Relative land subsidence in the lagoon
of Venice, Italy, at the beginning of the new millennium
L. Carbognin, L. Tosi
Istituto per lo Studio della Dinamica delle Grandi Masse, CNR, Venezia,
Italy
P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
ABSTRACT
Venetian land subsidence, both natural and due to groundwater withdrawal, and
eustasy have caused 23 cm of ground elevation reduction referred to the mean
sea level over the last 100 years. This relative elevation loss has been vital
for Venice's existence, in as much as Venice lives in the water. After a short
overview of the phenomenon during the past decades, the actual trend is analysed
by combining high precision levelling, remote sensing measurements and tide gauge
records. Geodetic and SAR data evidence the present ground stability of the
central part of the lagoon, where the city of Venice is located, and slight
sinking trends at the northern and southern extremities of the lagoon edges and
at some places in the central and northern littorals. At the same time the
latest tide gauge records indicate a renewal in the sea level rising trend.
