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Coastal processes of the Elwha River delta: Chapter 5 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal

Scientific Investigations Report 2011-5120-5

This report is Chapter 5 in in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal. For more information, see: Scientific Investigations Report 2011-5120
By:
, , , and
Edited by:
Jeffrey J. Duda, Jonathan A. Warrick, and Christopher S. Magirl

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Abstract

To understand the effects of increased sediment supply from dam removal on marine habitats around the Elwha River delta, a basic understanding of the region’s coastal processes is necessary. This chapter provides a summary of the physical setting of the coast near the Elwha River delta, for the purpose of synthesizing the processes that move and disperse sediment discharged by the river. One fundamental property of this coastal setting is the difference between currents in the surfzone with those in the coastal waters offshore of the surfzone. Surfzone currents are largely dictated by the direction and size of waves, and the waves that attack the Elwha River delta predominantly come from Pacific Ocean swell from the west. This establishes surfzone currents and littoral sediment transport that are eastward along much of the delta. Offshore of the surfzone the currents are largely influenced by tidal circulation and the physical constraint to flow provided by the delta’s headland. During both ebbing and flooding tides, the flow separates from the coast at the tip of the delta’s headland, and this produces eddies on the downstream side of the headland. Immediately offshore of the Elwha River mouth, this creates a situation in which the coastal currents are directed toward the east much more frequently than toward the west. This suggests that Elwha River sediment will be more likely to move toward the east in the coastal system.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Coastal processes of the Elwha River delta: Chapter 5 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal
Series title:
Scientific Investigations Report
Series number:
2011-5120-5
Year Published:
2011
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Western Fisheries Research Center
Description:
20 p.
Larger Work Type:
Report
Larger Work Subtype:
USGS Numbered Series
Larger Work Title:
Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal (SIR 2011-5120)
First page:
111
Last page:
130
Country:
United States
State:
Washington
Other Geospatial:
Elwha River