`Set up rain gauges in areas prone to flooding'

`Set up rain gauges in areas prone to flooding'

The Hindu

IMD Director stresses need to design system to deal with rain-related problems in interior areas

# Rain havoc on May 28, 2005 A woman and a man were killed
# Heavy water logging was reported from 35 areas in southern and eastern parts of the city
# The Fire and Emergency Services had to press in 20 vehicles to clear uprooted trees and pump out water in flooded areas
# 434 electric poles were uprooted. BESCOM suffered a loss of Rs. 4.8 crore
# A number of trees were uprooted, damaging a BMTC bus, a car and three other vehicles



Bangalore: The Bangalore Mahanagara Palike, Indian Meteorological Department (IMD), Bangalore Development Authority and the Drought Monitoring Cell should chart out a methodology to identify areas and set up more rain gauges in places which are vulnerable to flooding, according to IMD Director A.L. Koppar.

Though steps to deal with cyclones have been chalked out for coastal areas, there is a need to chalk out a system to deal with rain-related problems in interior areas, Dr. Koppar told The Hindu . Besides just a forecast, there was also a need to monitor rainfall as and when it happened. Hence it was essential to install more rain gauges in strategic places where continuous data is sent to the control rooms, so that the rainfall could be measured cumulative to the time so as to forecast a flood, he said.

The extreme weather events come as a coincidence and happen when there is a precipitated and intense rainfall within a short span of time. Precipitation, intensity and the duration of time are the key elements that decide if the rain could cause flooding.

Sometimes even 8 cm to 10 cm of rainfall in a short span of time could cause flooding, and if it occurred in a matter of one or two days, the water seeps into the soil. Even a 30 mm rainfall in a matter of 30 minutes could cause flooding, especially in the low-lying areas, he said.

Frequent thunder showers accompanied by squall and hail being the characteristic of the month of May, the local municipal bodies should take measures to avoid uprooting of trees which is a usual occurrence this season, he added.

The BMP, he said, should ascertain that hoardings and the banners were strengthened so that they did not collapse. Frequent thunderstorms usually occur during afternoons and evenings this month and sometimes might come with hail or squall. May is also likely to witness copious rainfall accompanied by squally weather.

The highest rainfall recorded on a single day has been 10 cm during the month of May in 2002. The closest in record to this was 9 cm recorded in 1991 on a single day.

Clarifying that the high temperature this summer would not have any impact on the monsoon, sources said that this year the highest temperature was recorded at 37 degrees Celsius on May 2 while the highest ever has been in 1931 when the temperature touched 38.9 degrees Celsius. "The temperature last year same time was a little more than this year, 37.4 degrees Celsius," Dr. Koppar said.

Forecast

Stating that the forecast of the monsoon was possible only after May 20 which was the normal date of onset of Monsoon, IMD sources said that May 2005 witnessed a good amount of rainfall of 150.1 mm. May 2004 received the heaviest rainfall of 207.9 mm next to May 1957 which recorded a rainfall of 287.0 mm.

Earlier, 1999 witnessed 200.6 mm rainfall and the lowest rainfall recorded has been 1.3 mm in 2003. The heaviest rainfall in 24 hours has been 153.9 on May 6 1909.

The IMD is taking steps to provide early warning to the authorities concerned. The cyclone warning service is also a regular exercise offered during May and October.