Metro Matters: This monsoon in Delhi, let’s give lowly creepers and hedges a chance
Delhi sees multiple plantation drives every monsoon but most plants wilt away due to lack of water and care. Maybe planting humble hedges is a better ideaUpdated: Aug 28, 2017 16:20 IST
In Delhi’s official calendar, the monsoon is the season dedicated to plantation drives. Every year, millions of saplings are planted with the hope that one day they will grow into robust trees to fight air pollution, prevent flooding and lower the temperature.
Alongside, Delhi’s civic agencies also plant as many shrubs, mainly on road medians, traffic islands and on the pavements. Unlike planting a tree, there is no noble intention or emotion attached to planting a shrub or a hedge. It is the most perfunctory gardening exercise.
Perhaps that is why we don’t see them flourishing except for some along a few important roads. Trampled by pedestrians, devoured by animals, or just left to wilt because of lack of water, most of these plants don’t live to see the next season. Even the ones that survive can barely breathe under the weight of the construction rubble dumped everywhere.
But these humble and uncared for hedges can have as many benefits for a city as full-grown trees. A study published in the journal Atmospheric Environment in May this year found that low hedges reduced the impact of pollution from vehicles in cityscapes, where there are large buildings close to roads, far more effectively than taller trees. That is because hedges trap toxins at a vehicle’s exhaust pipe level before they disperse into the air.
While Delhi is mostly a flat city, the vertical neighbourhoods in the suburbs and the business districts, which are tightly packed with tall buildings and have become hotspots of pollution, could benefit immensely from shorter greens.
Elsewhere in Delhi, too, shrubbery can be an invaluable asset. It can replenish groundwater by soaking up storm water and recharging local aquifers that have already been sucked dry. A dense growth of plants is also the most visually appealing noise barrier a neighbourhood could have.
Impressed with the landscaping around the Delhi airport, Lieutenant Governor Anil Baijal recently instructed the public works department to green the central verges along the city’s 1,250 km of roads. He wants the agency to first study the soil type and identify the plants that could survive on this road space and tie-up with the nearest sewage treatment plant for regular watering.
If established and nurtured, these short walls of green along the roads could be huge visual relief to the national capital’s otherwise dusty cityscape. But Delhi can do more. Many cities around the world are using their built environment – pillars supporting elevated roads and flyovers, and tall buildings – to develop vertical gardens.
Singapore pioneered the concept of vertical green in Asia. In 2009, its National Parks Board launched the Skyrise Greenery Incentive Scheme, which subsidises up to 50% of the installation costs. By 2030, the city state targets to expand its 81 hectares of sky rise greenery to 200 hectares.
Only this year, Stefano Boeri, the Italian architect famous for designing the Vertical Forest skyscraper complex in Milan launched a similar project in China’s Nanjing. Mexico City, where air pollution levels once surpassed that of Delhi, is also building 40,000 metres of vertical gardens on its elevated roads, walls, and creating “living, breathing” sculptures.
Officials from VerdMX, a non-profit outfit doing the job in Mexico City, told the Toronto Star that a garden covering the façade of a typical four-storey building could filter 40 tonnes of noxious gases per year, while also trapping and breaking down 15 kg of heavy metals. Acting as a natural muffler, it can reduce local noise pollution by 10 decibels.
Bengaluru has already borrowed the concept and is on its way to create its second vertical garden on the pillars of its newly opened Metro lines. In June this year, Kochi Metro announced similar green covers on every sixth Metro pillar. These initiatives should not only help in cleaning up foul air but also improve the urban aesthetics.
Delhi’s 80 flyovers and hundreds of pillars holding its 140 km of elevated Metro lines, makes its landscape grey and depressing. Greenery, on the other hand, stands for regeneration — symbolising hope, happiness and new life. It serves as an instant mood lifter. It’s time one of the world’s greenest capitals also gave the humbler plants and creepers a chance.
First Published: Aug 28, 2017 16:17 IST