A systems method based on a Boolean approach is used to predict medium- to long-term behaviour of estuary morphology. Boolean networks are formed for various types of generic estuaries by taking into account the feedback involved between various estuary elements and external forcing which drive morphological evolution. A logical framework is then developed, and the Boolean matrix is derived. Various different potential morphological evolutionary pathways are then selected from the Boolean matrix, analysed, and discussed.

The Boolean method provides a complementary approach for qualitative modelling of complex estuary systems. The method was applied to the Ribble Estuary in northwest England, and the predictions from the Boolean approach were in very good qualitative agreement with the observed morphological evolution of the Ribble Estuary during the last 150 years.