Question 19
Rivers and River LandformsThe presence of gorges in the upper section of rivers is due to the fact that
- A.the rocks in the upper course are less resistant
- B.the volume of the river is small
- C.hanging valleys join the main valley as waterfalls to cause the gorges
- D.the upper course has a steep gradient
- E.the water contains chemicals which dissolve the rocks
Show the answer and explanation
Answer: D (the upper course has a steep gradient)
Explanation
A steep gradient gives fast water and strong downward (vertical) erosion, cutting deep narrow gorges.