Rivers KO

Question 1

Upper course channel characteristics

Answer 1

Narrow and shallow. Likely to have large rocks in it. Water flow is turbulent and speed is variable. Where water is shallow the will be friction and so slow flow. Where water is deeper flow will be quick

Question 2

Upper course valley characteristics

Answer 2

Steep sided. V-shaped.

Question 3

Upper course processes happening here

Answer 3

Vertical erosion in dominant.

Question 4

Upper course land forms found here

Answer 4

Interlocking Spurs. V-shaped valleys. Waterfalls. Gorges.

Question 5

Middle course channel characteristics

Answer 5

The river channel is wider and deeper as tributaries have added additional water. Flow is faster than in the upper course as there is less friction between the water and the river bed and banks.

Question 6

Middle course valley characteristics

Answer 6

Wide gently sloping.

Question 7

Middle course land forms found here

Answer 7

Meanders. Ox-bow lakes.

Question 8

Middle course processes found here

Answer 8

Lateral (sideways) erosion, transportation and deposition.

Question 9

Lower course channel characteristics

Answer 9

River is deepest and widest in this section. Flow will be slow because this is where the river meets the sea.

Question 10

Lower course valley characteristics

Answer 10

Very wide. Very gently sloping.

Question 11

Lower course processes happening here

Answer 11

Deposition

Question 12

Lower course landforms found here

Answer 12

Meanders, Estuaries. Levees. Deltas.

Question 13

Formation of waterfalls and gorges.

Answer 13

Found mostly in the upper course of river or where upper course becomes middle course.

1. hard rock overlays soft rock
2. a break or gap in the hard rock layer allows the softer rock to be eroded more quickly forming a drop
3. The drop means that erosion happens more quickly. A plunge pool is formed.
4. the water movement upstream forms a gorge (a narrow steep sided valley)

Question 14

Formation of Meanders and Ox-bow lakes.

Answer 14

Found mostly in lowland areas in the middle course of a river

1. On a bend the river flows more quickly on he outside then it does on the inside
2. This causes erosion on the outside of the bend and deposition on the inside of the bend.
3. The bed becomes exaggerated forming a meander.
4. Over time the meal of the meander is eroded
5. The meander is cut by erosion and sealed off my deposition. The river is now flowing in a much straighter line.
6. The old sealed off meander has become an ox-bow lake

Question 15

Formation of floodplains

Answer 15

When a river floods in the lower course, it deposits very fine sediment (silt). Layer after layer builds up to form a thick deposit of silt across a very flat wide valley. The floodplain is made wider due to large meanders that wind across the floodplain.

Question 16

Formation of levees

Answer 16

When a river floods, the speed of a river decreases = less energy = deposition.
•heavier coarser sand and small stones are deposited first next to the river bank
•lighter silt/mud is deposited further across the floodplain.
•over time the height of the banks are raised my a buildup of coarser sand deposits = levees.