Interpolation of water surface profile in unsteady open channel flow using the adjoint method based on 2D shallow water equationsAkihide Watanabe, Takashi Kojima, Tetsuaki Mikami, Kazuhiko Matsunobu, Hiromi Suzuta and Shinjiro TomizawaE3S Web Conf., 40 (2018) 06030DOI: https://doi.org/10.1051/e3sconf/20184006030