GUWAHATI, June 20 � �For 33 years, since 1981, there was no abnormality recorded in the area of pre-monsoon rainfall in the NE part of India. Thunderstorm activities primarily determine rainfall activities in this region and the rainfall of this season is convective in nature. However, under the influence of the factors that lead to year-to-year variations, there are variations in rainfall activities in the region during the season�, said Sunit Das, Meteorologist of the Borjhar-based Regional Meteorology Centre (RMC) here.
The region is divided into three meteorological subdivisions � Arunachal Pradesh, Assam and Meghalaya and Nagaland-Manipur-Mizoram-Tripura. Talking to this correspondent, Das maintained that during the decade 1981-1990, Arunachal Pradesh recorded excess pre-monsoon season rainfall in five years. However, the subdivision recorded normal rainfall for three years and deficit rainfall for two years.
Assam and Meghalaya subdivision recorded excess rainfall in two years, normal rainfall in seven years and deficit rainfall in one year during the 1981-1990 decade. During the same decade, NMMT subdivision recorded excess rainfall in five years. It received normal rainfall for the same number of years during the decade.
During the 1991-2000 decade, Arunachal Pradesh received excess rainfall for four years and normal rainfall for five years and deficit rainfall for one year. On the other hand, Assam and Meghalaya subdivision received excess rainfall in three years, normal rainfall in five years and deficit rainfall in two years. NMMT subdivision recorded excess rainfall in four years and normal rainfall in six years during the decade.
During the 2001-2010 decade, Arunachal Pradesh recorded normal rainfall in six years and deficit rainfall in four years. Assam and Meghalaya recorded excess rainfall in two years, normal rainfall in five years and deficit rainfall in three years. NMMT subdivision recorded excess rainfall in four years, normal rainfall in equal number of years and deficit rainfall in two years during the decade.
During the current decade, Arunachal Pradesh and Assam and Meghalaya subdivisions recorded deficit rainfall in 2011 and 2012. But the subdivisions experienced normal rainfall in 2013. NMMT recorded normal rainfall activities in 2011 and 2013 and in 2012, it recorded deficit rainfall, said Das.
