Recent short-term evolution of a Venice Lagoon salt marsh (Italy)

The recent geomorphological evolution of a Venice lagoon salt marsh was identified through the analysis of high resolution aerial photographs taken from 1938 to 2007, and compared with the yearly time series of relative sea level rise (RSLR) measured in Venice in the same period. The investigations pointed out a significant retreat of the southern salt marsh margin and modifications of the marsh drainage network. In the last century, relative sea level variations, decrease of sediment input, and hydrodynamic processes were responsible for erosion in large portions of the Venice lagoon tidal flats. In contrast with this general trend, the studied salt marsh was able to offset RSLR. Although this behavior reflected the system's local response to many factors, relations between geomorphological modifications and sea level changes appeared clearly evident.