Changes in precipitation intensity-duration-frequency curve : a comparison based on CMIP5 and CMIP6

![CDATA[In recent years, India has experienced a considerable loss of lives and properties due to an increase in extreme precipitation events as a potential consequence of global warming. In particular, the short-duration but intense precipitation events have significantly impacted the major Indian cities in the past, and the number of such events is rising. In this context, it is critical to assess the design capacity of urban drainage networks in order to effectively mitigate the potential disasters caused by heavy precipitation in the future. The Intensity-Duration-Frequency (IDF) curve is one such crucial piece of information that plays a major role in infrastructure design and reflects the climate change impact on the precipitation characteristics. In this study, we have utilized hourly observed precipitation data at four metropolitan cities in India, namely Ahmedabad, Kolkata, Mumbai, and Chennai, to analyse the change in the IDF relationships between the past and future. The changes in the future are analysed based on the simulated outputs from multiple Global Circulation Models (GCMs) of Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 6 (CMIP6). Two different scenarios for each phase have been considered in this study, i.e., RCP4.5, RCP8.5 from CMIP5, and SSP245, SSP585 from CMIP6. Apart from quantifying the changes in IDF in the future, this study further provides important insight into the comparative assessment between CMIP5 and CMIP6 with respect to the changes in the IDF. Outcomes are beneficial for future planning and designing of various hydraulic infrastructures in the context of changing climate using the updated IDF relationships.]]