Philip Orton, Doug Wilson, David Jay, Annika Fain Oregon Graduate Institute, Environmental Science &...
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Transcript of Philip Orton, Doug Wilson, David Jay, Annika Fain Oregon Graduate Institute, Environmental Science &...
Philip Orton, Doug Wilson, David Jay, Annika FainOregon Graduate Institute, Environmental Science & Engineering
Funded by The National Science Foundation LMER project
Sediment analyses by Denise Reed at U. New Orleans
High-resolution sediment dynamics in a salt-wedge
estuary
2
Summary
• Inverse analysis: optical and acoustical SPM
• Several advantages– detection of wide range of sediment sizes– concentrations by settling velocity (Ws) classes– high-resolution compared to tidal timescales
• Fraser River estuary - erosion thresholds, resuspension mechanisms
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Fraser River estuary, July ‘99
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Field Measurements
• R/V Sproul - 1999 anchor stations
– ABS: 300 kHz BB-ADCP, t=20 sec
– OBS: CTD-OBS profiles, t=30 min
– Concentration (C), t=2 hrs
– Settling rate (Ws), t=2 hrs
– Zooplankton, primary productivity, etc
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Anchor Station Observations, Ebb Tide
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INVERSE
ANALYSES
Inverse Analysis Approach
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Inverse Analysis: ABS Stage I
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Inverse Analysis: OBS Stage I
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Theoretical Responses
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OBS response coeff. : ABS response coeff.
Inverse Analysis Stage II
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Response-Modified Acoustic C at 1 m
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Response-Modified Acoustic C at 1 m
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Future Analyses
• Wealth of data from the Columbia River estuary and the Fraser River estuary
• Multi-frequency acoustics
• For 2000, LISST particle size observations
• Modify approach to include advection
• Sensitivity analyses are critical
14
Fraser 1999 Conclusions
• Joint acoustic/optic approach invaluable due to wide range of sediment types
• IA allows us to... – study sediment erosion, transport by Ws-class– achieve resolution not available with
conventional sediment monitoring tools