Site One - Confined Big Cottonwood

Site One - Confining

Methods

I used Google Earth to help determine the boundaries of the river area, active floodplain, valley bottom margin, confinement and constriction. The elevation/terrain pictures came from Google Earth. I used data from the Riverscapes Warehouse, specifically the TauDEM, Channel Area, and Riverscapes Context to estimate the valley bottom and active floodplain. I have included a screenshot of the Height Above Nearest Drainage (Hand). I am also familiar with this area and I am using previous experiences to help determine all of the areas.

I used Google Earth Pro to create a polygon of the river length, river area, active floodplain, valley bottom margin, confinement, and constricted. In many cases I had to create multiple polygons to encompass the whole intended area and in this case I made sure to add them all up for the combined total. All the cells in blue are the raw calculations and everything else are calculated numbers. For the confined and constricted percentage I did an educated guess. For the rivers width I used an integrated width method. Which is calculated by the river length divided by the river area. I used the integrated measurement because the river's width changes throughout the whole reach and it would be more accurate than taking an average of multiple width measurements in different places.

This reach is in between two very steep hill slopes and an elevated highway. The sides of this river consist of large boulders and even though HAND shows there can potentially be floodplain pockets I don't believe this is a possibility. Instream Geomorphic Units are rapids because this reach has a slope of 23% and there is no Floodplain Geomorphic Units.