Future Projection of Extreme Rainfall for Flood Management due to Climate Change in an Urban Area
Subrata Halder, Ujjwal Saha
Abstract
In urban areas, due to climate change, frequent occurrence of shorter duration rainfall extremes will increase the possibility of damaging flash floods. It is crucial to assess the impacts of climate change on rainfall extreme in the future to avoid or reduce severe damage due to urban flooding. Hence, future design rainfall intensity has to be estimated reliably accounting the uncertainties due to climate change. In this study, a quantile perturbation based downscaling model is developed to investigate the changes in rainfall extreme in Kolkata, India over two future time slices in terms of intensity-duration-frequency relationships using four general circulation models outputs with seven shared socioeconomic pathways. The model shows significant increments of relative percentage change with a maximum of 44.91% and 70.19% in two cases and some negative changes with a maximum of 39.76% in one case. The changes in rainfall intensity in future period should be considered for the design of stormwater infrastructure systems.