Spatio-temporal variability of rainfall and temperature in Northeast India

Abstract

This paper deals with the spatial and temporal pattern in monthly rainfall and temperature (maximum and minimum) distribution over the Northeast India. Five meteorological stations have been chosen for this study. The stations considered for analysis of temperature are Dibrugarh (1952-2000), Guwahati (1951-2000), Cherrapunji (1952-2000), Imphal (1954-2000), and Darjeeling (1952-2000). The rainfall analysis has been done for all the above stations for the period 1951-2010.The Mann-Kendall trend test was carried out to assess the trend in rainfall and temperature for different seasons during study period. The analysis has shown that these stations of Northeast India have not experienced any specific trend in rainfall in winter and monsoon seasons. The pre-monsoon season has an increasing trend in rainfall while during post-monsoon season a declining trend in rainfall was observed in two stations. All the stations experienced insignificant rise in maximum temperature during the post monsoon period while rest of the seasons have not shown any persistent trend over the region. An increasing trend in minimum temperature was observed in these stations during postmonsoon season, except Imphal and Cherrapunji. Dibrugarh is the only station which observed an increasing trend in minimum temperature in all of the seasons except winter. In winter minimum temperature increased insignificantly in Guwahati and Darjeeling stations. Even though insignificant, the later indicated a warming tendency for the region.