Basic River Info

Question 1

what is vertical erosion

Answer 1

the deepening of the river bed by hydraulic action and other erosional processes

Question 2

what is lateral or horizontal erosion

Answer 2

the widening of the river bed by hydraulic action and other erosional processes

Question 3

what does the hjustrom curve show

Answer 3

• it shows the different critical velocities of water

- at which erosion, transportation and deposition occurs based on size of material

Question 4

what correlation does the hjustrom curve show

Answer 4

• as the size of pebbles increase so does the velocity of river
• an increase in the velocity of water results in an increase of the size of pebbles
• the size of pebbles is directly proportional to the velocity of the river

Question 5

what is the channel cross profile of a river

Answer 5

a section taken sideways across a river channel

Question 6

what is the valley cross profile of a river

Answer 6

a section taken sideways of a channel, valley, floor and the slopes of the sides of the valley

Question 7

what are the three courses of a river

Answer 7

upper, middle and lower course

Question 8

how is the upper course of a river formed

Answer 8

• the upper course is formed by the river eroding the riverbed vertically by hydraulic action and abrasion
• meaning its narrow and shallow

Question 9

how is the middle course of a river formed

Answer 9

• the middle course of formed by the joining of tributaries
• which increase volume of water
• and gives the river more kinetic energy and velocity
• and therefore more erosive power
• river channel becomes wider

Question 10

how is the lower course of a river formed

Answer 10

• the lower course is formed by more lateral erosion taking place
• which erodes river banks and makes channel wider
• some vertical erosion still takes place

Question 11

what is confluence

Answer 11

a term which describes a river or stream flowing into the main river channel

Question 12

what is a tributary

Answer 12

a tributary is the point at which two rivers meet

Question 13

what is watershed

Answer 13

watershed is an area of land that separates and prevents waters flowing to different rivers, basins or seas

Question 14

what would you expect to find in the upper course

Answer 14

• vertical erosion
• spurs
• large boulders
• steep gradient

Question 15

what do you expect to find in the middle course

Answer 15

• more lateral erosion
• increased discharge and velocity
• meandering of the river

Question 16

what do you expect to find in the lower course

Answer 16

• more lateral erosion and less vertical
• wide and deep channel
• high velocity and discharge