Development of a stochastic rainfall generator to yield unprecedented rainfall events

Rasool, T and Sahoo, S and Das Bhowmik, R and Nagesh Kumar, D (2024) Development of a stochastic rainfall generator to yield unprecedented rainfall events. In: Journal of Hydrology, 641 (131809).

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Abstract

Unprecedented rainfall events are defined as rainfall events that have extremely high magnitude with low probability of occurrence. Although such events have occurred in the recent past, there might be no historical record of unprecedented rainfall. While significant efforts have been made to understand the major drivers of unprecedented events, the use of statistical modelling to estimate the likelihood of unprecedented events has gained little to no attention. The current study proposes a �serial� type stochastic rainfall generator (SRG) to simulate daily rainfall with an additional focus on unprecedented events. The study introduces resampling of model parameters to yield the non-stationarity in simulated rainfall distribution. The proposed approach is applied to simulate daily rainfall over twenty-six grid points in Southeast Texas, which experienced Hurricane Harvey in 2017. Towards this, the study obtains rainfall accumulation data during Harvey from eight weather stations during. We found that the proposed approach can successfully generate unprecedented events if two power law tail tuning parameters are adjusted with respect to future warming levels. Rainfall magnitudes correspond to 50, 100, 250 and 500-year return periods simulated by the proposed model are found to be substantially higher than historical (i.e., observed) return period. Furthermore, the study found that the estimated return periods of Hurricane Harvey like rainfall is almost the same as the return period estimated by a former study of Emmanuel (2017). The potential benefit of the proposed approach in hydrological risk assessment has also been discussed. © 2024 Elsevier B.V.

Item Type:	Journal Article
Publication:	Journal of Hydrology
Publisher:	Elsevier B.V.
Additional Information:	The copyright for this article belongs to the publisher.
Keywords:	Daily rainfall; Historical records; Hurricane harvey; Lower probabilities; Probability of occurrence; Rainfall event; Return periods; Stochastic rainfalls; Unprecedented; Weather generator
Department/Centre:	Division of Interdisciplinary Sciences > Interdisciplinary Centre for Water Research Division of Mechanical Sciences > Civil Engineering
Date Deposited:	30 Aug 2024 06:06
Last Modified:	30 Aug 2024 06:06
URI:	http://eprints.iisc.ac.in/id/eprint/85962

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