geomorphic floodplains and the use of process domains to ... · u.s. department of the interior...
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U.S. Department of the InteriorU.S. Geological Survey
Geomorphic floodplains and the use of process domains to guide restoration strategyRose WallickJim O’ConnorKrista JonesMackenzie KeithCharles Cannon
Brian Cluer (NOAA Fisheries)Anne Mullan (NOAA Fisheries)Leslie Bach (The Nature Conservancy)
Thinking outside of the channel (from the perspective of a geomorphologist)
Willamette River Basin (Photos courtesy of Freshwaters Illustrated)
Emerging management challenges require floodplain framework
Gravel pits
Willamette River
Floodplain
1 km TNC’s Willamette Confluence Project, Middle Fork of the Willamette River
What is the geomorphic floodplain?Suite of geomorphic surfaces created and shaped by
fluvial processes by ‘modern’ climatic regime
Pleistocene alluvium
Holocene(or geomorphic)
floodplainActive
channel
Holocene alluvium
What is the geomorphic floodplain?
Upper Willamette River
Floodplain(Fine sediment deposition)
Active channel(Annual erosion & deposition)
Pleistocene Terrace(Rarely inundated)(Photo courtesy Freshwaters Illustrated)
Process-based definition; not a regulatory boundary
Why use the geomorphic floodplain?Broader context for site-based restoration
Sprague RiverPhotograph by Patricia McDowell, UO
2000 channel1940 channel
Geomorphic floodplain
Meander cutoffs
Avulsion
Sprague River(mapping by UO and USGS)
Why use the geomorphic floodplain?Broadly similar bank materials & landforms
South Fork Coquille River
Upper Willamette River
Bank height, vegetation and particle size may vary, but
Holocene alluvium is typically unconsolidated & very erodible
Why use the geomorphic floodplain?
Chetco River 1939-1995(mapping by USGS)
1995
19391943
Geomorphic floodplain
Active channel changes over time
Bare bars and wetted channel
Static, repeatable spatial reference frame
Active channel tricky to define
Applegate River, 2009
Vegetated bars & side channels
How do we map the geomorphic floodplain?
Simple approach Map floodplain from
existing datasets (see metadata for methods)
Identify landforms of interest
Floodplain transects (‘SLICES’) provide spatial units for tracking change, storing data
Holocene Floodplain
Upper Willamette Floodplain(mapping by UO & OSU)
SLICES framework
1995 channel
1km
How do we map the geomorphic floodplain?Comprehensive approach Define the geomorphic
floodplain Contiguous mapping of all
landforms Relate landforms with
process Relate ecosystems with
landforms
Landforms
Bar and scroll morphology
Columbia River:Sauvie Island
Mapping by Charlie Cannon (USGS)
Upper Willamette RiverMapping by Sarah Schanz
Historical channels
Revetments
• Relict processes or events (volcanism, landslides)• Historical processes (large floods, channel migration)• Ongoing processes (altered flow, sediment, wood regime)
Applications:Linking landforms with processes
Columbia River
Sandy River Delta
Lower Columbia RiverMapping by Charlie Cannon & Mary Ramirez
Active erosion
& deposition
Applications: Re-naturalizing complex floodplains
Hanson Russian River Restoration Project Site
(Photograph by Brian Cluer)
Applications: Process-based monitoring framework
McKenzie River floodplainTwo-year flood inundation provides pragmatic monitoring framework while still capturing floodplain characteristics
Geomorphic floodplainActive Channel
2 year flood inundationInundation map courtesy of River Design Group
Acknowledgements
Stan Gregory (OSU)Dave Hulse (UO)Sarah Schanz (Univ. Washington)Joseph Mangano (Colorado State Univ.)Patricia McDowell (UO)Pollyana Lind (UO)Christine Rasmussen (USGS)Pam Wiley (MMT)Eric Jones (MMT)Ken Bierly (OWEB)Jenny Ayotte (BSWCD)Jeremy Monroe (Freshwaters Illustrated)Pete Klingeman (OSU-retired)Greg Taylor (USACE)Steve Smith (USFWS-retired)
Funding:Benton Soil and Water Conservation District, Meyer Memorial Trust, Oregon Watershed Enhancement Board, BPA, USFWS, USACE, Oregon Dept. State Lands, USGS
Gordon Grant (OSU)Steve Cline (EPA)Kathryn Boyer (OSU; NRCS-retired)Joe Moll (McKenzie River Trust)Chris Vogel (McKenzie River Trust)Dan Bell (TNC)Jason Knuckles (TNC)Chris Budai (USACE)Rick Bastach (City of Portland)Scott Wright (RDG)Troy Brandt (RDG)Janine Castro (USFWS/NOAA)Rob Markel (NOAA Fisheries)Brian Bangs (ODFW)Kirk Schroeder (ODFW)
Assistance and insight to floodplain issues:
Questions? USGS geomorph projects:
Rose Wallick ([email protected]) Krista Jones ([email protected]) Jim O’Connor ([email protected])
Russian River Restoration: Brian Cluer ([email protected])
TNC Confluence Restoration site: Leslie Bach ([email protected])
Willamette GIS datasets: http://ise.uoregon.edu/slices/main.html
USGS GIS floodplain coverages with metadata:http://water.usgs.gov/lookup/getgislist
• Chetco River• Coquille River Basin• Hunter Creek• Rogue Basin
• Umpqua Basin• Sprague River• Tillamook Bay tributaries
