Abstract
In this thesis, Structure from Motion techniques and an off the shelf Unmanned Aerial Vehicle were used to conduct a geomorphologic study in 3 mountain meadow streams. A total of 4 study sites were chosen to track channel changes over water year 2018. The study focused on mappable changes in gravel bars, meanders and cut banks. Accuracy of each Structure from Motion (SfM) created map was tested using a proprietary Python script to compare GNSS surveyed points to the SfM generated point clouds. The resultant digital maps were used for DEM of Difference evaluation of surface changes. These evaluations show gravel bar enlargement as well as significant cut bank erosion. The addition of 2014 LiDAR data to this study extended the timeframe in which channel changes could be studied. This led to the revelation that in one of the English Meadow study areas, a cut bank may be migrating northward at a rate of 2 meters per year, from 2014 to 2018. This study was successful in showing significant changes in English Meadow, while also showing good channel stability in the restored Goodrich Meadow. Goodrich Meadow’s channel shows signs of slowing flow, possibly increasing water residence time within the meadow. Cross sections from the SfM created DEMs were used to estimate stream discharge and shear stress. From this, it was possible to estimate the grain size each meadow stream is capable of moving at peak discharge. These grain sizes were verified using placed rocks of known size and compared successfully to calculated grain size portability.