Stop losing grass and hedges for asphalt tiles and metal barriers
Removal of trees, shrubs and grass cover on NH-24 is not merely an aesthetic loss. Those were also our best defence against vehicular and dust pollution, urban flooding and rising temperatures.
It is not that the authorities cannot do any better. Despite frequent onslaughts, roadside greenery flourishes along a number of stretches in the national capital. With its treelined pavements, blooming hedges and lush grass patches, the Salimgarh bypass is my favourite.
Yet in other places, fullgrown trees are chopped for flimsy reasons such as “to allow the machinery to move freely for road widening”, says Rao. Grass and hedges are uprooted to put tiles and metal railings, which the authorities claim are easier to maintain. But they keep digging pavements and central verges and replacing tiles round the year.
In many stretches where hedges and grass patches have not been replaced by concretisation, they are trampled by pedestrians, devoured by animals, or just left to wilt due to lack of watering. Most can barely breathe under the weight of the construction rubble and concrete dust.
Given a chance, the humble hedges have as many benefits as full-grown trees. Planted along the road, hedges trap toxins at a vehicle’s exhaust pipe level before they disperse into the air. Grown on the median, they cut glare from the headlights of vehicles approaching on the opposite lanes. While tiles seal the ground, green surfaces prevent water-logging by soaking up stormwater and recharge aquifers. A wall of dense shrubbery is also an effective noise barrier.
C R Babu, professor emeritus at the Centre for Environment Management of Degraded Ecosystems at Delhi University, lists out the hedges most suitable for Delhi: Hibiscus rosa-sinensis, Tecoma stans, Callistemon and Calliandra are the best for their flowers. Murraya paniculata and Murraya koenigii or curry tree can be grown as both tall and mediumsized hedges. An effective dusttrapper, Bougainvillea filters the air of pollutants and grows best when left untended. Nerium indicum is a plant cattle do not eat and Acalypha tricolor tolerates shade and can grow even under a flyover.
Grass binds the soil, acts as a dust trap and absorbs rainwater. It also hosts larvae of insects, which is the best food for birds. “Sparrows disappeared from Delhi because the grass disappeared,” points out Babu. On his list of sturdy grass species, which cannot be easily trampled, are Oplismenus burmannii, Dichanthium annulatum, Cenchrus ciliaris, Bothriochloa and Sporobolus.
The NHAI’S own Green Highways Policy 2015 lists the many benefits of growing trees, shrubs and grass along roadways.
In fact, the NHAI official quoted above said that plantations would be an integral part of the second phase of NH-24 widening in the Ghaziabad segment. Yet, the authority sidestepped its own policy — ‘envisaging a holistic approach to the entire stretch’ — when it came to Delhi, which perhaps needed the green barriers the most.
The country’s car capital that spends huge funds in buying vacuum-cleaners for roads must utilise every yard of available space to grow its green defence against air, noise and light pollution. The Delhi government’s last budget proposed to landscape 500 km of roads. The city also needs a policy to stop replacing roadside shrubs, climbers and grass with concrete, metal and potted plants, and to restore status quo wherever possible.