2025 Duluth Watersheds Geologic & Fluvial Geomorphic Information

Abstract

Uplift or base level fall in bedrock rivers can produce knickpoints (waterfalls) that propagate upstream to adjust the elevation of the longitudinal profile to reach a steady state. The migration rate of knickpoints is influenced by factors like local channel slope, drainage area (a proxy for discharge), and substrate erodibility. This dataset was used to investigate the geologic controls on bedrock landscape evolution following base level fall. Three map packages for three watersheds in the Duluth area (Amity Creek, Lester River, Mission Creek) are included in this dataset. A geologic map (“ExposureMap”) for each watershed was created to determine what the substrate control was on fluvial erosion. Point files contain information relating to stream characteristics (channel elevation, upstream area, distance from mouth, channel slope, modeled Erosion Index (“Stream Power”)), location of knickpoints (spikes in slope/Stream Power), and substrate erodibility in the channel (uniaxial compressive strength, fracture density, fracture intensity). Additional raster datasets include a Digital Elevation Model (DEM) of the watershed and a hillshade map.