Double-substrate-layer green roof structure designed for local climate differentiation

Abstract

The invention discloses a double-substrate-layer green roof structure designed for local climate differentiation. The structure comprises a vegetation layer, a double-substrate layer, a root blocking layer and a waterproof layer; the double-substrate layer is composed of an upper portion and a lower portion; the upper portion of the double-substrate layer is a planting layer, and the lower portion of the double-substrate layer is biochar modified soil; the vegetation layer is planted on the upper portion of the planting layer; the root blocking layer is arranged on the lower portion of the biochar modified soil; the waterproof layer is arranged on the lower portion of the root blocking layer; and the lower portion of the waterproof layer is attached to an exposed roof. In areas with low rainfall, the double-substrate layer adopts a structural form of thick biochar modified soil and a thin planting layer; and in a areas with abundant rainfall, the double-substrate layer adopts a structural form of a thick planting layer and thin biochar modified soil. According to the double-substrate-layer green roof structure designed for local climate differentiation, the double-substrate layer is adopted to cultivate plants and store rainwater, and by adjusting the thickness distribution of an upper substrate layer and a lower substrate layer, the infiltration and storage adjusting function of a green roof is achieved flexibly at low cost; and the biochar modified soil is high in water storage capacity, capable of reducing soil nutrient loss, more environmentally friendly and higher in durability.

Description

technical field [0001] The invention relates to the field of construction engineering, in particular to a double matrix layer green roof structure designed for local climate differentiation. Background technique [0002] The continuous acceleration of the current urbanization process also means that there is less and less natural land, the increase of urban impermeable surface causes the peak value of runoff in the city to increase, the buffer time of drainage pipes is short, and it is more difficult for rainwater to seep into the ground, etc., which brings urban waterlogging and water resources. Waste and other issues. In addition, due to the replacement of natural land by impermeable surfaces, the urban "heat island effect" is significantly enhanced, increasing the risk of urban flood disasters and reducing urban livability. However, roofs account for a large proportion of urban impermeable surfaces, so it is of great significance to control roof runoff. At present, it i...

AI Technical Summary

Problems solved by technology

[0003] The main component of the matrix of the traditional green roof structure is pastoral soil, which has a high permeability rate, high bulk density, and weak water storage capacity, which easily leads to nutrient loss, requires frequent watering, and requires long-term topdressing after being put into use, and the operating cost is relatively high.

Moreover, the thickness of the paving is relatively rigid, failing to take into account the climate differences and rainfall characteristics in different regions. Most of the thinner substrates are composed of a layer of soil. Although they have a certain ability to infiltrate and store rainwater, they cannot be flexibly stored. Harvesting rainwater and reducing runoff cannot achieve a good water storage effect, and it is difficult to have the ability to alleviate urban waterlogging; thicker substrates meet the water storage requirements, but studies have shown that substrate runoff pollutants increase with the thickness of the substrate And increase, and increase the roof load

The common solution is to add a layer of drainage and storage boards and other water storage structures under the soil layer. However, there are disadvantages such as corrosion and aging of drainage and storage boards, and difficult maintenance.

[0004] CN105993569A discloses a double-matrix-layer expanded green roof structure in which the upper layer is a nutrient matrix and the lower layer is an adsorption matrix. This type of matrix improves the ability of the matrix to absorb pollution, but does not improve the water storage capacity of the green roof

The existing first type of green roof structure mostly adopts commercial integrated storage and drainage boards for water storage and drainage, which cannot reasonably distribute water storage and drainage; storage and drainage boards cannot filter chemical fertilizers such as nitrogen and phosphorus in the planting soil, Direct discharge into municipal pipes or flow into nature will produce chemical pollution

The growth substrate of the second type of green roof structure is to add modified materials such as fly ash and peat soil to the pastoral soil, and mix them to achieve the purpose of improving the physical properties of the soil. This kind of growth substrate has a certain water seepage and water retention capacity, but The outflow of pollutants increases, making the water outflow from the soil more polluted than ordinary pastoral soil

The third type of green roof structure is some green roofs with double matrix layers. The two-layer matrix of this type of roof is composed of nutrient matrix and adsorption matrix. There is no specific basis for the distribution of the thickness of the two-layer substrate, and it is not clear and flexible when assigning the thickness of the two-layer substrate

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