Context: Why cloudburst forecast in India still remains elusive
Forecasting of cloudbursts:
- While satellites are extensively useful in detecting large-scale monsoon weather systems, the resolution of the precipitation radars of these satellites can be much smaller than the area of individual cloudburst events, and hence they go undetected.
- The IMD’s forecasts, and in general, the weather prediction scenario, have advanced such that widespread extreme rains can be predicted two-three days in advance.
- Cyclones can be predicted about one week in advance. However, cloudburst forecasts still remain elusive.
- Multiple doppler weather radars can be used to monitor moving cloud droplets and help to provide nowcasts (forecasts for the next three hours).
- This can be a quick measure for providing warnings, but radars are an expensive affair, and installing them across the country may not be practically feasible.
- A long-term measure would be mapping the cloudburst-prone regions using automatic rain gauges. If cloudburst-prone regions are co-located with landslide-prone regions, these locations can be designated as hazardous.
- The risk at these locations would be huge, and people should be moved, and construction and mining in nearby regions should be restricted as that can aggravate the landslides and flash flood impacts.
- Climate change is projected to increase the frequency and intensity of cloudbursts As the air gets warmer, it can hold more moisture and for a longer time. We call this the Clausius Clapeyron relationship.
- A 1-degree Celsius rise in temperature may correspond to a 7-10% increase in moisture and rainfall.
- This increase in rainfall amount does not get spread moderately throughout the season. As the moisture holding capacity of air increases, it results in prolonged dry periods intermittent with short spells of extreme rains. More deeper cumulonimbus clouds form and the chances of cloudbursts also increase.
Must Read: Cloudbursts
Source: The Hindu