Landslide displacement estimation by archival digital photogrammetry

Archival multi-temporal aerial photogrammetry allows to measure displacements of a landslide area when images are co-registered in the same reference system. In this paper we investigated three photogrammetric surveys performed in 1998, 2004 and 2007 in an area of the northern Apennine (Bologna). The study of morphological changes was carried out measuring in stereoscopic vision twelve natural points as roof corner of buildings. Changes were estimated comparing the respective coordinates of the points. Our DEM shows the morphological features and the kinematic of this sliding area with an average grid resolution of 5 m and a maximum elevation error of about 10 cm. Results can improve the geomorphological studies of sliding areas and assist in reducing future hazards