch pipes with the diameter of 3 cm and the length of approximately 5 cm, the annular main pipe is provided with a branch pipe every 30°, and the branch pipe is horizontally placed and is connected to the inner side of the main pipe, the water source flows into the main pipe and then flows out from each branch pipe to irrigate the vegetation in the sunken green space. The upper bumps are formed by stacking a number of cobblestones. The guiding infiltration column is an annular circle with a thickness of approximately 10 cm from a top view and is arranged outside the overflow well, is composed of coarse sand and fine sand; when the rainfall is small, the rainwater can completely infiltrate the coarse sand layer I and the fine sand layer I through the guiding infiltration column and return to supplement the underground water after purified by the coarse sand layer I and the fine sand layer I; when the rainfall is heavy, a small part of the rainwater enters under the ground through the guiding infiltration column, and most of the rainwater enters the water tank I through the overflow well.

[0025] The rainwater is stored in the water tank I after purified by the vegetation and soil, and is lifted by the submersible pump I to the rainwater recycling system. After a rainwater utilization, the rainwater is filtered by the coarse sand layer II and the fine sand layer II and is recycled by the water collecting tank, the rainwater enters the rainwater recycling system and irrigates the vegetation by the annular irrigation sprinkler, realizing recycling use. In order to realize a landscape effect and a maximum water storage capacity of the green space, the reservoir is provided with a rectangular reservoir and a trapezoidal reservoir, the rectangular reservoir is stored with water for a long time, and the trapezoidal reservoir is generally free of water or has a small amount of water, under the situation of a large amount of water, the trapezoidal reservoir can be filled with water but cannot last long. The two combined reservoirs have the characteristics of a recessed depth and a large water storage space, which enhances the water storage capacity. There are various kinds of plants, including both terrestrial plants and aquatic plants, three layers of annular upper

2019101161 30 Sep 2019 bumps are arranged on the surface of the green space, which is able to slow down the flow velocity of the runoff and lengthen the retention time of the runoff in the vegetation, thereby improving the water purification effect. The rainwater recycling system is provided with a rainwater utilization device for self-service car washing, which has the functions of water storage and water purification, and also has the function of water utilization, thereby providing a variety of functions. A layer of river sand is laid on the planting soil layer, and the river sand prevents soil from hardening. Overlooking the multifunctional sunken green space is a circle shape, and a variety of plant types, creating a scenic landscape.

Claims

WHAT IS CLAIMED IS:

1. A multifunctional sunken green space, characterized in that, comprising a planting soil pit with a cylindrical structure, and a circumferential side wall of the planting soil

5 pit is piled with a water permeable brick I (1); a planting soil layer (17), a coarse sand layer I (11) and a fine sand layer I (12) are successively laid in the planting soil pit from top to bottom, a non-woven geotextile (15) is arranged between the planting soil layer (17) and the coarse sand layer I (11) and between the coarse sand layer I (11) and the fine sand layer I (12); a middle part of the planting soil layer (17) is recessed

10 to form a circular reservoir (6), and the circular reservoir (6) is planted with aquatic plants; a middle part of the planting soil layer (17) is provided with an overflow well (10), and one end of the overflow well (10) is erected in the circular reservoir (6), and the other end of the overflow well (10) leads to a water tank 1(14) outside the planting soil pit, one end of the overflow well (10) located in the circular reservoir (6) is

15 provided with a water permeable manhole cover; a periphery of the planting soil layer (17) close to the water permeable brick I (1) is planted with a protective shrub (3), and an annular irrigation sprinkler (2) is arranged along the water permeable brick I (1) of the planting soil pit; a submersible pump I (13) is arranged in the water tank 1(14), and the submersible pump I (13) is connected to a conveying pipeline (24), the other end of

20 the conveying pipeline (24) is connected to a water tank II (21), a submersible pump II (25) is arranged in the water tank II (21), and the submersible pump II (25) is connected to the sprinkler nozzle (20) through a water pipe; a water permeable brick II (26) is arranged uprightly below the sprinkler nozzle (20), and a coarse sand layer II (27), a fine sand layer II (28) and a water collecting tank (22) are successively followed below

25 the water permeable brick II (26), one end of the water collecting tank (22) is connected to a return pipeline (23), and the other end of the return pipeline (23) is connected to a water inlet of the annular irrigation sprinkler (2), and the return pipeline (23) is inclined from one end of the water collecting tank (22) to one end of the annular irrigation

2019101161 30 Sep 2019 sprinkler (2) so that water in the return pipeline (23) flows into the annular irrigation sprinkler (2) owing to gravity.
2. The multifunctional sunken green space according to claim 1, characterized in that, the water permeable manhole cover comprises a coarse sand (8) and a fine sand (9), and

5 the non-woven geotextile is arranged between the coarse sand (8) and the fine sand (9); the coarse sand (8) and the fine sand (9) are wrapped as a whole by a steel wire mesh (19).
3. The multifunctional sunken green space according to claim 1, characterized in that, the circular reservoir (6) comprises a trapezoidal reservoir (6-1) having a trapezoidal

10 cross section and a rectangular reservoir (6-2) having a rectangular cross section, and the rectangular reservoir (6-2) is formed by a lower base of the trapezoidal reservoir (6-1) annularly recessed.
4. The multifunctional sunken green space according to claim 3, characterized in that, a trapezoidal waist of the trapezoidal reservoir (6-1) is planted with zoysia matrella (5),

15 and the lower base of the trapezoidal reservoir (6-1) is planted with emergent plants (18), and the trapezoidal reservoir (6-1) is planted with floating plants (29).
5. The multifunctional sunken green space according to claim 3, characterized in that, the lower base of the trapezoidal reservoir (
6-1) is provided with a plurality of upper bumps (4) composed of a number of cobblestones.

20 6. The multifunctional sunken green space according to any one of claim 3 to 5, characterized in that, the planting soil layer (17) is laid with a river sand (16).
7. The multifunctional sunken green space according to claim 1, characterized in that, the overflow well (10) is a pvc pipe.