Urbanization Further Intensifies Short‐Duration Rainfall Extremes in a Warmer Climate.
In: Geophysical Research Letters, Jg. 51 (2024-03-16), Heft 5, S. 1-11
Online
academicJournal
Zugriff:
Intensification of short‐duration rainfall extremes contributes to increased urban flood risk. Yet, it remains unclear how upper‐tail rainfall statistics could change with regional warming. Here, we characterize the non‐stationarity of rainfall extremes over durations of 1–24 hr for the rapidly developing coastal megalopolis of the Greater Bay Area, China. Using high‐resolution, multi‐source, merged and gridded data we observe greater increases in rainfall intensities over the north‐central part of the region compared with the southern coastal region. Our results show, for the first time, that urbanization nonlinearly increases rainfall intensities at different durations and return periods. Over short durations (≤3‐hr) and short return periods (2‐yr), urban areas have the greatest scaling rates (≥19.9%/°C). However, over longer durations (≥9‐hr) rural areas have greater scaling rates, with a lower degree of dependency on both durations and return periods. Plain Language Summary: Short‐duration (sub‐daily) rainfall extremes are major drivers of flash floods and hence significant disruptions to society. Previous modeling and statistical studies show that urbanization intensifies short‐duration rainfall extremes. However, there has been less attention to regional variations in rates of rainfall intensification under a warming climate, particularly for extreme events with return periods that are comparable to or longer than the years of record. In this study, we investigate changes in rainfall extremes over the Greater Bay Area, China using long records of high‐resolution data merged from gauge networks, satellite observations, and reanalysis products. This enables us to evaluate changes in low‐frequency rainfall extremes (2‐ to 100‐yr return periods) over different land surfaces, under a warming climate. We find that increases in rainfall extremes significantly depend on the duration and return period of events, with the largest scaling occurring for short‐duration "nuisance" rainfall intensities over urban areas. Key Points: Non‐stationarities of sub‐daily rainfall extremes over a coastal megalopolis exhibit marked land cover and duration dependenciesUrban areas show more prominent intensification of events over short durations and short return periods compared with rural areasRural areas show smaller nonstationary variabilities across durations and return periods and a lower peak scaling rate than urban areas [ABSTRACT FROM AUTHOR]
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Urbanization Further Intensifies Short‐Duration Rainfall Extremes in a Warmer Climate.
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Autor/in / Beteiligte Person: | Yan, Haochen ; Gao, Yao ; Wilby, Robert ; Yu, Dapeng ; Wright, Nigel ; Yin, Jie ; Chen, Xunlai ; Chen, Ji ; Guan, Mingfu |
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Zeitschrift: | Geophysical Research Letters, Jg. 51 (2024-03-16), Heft 5, S. 1-11 |
Veröffentlichung: | 2024 |
Medientyp: | academicJournal |
ISSN: | 0094-8276 (print) |
DOI: | 10.1029/2024GL108565 |
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