Unfortunate deaths due to falling of trees—be it in Cyclone Tauktae or heavy rains that lash Mumbai each year—are not uncommon. In view of such tree fall incidents and deaths due to trees falling, the Brihanmumbai Municipal Corporation (BMC) has appointed a “tree surgeon” or arborist to conduct a scientific risk assessment of Mumbai trees.
Arborists are those who take care of trees and make sure that they are healthy and safe. They work on cultivation, management, and study of individual trees, shrubs, vines, and other perennial woody plants in dendrology and horticulture.
The BMC has appointed renowned arborist Vaibhav Raje to lead a pilot project in Mumbai. For the first time in the country, any such corporation has appointed such an expert. The BMC aims to mitigate the likelihood of trees falling and causing property damage or even deaths, as an outcome of this audit of trees. This pilot project will be launched in D ward where old trees in the south Mumbai neighbourhood of Nepean Sea Road, Malabar Hills and Lamington Road, will be scientifically examined for their health.
The Daily Guardian spoke to Raje to try and understand how he will go about his task. Raje said: “This survey will give an idea of urban tree management in Mumbai. Risk assessment basically involves looking after the tree and finding defects in the tree in terms of managing its risk. In order to do this, you measure the tree—the approximate height, image of the tree trunk, diameter and image of the canopy spread—basically the physical parameters of all the trees.”
He continued, “Then you observe from all sides of the tree right, from the top to bottom, to identify the structural and physiological defects in the tree. You make a note of it and depending upon the condition of the tree and condition of the site, you assess the tree. You put in your recommendations and mitigation measures in certain conditions where the tree has a lot of internal damage or cavity inside. Where you visually can’t tell what is wrong with the tree, in those situations, you have to use advanced diagnosis instrument.”
Raje said that he has a Resistograph which drills inside the trees and measures the resistance of the wood to find out whether it’s healthy inside the trunk. “If it’s healthy, it will show an increase in the graph and wherever there is a decay in the wood or there is unhealthy wood, there is a dip in the graph and this will quantify at what depth and what quantity of the wood is healthy inside. Then you do this exercise, this assessment at various levels and at various angles. They you download the information into a software and you conclude and analyse the data and based on the findings, the trees are treated and canopy management is done.”
He also pointed out that assessment of trees is a relatively new concept in India, but it is critical for cities where a large population coexists with trees, putting trees under a lot of stress. It is critical to maintain and treat trees in good condition.
Around 2,000 incidents of trees collapsing have been reported and at least 40 people have lost their lives since 2012 in tree-related accidents. Concerns over climate change affecting weather conditions in Mumbai, have increased. Reports suggest that the Arabian Sea is now witnessing a higher number of cyclones that hit the coastal areas of Mumbai, wreaking havoc and claiming lives.