CHANNEL MORPHOMETRY ANALYSIS OF HEADWATER STREAMS USING A TERRESTRIAL LASER SCANNER IN TWO DIFFERENT ECOREGIONS

Two headwater streams were fully scanned from the headwater to the mouth in two different ecoregions. Vishnu Creek is located in a wildlife sanctuary owned by Western Illinois University in west-central Illinois and merges into the LaMoine River. Thompson Creek is located 40 miles south of Washington DC in a protected regional park owned by the Bureau of Land Management in Fairfax County, Virginia. Using a Leica Scanstation C10 terrestrial laser scanner, along with scanning targets, each stream was scanned, at medium resolution, to produce a 3D point cloud environment. 360° photographs were also taken at each scan site to be draped over the point clouds. The data was imported into the Cyclone software suite and registered using overlapping points and targets from adjacent scans. Point cloud model-spaces for various sites throughout the two streams were created to extract geometric data on each of the stream’s channel morphology. The morphologic data was analyzed in Excel to compare upstream, downstream, and seasonal trends within each stream, but also to compare the two streams with each other. Both streams exhibited fluctuations in bank slopes and thalweg depths, with greater slopes and depths occurring along the outsides of meander curves as well as in areas with low amounts of canopy cover (and thus higher exposure to precipitation). Further analysis of data will reveal finer geomorphic variations and similarities between these streams to determine the best conservation practices.