Innovative trend analysis of long-term rainfall variation over West Bengal, India

This study uses 115 years’ gridded rainfall data from 121 gauge stations to observe long-term changes in annual and seasonal rainfall in the entire West Bengal, India. The significance and amplitude of these changes and overall trends are assessed with the use of such gridded data for the period from 1901 to 2015 collected from the India Meteorological Department, by applying innovative trend analysis. According to the findings of the study, rainfall in the study area decreases significantly during the winter season and pre-monsoon season, while increases significantly during the monsoon season and post-monsoon season. The monsoon rainfall experiences the largest increase at 4.68 mm/year and the smallest decrease at 2.95 mm/year. The overall trends of seasonal rainfalls are found to be statistically significant at the 5% significance level except for a few districts for pre-monsoon, monsoon, and post-monsoon rainfalls. This work aims to provide scientific support to recognize and strategically mitigate the impact of climatic changes on water management in West Bengal and thereby reduce the risk of climate change.