Flood threat anomaly for the low coastal areas of the English Channel based on analysis of recent characteristic flood occurrences |
| |
| Authors: | Paolo Antonio Pirazzoli Stéphane Costa Uwe Dornbusch |
| |
| Institution: | (1) Laboratoire de Géographie Physique, CNRS, Meudon, France;(2) Géophen, Université de Caen Basse-Normandie, Caen Cedex, France;(3) University of Sussex, Falmer, Brighton, BN1 9QJ, UK |
| |
| Abstract: | In the English Channel, extreme surge heights did not occur at the time of extreme high tides during the last decades and
maximum recorded heights usually do not exceed the maximum astronomical tide by more than a few decimetres. To understand
whether this lack of coincidence may be due to specific phenomena or only to chance, we have studied hourly tide records lasting
a few decades from nine English and nine French stations as well as air pressure and wind data from nearby meteorological
observatories. Among the case studies of moderate flooding at several coastal stations occurring during spring tide, we have
selected those of 24–25/10/1980 and of 30/01/1983 to 02/02/1983 as representative of a normal situation without any special
chance. The third case study 26–28/02/1990 was potentially more dangerous because of the storm intensity and duration; however,
by chance, surge peaks occurred near the low tide. Finally, the propagation of the surge peak of 15–16/10/1987, which reached
the maximum height recorded during all the instrumental period at several stations, has been followed all along the English
Channel, using the hourly records of 12 tide-gauge stations and of 16 meteorological stations. The surge peak of this great
storm, probably the strongest in the last two centuries, occurred everywhere at high tide and spread with the same velocity
of the tidal wave. Fortunately, no major flooding occurred because it was the day after a neap tide. In conclusion, some good
fortune has saved the low coastal areas of the English Channel from major floods during the last decades. However, the occurrence
of the peak of a strong storm surge arriving near the western entrance of the Channel at the time of a great astronomical
high tide is a possible event that could be devastating along both sides of the Channel coasts.
Main parts of this paper have been presented orally in June 2005 at the joint INQUA–IGCP 495 Meeting “Dunkerque 2005” and
in February 2006 at the ASLO-TOS-AGU “Ocean Sciences Meeting” (Honolulu, HI). |
| |
| Keywords: | Sea level Storm surge Tide Coastal flooding English Channel |
| 本文献已被 SpringerLink 等数据库收录！ |
|
