Question

Which statements correctly differentiate the erosive power between the river courses?

1. The upper course has the greatest erosive power due to fast-flowing water.
2. The middle course exhibits more erosion than the lower course.
3. The lower course has significant erosive power, shaping canyons.
4. Erosive power is uniform across all three river courses.

• A. 1, 3
• B. None of these
• C. 1, 2
• D. 2 only

Answer 1

Answer:

C. 1, 2

THE UPPER OR MOUNTAIN COURSE

• Here the water is fast flowing and runs through a 'V' shaped valley with unstable banks.

• The fast flowing water has great erosive powers, particularly after rains, being able to move large stones and roll them along.

• Angular stones washed into the river are rubbed against one another, to form rounded pebbles.