Evaluate land use impacts on sediment, salinity, and selenium distribution
Stinking Water Gulch near Rangely, Colorado
In many areas of western Colorado, the Cretaceous Mancos Shale Formation is present and a natural source of sediment, salinity, and selenium to surface waters (Presser and others, 1994; Elliott and others, 2008). As a result, one of the water quality goals of the of the Bureau of Land Management (BLM) and the Colorado River Basin Salinity Control Forum is to minimize land use actions that increase the release of stored sediment, salinity, and selenium from Mancos Shale landscapes. Meeting this goal makes understanding if and how common land uses affect channel storage, especially in Mancos Shale areas, a crucial requirement.
In an effort to evaluate the possible impacts of land use on areas of Mancos Shale in Colorado, the U.S. Geological Survey (USGS) in cooperation with the BLM used UAS to collect data over four 400-acre basins that have been subject to different types of land use. More tradition data collection methods in these areas have been challenged by erosion-sensitive ground species, and steep and unstable terrain, therefore UAS have the potential of being a more effective and less invasive method. The required high resolution image data was collected in early September of 2016 with a Ricoh GR camera mounted on a 3D Solo platform. Once collected this data was used to generate topography mapping of each basin based on structure from motion techniques which can produce better topography of open areas with limited vegetation. Comparison of the different mappings allow for more accurately characterizing geomorphic and volumetric differences within and between the basins.