Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Definition and classification of estuaries
- 2 Estuarine salinity structure and circulation
- 3 Barotropic tides in channelized estuaries
- 4 Estuarine variability
- 5 Estuarine secondary circulation
- 6 Wind and tidally driven flows in a semienclosed basin
- 7 Mixing in estuaries
- 8 The dynamics of estuary plumes and fronts
- 9 Low-inflow estuaries: hypersaline, inverse, and thermal scenarios
- 10 Implications of estuarine transport for water quality
- Index
- References
1 - Definition and classification of estuaries
Published online by Cambridge University Press: 06 July 2010
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Definition and classification of estuaries
- 2 Estuarine salinity structure and circulation
- 3 Barotropic tides in channelized estuaries
- 4 Estuarine variability
- 5 Estuarine secondary circulation
- 6 Wind and tidally driven flows in a semienclosed basin
- 7 Mixing in estuaries
- 8 The dynamics of estuary plumes and fronts
- 9 Low-inflow estuaries: hypersaline, inverse, and thermal scenarios
- 10 Implications of estuarine transport for water quality
- Index
- References
Summary
This chapter discusses definitions and classification of estuaries. It presents both the classical and more flexible definitions of estuaries. Then it discusses separate classifications of estuaries based on water balance, geomorphology, water column stratification, and the stratification–circulation diagram – Hansen–Rattray approach and the Ekman–Kelvin numbers parameter space.
The most widely accepted definition of an estuary was proposed by Cameron and Pritchard (1963). According to their definition, an estuary is (a) a semienclosed and coastal body of water, (b) with free communication to the ocean, and (c) within which ocean water is diluted by freshwater derived from land. Freshwater entering a semienclosed basin establishes longitudinal density gradients that result in long-term surface outflow and net inflow underneath. In classical estuaries, freshwater input is the main driver of the long-term (order of months) circulation through the addition of buoyancy. The above definition of an estuary applies to temperate (classical) estuaries but is irrelevant for arid, tropical and subtropical basins. Arid basins and those forced intermittently by freshwater exhibit hydrodynamics that are consistent with those of classical estuaries and yet have little or no freshwater influence. The loss of freshwater through evaporation is the primary forcing agent in some arid systems, and causes the development of longitudinal density gradients, in analogy to temperate estuaries. Most of this book deals with temperate estuaries, but low-inflow estuaries are discussed in detail in Chapter 9.
- Type
- Chapter
- Information
- Contemporary Issues in Estuarine Physics , pp. 1 - 11Publisher: Cambridge University PressPrint publication year: 2010
References
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