Lookup NU author(s): Angelo Forestieri,
Dr Stephen Blenkinsop,
Professor Hayley Fowler
This is the authors' accepted manuscript of an article that has been published in its final definitive form by John Wiley & Sons Ltd., 2018.
For re-use rights please refer to the publisher's terms and conditions.
Increasing precipitation extremes are one of the possible consequences of a warmer climate. These may exceed the capacity of urban drainage systems and thus impact the urban environment. Since short-duration precipitation events are primarily responsible for flooding in urban systems it is important to assess the response of extreme precipitation at hourly (or sub-hourly) scales to a warming climate. This study aims to evaluate the projected changes in extreme rainfall events across the region of Sicily (Italy) and, for two urban areas, to assess possible changes in Depth-Duration-Frequency (DDF) curves. We used Regional Climate Model (RCM) outputs from EURO-CORDEX ensemble simulations at a ~12 km spatial resolution, for the current period and two future horizons under the Representative Concentration Pathways (RCPs) 8.5 scenario. Extreme events at the daily scale were first investigated by comparing the quantiles estimated from raingauge observations and RCM outputs. Secondly, we implemented a temporal downscaling approach to estimate rainfall for sub-daily durations from the modelled daily precipitation and, lastly, we analyzed future projections at daily and sub-daily scales. A frequency distribution was fitted to annual maxima time series for the sub-daily durations to derive the DDF curves for two future time horizons and the two urban areas. The overall results showed a raising of the growth curves for the future horizons, indicating an increase in the intensity of extreme precipitation, especially for the shortest durations. The DDF curves highlight a general increase of extreme quantiles for the two urban areas, thus underlining the risk of failure of the existing urban drainage systems under more severe events.
Author(s): Forestieri A, Arnone E, Blenkinsop S, Candela A, Fowler H, Noto LV
Publication type: Article
Publication status: Published
Journal: Hydrological Processes
Print publication date: 30/01/2018
Online publication date: 17/12/2017
Acceptance date: 06/12/2017
ISSN (print): 0885-6087
ISSN (electronic): 1099-1085
Publisher: John Wiley & Sons Ltd.
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