GUWAHATI, Aug 23 � Monsoon rainfall in the entire NE region of the country is not even and it can be assumed that the amount of rainfall in the region has gradually gone down in recent years. The figures available on monsoon rainfall in the region since 1982, provide such a hint. However, detailed data to provide a comprehensive picture on the exact amount of rains received by every part of the region is not available with the Regional Meteorology Centre (RMC) here.
It may be mentioned that the rainfall during the current decade over the Assam-Meghalaya meteorological subdivision is comparatively less than that received in the 1980s and 1990s. In the other two meteorological subdivisions of Arunachal Pradesh and Nagaland-Manipur-Mizoram-Tripura (NMMT), annual variation in rainfall have been observed, said the Deputy Director General, Meteorology (DDGM) of the RMC, Hargovinda Pathak.
Pathak told this newspaper that between 1982 and 1990, Arunachal subdivision received more rain compared to the Assam-Meghalaya subdivision. On the other hand, though the NMMT subdivision had received normal rainfall during the period, it had a negative aspect�i.e., it was within the category of minus 19 per cent.
It needs mention here that in meteorology, plus (excess) /minus (deficit) 19 per cent around the normal is regarded as normal in matters of rainfall.
The region recorded deficit rainfall in 1986. While Arunachal Pradesh recorded 25 per cent deficit rainfall in the year, Assam-Meghalaya recorded a deficit rainfall of 32 per cent and NMMT recorded a deficit rainfall of 25 per cent in that year.
In the 1991-2000 decade, Arunachal recorded excess rainfall in 1993 (34%), 1995 (30%), 1998 (47%) and deficit rainfall in 1992 (23%), while the subdivision recorded normal rainfall in the range of minus 19 per cent during the rest of the decade.
The Assam-Meghalaya subdivision recorded deficit rainfall in 1994 (20%). The subdivision recorded normal rainfall in the rest of the decade with minus four per cent in 1991, minus 17 per cent in 1992, minus 11 per cent in 1996, minus six per cent in 1997 and minus seven per cent in 1999. It recorded plus 13 per cent rainfall in 1993, plus 11 per cent in 1995, plus nine per cent in 1998 and plus one per cent in 2000, Pathak said.
NMMT recorded a deficit rainfall of 37 per cent in 1992, followed by another year of deficit rainfall to the tune of 34 per cent in 1994 and a deficit rainfall of 21 per cent in 1996. It recorded normal rainfall during the rest of the decade, though only in two years�1993 and 1997�the subdivision recorded normal rainfall on the positive side with plus nine per cent and plus two per cent respectively. During the rest of the decade, the subdivision recorded normal rainfall in the minus 19 per cent category.
In the current decade, Arunachal Pradesh recorded deficit rainfall in 2001 (28%), 2002 (22%), 2009 (32%) and this year (till the 20th of the current month) (31%). During the rest of the period, the subdivision recorded normal rainfall, though only in 2008, it could record such normalcy on the positive side with plus 3 per cent rainfall.
Assam-Meghalaya subdivision recorded deficit rainfall in 2001 (23%), 2002 (21%), 2005 (23%), 2006 (37%), 2009 (30%) and this year (till the 20 th of the current month) (29%). Though it recorded normal rainfall during the rest of the decade, it recorded such rainfall on the positive side (plus 4%) only in 2003.
NMMT recorded deficit rainfall in 2005 (22%), 2003 (21%), 2009 (34%) and this year (till the 20th of the current month) (26%).
The State-wise break up of the rainfall received by the NE region during the current monsoon is � Arunachal Pradesh (-) 31 per cent, Assam (-) 10 per cent, Manipur (-) 52 per cent, Meghalaya (-) 54 per cent, Mizoram (-) 11 per cent, Nagaland (-) 24 per cent and Tripura (-) 20 per cent, Pathak said.
However, he maintained that such deficiency in rains should not be a cause of worry. Proper irrigation facilities will help overcome such situations of less rainfall observed only in some pockets.
