Structural changes in an estuary, described by models and using exergy as orientor

It is often of interest to determine which structure of an ecosystem among the possible ones will prevail under given environmental circumstances. The authors show that it is feasible using models and an exergy index. The hypothesis is that the structure giving the highest exergy will prevail. The exergy calculations are however still very uncertain, which implies that a clear difference in exergy must be required. The method has been tested successfully in this paper presenting the case study of Mondego Estuary, Portugal. The method seems to have a general applicability as it also has been used successfully to predict structural changes and to improve model calibrations (see for instance Jّrgensen et al., submitted for publication and Jّrgensen, 2002).