Shallow flow over a bed with a lateral change of roughness Victor Dupuis, Frédéric Moulin, Sébastien Cazin, Moïse Marchal, Pierre Elyakime, Jean-Dominique Barron and Olivier Eiff E3S Web Conf., 40 (2018) 02039 Published online: 05 September 2018 DOI: 10.1051/e3sconf/20184002039