Every day, a photograph, a poem. Today we ate lunch by the beach in front of the “sand hill” the grandkids once tumbled down into the cold waters of Crescent Bay on Lake Roosevelt of the Columbia River.
This was a favorite place, always, even if we “camped” elsewhere for the day, a trip to this beach was always part of the fun.
In front of the hill, the hill keeps going down, so diving into the lake right from shore is always a thing to do– no wading needed. The lake fluctuates since it is a reservoir to irrigate the dry lands of the Columbia Basin and generate electricity. [history]
Squealing as they ran,
almost tumbling, in the sand—
racing to the lake.Sheri Edwards
We noticed how much the sand hill has changed, and since we’ve been taking pictures of the kids here for years, I searched through our images and took a screenshot of the two images together— the left is April, 2021 and the right is August, 2011. You can see the changes in ten years time. Click the images for a larger view.
You can see the large “island of grasses” that has sloughed down over the years — did it happen quickly or inch by inch?
Notice the recent slide on the left.
On the top left, you can see an entire strip of grassy area has dropped after the sand beneath it washed away.
Erosion: a powerful force.
Another thing to consider is the “angle of repose” — or the slope at which a granular material will or will not slump. Here’s an “Engineer’s Toolbox” about that, and a Scientific American article too.
We’ve always wondered about the angle of repose of that hill.
Geeky Gramma ~~
Retired Middle School Language Arts/Media Teacher ~~
Writer and Thinker~~
Art from the Heart