Flooding threshold rainfall events in Bermuda

Abstract

Recent localized flooding events in Bermuda motivate an examination of the daily rainfall record, 13 to determine trends and variability of rainfall accumulations. A conservative catalogue of flood 14 reports is constructed from anecdotal reports of flooding for the last decade. The flood catalogue 15 events are related to daily rainfall amounts to develop a threshold daily rainfall for flood events, 16 determined to be on average 39.3mm of rain. This threshold was used as a basis for examination 17 of the historical record of daily rainfall 1949-2016, in order to assess return frequencies of flood 18 inducing rainfall events. A return period of approximately 2 months for the average daily rainfall 19 amount flood threshold was calculated. A trend in the daily rainfall accumulations indicate an 20 increasing trend in rainfall amounts and counts of days on rain was recorded ('rain days') since 21 1949.