Sustainable Urban Flood Solutions: The Role Of Green Infrastructure In Smart Cities

(MENAFN- Kashmir Observer) Green Roofs

Green roofs are a modification of traditional roofs which consists of placing a waterproof membrane overlayered by growing media where vegetation is grown. These roofs absorb the rainwater, a part of which is used by plants and returned to the atmosphere via evapotranspiration. They can retain up to 70-90% of the rainfall that falls on them, significantly reducing stormwater runoff and thus reducing the strain on sewer systems during peak flow periods. Green roofs mitigate the urban heat island effect by providing a natural green cover in urban areas, thereby moderating the temperature of the buildings. Beyond these benefits, green roofs have been attributed to result in improved air quality, noise reduction, enhanced biodiversity and overall better health and wellbeing.

Bioretention Cells

Bioretention cells are the artificial imitation of an ideal natural soil system with comparatively higher hydraulic conductivity and significant water quality improvement potential designed for managing urban stormwater. They are the most widely adopted green infrastructure practices for managing urban stormwater. A typical bioretention cell can infiltrate as much as between 85 to 90% of the annual stormwater runoff, replenishing our groundwater resources. They have been found to be very effective in attenuation of peak rates of stormwater runoff generated by rainfall events of varying intensities. In addition to reducing runoff, bioretention cells are highly effective in mitigating pollution and enhancing groundwater recharge. Bioretention cells can also be constructed economically using the locally available material and growing native plant species. The cost of construction varies between Rs. 125 to 250 per square foot to 335 to 500 per square foot (Albert Jarrett, 2022).

Permeable Pavements

Conventional pavements consist of hard concrete surfaces that prevent water infiltration, leading to the accumulation of stormwater and resulting in flash floods. Permeable pavements, on the other hand, are designed to treat, infiltrate, and replenish groundwater. Permeable pavements include porous asphalt, pervious concrete and permeable interlocking concrete pavers. Permeable pavements aim to restore the hydrological balance of urban paved areas by capturing rainwater and allowing it to slowly infiltrate the ground instead of flowing into stormwater drains. The cost of installation may vary between Rs. 170- 335 per square feet depending upon the type of permeable pavements installed (Minnesota Stormwater Manual).

Bioswales

Bioswales are linear shallow landscaped depressions designed for the collection, filtration, infiltration and conveyance of stormwater. The working principle is the same as that of bioretention cells, however unlike bioretention cells which are excavated depression, bioswales are vegetated channels that treat and infiltrate stormwater while conveying the same. Bioswales are best suited for highways and residential road runoff due to their linear nature. They are aesthetically pleasing than the traditional concrete gutters and use native plants and soil mix to absorb and filter stormwater.

Green Streets and Alleys

Green streets and alleys represent an excellent and innovative concept of integrating all green infrastructure practices in the urban infrastructure design process. Bioretention cells, bioswales, permeable pavements and trees can be used together to provide different environmental benefits in an urban ecosystem. The greenery and effective drainage in addition to growing biodiversity provide an excellent space for the local community to walk, play and interact. They turn uninviting alleys and streets into inviting and aesthetically pleasing public spaces bustling with various recreational activities.

Prioritizing green infrastructure not only enhances environmental sustainability but also improves the quality of life in urban areas. By integrating these practices, cities can mitigate environmental impacts and create vibrant, resilient communities that thrive amidst urbanization. It is a need of hour to embrace the concept to create a favorable urban living space for our future generations.

• The author is working as Assistant Professor at PG Department of Agriculture, Khalsa College Amritsar (Punjab)

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