Mumbai: Rinking alarm bells for Indian cities, scientists have warned that a short burst of intense rainfall is likely to increase with global warming.
The Paris International Agreement to reduce greenhouse emissions that causes global warming aims to maintain a global temperature increase to below 2 degrees.
The study also found that extreme increase three hours almost doubled from daily rainfall for the same heating scenario.
For each degree of heating, a person can generally expect 6% to 7% daily rainfall increases, said Vimal Mishra, a scientist with Iit-Gandhinagar who jointly write studies.
That’s because atmospheric capacity to hold water increases when the temperature increases.
But short duration precipitation seems more sensitive to warming up.
“In most places, we find that extreme sub-day precipitation increases faster than extreme daily – so it is more sensitive to warming,” Mishra said.
Interestingly, another study last year found that extreme daily rain removal did not increase beyond a certain level with increasing temperature – but extreme three hours do it.
One reason for that, the word Iit-Bombay Professor of the Subimal Ghosh, could not have enough moisture in the air most of the time to maintain the level of rainfall throughout the day.
“If the rainfall goes down at 100mm per hour, there is enough supply of moisture in the atmosphere for three hours of it, but not 24 hours,” said Ghosh, his studies also found that high-intensity rainfall events Increased with heating, which led To “Extreme Streamflow” in smaller catches such as urban areas.
This trend is very important, he said, because the explosion of rain which suddenly is more likely to lead to flash floods that leave a little time for evacuation or warnings.
This trend is also risky for cities because storm waterways that are outdated and concretize prevents drainage, which causes flooding types seen on Sunday.
Mumbai currently expand the capacity of storm water from 25 mm rainfall one hour to 50mm per hour, but what is needed now is a system that can handle rainfall of more than 100 mm in one hour, said Kapil Gupta, an urban drainage expert in IIT Bombay.
Gupta, which suggested the National Disaster Management Authority on new urban flood guidelines, recommended increased capacity for climate change scenarios, keeping rivers and sewers, and building underground storage tanks to absorb extra water.
“We need to improve our system to explain extreme increases,” he said.