Sediment Mixing in Moccasin Creek

sediment mixing
Sediment plumes and mixing during rainfall.

This is Moccasin Creek in Uwharrie National Forest, North Carolina after an extended period of rainfall. At least three sediment trails are visible. The light orange and tan in the thalweg of the stream is the result of sediment influx upstream some distance. (The stream is flowing away from you.)

A tributary on the right side of the channel is transporting bright orange suspended sediment derived mostly from runoff on a gravel road to the right. The tributary is fairly shallow, so most of the suspended load is still near the trunk stream’s surface. On the left, fine particles are being lifted from a recent excavation in the low-velocity margin of the larger stream.

Although the sediment plumes, especially in the central channel, show turbulent and convoluted flow, there is little mixing in this fairly straight channel. The margin of the bright orange plume shows evidence of eddies and vortices.

Image © Andy R. Bobyarchick.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.