I spent the week at the beach in North Carolina with my family.  I still had to work a bit and didn’t get as much time at the beach and spending time with my kids as I would’ve liked.  I don’t relax easily, especially when I’m not home,  when I have a lot on my mind, or if I’m feeling under stress.  My work has slowed in this current environment, and that makes things more stressful, so my mind hasn’t been able to clear easily.  Also I worry about making sure my kids have a good time and that any troubles they have between each other are minimal and can be used as learning moments.  That may be an unreasonable expectation for a group of five children, all close in age, but I have high hopes.  With all those things circling in my mind, I was worried I would have a hard time having a good time. I needed to reset my mind. 

One of my favorite parts of going to the beach is the morning walk.  It’s not quite hot, but the air is warming.  The morning beach shows how the tides reset the sand over the night, almost like the morning after a fresh snow.  There are fewer footprints, sand castles, and most importantly to me, fewer people than during the day. It feels like a new space and a new opportunity.  You don’t quite get that experience in your house or at your office, when the things you have left unfinished are still there when you arrive after leaving or waking up.

Streams also constantly reset.  The water we see at any moment flows from springs in the headwaters and from storm water flowing overland to stream channels from precipitation.  Precipitation feeds the stream through a slow groundwater transfer and through more rapid stormwater flows or floods.  I am fond of the quote from the great author and conservationist, Tim Palmer, ”Streams represent constant rebirth.  The water flows in, forever new, yet forever the same, they complete the journey from beginning to end, and then they embark on the journey again.” 

On my morning walks with my wife along the beach, we would talk, connect, think about the daily menu, look for shells and sea glass, and just observe the water and the beach.  We’re both water people and science/engineering people.  One morning we observed the remnants from tide pools and my wife took some nice photos and we discussed the cool ways they formed.  I was struck by the different accumulations of sand, shells and small stones.  They reminded me of the stream bedforms I have observed.  

Sand bed streams exhibit different bedforms but with similar patterns to gravel, cobble and boulder bedded streams.  Per geologylearnblogspot.com, a bedform is a morphological feature formed by the interaction between a flow and cohesion less sediment on a bed.  

Sand bed channels have ripples, dunes, antidunes, and plane bed features.  Gravel and cobble bedded channels are often riffle, run, pool and glide channels.  In steeper channels, cascade and step pool bedforms have a tendency to develop.  Reading and understanding the geology, geomorphology, hydraulics and hydrology of these bedforms can help us be more successful fishing.  

Sand Bed Channel Bed Forms from : http://marinespecies.org/introduced/wiki/Bedforms_and_roughness

Water flowing down a plane has energy from the weight and speed of the water.  The force generated is the mass and acceleration of the water.  Often in fluvial geomorphology and hydraulic analysis projects this force is referred to as shear stress.  This is the energy that is applied to the boundary on which the water is flowing.  The particles of sand, gravel, boulders, and sometimes fallen trees that comprise channel boundaries each have weight and shapes that resist the flowing force of the water through friction forces.  The particles must resist the drag (pushing force of the water) and the buoyancy (lifting force of the water).  If a particle is set in motion from the forces it can be pushed and rolled along the bottom, often called saltation.  Or it can be lifted into the water column to muddy the water and make it turbid.   

When larger materials collect together, they become harder to move.  They then change the flow paths of the rivers or currents and form the features we see in the photos. Water backs up behind the clasts of larger materials (riffles, cascades, or steps) to form pools.  Runs are the transitions from a riffle to a pool, where the water surface begins to flatten and the channel bed (and water depth) deepens.  Glides are the transition from a pool to a riffle, where the flow shallows, often with a glossy type water surface as the water begins to steepen to flow into the riffle.  

Riffle Pool and Step Pool Morphology from http://ksuweb.kennesaw.edu/~jdirnber/limno/LecStream/riff%20pool.jpg

Coincidentally, I brought Tactical FlyFishing by Devin Olsen as my beach reading this year.  It is a fantastic book, with great detail on how to develop a plan for fishing different types of water and strategies to problem solve through the different challenges they create.  The photos, graphics and descriptions are very helpful and clear.  I finished it in just a few days and I highly recommend it.  

Thoughts of trout fishing are frequently in my mind.  The books I read, the things I watch on YouTube, what I write about focus on fly fishing.  My focus on fishing is underlain with an admiration, respect and sense of wonder about nature.  I really appreciated how walking along the beach with my wife helped me to reset and connect with those parts of myself.  It is cool to me that nature arranges itself to be diverse and in energy balance. As the resistance for one aspect builds, the opposing force rises to adjust, just as the streams form bedforms to resist the flow of water. Life adjusts to this cycle and it creates niches for different lifeforms to exist. I appreciated the feeling of newness from observing the beach, the wonder from observing and talking about the bedforms and tidepools, and ability to share it with the woman I love. I was reminded that even though the flows of life may be trickles or strong currents, that the substrate and bedforms will adjust and create newness for the next day.  Time to reset.

2 Replies to “Bedforms”

  1. Nature has such a brilliant way of communicating through sensory and visual imagery. I’m glad you found your center on those walks. It did make me think of all of my water experiences and how they’ve shaped my understanding of being human. We used to go 4-wheeling up the Bill Williams River, which was really a giant river bed. Oh it was mighty. I loved it. One time we got stuck in it for 6 hours. And the swimming under water along the bottom of the Colorado River, feeling the way the earth changed. Watching how the water and its edges would shift with each season became a part of being one with it. And lastly, after I moved to the East Coast, sitting at the edge where the water meets the sand and feeling, with each wave, the sand shift and be washed away beneath my bottom. There was something so incredibly validating about both my smallness and my connection to humanity in those moments. Wave after wave, and me. Thanks for your continued sharing.

  2. The beach is ever changing! I see the simple, interesting scene! You see a deeper force of nature! How great that there are so many levels – all amazing! All there for us to enjoy and appreciate!
    Can’t beat the experience! I am so glad it refreshed you!

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