NEW DELHI: Hydrological cycle pan India is changing with respect to climate change. When it comes to the national capital which belongs to the Yamuna basin, the impact of climate change on the hydrological
cycle may result in higher intensity of rainfall.
“For Delhi, the worst thing can happen on account of climate change is that a very small glacier at the source of the Yamuna, when it starts depleting, may hinder the water inflow,” said Professor Emeritus of IIT Delhi, A K Gosain.
Recently, the IIT Delhi had conducted a seminar on water security and sustainable development related to climate change. Professor Gosain, who was the moderator, said there were areas that were witnessing floods in urban landscapes because of high-intensity rainfall.
“The drainage system is not efficient to drain the whole area and it gets flooded,” said Gosain. “More water is certainly coming but it has its repercussions. When more water comes and intensity is higher, then the chances of that water getting absorbed by soil and turning into groundwater don’t happen. Most of the
water just flows over the surface and goes into the rivers,” he added.
This year, the national capital yielded 1,169.7mm of rainfall, the third-highest, as per the India Meteorological Department (IMD). It was one of the most delayed and erratic monsoons of the city. The September rainfall this year has been in marked contrast to the last year when the city got a meagre 20.9 mm precipitation in the month against a normal of 129.8 mm.
“Delhi received water in a day which it had not received in the last 50 years. When you talk of intensity, rainfall can be very high for 15 minutes,” Professor Gosain explained. He added, “If it rains for an hour, the intensity over this longer period will be lower than the intensity of 15 minutes