River Profiles and Course Characteristics
Rivers change dramatically as they flow from source to mouth, creating three distinct courses with unique characteristics. The upper course near the source features steep gradients, narrow shallow channels, and vertical erosion that carves V-shaped valleys between interlocking spurs.
As rivers mature into the middle course, channels become wider and deeper whilst gradients gentle out. The bedload transforms from large, angular rocks to smaller, more rounded materials as the river's energy shifts focus.
The lower course approaching the sea shows rivers at their most powerful for transportation. Here you'll find very gentle gradients, U-shaped channels, and fine sediment deposition creating broad floodplains where deposition dominates over erosion.
Quick Tip: Remember the pattern - narrow and steep at the source, wide and gentle at the mouth!