Rapid response of tidal channel networks to sea-level variations (Venice Lagoon, Italy)

The aim of the present paper is to examine the effects of long- and short-term sea-level fluctuations (i.e. relative sea-level rise and tides) on the geomorphologic evolution of modern tidal channels through the joint interpretation of channel modifications, the 1938–2010 yearly time series of relative sea-level rise, and the variations of strength and frequency of high tides which occurred in the same period. lyzed a salt marsh area not particularly modified by human interventions, located in the northern Venice Lagoon, Italy. ailability of a long historical record of high-resolution aerial photographs provided us the opportunity to reconstruct in detail the evolution of the drainage patterns from 1938 to the present. s from our analyses gave us information about the degree of control of long- and short-term sea-level fluctuations on planimetric development of tidal channels and provided demonstration of the rapid response of the drainage network to these oscillations. nd that both relative sea-level rise and high tide frequency greatly influenced salt marsh margin shift and meander evolution of tidal channels in the long term, but short-term sinuosity changes of creeks were often also closely related to tide variations. Channels nearer the marsh margin were more exposed to the action of the increasing tides.