Final answer:
Downstream refers to the direction of flow in a river or stream, where the width of the channel widens and the current slows down. This slow-moving water carries more sedimentation.
Step-by-step explanation:
Downstream refers to the direction of flow in which the water is moving in a river or stream. As the water flows away from the source, the width of the channel gradually widens and the current slows down. This slow-moving water, caused by the decrease in gradient and the increase in volume as tributaries unite, carries more sedimentation.