GPR applications in dense cities: Detection of paleochannels and infilled torrents in Barcelona GPR applications in dense cities

Barcelona is placed in a basin delimited by the Mediterranean Sea (E), the Collcerola Mountains (W) and the rivers Besos (N) and Llobregat (S). The city was built on Quaternary alluvial deposits and on the Tertiary and Palaeozoic materials of the surrounding mountains. The Quaternary materials are preponderant in the plane of the city, presenting a high lateral variability due to the paleochannels and infilled torrents existing between the Sea and the Mountains. The city was built on these heterogeneous materials. In order to prepare a detailed vulnerability map of the Barcelona city, a GPR survey provides information about the position of these geological structures. Results were compared to H/V spectral ratio measurements and soundings.