Question

Describe the fundamental physics of the erosion of creek beds in function of the radius of the particle.

Answer 1

There are two aspects of this answer. Firstly i might wish to discuss the effect of the radius or the dimensions of the particles that are present on the stream bed with the degree of abrasion . Minimum flow velocity required to erode materials decreases with the dimensions of particles. So, it becomes easier for the method of abrasion to erode material mainly consisting of fine grained bed materials as compared to larger sized particles. This phenomenon breaks continuity for clay sized materials. Clay sized fine grained materials possess cohesive forces. This force holds clay particles together and makes them harder to be eroded. So, the method of abrasion is heavily impeded when the stream beds are dominantly composed of clay rich materials.
Now let's come to the connection between the dimensions of the particles and their ability to erode stream beds. When the particle size is bigger , they're more capable of manufacturing deeper dents within the stream beds. They apply greater momentum to the bed surface at the time of impact. So, larger fractions of materials are eroded from the bed on each collision with the stream bed. This relation has recently been supported by experimental and numerical studies of the topic .