TY - JOUR
T1 - Global compound floods from precipitation and storm surge
T2 - Hazards and the roles of cyclones
AU - Lai, Yangchen
AU - Li, Jianfeng
AU - Gu, Xihui
AU - Liu, Cancan
AU - Chen, Yongqin David
N1 - The work described in this paper was supported by grants from the Research Grants Council of the Hong Kong Special Administrative Region, China (HKBU12303517 and HKBU12302518), the National Key R&D Program of China (Project No. 2019YFC1510400), Guangdong-Hong Kong Joint Laboratory for Water Security (2020B1212030005), and the National Natural Science Foundation of China (U1911205 and 41901041).
PY - 2021/10/1
Y1 - 2021/10/1
N2 - During simultaneous or successive occurrences of precipitation and storm surges, the interplay of the two types of extremes can exacerbate the impact to a greater extent than either of them in isolation. The compound flood hazards from precipitation and storm surges vary across regions of the world because of the various weather conditions. By analyzing in-situ observations of precipitation and storm surges across the globe, we found that the return periods of compound floods with marginal values exceeding the 98.5th percentile (i.e., equivalent to a joint return period of 12 years if the marginal variables are independent) are < 2 years in most areas, while those in northern Europe are > 8 years due to weaker dependence. Our quantitative assessment shows that cyclones (i.e., tropical cyclones (TCs) and extratropical cyclones (ETCs)) are the major triggers of compound floods. More than 80% of compound floods in East Asia and > 50% of those in the Gulf of Mexico and northern Australia are associated with TCs, while in northern Europe and the higher latitude coast of North America, ETCs contribute to the majority of compound floods (i.e., 80%). Weather patterns characterized by deep low pressure, cyclonic wind, and abundant precipitable water content are conducive to the occurrence of compound floods. Extreme precipitation and extreme storm surges over Europe tend to occur in different months, which explains the relatively lower probability of compound floods in Europe. The comprehensive hazard assessment of global compound floods in this study serves as an important reference for flood risk management in coastal regions across the globe.
AB - During simultaneous or successive occurrences of precipitation and storm surges, the interplay of the two types of extremes can exacerbate the impact to a greater extent than either of them in isolation. The compound flood hazards from precipitation and storm surges vary across regions of the world because of the various weather conditions. By analyzing in-situ observations of precipitation and storm surges across the globe, we found that the return periods of compound floods with marginal values exceeding the 98.5th percentile (i.e., equivalent to a joint return period of 12 years if the marginal variables are independent) are < 2 years in most areas, while those in northern Europe are > 8 years due to weaker dependence. Our quantitative assessment shows that cyclones (i.e., tropical cyclones (TCs) and extratropical cyclones (ETCs)) are the major triggers of compound floods. More than 80% of compound floods in East Asia and > 50% of those in the Gulf of Mexico and northern Australia are associated with TCs, while in northern Europe and the higher latitude coast of North America, ETCs contribute to the majority of compound floods (i.e., 80%). Weather patterns characterized by deep low pressure, cyclonic wind, and abundant precipitable water content are conducive to the occurrence of compound floods. Extreme precipitation and extreme storm surges over Europe tend to occur in different months, which explains the relatively lower probability of compound floods in Europe. The comprehensive hazard assessment of global compound floods in this study serves as an important reference for flood risk management in coastal regions across the globe.
U2 - 10.1175/jcli-d-21-0050.1
DO - 10.1175/jcli-d-21-0050.1
M3 - Journal article
SN - 0894-8755
VL - 34
SP - 8319
EP - 8339
JO - Journal of Climate
JF - Journal of Climate
IS - 20
ER -