Bivek Chakma, D Jhajharia, G S Yurembam, Ghanshyam T. Patle
College of Agricultural Engineering & Post Harvest Technology (C. A. U. Imphal)
The rainfall received in an area is one of the determining factors for the socio- economic activities, including agriculture, forestry and bio-diversity, water resources management, industry and tourism of the region. It is a well-known fact that climate change may lead to changes in runoff and water availability due to alterations in rainfall patterns, and changes in rainfall patterns may cause heavy floods in some areas, while other areas may experience frequent droughts. The standardized precipitation index (SPI) based on rainfall is used in this study to identify the wetness episodes over three raingauge stations, namely, Agartala, Belonia and Dharmanagar situated in the districts of West Tripura, South Tripura and North Tripura, respectively. Also, wetness episodes characterized by three attributes: wetness-severity and duration; and interval-arrival of wet episodes were estimated through the SPI 1-month by using monthly rainfall data from 1971 to 2022. At Agartala (Belonia) station, the wetness episode’s highest severity and duration were found to be 9.76 occurring from September 2000 to March 2001 for 7-months (14.17 occurring from September 2000 to March 2001 for 7 months) and the highest inter-arrival time for wet events were found to be 19 months from April 2005 to October 2006 (52-months starting from October 2009 to February 2014). Similarly, the results of the SPI 1-month at Dharmanagar revealed that the wetness episode’s highest severity and duration (the highest inter-arrival time for wet events) were found to be 13.23 occurring from May 1996 to December 1996 for 8-months (50-months starting from December 2009 to February 2014). The findings presented in this study can provide data support to help the water managers in the wetness management in the state of Tripura, northeast India.