What characterizes noncohesive bank material?

Answer: C — Removed grain by grain from the streambank

Noncohesive bank material is characterized by its granular nature, which means that the particles, often made up of sand or gravel, do not stick together effectively. This lack of cohesion results in a situation where the material can be removed grain by grain from the streambank as water flows over it. The individual particles are easily displaced because they do not have significant inter-particle bonding, making erosion more likely to occur, particularly during high flow events. The other options, while relevant to the discussion of bank materials, do not accurately characterize noncohesive materials. For instance, noncohesive materials are indeed susceptible to rapid erosion, but this is more a consequence of their characteristics rather than defining them. Similarly, the idea that they are strongly bonded with soil contradicts the very essence of noncohesive materials, which inherently lack such bonding. Lastly, their resistance to water flow also doesn’t apply, as noncohesive materials are often less resistant and can be easily eroded under flowing water conditions.