ABSTRACT
The classical equation for tidal wave celerity (see Pillsbury, 1956; or Harleman, 1966) is widely used to describe the propagation of a tidal wave in estuaries. The conditions for the equation’s derivation (i.e. constant cross section and no friction) do not apply in alluvial estuaries, where the cross section varies exponentially along the estuary axis and friction cannot be neglected. The tidal damping in an estuary appears in one of three types: amplified, un-damped (ideal) or damped. The phase lag between HW and HWS (as well as between LW and LWS) lies between zero and /2π . Determination of tidal damping and phase lag has received not much attention nor their effect on tidal wave celerity. Savenije et al. (2007) used a simple harmonic solution with the complete non-linearized Saint-Venant equations and developed a set of new equations describing these three main characters of the tidal wave in an estuary. This set of equations showed good agreement with observations.
