Combination of systematic skew surges and historical water levels for the estimation of extreme water levels
Abstract
Coastal planning needs to consider the risk of marine submersion. The estimation of extreme coastal water levels is crucial for the design of coastal facilities. The estimation of extreme water level at high tide is usually based on the estimation of the statistical distribution of skew surge since its other component, the astronomical high tide, can be predicted. The estimation of extreme skew surges can be improved using historical information - i.e. major water levels observed before the beginning of the tide gauge recordings, the corresponding skew surges of these historical water levels can be deduced. Some extreme historical skew surges can easily be missed if, coinciding with low or moderate high tides, they do not generate extreme water levels. The exhaustiveness of historical extreme skew surges cannot be guaranteed yet, the exhaustiveness of historical information is an essential criterion for an unbiased statistical inference. This study proposes, in a single Bayesian inference procedure, the combination of information of two different nature: recorded skew surge for the recent period and observed major water levels for the historical period. The proposed model appears to be more reliable and accurate than previously published approaches integrating historical skew surges. The robustness of the proposed model is discussed. The proposed model is applied to various locations on the Atlantic, Channel and North coasts.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.A32D..06S