The paper describes the concept of a network model for the morphologic
al behaviour of a near-resonant multiple-inlet tidal basin, as part of
a model system which includes the barrier island coasts and the outer
deltas. It addresses the question whether a small interference somewh
ere in such a basin can have major effects on sediment transport and m
orphology elsewhere in the system. In order to explain the basic ideas
of the model, only the main tidal constituent (M(2)) and the associat
ed topography-induced residual current are considered, not the overtid
es. Furthermore, the model concerns only non-cohesive sediment (sand).
In spite of these simplifications, the model concept is shown to be e
ffective, in that it results in a morphological evolution equation for
each branch of the network and a picture of the influence of each bra
nch on the resonance-sensitivity of the system as a whole.