Why why does bed load change as it goes downstream?

Answer 1

The size of the pebble will decrease down stream because the further downstream you go the quicker the river velocity. This means there will be more abrasion against the sides and bed of the river and the friction will be greater, this wears away the river load making it decrease in size. Increase velocity means that bigger material will be picked up by the river and carried as river load. More load in the river and increased size of load will mean more attrition and the river load will keep colliding into each other smoothening and rounding their shape.

Brap brap !!

Answer 2

Bedload decreases downstream due to the fact that the rocks and pebbles would be bumping into each other and breaking bits off (abrasion and attrition). Also, faster river velocities are capable of carrying greater amounts of bedload and transporting them farther and faster. The shape of the sediments of the bedload would therefore be exposed to more physical weathering which would progressively round the sediments and also decrease their size.

Answer 3

because the river picks up speed so it is able to erode the bedload better so the river gets less and less bedload.

Answer 4

Usually because the downstream portion of a streambed receives the most flow and therefore more scour and smoothing of the streambed.

Answer 5

the bed load gets more rounded and angular as erosion occurs