ABSTRACT
CONTENTS Introduction .............................................................................................................................................. 19 Background .............................................................................................................................................. 20
Physical Processes.......................................................................................................................... 20 Types of Currents ........................................................................................................................... 20
Tidal................................................................................................................................... 20 River Inflows ..................................................................................................................... 22 Wind-Induced Currents ..................................................................................................... 22
Other Physical Processes ............................................................................................................... 22 Approach ........................................................................................................................................ 22 Numerical Modeling System — GEMSS...................................................................................... 23 Applications.................................................................................................................................... 24
Results ...................................................................................................................................................... 25 The Salinity Mixing Problem ........................................................................................................ 25 Residence/Flushing Time Analysis in Indian River/Rehoboth Bay, Delaware............................. 27
Beyond Physical Processes — Water Quality Modeling........................................................................ 27 Conclusions .............................................................................................................................................. 29 References ................................................................................................................................................ 31
An estuary can be described as an arm of the sea, where the tide meets and mixes with fresh water runoff from the land, rivers, and rain from the atmosphere. It is a semienclosed region, bordering a sea, with boundaries and bathymetry that influence the circulation of the estuary volume. The tide, wind, freshwater inflows, density stratification, and the Earth’s rotational effects can act at various levels to control the circulation. As human population pressures mount in these coastal areas, stewards need to understand the physics of their estuary to avoid the negative affects of this growth and mitigate them if possible.
