The lucky run of a normal southwest monsoon for the last 12 years
looks set to end. P. S. SUNDERARAJAN on what the weatherman says.
THE PICNIC could finally be over. The country, which had been
enjoying a normal southwest monsoon for the last 12 years, may
have run out of luck. It is becoming clearer by the day that the
coming monsoon may be below par.
The shortfall may be over 10 per cent. On an average, the country
receives 88 cm of rain during the four-month season beginning
June. This year the forecast is that it will at most be 79 cm.
The scenario is grim considering that the southwest monsoon
accounts for as much as 80 per cent of the annual rainfall. Even
when the national average is normal, there can be deficiencies in
some areas. Last year, for instance, the rainfall during the
season was 96 per cent of its long period average (LPA) value,
which falls within the category of normal monsoon. Inspite of
this, there is a severe drought in several parts of the country.
This is because rainfall occurs in association with the movement
of what are called depressions and low-pressure systems. Last
year, though the number of depressions and low-pressure areas
were as per their normal frequency, their paths were confined to
the eastern and central parts of the country. As a result, there
was excess rain in these regions and less rain over Gujarat and
northwest India.
Moreover, rainfall was not spread out evenly over the season.
While the progression of the monsoon was close to the normal
pattern with the onset over Kerala taking place a week before the
usual date, there were only two spells of subdued rain in the
peak monsoon period of July and August - one from the end of June
till mid-July and another from the middle of August till the end
of the month. Widespread rain in September saved the day for the
country, except some areas.
In 1998, which was considered to have had one of the best
monsoons with a seasonal yield of 106 per cent of the LPA,
rainfall was deficient in 75 districts. Madhya Pradesh accounted
for the maximum of 21 deficient districts, followed by eight in
Orissa. The other 46 were in Bihar and Rajasthan (seven districts
each), Tamil Nadu (five), Himachal Pradesh and Jammu and Kashmir
(four each), Punjab, West Bengal, Assam (three each), Uttar
Pradesh, Gujarat, Maharashtra and Kerala (two each) and Mizoram
and Nagaland (one each).
Again in 1997, the country received rainfall of 102 per cent
despite apprehensions of monsoon failure because of the havoc
caused elsewhere in the world by El Nino. In 1999, three
meteorological sub- divisions - Telengana in Andhra Pradesh and
Marathwada and Vidarbha in Maharashtra - had deficient rain to
the extent of 27 per cent, 32 per cent and 22 per cent
respectively.
In 1996 also, while the overall rainfall for the country was 103
per cent, as much as 10 per cent of the geographical area of the
nation had deficient rain. The deficiency was particularly marked
in Vidarbha (minus 25 per cent), Orissa (minus 24 per cent) and
Nagaland, Manipur, Mizoram and Tripura (minus 21 per cent).
The story was the same in 1995, when the country received 100 per
cent of the LPA. Then too, rain was deficient in Saurashtra and
Kutch (minus 28 per cent), Gujarat region (minus 22 per cent) and
Marathwada (minus 20 per cent).
In 1987, the last time the country experienced a drought,
rainfall as a whole was short by 19 per cent. Over 57 per cent of
the districts had deficient rain.