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Title: Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: I. Along-channel Water Level Variations, Pacific Ocean to Bonneville Dam

This two-part paper provides comprehensive time and frequency domain analyses and models of along-channel water level variations in the 234km-long Lower Columbia River and Estuary (LCRE) and documents the response of floodplain wetlands thereto. In Part I, power spectra, continuous wavelet transforms, and harmonic analyses are used to understand the influences of tides, river flow, upwelling and downwelling, and hydropower operations ("power-peaking") on the water level regime. Estuarine water levels are influenced primarily by astronomical tides and coastal processes, and secondarily by river flow. The importance of coastal and tidal influences decreases in the landward direction, and water levels are increasingly controlled by river flow variations at periods from ≤1 day to years. Water level records are only slightly non-stationary near the ocean, but become increasingly irregular upriver. Although astronomically forced tidal constituents decrease above the estuary, tidal fortnightly and overtide variations increase for 80-200km landward, both relative to major tidal constituents and in absolute terms.
Authors:
; ; ;
Publication Date:
OSTI Identifier:
1173022
Report Number(s):
PNNL-SA-98787
400403209
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Estuaries and Coasts, 38(2):415-433
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English