Changing Spatio-Temporal Rainfall Fluctuation over North East India
This study is analysis of changes in rainfall fluctuation in North East India. Using the longest instrumental monthly rainfall data of well spread 316 stations across India available from Indian Institute of Tropical Meteorology (IITM), the fluctuation characteristics as well as the spatial-temporal variability of the seasonal, monsoon monthly and annual rainfall pattern over the north eastern region of India (NER) have been examined. On an average, NER receives about 2450 mm of rainfall with 1093.0 mm as its annual evapo transpiration. The winter (JF) rainfall contributes 2.1% to the annual rainfall; summer (MAM) rainfall 24.3%; summer monsoon (JJAS) rainfall 65.1% and the post-monsoon (OND) rainfall contributes 8.5% to the annual rainfall. The region shows great variation in surface temperature regime (15oC to 32oC in summer and 0 to 26oC in winter). The spatial-temporal rainfall variability shows random fluctuating characteristics of expansion / contraction of desert area but overall it is showing a slight decreasing over the NER as well as whole India.