Analysis of Rainfall Intensity Trends and Flood Risk in Bangladesh

This study analyzes long-term rainfall patterns, intensity trends, and associated flood risk in Bangladesh using historical monthly rainfall data from 1901 to 2015. A comprehensive statistical and graphical approach is applied, including time series analysis, annual and monthly aggregation, trend analysis, variability assessment, and extreme rainfall identification. The results show a strong seasonal pattern, with pronounced rainfall peaks during the monsoon months (June–September). While the long-term average rainfall trend remains relatively stable, extreme rainfall events and annual maximum rainfall show increasing tendencies, indicating a growing flood risk. Rainfall anomaly and variability analysis further reveal irregular fluctuations, suggesting the influence of climate variability. Overall, the findings highlight that flood risk in Bangladesh is more strongly driven by extreme rainfall events and increasing variability rather than changes in average rainfall. This study provides important insights for hydrological planning, flood risk management, and climate-resilient infrastructure development.