ABSTRACT
According to the classical definition by Cameron and Pritchard an estuary is a body of water appreciably diluted by freshwater supplied by runoff from land. This definition of the word estuary does not, of course, give any idea about the hydrographical and dynamical effects of the runoff. A large number of external factors may be of importance for the hydrography and circulation in an estuary. This chapter introduces a few nondimensional numbers formed by different, dynamically significant, combinations of external parameters. From these numbers a rough dynamic classification of estuaries may be performed. The chapter demonstrates that topography to a large extent controls both horizontal and vertical transport processes and thereby the stratification and circulation in estuaries. It provides a summary of the most important ways in which topography controls the stratification and circulation in estuaries.
