Low-lying green space flow limiting facility for relieving small-watershed waterlogging disaster of city

Abstract

The invention discloses a low-lying green space flow limiting facility for relieving a small-watershed waterlogging disaster of a city. The low-lying green space flow limiting facility comprises low-lying green spaces arranged on the periphery of a road, wherein edges of the low-lying green spaces are lower than the surface of the road; the elevations of the low-lying green spaces are gradually reduced towards the middles so that a middle low-point area for storing rainwater is formed; and the middle low-point area is provided with a catch basin which is connected with a municipal drainage pipe network. By using the low-lying green space flow limiting facility, rainwater on the surface of the road is stored in the peripheral low-lying green spaces, and then is drained in the municipal drainage pipe network through the catch basin of the middle low-point area. By the design, the water logging time of the low-lying green spaces is shortened, water in soil of the green spaces is drained, the number of rainwater openings in sides of the road is reduced, the water drainage ability of the existing municipal drainage pipe network is sufficiently utilized, blockage is relieved, long-time and high-quantity rainstorm can be handled easily, heavy rain which was not encountered in the past 50 years can be effectively handled, requirements on a new city water drainage and waterlogging prevention outline can be met, the planning design on the low-lying green spaces is improved fundamentally, and the small-watershed waterlogging disaster of the city is relieved.

Description

technical field [0001] The invention is used in the field of urban drainage engineering, and in particular relates to a flow-limiting facility for low-potential green areas for alleviating waterlogging disasters in urban small watersheds. Background technique [0002] Low-level green space (also known as "sunken green space", collectively referred to as "low-level green space" in this application) refers to the elevation, which is relatively lower than the surrounding ground or road surface (driveway, sidewalk, square pavement, etc., hereinafter collectively referred to as road surface). A green area that accumulates and infiltrates itself and the surrounding stormwater runoff. The focus of the existing low-level green space plan is to store and retain rainwater as much as possible through low-level green space, reduce the runoff coefficient, create infiltration conditions to replenish groundwater resources, and even aim at 100% interception, hoping to reduce the runoff coef...

AI Technical Summary

Problems solved by technology

[0003] The above ideas have the following three limitations: ① The effect of low-level green space on reducing the runoff coefficient varies with the magnitude and duration of rainstorms. The rain patterns in existing studies are mostly based on short-duration rainstorm intensity formulas, which are difficult to fully reflect For a complete rain pattern, the conclusions of peak clipping and runoff coefficient reduction are often limited by specific boundary conditions, and the obtained runoff coefficients are often too small, which does not reflect the dynamic changes of runoff coefficients. bring adverse effects

②In order to infiltrate and replenish groundwater resources as much as possible, the residence time of rainwater in the green space must be prolonged. On the one hand, it prolongs the flooding time of the green space and affects the use of the green space; Significantly reduced the ability to deal with the peak shaving of the rain pattern after the peak of the main rainfall

③The increase of infiltration means that the rainwater flow into the municipal pipe network is reduced. Under the condition of low return period, the drainage capacity of the rainwater pipe network cannot be fully utilized, and the drainage scour capacity is weakened. The ability to cope with heavy rain in the return period needs to increase the workload of dredging and maintenance

[0004] In addition, at present, most of the municipal stormwater outlets are arranged along the side of the road. The original side-entry stormwater outlet has a small range of steep slopes at the stormwater outlet, which has potential safety hazards and has been seldom used. At present, the flat entry type is used. gullies

On the one hand, the rainwater outlet on the side of the road affects the smoothness of the road surface and is prone to noise; on the other hand, it is easy to be blocked when the road is cleaned and it is close to shops and residential areas.

[0005] Furthermore, the current rainwater wells mostly adopt brick or reinforced concrete structures, and the well walls are impermeable, especially for the rainwater wellheads in low-lying green lands. If the well walls are impermeable, the residual soil in the surrounding soil cannot be drained. Rainwater makes the soil saturated for a long time after rain, affecting plant growth and site utilization

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