GEOMORPHIC ANALYSIS OF THE LUCKIAMUTE WATERSHED, CENTRAL COAST RANGE, OREGON:

INTEGRATING APPLIED WATERSHED SCIENCE WITH UNDERGRADUATE RESEARCH AND COMMUNITY OUTREACH

Steve TaylorEarth and Physical Sciences Department

Western Oregon UniversityMonmouth, Oregon 97361

• Introduction

Watersheds as Undergraduate Service Learning Laboratories

Geomorphic Significance of the central Oregon Coast Range

• Luckiamute River Study Area

• Results of Geomorphic Analyses

• Summary and Conclusion

INTRODUCTION

WATERSHEDS AS SERVICE LEARNING LABORATORIES: Natural outdoor science laboratories with defined boundaries

Local, place-based contextual learning facilities

Promote university-community linkages

Complex multivariate systems w/ process-response feedbacks

Amenable to quantitative techniques and geospatial technology

SIGNIFICANCE OF THE LUCKIAMUTE WATERSHED TO WOU: “THE” local WOU watershed, socially relevant

Close proximity to campus, logistically accessible

Amenable to long-term studies in fluvial geomorphology, environmental geology, conservation biology, and hydrology

Opportunities for cross-collaboration and community outreach

1999-Present WOU Earth Science-Biology-Chemistry Class Field Trips and Contextual Learning Modules (Fluvial Geomorphology, Geologic Mapping, Hydrogeology, Environmental Geology, Botany, Aquatic Invertebrates, Environmental Chemistry, Water Quality, Geographic Information Systems)

2001 Environmental Science Institute Course(Geomorphology, Env. Chemistry, Botany, Climatology)

2002 Proposal Development (Watershed Learning Model)

2003-2004 Watershed Assessment with Luckiamute Watershed Council

2003-Present Community Support of Luckiamute Watershed Council

2004-Present Funded Research: Hydrogeomorphic Analysis (USGS / CWest)

2004-Present Funded Research: Spatial Distribution of Invasive Plants (OCF)

SUMMARY OF LONG-TERM RESEARCH AND COMMUNITYSERVICE INITIATIVES IN THE LUCKIAMUTE BASIN

Will

amet

te

Cas

cad

e

Ran

ge

K lamath

MountainsL

ow

lan

d

Co

ast

Vo

lcan

icA

rc

Ca

sc

ad

ia

Su

bd

uc

tio

n

Zo

ne

0 75 km

PHYSIOGRAPHIC MAP OF W ESTERN OREGON

Oregon Coast Range

Unglaciated, forested landscape

Paleogene-Neogene marine volcanic and sedimentary rocks (Walker and MacLeod, 1991)

Long history of oblique convergence and tectonic accretion (Wells et al., 1984)

Active mountain building during the past 10-15 Ma (Snavely et al., 1993)

Pleistocene uplift rates = 0.1-0.3 mm/yr (Kelsey et al., 1996)

Historic uplift rates = 1-3 mm/yr (Mitchell et al., 1994)

Eastward tilting = 1 x 10-8 rad/yr (Adams, 1984)

Holocene erosion rates = 0.05-0.33 mm/yr (Roering et al., 2005)

Geomorphic Significance of the Oregon Coast ange

StudyArea

Pierson (1977) Debris flow processesDietrich and Dunne (1978) Sediment budgetsJackson and Beschta (1982) Bedload transportBurroughs (1985) Landslide modelingDietrich and others (1986) Hillslope processesMontgomery and Dietrich (1988) Landscape evolutionBenda (1990) Debris flow processesBenda and Cundy (1990) Debris flow processesReneau and Dietrich (1990) Debris flow processesReneau and Dietrich (1991) Landscape evolutionPersonius and others (1993) Terrace chronologiesMontgomery and Dietrich (1994) Landslide modelingBenda and Dunne (1997) Debris flow processesMontgomery and others (1997) Hillslope process experimentsRoering and others (1999) Hillslope process experimentsMontgomery and others (2000) Landslide modelingHeimsath and others (2001) Weathering processesSchmidt and others (2001) Slope stabilityAnderson and others (2002) Weathering processesMay (2002) Debris flow processesCasebeer (2003) Sediment budgetsLancaster and Hayes (2003) Debris flow processesMay and Gresswell (2003) Sediment productionRoering and others (2003) Slope stabilitySchmidt and others (2003) Slope StabilityKobor and Roering (2004) Bedrock-channel processesRoering and others (2005) Slope processes / Landscape Evolution

SAMPLINIG OF PREVIOUS WORK IN TYEE LANDSCAPES OF “THE OCR”University of Washington – UC Berkeley Geomorphic Offspring and Related Cousins

Salem

LuckiamuteStudy Area

Eugene

Tyee FmOutcrop Belt

(Eocene, arkosic ss,delta-submarine fan)

0 50 km

Focus of ExistingCoast Range

Studies (27+ yrs)

Coos Bay

Study Area

Oregon

LUCKIAMUTE RIVERSTUDY AREA

River

Soap Ck

River

Rickreall

Will

amet

te

Cal

apo

oya

Riv

er

Fanno Pkel 1016 mpcp 3531

Maxfield CkWoods Ck

Luckiamute

Riv

er

Marys

Ck

N

LuckiamuteLandingel 46 mpcp 1143

Luckiamute

LittleFanno Ridge

0 5 km

W esternOregon

University

Mean AnnualPrecipitation (mm)

pcp

Tsr Tsr

Tt

Tt

Tt

Tsr

Ty

T y

T y

T y

T y

T y T y

Tsr

T y

T y

T s s

T s s

T s s

T s s

H a l

Q a l

Q a l

Q a l

Qal

N

T y

0 5 km

Tss

Ty

Tt

I I I

I V

I

I I

Holocene alluviumQ uaternary a lluviumO ligocene intrusiveYam hill Form ationSpencer Form ationTyee Form ationS iletz R iver Volcanics

HalQal

TyTssTtTsr

Fault

0 5 km

TyeeDomain (29%)

Siletz Domain (19%)

SpencerDomain (29%)

YamhillDomain(23%)

Hillslope-Colluvial

Hillslope-Colluvial

Hillslope-Colluvial

Valley Floor-Alluvial

0 100002000030000400005000060000700008000090000100000

Channel Distance from Divide (km )

0

200

400

600

800

1000

Ch

ann

el E

leva

tio

n (

met

ers)

0 20000 40000 60000 80000 100000

Luckiamute

Little Luckiamute

TributaryJunction

Confluence withWillamette River

0 10 20 30 40 50 60 70 80 90 100

HSP

Luckiamute River at Helmick State ParkBankfull Stage 3/27/05 3800 cfs

Willamette Silt

el 470 ft

el 220 ft

Qtm (Bela, 1981)

Qff2 (O’Connor et al., 2001)

Max Missoula Flood El. = 400 ft)Ts

Spencer-Valley Fill Domain

Siletz Domain

Spencer Domain

Yamhill-Intrusive Domain

Willamette Valley

Little Luckiamute River - Yamhill Domain

Tyee-Domain Landscape (from Roering et al., 2005)

MORPHOMETRIC ANALYSES

S p e n c e r D o m a i nS u b b a s i n s ( n = 6 )

S i l e t z D o m a i nS u b b a s i n s ( n = 6 )

T y e e D o m a i nS u b b a s i n s ( n = 5 )

Y a m h i l l D o m a i nS u b b a s i n s ( n = 5 )

0 5 k m S 6

S 5S 4

S 3

S 2S 1

T 1

T 2

T 3T 4

T 5

Y 1

Y 2Y 3

Y 4

Y 5

S P 1

S P 2

S P 3

S P 4

S P 5S P 6

Total LuckiamuteAd = 815 km2

Avg SubbasinAd = 10-20 km2

Methodology

● GIS analysis of USGS 10-m DEMs

● Software: ArcGIS and Terrain Analysis System (TAS v1.5; Lindsay, 2002)

● Subbasin boundaries and channel network derived by the Coastal Landscape Analysis and Modeling (CLAMS) group at PNW Forest Research Lab (Miller et al., 2001)

0

10

20

30

40

50D

rain

age

Are

a (s

q.

km)

Siletz

Tyee

Spencer

Yamhill

(n=6)

(n=6)

(n=5)

(n=5)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Bas

in R

elie

f (k

m)

Siletz

Tyee

Spencer

Yamhill

(n=6)

(n=6)

(n=5)

(n=5)

Average

Median

1

1.5

2

2.5

3D

rain

age

De

nsi

ty (

km-1

)

Siletz

Tyee

Spencer

Yamhill

(n=6)

(n=6)

(n=5)

(n=5)

0

0.5

1

1.5

2

Bas

in R

ug

ged

nes

s

Siletz

Tyee

Spencer

Yamhill

(n=6)

(n=6)

(n=5)

(n=5)

Average

Median

Valley Fill- Siletz Yamhill- TyeeSpencer Intrusive

Max Slope 56.8o 61.9o 59.0o 62.0o

Avg Slope 3.2o 12.7o 11.9o 14.5o

Std Dev 3.98o 7.90o 7.97o 9.18o

Variance 15.84o 62.49o 63.51o 84.25o

90th 9o 24o 24o 28o

Percentile

% Cells >20o 0.7 18.3 15.4 25.9

% Cells >25o 0.2 7.7 7.9 14.3

No. Cells 2290702 1510287 1926899 2409140

Summary of Slope Parameters for the Luckiamute Watershed

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Rel

ativ

e S

trea

m P

ow

er I

nd

ex

Siletz

Tyee

Spencer

Yamhill

(n=6)

(n=6)

(n=5)

(n=5)

RSP = A d x Tan()

Calculated at BasinOutlet (A d in km 2)

Channel Distance from Divide (km )

0

100

200

300

400

500

600

700

800

900

1000

Val

ley

Wid

th (

met

ers)

0 10 20 30 40

Luckiamute River(Tyee Domain) Max Valley W idth = 938 m Avg Valley W idth = 274.1 m Stdev Valley W idth = 231.5 m No. = 67

Little Luckiamute River(Yamhill-Intrusive Domain) Max Valley W idth = 334 m Avg Valley W idth = 109.0 m Stdev Valley W idth = 73.2 m No. = 43

LuckiamuteYamhill Domain

Little LuckiamuteTyee Domain

SUMMARY AND CONCLUSION

Tyee Domain in the Luckiamute Basin:

• Steeper, rugged hillslopes• More finely dissected by low-order channels• Tendency to spawn debris flow• Lower stream-power index compared to Yamhill Domain• Higher average valley widths, increased sediment accommodation space

Working Hypotheses for Tyee Domain:

• Hillslope transport rates are greater than the ability of the channel system to export sediment

• Steep hillslopes and increased valley widths result in comparative decrease of net sediment-transport efficiency

The Luckiamute Watershed represents a model outdoor laboratory for contextual and service learning opportunities in the Natural Sciences at Western Oregon University

Geomorphic analysis suggests that spatial variation of bedrock lithology is a primary factor controlling slope gradients, hillslope delivery rates, and resulting sediment-transport efficiency of the channel system.

The Luckiamute Watershed is uniquely positioned at the northern terminus of the Tyee outcrop belt, thus providing an opportunity for comparative geomorphic analysis.

The rich body of work from other Tyee landscapes in the OCR will serve as the platform from which to extend future research into other bedrock domains.

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Concluding Statements

(4)

ACKNOWLEDGMENTS

Funding Sources:OSU Institute for Water and Watersheds (IWW)USGS Water Resources Small-Grants ProgramOregon Community FoundationWestern Oregon University Faculty Development Fund

WOU Student Research Assistants:Diane Hale, Jeff Budnick, Jamie Fisher, Chandra Drury,Katie Knoll, Rachel Pirot, Jeff Kent

WOU Faculty Colleagues2001 Environmental Science Institute: Bryan Dutton (Biology),

Pete Poston (Chemistry), Jeff Myers (Earth Science), Adele Schepige (Education)

Ongoing Research Collaboration: Bryan Dutton (Biology)