Every instance of wind storms in Delhi-NCR results in the uprooting of several trees. This mainly because the civic authorities have concretised roadsides in order to “protect trees and increase urban beauty”. The biggest case in point is Noida, where most roads have been heavily concretised by the Noida Authority, earning the ire of residents and environment activists alike.
“Both sides of the Sector 18 to Sector 62 Elevated Road are heavily concretised. There is an almost 25-feet wide concretised pedestrian pathway here, but pedestrians don’t use it as they find it very high to tread on,” points out Atul Gupta, Architect and President, Architects Association Noida Zone. “There is no breathing space left around the roots due to which some trees have already died. Concretisation should not be allowed in the 4-6 feet area around a tree,” he adds.
Horticulturists say that as per the norms, an area of 36 sq feet (six feet on each side) should be left around a tree so that the roots receive a good supply of air and water. Concretisation around roots is akin to slow poisoning the tree due to which both superficial and deep roots get impacted. As there is no scope of water percolation or deep root aeration, the roots get weak and the tree falls down.
“Concretisation also damages the extremely fertile top soil layer. In summers, the cement layer heats up and dries the roots. In the monsoon season, water gets stagnated in the cracks of the tiles rotting the tree,” says Sudha Krishnan, a retired Botany Teacher.
Cementing also prevents rain water from percolating down, which depletes the ground water level on one hand and leads to flooding of areas on the other. “Nowhere in our district, is ground water available above 120 ft. Even at this level, we don’t get drinking water, which is available only beyond 180ft under the earth. The depletion rate, 2m per year, is abnormally high. Depleting ground water level also means an increased chance of contamination,” says Vikrant Tongad, Founder-Member, Social Action for Forest & Environment. “Till about a decade ago, good quality drinking water was easily available at 40ft depth,” he informs.
The residents are puzzled as to why the authorities have not opted for greener options that appear soothing, help in water conservation and increase the lifespan of trees. “These concretised pavements are very high from the ground level,” says Commander (retd) NK Mahajan, a resident of Jal Vayu Vihar. “Repeated cementing raises the level. Pedestrians don’t use these pathways, which have now become dumping grounds for garbage or get occupied by illegal hawkers. My area is a burning example of this. Leaving the area green is better than undertaking this expensive exercise,” he adds.
Architect Gupta advocates the use of permeable or perforated paver blocks as these allow the soil to breathe and the water to seep deep. “The interlocking blocks fixed in Sector 28, 29 too offer some respite as the porous joints allow water to seep into the earth,” he says.