Articles | Volume 15, issue 3
https://doi.org/10.5194/nhess-15-527-2015
https://doi.org/10.5194/nhess-15-527-2015
Research article
 | 
11 Mar 2015
Research article |  | 11 Mar 2015

Long-term variability of storm surge frequency in the Venice Lagoon: an update thanks to 18th century sea level observations

F. Raicich

Abstract. Sea level observations made in the Venice Lagoon between 1751 and 1792 have been recovered, consisting of two time series of daily data on high and low waters in Venice and Chioggia. From comparisons with modern observations, the quality of the 18th century data appears to be good enough to allow a useful analysis. A composite time series of daily mean sea level is obtained by merging the 18th century data and 1872–2004 observations in Venice Punta della Salute. The absence of reliable information on vertical references prevents the connection of the two 18th century time series with each other and with modern observations. However, daily sea level anomalies relative to the mean sea level enable us to recognize storm surge events that appear to occur more frequently in the second half of the 18th century than in the late 19th and 20th centuries, particularly during the 1751–1769 period. The record-breaking storm surge of 4 November 1966 turns out to be a remarkable event even in comparison to the events extracted from the 18th century time series. Further work is required to fill the gap between the old and modern observations.

Download
Short summary
Daily sea level data of the Venice Lagoon observed in the 18th century allow us to obtain a composite the time series of sea level anomalies relative to the mean sea level, spanning 1751--1769 and 1872--2004. From these data the frequency of remarkable storm surges is estimated. They appear to be more frequent in the second half of the 18th century than in the late 19th and 20th centuries. The historical flood on 4 November 1966 turns out to be the most severe during the entire period.
Altmetrics
Final-revised paper
Preprint