Future trends in short-duration rainfall: A statistical analysis using bias-corrected GCM ensembles

High-intensity, short-duration rainfall can cause significant losses. These events are influenced by intricate and interrelated hydro-climatic interactions that are being modified due to climate change. These alternations in rainfall need to be accounted for in future development and design of hydrological systems. Climate model projections have been the primary tools for providing crucial information about the future climate. However, the accuracy of future predictions for shorter-duration rainfall has higher uncertainties and may not be used directly in infrastructure planning and design. Nevertheless, the climate projections' trend, direction, and magnitude might be extrapolated to the future in order to evaluate the alterations in shorter-duration rainfall. This study uses this concept to understand the changes in the direction and magnitude of shorter-duration rainfall using statistical distribution and fitting the Intensity-Duration-Frequency (IDF) relationship under climate change scenarios. Five best-suited bias-corrected Global Climate Model (GCM) ensemble model outputs are analysed to understand the changes in the nature of shorter duration rainfall with the baseline of (1951-2005) as a reference for the comparison to mid-century (2021-2050) and distant future (2051- 2080) under RCP4.5 and RCP8.5 scenarios. The analysis shows a significant unidirectional change in the shorter-duration rainfall intensities as compared to the baseline.