Formation of graded profiles

Question 1

formation of graded profiles

Answer 1

time
climate
geology and tectonics
changes in base level
reservoirs and dams
land use

Question 2

time

Answer 2

everything stays the same, erosion by the river will reduce its height above base level. sediment is carried as load and will be deposited into the sea forming a delta

Question 3

climate

Answer 3

precipitation is the input into the river system. long term changes in climate will alter the rate at which a river can adjust its long profile to local variations in other factors. It will speed up when precip is high and vice versa for low

Question 4

geology and tectonics

Answer 4

resistant intrusions prevent the smooth graded profile from developing. some features such as waterfalls are caused by the lowering of the long profile downstream with different rock resistances

Question 5

changes in base level

Answer 5

a fall in sea level or rise in the land will lead to erosion by increasing the potential energy available. A fall to the sea creates a “nick point” of potential energy which trsvels upstream encountering varying levels of erosion depending on the river geology

Question 6

reservoirs and dams

Answer 6

reservoirs control flood flows and reduces the winter energy surplus in rivers. waterfalls no longer retreat upstream with dam projects and new base level may be created

Question 7

land use

Answer 7

overgrazing; destruction of the vegetation cover in the catchment area has noticiblee effects on the sediment carried, transporting the load uses up energy and reduces the rate of erosion

Question 8

upper course consists of

Answer 8

v- shaped valleys
straight channels
waterfalls
gorges
rapids

Question 9

middle course consists of

Answer 9

riffles and pools
point bars
alluvial fans
braiding

Question 10

lower course consists of

Answer 10

esturies

deltas