Experimental Trench in Armored Riverbed in Alaska

A trench through the armor layer of gravel and cobbles in a stream bed underlain with mostly sandy material might be expected to cause subsequent stream bed erosion. To test this, an experiment was performed at a channel site on Eagle River near Anchorage, Alaska. The experiment was no conclusive but provides reasonable evidence that a cross-channel trench through the armor layer will not cause erosion.