An experimental investigation on the flow resistance over a porous gravel-bed surface and its non-porous counterpartChristy Ushanth Navaratnam, Jochen Aberle, Jie Qin and Pierre-Yves HenryE3S Web Conf., 40 (2018) 05073DOI: https://doi.org/10.1051/e3sconf/20184005073