Synthetic Aperture Radar Interferometric (InSAR) techniques are widely applied to detect ground displacements caused by both natural and anthropogenic effects. Such techniques are a powerful tool for monitoring the ground motion, however, they have limitations such as temporal and geometrical decorrelation. Persistent Scatterer Interferometry (PSI), a pixel based methodology, has been developed to overcome such constraints. Nevertheless, also with PSI poor spatial coverage is observed in many case studies, especially over natural environments. In this contribution, we propose a methodology using elements from InSAR and PSI techniques in order to improve the spatial coverage with valid information over natural landscapes. For testing the applicability of this methodology, we selected as a test area the Venice Lagoon and specifically an area covered by saltwater marshes. The synergistic approach shows a good potential to achieve a good spatial coverage over the study area.