A tree pit for storing rainwater for irrigation reuse

Abstract

This invention relates to a tree pit for storing rainwater for irrigation and reuse, belonging to the field of landscaping engineering technology. It includes a plant growth area and a water storage area. The plant growth area includes an irrigation reuse area and a root controller. The root controller comprises modular splicing pieces, each with permeable holes. The porosity and size of the permeable holes increase from top to bottom. By setting up a root controller composed of modular splicing pieces and opening permeable holes on the splicing pieces with increasing porosity and size from top to bottom, this invention forms a root-guiding structure. On the one hand, the smaller and denser permeable holes in the upper layer effectively prevent tree fibrous roots from growing upwards into the perforated area of ​​the cover plate, avoiding root exposure to air and potential "cutting" due to dryness or excessive temperature differences, thus protecting root health. On the other hand, the larger and sparser permeable holes in the lower layer guide the main root downwards and towards the water storage area, promoting deep root growth and fully utilizing the rainwater stored in the water storage area.

Description

Technical Field

[0001] This invention belongs to the field of landscape engineering technology, and specifically relates to a tree pit for storing rainwater for irrigation and reuse. Background Technology

[0002] Tree pits, as an essential infrastructure for planting urban street trees and landscaping trees, directly impact tree growth and urban stormwater management. Traditional tree pits typically function only as planting containers, lacking rainwater collection and irrigation capabilities. This necessitates extensive manual watering during dry seasons, increasing green space maintenance costs. Furthermore, rainwater runoff around the tree pits cannot be effectively utilized during the rainy season, resulting in water waste.

[0003] To address these issues, various tree pit designs with rainwater harvesting and irrigation functions have emerged in recent years.

[0004] However, existing rainwater harvesting irrigation techniques for tree pits still have the following shortcomings: First, root control is ineffective. In existing tree pit structures, due to ground hardening, water infiltration is slow, resulting in a vertical water distribution that is higher at the top and lower at the bottom. Because plant roots are attracted to water, their growth is limited to the upper part, sometimes even spreading outwards. This eventually causes the surrounding paving stones or curbs to arch up, creating a root arch effect. While some tree pits have root control structures, previous methods relied solely on physical methods, such as binding the roots with concrete slabs, without considering water distribution based on water and fertilizer attraction, or the "air shearing" effect.

[0005] Secondly, balancing filtration and permeability is difficult. Existing tree pits typically use geotextiles or non-woven fabrics as filter layers. While these can prevent soil particle loss, they are prone to clogging after long-term use, affecting rainwater infiltration and the normal supply of irrigation water. On the other hand, using filter structures with larger pores can lead to the loss of fine soil particles, reducing soil fertility and potentially clogging downstream water storage structures.

[0006] Third, the efficiency of irrigation water use needs to be improved. Existing tree pits mostly rely on gravity infiltration or water pumping for irrigation. The former results in uneven water distribution, which can easily lead to localized over-wetting or under-drying; the latter requires external energy, increasing operating costs and maintenance difficulties.

[0007] Therefore, developing a new tree pit structure that can take into account precise root control, graded filtration, and efficient irrigation is of great significance for improving the efficiency of urban rainwater resource utilization and improving the growth conditions of street trees. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a tree pit for storing rainwater for irrigation and reuse. By setting high, medium, and low gradient pore densities on a porous root control device, it achieves a differentiated guiding effect on root growth, thereby realizing precise root control by limiting lateral roots in the upper part, guiding the main root in the middle part, and promoting deep roots in the lower part.

[0009] To achieve the above objectives, the present invention provides the following solution: A tree pit for storing rainwater for irrigation and reuse includes a plant growth area and a water storage area. The plant growth area includes an irrigation reuse area, a root controller disposed within the irrigation reuse area, improved soil disposed within the root controller, and a cover plate disposed on top of the irrigation reuse area. The cover plate has a through hole for the root controller to communicate with the outside. The water storage area is connected to the irrigation reuse area. The root controller includes gradient modular splicing pieces connected sequentially from top to bottom with gradually increasing size. Each splicing piece is provided with a water-permeable hole, and the porosity and size of the water-permeable hole gradually increase from top to bottom.

[0010] Preferably, the permeable holes in the upper region have a pore size of 0.5-1.0 mm and a porosity of 15-25%; the permeable holes in the middle region have a pore size of 1.5-3.0 mm and a porosity of 30-45%; and the permeable holes in the lower region have a pore size of 4.0-8.0 mm and a porosity of 50-70%.

[0011] Preferably, the water storage area includes an upper water guiding area and a lower water storage area that are interconnected, a gravel layer disposed on the upper water guiding area, and a cover plate disposed on the top of the gravel layer and flush with the ground. An overflow outlet is provided on the side of the lower water storage area near the tree root controller, and the overflow outlet is connected to the irrigation reuse area. A water pipe is inserted into the right side of the upper water storage area and connected to the drainage ditch cover plate.

[0012] Preferably, a partition with a connecting hole is provided between the upper water guiding zone and the lower water storage zone, the upper water guiding zone and the lower water storage zone are connected through the connecting hole, and a float valve is provided at the connecting hole.

[0013] Preferably, the system also includes a water storage tank located outside the irrigation reuse area. The water storage tank is connected to the overflow outlet and the irrigation reuse area via pipes. Control valves are installed on the pipes between the water storage tank and the irrigation reuse area, as well as on the pipes between the water storage tank and the overflow outlet.

[0014] Preferably, the upper water guiding zone and the lower water storage zone are provided with a gravel layer, a transition layer and a filter layer on the side near the irrigation reuse zone. The gravel layer, the transition layer and the filter layer are sequentially attached and connected, and the gravel layer is close to the irrigation reuse zone. The particle size of the gravel layer is 20mm to 30mm, the particle size of the transition layer is 10mm to 20mm, and the filter layer is a wire mesh with a thickness of no more than 2mm.

[0015] Preferably, the outer side of the tree root controller is wrapped with geotextile.

[0016] Preferably, the root controller is filled with improved soil, and the improved soil is equipped with a water storage component.

[0017] Preferably, the water storage assembly includes a cement board, a second circular plate, and a first circular plate. Two circular covers are fixedly installed on the lower end face of the cement board. The circular cover on the left side is fixedly connected to the first circular plate, and the circular cover on the right side is fixedly connected to the second circular plate. The outer surface of the first circular plate is machined with a groove.

[0018] Preferably, the cover plate is provided with multiple through holes.

[0019] The present invention achieves the following technical effects compared to the prior art: This invention employs a root controller comprised of modular splicing panels with permeable holes. The porosity and size of these holes increase progressively from top to bottom, creating a root-guiding structure. On one hand, the smaller, denser permeable holes in the upper layer effectively prevent fibrous roots from growing upwards into the perforated area of ​​the cover plate, avoiding root damage from dryness or extreme temperature fluctuations and thus protecting root health. On the other hand, the larger, more sparser permeable holes in the lower layer guide the main root downwards towards the water storage area, promoting deep root growth and fully utilizing the rainwater stored in the water storage area. Simultaneously, the irrigation reuse area is connected to the water storage area, allowing stored rainwater to be returned to the improved soil as needed, ensuring stable moisture and good aeration in the root zone, further reducing the conditions for "air pruning." This structure, by combining rainwater collection and irrigation reuse with physical guidance and water-air environment regulation, synergistically solves the problem of "air pruning," significantly improving tree survival rate and growth quality. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an overall structural diagram of the present invention; Figure 2 This is a top view of a tree pit for storing rainwater according to the present invention; Figure 3 This is a schematic diagram of the water storage component structure of the present invention; Figure 4 This is a cross-sectional view of the geotextile of the present invention; Figure 5 This is a anatomical diagram of the plant used in this invention; Figure 6 This is a schematic diagram of the tree root controller of the present invention; Among them, 1. Porous cover plate; 2. Tree root control device; 3. Irrigation reuse area; 4. Soil improvement; 401. Plants; 5. Drainage ditch cover plate; 6. Gravel layer; 7. Water pipe; 8. Upper water guiding area; 9. Float valve; 10. Lower water storage area; 11. Air inlet; 12. Overflow outlet; 13. Geotextile; 15. Cement board; 16. Second circular plate; 17. Circular cover; 18. Groove; 19. First circular plate; 20. Water storage component; 21. Splicing piece; 22. Water permeable hole. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides a tree pit for storing rainwater for irrigation reuse. Based on rainwater collection and irrigation reuse, it solves the problem of "air pruning" from both physical guidance and water and air environment regulation, which significantly improves the survival rate and growth quality of trees.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] refer to Figures 1 to 6A tree pit for storing rainwater for irrigation and reuse includes a plant growth area 401 and a water storage area. The plant growth area 401 includes an irrigation reuse area 3, a root controller installed in the irrigation reuse area 3, improved soil 4 installed in the root controller, and a cover plate installed on top of the irrigation reuse area 3. The cover plate has through holes for the root controller to communicate with the outside. The water storage area is connected to the irrigation reuse area 3. The root controller includes gradient modular splicing pieces 21 connected sequentially from top to bottom with gradually increasing size. Each splicing piece 21 is provided with a water permeable hole 22, and the porosity and size of the water permeable hole 22 gradually increase from top to bottom. Specifically, the root controller is installed inside the irrigation reuse area 3, and the improved soil 4 fills the inside of the root controller to provide nutrients and physical support for tree growth. A cover plate is installed on top of the irrigation reuse area 3, and through holes are provided on the cover plate to connect the root controller with the external environment. The root controller is constructed of modular splicing pieces, with permeable holes on the splicing pieces. The porosity and size of the permeable holes increase from top to bottom, forming a root-guiding structure. On the one hand, the smaller and denser permeable holes in the upper layer effectively prevent tree fibrous roots from growing upwards into the through-hole area of ​​the cover plate, avoiding root damage from dryness or excessive temperature differences, thus protecting root health. On the other hand, the larger and sparser permeable holes in the lower layer guide the main root downwards and towards the water storage area, promoting deep root growth and fully utilizing the rainwater stored in the water storage area. Simultaneously, the irrigation reuse area is connected to the water storage area, allowing stored rainwater to be returned to the improved soil as needed, ensuring stable moisture and good aeration in the root layer, further reducing the conditions for "air-induced root pruning."This structure, based on rainwater collection and irrigation reuse, synergistically solves the "air pruning" problem from both physical guidance and water and air environment regulation aspects, significantly improving tree survival rate and growth quality. The water storage area is connected to the irrigation reuse area 3, used to collect and store rainwater infiltrating from the plant 401 growth area, and during drought periods, the stored rainwater is reversed to supply the irrigation reuse area 3, achieving non-powered or low-powered irrigation for the trees. The tree root controller is one of the core components of this tree pool. It adopts a modular splicing structure, consisting of several splicing pieces 21 connected vertically from top to bottom. Each splicing piece 21 is provided with a water-permeable hole 22, and the porosity and single-hole size of the water-permeable holes 22 of the splicing pieces 21 located at different heights are different. The dimensions change in a gradient: from top to bottom, the porosity of the permeable holes 22 gradually increases, and the size of each hole also gradually increases; the upper splicing plate 21 has smaller porosity and smaller pore size for the permeable holes 22, forming a high-density filtration zone, mainly used to intercept fine particulate pollutants brought in by surface runoff, while limiting the excessive horizontal expansion of lateral roots in shallow soil; the middle splicing plate 21 has medium porosity and medium pore size for the permeable holes 22, forming a medium-density transition zone, allowing the taproot to grow downwards smoothly, while also guiding and controlling the lateral roots to a certain extent; the lower splicing plate 21 has larger porosity and larger pore size for the permeable holes 22, forming a low-density water-conducting zone, facilitating rapid water infiltration and the extension of deep roots towards the water storage area, promoting the deep development of tree roots. Through the gradient setting of increasing porosity and pore size from top to bottom, the root controller achieves a synergistic function of decreasing filtration accuracy, increasing water permeability, and decreasing root control intensity in the vertical direction. Furthermore, the larger lower pores allow more water to accumulate downwards, and the root system's hydrotropism induces downward growth. The smaller upper pores, connected to the outside environment, along with the overflow valve control, primarily guide water downwards, while the lower pores, with less moisture and more air, effectively control root growth.

[0026] Furthermore, the splicing pieces 21 are connected by detachable mechanical means (such as snap-fit ​​connection, bolt connection or slot connection), which makes it easy to adjust the number, height combination and pore gradient distribution of the splicing pieces 21 according to the depth of the tree pit, tree species or soil conditions, so as to realize the modular customization of the tree root controller and subsequent maintenance and replacement.

[0027] Furthermore, the splicing piece 21 can be made of porous concrete containing water-retaining materials.

[0028] refer to Figure 6The permeable holes 22 in the upper region have a pore size of 0.5-1.0 mm and a porosity of 15-25%. They effectively intercept sediment, fine particles, and some organic matter brought by surface runoff, preventing the loss of the fertile topsoil 4 and avoiding these impurities from clogging the water storage structure in the lower layer. The smaller pore size physically hinders the excessive horizontal expansion of lateral roots in the shallow soil, forcing the roots to seek growth space downwards and preventing lateral roots from "coiling" or damaging the road surface. The permeable holes 22 in the middle region have a pore size of 1.5-3.0 mm and a porosity of 30-45%. The main roots of trees (usually with a diameter greater than 3 mm) can pass through this area smoothly, ensuring that the trees have a stable root system. This pore size can inhibit excessive branching of lateral roots in this layer and guide root energy. The roots develop towards the taproot and deep roots, ensuring that irrigation water and rainwater can infiltrate at a moderate rate, preventing water accumulation due to excessive density at the top and rapid leakage due to excessive sparseness at the bottom. The permeable holes 22 in the lower region have a pore size of 4.0-8.0 mm and a porosity of 50-70%. This provides an unobstructed growth channel for the taproot and thick roots that have penetrated the middle, encouraging the root system to extend into deeper water storage areas. This allows the tree to utilize deep water and nutrients, enhancing its drought resistance and lodging resistance. The high porosity ensures that water in the water storage area (through capillary action or gravity) can be smoothly and quickly transported upwards to the root layer, while also allowing excess rainwater to quickly infiltrate and be stored. This area is directly connected to the water storage area, forming a "root-water" interaction interface, which facilitates the root system to directly absorb water stored in the water storage area.

[0029] refer to Figure 1The water storage area includes an interconnected upper water guiding area 8 and a lower water storage area 10. The upper water guiding area 8 is equipped with a gravel layer 6, which fills the interior of the upper water guiding area 8 and serves as a primary filter for rainwater entering the water storage area, intercepting suspended impurities such as leaves and coarse silt. A cover plate is installed on top of the gravel layer 6, flush with the ground surface. This facilitates smooth runoff of surface rainwater into the water storage area while maintaining a flat and aesthetically pleasing surface, preventing pedestrians from tripping or vehicles from bumping against it. The cover plate is preferably a drainage ditch cover plate 5, with several inlet holes for collecting surface rainwater and initially intercepting large debris. An overflow outlet 12 is located on the side of the lower water storage area 10 near the tree root controller, and this overflow outlet 12 is directly connected to the irrigation reuse area 3 in the plant growth area 401. When the rainwater level in the storage area exceeds the height of the overflow outlet 12, the excess water is automatically discharged into the irrigation reuse area 3 through the overflow outlet 12, providing additional water supply to the tree roots. Simultaneously, the overflow outlet 12 also controls the maximum water level in the storage area, preventing excessive water levels from causing prolonged immersion of the tree roots and affecting root respiration. A water pipe 7 is inserted into the right side of the upper water guiding area 8, with one end connected to the upper water guiding area 8 and the other end connected to the drainage ditch cover 5. The water pipe 7 can be connected to the side wall or bottom interface of the drainage ditch cover 5. When rainfall is heavy and the water level in the storage area continues to rise above the height of the water pipe 7 interface, excess rainwater is directly discharged into the municipal stormwater network through the water pipe 7, or guided to subsequent stormwater treatment facilities for purification and utilization. Through this structure, the storage area achieves the coordinated functions of graded water storage, automatic overflow irrigation, and excess discharge.

[0030] refer to Figure 1 A partition is installed between the upper water guiding zone 8 and the lower water storage zone 10. This partition is horizontally or slightly inclined and positioned in the middle of the water storage zone, vertically dividing it into two relatively independent water storage spaces. One or more connection holes are provided on the partition, allowing the upper water guiding zone 8 and the lower water storage zone 10 to communicate with each other, thus facilitating water exchange between the two zones. A float valve 9 is installed at each connection hole. The float valve 9 includes a valve body, a valve core, a float, and a connecting rod. The valve body is fixedly installed inside or below the connection hole, and the valve core cooperates with the valve body to control the opening and closing of the connection hole. The float is located in the lower water storage zone 10 and is linked to the valve core via the connecting rod. The float valve 9 is configured such that when the water level in the lower water storage zone 10 changes, the float moves up and down with the water level, and through the connecting rod, it drives the valve core to automatically open or close the connection hole.

[0031] The working mode of the float valve 9 is as follows: (a) Water storage mode: When the water level in the lower water storage area 10 is low and the water volume is insufficient, the float is in a low position under the action of gravity. At this time, the valve core is in the open state and the connection hole remains unobstructed. Rainwater in the upper water guiding area 8 is replenished to the lower water storage area 10 through the connection hole under the action of gravity until the water level in the lower water storage area 10 rises to the set height.

[0032] (ii) Water retention mode: When the water level in the lower water storage area 10 rises to the set height, the float rises to the predetermined position and drives the valve core to close the connection hole through the connecting rod. At this time, the water exchange between the upper water guiding area 8 and the lower water storage area 10 is cut off, and the water volume in the lower water storage area 10 is maintained, forming a relatively closed water storage space, which facilitates continuous water supply to the plant 401 root system during drought.

[0033] (III) Overflow prevention mode: When the water volume in the upper water guiding zone 8 is too large or the water level is too high, even if the lower water storage zone 10 is already full, the float valve 9 remains closed, and the excess water cannot continue to flow into the lower water storage zone 10. Instead, it is discharged through the overflow port 12 or the water pipe 7, thereby preventing the lower water storage zone 10 from being soaked due to excessive water filling.

[0034] Referring to the diagram, the tree pit for storing rainwater for irrigation also includes a water storage tank located outside the irrigation reuse area 3. The water storage tank is independent of the main tree pit structure and can be buried underground around the tree pit or installed above ground, with the specific location determined based on site conditions and landscape requirements. The water storage tank is connected to the overflow outlet 12 and the irrigation reuse area 3 via pipes. The first pipe connects the overflow outlet 12 to the inlet of the water storage tank, used to guide rainwater exceeding the overflow level in the storage area to the water storage tank for temporary storage. The second pipe connects the outlet of the water storage tank to the irrigation reuse area 3, used to return the rainwater stored in the water storage tank to the irrigation reuse area 3 when irrigation is needed, for absorption and utilization by the tree roots.

[0035] A first control valve is installed on the first pipeline to control the opening and closing of the pipeline and the flow rate between the overflow port 12 and the water storage tank; a second control valve is installed on the second pipeline to control the opening and closing of the pipeline and the flow rate between the water storage tank and the irrigation reuse area 3. The first and second control valves can be selected as manual valves, solenoid valves, or electric valves according to actual needs.

[0036] Through the configuration of the above-mentioned water storage tank and control valve, the present invention achieves flexible switching between the following multiple working modes: (a) Rainwater Buffering Mode In the initial stages of rainfall or under light to moderate conditions, the water storage area first receives and stores rainwater. When the water level in the storage area rises to the height of the overflow outlet 12, the first control valve is opened and the second control valve is closed, and excess rainwater enters the storage tank through the first pipe for temporary storage. This mode significantly expands the system's rainwater storage capacity and reduces rainwater discharge without increasing the main volume of the tree pit.

[0037] (II) Supplemental Irrigation Mode During dry seasons or periods without rain, when the water stored in the reservoir is insufficient to meet the transpiration needs of the trees, the second control valve can be opened and the first control valve closed. Rainwater stored in the tank will then flow into the irrigation reuse area 3 through the second pipe under gravity or with an auxiliary pump, replenishing the tree roots. This method effectively extends the system's autonomous irrigation cycle and reduces the frequency of manual watering.

[0038] (III) Self-circulating flushing mode When it is necessary to flush the root controller or irrigation reuse area 3 to prevent blockage, the first and second control valves can be opened simultaneously, and the original passage between the water storage area and irrigation reuse area 3 can be closed, forming a circulation loop between the water storage tank, overflow port 12, and irrigation reuse area 3. During the circulation process, the water in the water storage tank flushes the relevant pipes and areas, carrying away accumulated impurities and keeping the system unobstructed.

[0039] (iv) Synergistic model of rainy season drainage and dry season water storage During the rainy season, the first control valve is normally open and the second control valve is normally closed. The storage tank acts as a buffer for rainwater, continuously receiving overflowing rainwater. Before the dry season arrives, the first control valve is closed, locking the water in the storage tank for later use via the second control valve. This system enables inter-temporal distribution of rainwater, improving the efficiency of rainwater resource utilization.

[0040] Referring to the diagram, the upper water guiding zone 8 and the lower water storage zone 10 are equipped with a gravel layer 6, a transition layer, and a filter layer on the side near the irrigation reuse zone 3. The gravel layer 6, the transition layer, and the filter layer are sequentially attached and connected, with the gravel layer 6 close to the irrigation reuse zone 3. The particle size of the gravel layer 6 is 20mm to 30mm, the particle size of the transition layer is 10mm to 20mm, and the filter layer is a steel wire mesh with a thickness of no more than 2mm. Through the synergistic cooperation of the above three-layer structure, a filtration barrier is formed from coarse to fine, step-by-step refinement. This effectively intercepts suspended particles, silt, impurities, and organic debris carried in the water during the process of transporting the irrigation reuse water from the water storage zone to the irrigation reuse zone 3, ensuring the cleanliness of the water entering the irrigation reuse zone 3 and preventing clogging of the tree root controller and the improved soil 4.

[0041] Furthermore, the outer side of the root controller is wrapped with geotextile 13, which can prevent the improved soil particles 4 inside the root controller from seeping out, while allowing water and dissolved nutrients to pass through smoothly. This maintains the structural integrity and fertility of the soil layer on the one hand, and prevents fine soil particles from entering the water storage area or filter layer on the other hand, avoiding siltation in the water storage area and blockage of the filter structure.

[0042] refer to Figure 3 The root controller is used to fill the improved soil 4, and the improved soil 4 is equipped with a water storage component 20.

[0043] refer to Figure 3 The water storage component 20 includes a cement plate 15, a second circular plate 16, and a first circular plate 19. Two circular covers 17 are fixedly installed on the lower end face of the cement plate 15. The circular cover 17 on the left side is fixedly connected to the first circular plate 19, and the circular cover 17 on the right side is fixedly connected to the second circular plate 16. The outer surface of the first circular plate 19 is machined with grooves 18, and the first circular plate 19 is columnar. Multiple grooves 18 are evenly distributed on the first circular plate 19. The side view cross-section of the grooves 18 is circular. In this way, rainwater in the water storage tank can flow into the soil around the plant 401 through the grooves 18 to nourish the green plant 401 and make full use of rainwater. The inside of the grooves 18 is provided with a permeable net, which is fixedly connected to the grooves 18. The permeable net can prevent excessive rainwater from flowing into the area around the plant 401 and causing the plant 401 to become waterlogged, and it can also prevent the soil around the plant 401 from entering the water storage tank and affecting the use of rainwater.

[0044] refer to Figure 1 The cover plate has multiple through holes.

[0045] The working principle and usage process of this invention: The water storage area is located at the original municipal road drainage ditch, as part of the municipal road drainage system. A baffle with a float valve 9 is set at 1 / 2 of the water storage area. The perforated concrete cover is made of cement concrete. The edges of the perforated cover 1 are raised to facilitate rainwater collection. The perforated root control device 222 is made of concrete slab, which has the characteristics of corrosion resistance, durability, and non-deformation. The soil improvement method 4 can increase the thickness of the sandy soil layer, improve the texture, and enrich the soil, or use quicklime and some alkaline soil conditioners to neutralize the soil acidity and increase the soil pH value. During rainfall, it collects runoff rainwater from the road surface. First, the water enters the gravel layer 6, and after filtration, it flows from the bottom of the gravel layer 6 into the upper water storage area 8. After the water level in the lower water storage area 10 rises, the float valve 9 closes as the water level rises, and excess rainwater is directly discharged or further treated. The rainwater overflows from the lower water storage area 10 into the plant 401 growth area, and is then irrigated after being filtered and intercepted by the porous cement concrete slab and the improved soil layer 4. During the interval between rainfalls, the water level in the lower water storage area 10 drops, the float valve 9 opens, and the rainwater in the upper water storage area 8 flows in, reaching the overflow outlet 12 and entering the plant 401 growth area. This reduces the amount of water used for manual watering, saves irrigation water, reduces the workload of greening workers, and consumes no energy, achieving both conservation and environmental protection.

[0046] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0047] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A tree pit for storing rainwater for irrigation reuse, characterised in that, The system includes a plant growth area and a water storage area. The plant growth area includes an irrigation reuse area, a root controller located within the irrigation reuse area, improved soil located within the root controller, and a cover plate on top of the irrigation reuse area. The cover plate has through holes for the root controller to communicate with the outside. The water storage area is connected to the irrigation reuse area. The root controller includes gradient modular splicing pieces connected sequentially from top to bottom with gradually increasing size. Each splicing piece is provided with permeable holes, and the porosity and size of the permeable holes gradually increase from top to bottom.

2. The tree well for storing rainwater for irrigation return according to claim 1, wherein, The permeable holes located in the upper region have a pore size of 0.5-1.0 mm and a porosity of 15-25%; the permeable holes located in the middle region have a pore size of 1.5-3.0 mm and a porosity of 30-45%; and the permeable holes located in the lower region have a pore size of 4.0-8.0 mm and a porosity of 50-70%.

3. The tree well for storing rainwater for irrigation return according to claim 1, wherein, The water storage area includes an upper water guiding area and a lower water storage area that are interconnected, a gravel layer set on the upper water guiding area, and a cover plate set on the top of the gravel layer and flush with the ground. An overflow outlet is opened on the side of the lower water storage area near the tree root controller. The overflow outlet is connected to the irrigation reuse area. A water pipe is inserted into the right side of the upper water storage area and connected to the drainage ditch cover plate.

4. The tree well for storing rainwater for irrigation return according to claim 3, wherein, A partition with a connecting hole is provided between the upper water guiding area and the lower water storage area. The upper water guiding area and the lower water storage area are connected through the connecting hole, and a float valve is provided at the connecting hole.

5. The tree well for storing rainwater for irrigation return according to claim 3, wherein, It also includes a water storage tank located outside the irrigation reuse area. The water storage tank is connected to the overflow outlet and the irrigation reuse area via pipes. Control valves are installed on the pipes between the water storage tank and the irrigation reuse area, as well as on the pipes between the water storage tank and the overflow outlet.

6. The tree well for storing rainwater for irrigation return according to claim 1, wherein, The upper water guiding zone and the lower water storage zone are provided with a gravel layer, a transition layer and a filter layer on the side near the irrigation reuse zone. The gravel layer, the transition layer and the filter layer are sequentially attached and connected, and the gravel layer is close to the irrigation reuse zone. The particle size of the gravel layer is 20mm to 30mm, the particle size of the transition layer is 10mm to 20mm, and the filter layer is a wire mesh with a thickness of no more than 2mm.

7. The tree well for storing rainwater for irrigation return according to claim 1, wherein, The root controller is wrapped with geotextile on the outside.

8. The tree well for storing rainwater for irrigation return according to claim 1, wherein, The root controller is filled with improved soil, and the improved soil is equipped with a water storage component.

9. The tree well for storing rainwater for irrigation return according to claim 8, wherein, The water storage assembly includes a cement board, a second circular plate, and a first circular plate. Two circular covers are fixedly installed on the lower end face of the cement board. The circular cover on the left side is fixedly connected to the first circular plate, and the circular cover on the right side is fixedly connected to the second circular plate. The outer surface of the first circular plate is machined with grooves.

10. The tree well for storing rainwater for irrigation return according to claim 1, wherein, The cover plate has multiple through holes.

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