“…This model was also developed by Benjamin and Lighthill [1954] following a different theoretical treatment based on a third-order expansion of the stream function. Application of Boussinesq-type equations to civil engineering was successful for the accurate description of flow over weirs, undular jumps, sand waves, Favre waves, dam breaks, overfalls, and slope breaks [Fawer, 1937;Iwasa, 1955Iwasa, , 1956Mandrup-Andersen, 1975Marchi, 1963Marchi, , 1992Marchi, , 1993Matthew, 1963Matthew, , 1991Engelund and Hansen, 1966;Basco, 1983;Hager, 1983;Hutter, 1984a, 1984b;Montes, 1986;Soares-Frazão and Zech, 2002;Mohapatra and Chaudhry, 2004;Dey, 2007, 2009;Chaudhry, 2008;Castro-Orgaz and Hager, 2009]. Castro-Orgaz et al [2012 demonstrated that Boussinesq-type enhanced equations also describe free surface groundwater flow.…”