Evaluating the state of constructed infills in the Venice Lagoon through remote satellite imagery

Abstract Introduction Salt‐marsh restoration is used to counter wetland loss, strengthen ecosystem resilience, and support dredged‐sediment reuse. In the Venice Lagoon, 63 constructed infills have been realized since the late 1980s, yet their eco‐geomorphological development and restoration performance remain incompletely assessed. Objectives The study conducted a landscape‐scale assessment of vegetation cover, tidal‐creek density, and emerged and submerged surfaces as indicators of infill condition and elevation. It also examined whether infill age, area, and spatial compactness were associated with these indicators. Methods A reproducible remote‐sensing workflow combined 30‐cm‐resolution imagery with manual digitization and QGIS analysis. Multiple linear regression evaluated associations between age, area, and Isoperimetric Quotient and the selected response variables. A 75% vegetation‐cover threshold was used to compare infills with vegetation establishment. Results The vegetation‐cover model explained 45.0% of variation, with age and compactness showing significant positive associations. The creek‐density model explained 21.4% of variation, with age as the only significant predictor. Age and compactness were also positively associated with emerged surface proportion, while no predictor significantly explained submerged surface proportion. Infills above and below the 75% vegetation threshold did not differ in mean age but differed significantly in mean compactness. Conclusion Constructed infills do not follow a uniform developmental pathway. Age and geometry partly explain vegetation establishment, but they do not adequately account for variation in hydrological configuration or ecological functionality. Basin‐scale evaluation should therefore treat vegetation, drainage, and inundation as related but distinct dimensions of restoration development.