Earth Science Malaysia (ESMY)

This study investigated the patterns of extreme daily rainfall indices over eight meteorological stations in Bangladesh from 1961 to 2020, utilizing monthly and seasonal data sets. The climate change-related indicators comprised frequency-based indices: R10mm, R20mm, CDD, CWD and Intensity-based indices: RX1day, RX5day, R95p, R99p, PRCPTOT, SDII. The amplitude of trends in extreme rainfall indices time series was estimated using the nonparametric Sen’s slope estimator method, and the statistical significance of the trends was assessed using the Mann–Kendall test. The result shows that rainfall in pre-monsoon has an increasing trend except for Dhaka station, with an increasing trend for monsoon Chittagong, Barisal, Maymensingh, and Rangpur, oppositely decreasing trend in the dry season for Dhaka, Barisal, Rangpur and Sylhet with the none-significant trend for any season. Frequency Indices had a significant increasing trend in Mymensingh, Rajshahi, and Rangpur stations, where Intensity Indices are followed by Rangpur station. Seasonal RX1 day and RX5 days there were no significant increases or decreases with time. Overall, rainfall trend analysis is critical in a variety of sectors, including water resource management, agriculture, climate change research, disaster risk reduction, and ecosystem management. It contributes to sustainable development and environmental preservation by providing essential information for planning and decision-making.