Anne liked yesterday's shot and sent me a couple links to relevant papers (both PDFs) on pool and riffle morphology. I haven't had time to look them over carefully (Honestly, I've just read the abstracts thus far.), but the first discusses how large woody debris (notice the lack of such in today's and yesterday's photos, compared to the left side of this one) influences characteristic pool spacing. The second involves an idea I hadn't heard before, "velocity reversals," but which makes intuitive sense to me. It's the idea that at low water, pools are lower velocity, but experience higher velocity than riffle areas during high water. This means that pools get scoured during high water, but riffles are depositional environments in those conditions. When the stream returns to a lower stage, it no longer has the competence to move the debris deposited in high water.
Photo unmodified. August 30, 2012. FlashEarth Location (pretty much guessing on this one too, but right general area).
Is This Your Hat?
2 years ago