Intensification of sub-daily rainfall extremes in a low-rise urban area

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Ressource 1Download: Huang 2022.pdf (2187.88 [Ko])
State: Public
Version: Final published version
License: CC BY 4.0
Serval ID
serval:BIB_94B450FC1E1F
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Intensification of sub-daily rainfall extremes in a low-rise urban area
Journal
Urban Climate
Author(s)
Huang Jamie, Fatichi Simone, Mascaro Giuseppe, Manoli Gabriele, Peleg Nadav
ISSN
2212-0955
Publication state
Published
Issued date
03/2022
Peer-reviewed
Oui
Volume
42
Pages
101124
Language
english
Abstract
Short-duration extreme rainfall events are the main trigger of flash and pluvial floods in cities. Depending on the local climate zone and urban fabric that affect meteorological variables such as air temperature, humidity, and aerosol concentration, the built environment can either intensify or reduce extreme rainfall intensity. This study examined how urbanization in a large metropolitan area characterized by open low-rise buildings, affected sub-daily extreme rainfall intensities over the period between 2000 and 2018. The research was conducted in the metropolitan region of Phoenix, Arizona, which is supported by a large and dense rain-gauge network (168 stations). The built area increased by 6% between 2001 and 2016 and the number of residences by 300,000. Over the study period, sub-daily extreme rainfall intensities intensified both in the urbanized area and in its rural surroundings but the intensification trend within the built area was considerably larger (3 times larger). We calculated a negative trend in aerosol concentration (−0.005 AOD y−1) but a positive trend in near-surface air temperature that was considerably larger in the urban areas (0.15 °C y−1) as compared to the rural counterpart (0.09 °C y−1) for the period between 2005 and 2018. Although built surfaces and open low-rise buildings contributed to an increase in air temperature, they did not affect air humidity. Changes in rainfall extremes approximately follow the Clausius–Clapeyron relation within the urban area with an increase at a rate of 7% °C−1. These results demonstrate that the warming effect associated with a low-rise urban area can cause an intensification of sub-daily rainfall extremes that is significantly larger than in nearby rural areas.
Keywords
Urban rainfall intensification, Clausius–Clapeyron, Rainfall-temperature relation, Urban heat island, Dense rainfall network, Extreme rainfall intensity
Open Access
Yes
Funding(s)
Swiss National Science Foundation
Create date
14/02/2022 11:11
Last modification date
21/11/2022 8:18
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