Monitoring of the evolution of “barene” borders and the safeguard of the Venice Lagoon morphology: a contribution from the Coastal Change From Space Project results

Abstract

Optical satellite imagery is widely used to monitor various earth phenomena and to understand their evolution. Thanks to the Copernicus program and the Landsat missions we can access a huge amount of data over a wide time and area span and with high revisit frequency. This research proposes the acquisition of a time series from optical satellites to observe changes in the Venice lagoon, an ecosystem which is very challenging to monitor by means of in situ survey activities, let alone using remote sensing techniques, given the presence of land and sandbars (vegetated intertidal areas), very difficult to discern. Following the successful delivery of the Coastal Erosion from Space project [1] an extension has been commissioned by the European Space Agency, which brought in ISPRA as a new partner and user community representative and included additional sites in Italy, among which, the Venice Lagoon. We will present the manner in which co-registration improves image spatial accuracy and allows us to obtain a long time-period, high revisit rate and highly accurate waterline/shoreline time series. The work that will be presented describes the specific validation process performed by ISPRA on the results obtained by this method as applied on some target sites of the Venice Lagoon, both natural and partially artificial islands, using fully artificial islands as reference. The evolution of the natural structures of the Lagoon is normally slow, but some anthropogenic actions may force rapid change in such dynamics; examples of this are the navigation channels and the vessels-induced waves. An important role in safeguarding the morphology of the Venice Lagoon, with respect to both anthropogenic drivers and sea level rise (expected as the result of climate change), can be managed by the possibility of developing tools to provide frequent monitoring of the evolution of the sandbars in the Lagoon.