This diagram shows the three courses of a river - the UPPER, MIDDLE and LOWER courses. Each course is very diferent and has unique features associated with it.
The upper course is where the source of the river is found and is typically a steep upland area with high levels of rainfall. The landscape will very sparsely covered with vegetation and will mostly consist of v-shaped valleys and interlocking spurs. Other common features found in the upper course are waterfalls and gorges.
Click on this link to watch an animation of how interlocking spurs are formed. During glaciation it is these interlocking spurs which are eroded by the glaciers and become the steep sides of the u-shaped valley known as truncated spurs.
