Site Two - Meandering Big Cottonwood

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 is an unconfined reach. There was not a lot of vegetation so I was able to map out the active river area/channel pretty accurately. I used HAND and vegetation cover to set the boundary for active and inactive floodplain. Google Earth helped a lot to distinguish the hill slopes that are not very visible from the aerial picture (Figure 2.3) but are present in Figure 2.1. I mapped the edge of the valley bottom margin at the highway but the valley margin would extend past the highway to the other side.

In-channel Geomorphic Units

Floodplain Geomorphic Units