Diagnostic Geomorphic Methods for Understanding Future Behavior of Lake Superior Streams What Have We Learned in Two Decades? Faith Fitzpatrick USGS WI Water Science Center, Middleton, WI fafitzpa@usgs.gov MN Lake Superior Watershed Stream Science Symposium January 7, 2013 Bark River (beaver dam washout) Photo from Dennis Pratt North Fish Creek photo by Dennis Pratt
Stream Behavior (Processes and Responses) Historical Range of Variability (HRV) Watershed Runoff and Sediment Diverse Biological Communities Glacial Geomorphology and Bedrock Time Climate Complexity in Channel Characteristics and Processes Human Disturbance People s Positive Perceptions and Reactions Resilient Fluvial Systems
Management Questions Where is all the sediment coming from? Has erosion and sedimentation increased? How do we best restore or protect habitat? Minnesota Grand Portage Cr Sand/gravel Clay Loam Peat Other Lake Superior Duluth North Fish Creek Bad River Wisconsin Michigan
North Fish Creek Historical Annual Sediment Budget in tonnes per year (late 20 th Century) Oct 2008 Peppler USDA-NAIP 2008 Fitzpatrick et al. 1999
Erosion Q s d 50 QS Long-term storage Sediment transfer Upland Upland valley Floodplain valley Large River Streamflow Magnitude Drainage Area STREAM POWER Channel slope From Lane (1955), Schumm (1977), Bull (1991), Church (2002), Gregory (2006)
Diagnostic Techniques Longitudinal Profiles Stream network position Historical Data Streamflow records and rating curves, floods Air photo interpretation General Land Office Notes and 1928 WI Land Economic Inventory Bridge designs Channel alterations Well logs/stratigraphy Geologic maps Multiple lines of evidence Field Data Morphologic measurements, streambed sediment type, slope Valley and channel cross section surveys and coring Sediment budgets Alluvial chronology & soil development Geomorphic mapping Sediment transport suspended and bedload Modeling Rainfall/runoff 1-D hydraulics Sediment transport GIS Analyses Watershed land cover, soils, geology, elevation, dams Laboratory Sediment texture and organic content Radiometric dating Sediment fingerprinting
North Fish Creek simulated floods and annual sediment loads for historical land-cover scenarios 80 70 60 50 40 30 20 DISCHARGE (M3/S) 10 0 3000 2000 1000 0 10 20 30 40 50 TIME, IN HOURS 0 SEDIMENT LOAD (TONNES) Gaged observed Current conditions Forested Detention basins 1928 agriculture Fitzpatrick and Knox, 2001
300 280 260 Human disturbance accentuated ongoing geomorphic Evolution North Fish Creek of channels Longitudinal Profile with Changes processes gives idea of future trajectory overbank sedimentation EXPLANATION A.D. 1995 A.D. 1870 Approx. 2,000 B.C. ALTITUDE IN METERS 240 220 200 North Fish Creek Longitudinal Profile 180 Lake Superior Transitional Fish Creek Upper main stem main stem Lower main stem Slough 160 30 25 20 15 10 5 0 RIVER KILOMETER ABOVE MOUTH AT CHEQUAMEGON BAY 60 Channel capacity flows Modern (M^3/S) 0 30 25 Pre Euro-American Settlement 20 15 10 RIVER KILOMETER 5 0 Fitzpatrick et al. 1999
Overbank Sedimentation North Fish Creek Middle Main Stem APPROXIMATE ALTITUDE (METERS) 206 205 204 203 1525+/-115 AD 202 201 200 1545+/-405AD Modern Modern channel Water level (HORIZONTAL DISTANCE NOT TO SCALE) Fine-grained sand Medium- and coarsegrained sand Terrace 1 Covered Silt Loam C. sand Pre-1946 Pre-1946 channel Organic material Gravel Terrace 2 1670+/-20 BC Soil development Pre-settlement surface Stratigraphic diagram of historical overbank sedimentation
ALTITUTE, IN METERS 500 450 400 350 300 250 200 150 Bad River Longitudinal Profiles Marengo River Bad River Bedrock Sandy glacial till, Poorly developed drainage network, no valley Clay plain, entrenched/alluvial valley Sandy post-glacial shorelines, entrenched valley 120 100 80 60 40 20 RIVER KILOMETER, FROM MOUTH 0
Typical Upper Great Lakes Long Profile and Valley Development
Channel Evolution Model (CEM) Headward Incision Stage I. Sinuous, Premodified h<h c Stage II. Constructed h<hc floodplain Stage III. Degradation h<hc Stage IV. Degradation and Widening h>hc terrace h h h h slumped material h c = = critical bank height direction of bank or bed movement Stage V. Aggradation and Widening h>hc terrace h Stage VI. Quasi Equilibrium h<hc terrace h bank bankfull aggraded material slumped material aggraded material Stages I, II precursor knickpoint primary knickpoint Stage III Stage IV top b a n Stage V plunge k pool d i r ection of flow Stage VI oversteepened reach secondary knickpoint aggradation zone aggraded material (Schumm, Harvey, and Watson, 1984; Simon and Hupp, 1986; Simon, 1989)
Evolution of Northern Lakes and Forest Streams
Segment scale channel classification based on: Drainage network position Slope Geologic setting Valley type Prediction of sensitivity and potential channel responses to disturbance Altitude in feet Duluth Area Streams Sensitivity to Disturbance (Fitzpatrick et al., 2006) 1,400 1,300 1,200 1,100 1,000 900 800 Shale 700 600 9 Duluth Project Rivers from West to East 7 5 3 River Mile Gabbro 1 Mission Cr Sargent Cr Stewart Cr Knowlton Cr Kingsbury Cr Keene Cr -1 http://pubs.usgs.gov/sir/2006/5029/
Post-Duluth Flood 2012 Keene Creek upper/middle mainstem, no valley Photos: Post-Flood Volunteers, Karl Koller, Molly Wick, Karen Gran Lester River middle mainstem entrenched valley Mission Creek Lower mainstem aggradation
Possible channel types along a long profile from headwaters to mouth (Montgomery and Buffington, 1993)