Cloudbursts in the western Himalayan region are now routine rather than an exception.
There have been around a half a dozen cloud-bursts between June 15 and June 25 in the flash flood hit states of Himachal Pradesh and Uttarakhand, shows the data of the Indian Meteorological Department (IMD).The June 16 cloud burst follow by flash-flood in Uttarakhand had resulted in deaths of hundreds, whereas another cloud burst in Himachal had caused huge loss to property in Kinnar district. After that two more cloud bursts each had hit the two states, the latest being on Wednesday in Mandi district of Himachal leaving three persons dead.
The June cloud bursts were much more than anything like that in the preceding years. Three major cloud bursts were reported from Uttarakhand in 2012 and two from Himachal that year. “The average cloudbursts in a year in last decade in these two states have been three as compared to 2.8 in 1990-200 period,” said a senior weather department official.
Even though frequency of cloud bursts has been increasing, many say because of climate change, India does not have a system to predict cloudburst resulting in flash-floods like the one for cyclones.
It is not that cloud-bursts cannot be predicted but for that one needs ground data and its proper analysis. “Installation of Doppler radars has improved cyclone warning system in coastal India. The same can be installed in the Himalayan region to predict cloud bursts,” said Chandan Ghosh, head of department of geo-hazard risk management at Indian Institute of Disaster Management (IIDM).
That many not suffice as there are many other factors that contribute to gush of water down in the hill after heavy rains.
One of them is the glacial lakes which became of faster melting of glaciers are getting excess water in the summer months. Himachal and Uttarakhand have over 250 glacial lakes which are not monitored on regular basis.
In 2004, a major disaster was averted when satellite monitoring of Parchu (glacial) lake on India-China border in Himachal showed it was over-flowing. “The ISRO (Indian Space Research Organisation) can monitor other glacial lakes also,” an official said.
Another key data required to gauge impact of flash floods in lower regions would geological and hydrological nature of upper Himalayan reaches. “The Central Water Commission can use 3D data modeling to predict floods in the hilly areas,” Ghosh said.
A study by the Indian Institute of Technology Roorkee on cloudbursts in Uttarakhand in 2012 said prediction of cloudbursts is challenging, and requires high-resolution numerical models and mesoscale observations, high-performance computers and Doppler weather radars.
The Department of Science and Technology has now proposed to install Doppler radars in the higher reaches of the Himalayas.