Hydrosphere

Question 1

what are some features of the upper course of a river?

Answer 1

narrow channel, v shaped valleys, fast flowing

Question 2

what are some features of the middle course of a river?

Answer 2

wide flat channel, gently sloping valley, meanders, fats flowing with a larger volume of water

Question 3

what are some features of a rivers lower course?

Answer 3

very wide channel, very flat banks and levees, slower flowing due to less gravity

Question 4

what is evaporation?

Answer 4

the pocess by which liquid water becomes gaseous

Question 5

what is evapotranspiration?

Answer 5

the total water lost to the atmosphere from a land surface (evaporation + transpiration)

Question 6

what is precipitation?

Answer 6

any liquid or frozen water that falls from the atmosphere to Earth

Question 7

what is interception?

Answer 7

interruption of the movement of water e.g by trees or vegetation

Question 8

what is an example of surface storage?

Answer 8

lakes/ponds/wetlands

Question 9

what is infiltration?

Answer 9

water moving through the soil and rock to be stored in the ground

Question 10

what is throughflow?

Answer 10

the lateral movement of water in the soil zone

Question 11

what is percolation?

Answer 11

the movement of water vertically through the soil

Question 12

what is groundwater and groundwater flow?

Answer 12

water that exists in the underground saturated zones is groundwater, and its movement is groundwater flow

Question 13

what is surface flow (surface runoff)?

Answer 13

excess water that flows over the Earths surface as river and streams

Question 14

what are some factors that increase surface run off (cause shorter lag times)?

Answer 14

impermeable rock
thin, saturated soil
a high water table
urban or deforested area
high drainage density
steep sided valleys

Question 15

what are some factors that decrease surface run off (cause longer lag times)?

Answer 15

permeable rock
thick, unsaturated soil
a low water table
rural or afforested area
low drainage density
gently sloping valleys

Question 16

what is the lag time of a hydrograph?

Answer 16

the difference between the times of peak rainfall and peak discharge

Question 17

what is a rivers discharge measured in?

Answer 17

cumecs

Question 18

what is hydraulic action?

Answer 18

where the force of the water forces air into cracks in the rock, breaking pieces off

Question 19

what is abrasion?

Answer 19

material in the rivers load is dashed against the banks and bed as it is swept past, wearing them away

Question 20

what is attrition?

Answer 20

where rocks and stones in the river load bash into each other and pieces break off, causing the average load to become smaller and rounder

Question 21

what is corrosion?

Answer 21

where acids in the water dissolve minerals in the rocks

Question 22

what are the four ways that material can be transported in a river?

Answer 22

traction, saltation, suspension and solution

Question 23

what is helicoidal flow?

Answer 23

the corkscrew movement of water from one side of a river to the other that carries material from the inside of one bend to the outside of another

Question 24

what are riffles and pools?

Answer 24

riffles are areas of faster moving shallow water while pools are areas of slower moving deeper water

Question 25

how does a meander form?

Answer 25

a river flows over obstacles causing it to move slower or faster this forms riffles and pools and the river becomes more sinuous water moves faster on the outside of a bend so greater erosion occurs there river beaches and cliffs are formed and helicoidal flow moves material between them meanders become more pronounced over time

Question 26

how are oxbow lakes related to meanders?

Answer 26

an oxbow lake is a meander that has been cut off from the main stream after a meander is formed it will become more pronounced and the neck will become thinner, eventually may be cut during a flood when flood waters recede, deposition will seal off the meander creating an oxbow lake

Question 27

waterfalls form where?

Answer 27

in the upper course where vertical erosion is high and a band of hard rock is overlying a band of softer rock

Question 28

waterfalls form what features?

Answer 28

plunge pools and steep sided gorges

Question 29

v-shaped valleys involve what process as well as the hydrological erosion?

Answer 29

weathering of the valley sides, often frost shattering

Question 30

explain the formation of a v-shaped valley?

Answer 30

Vertical erosion causes a straight river channel to become deeper and deeper, although the volume of water does not change so the river is just sunk into the ground. The valley sides are weathered and material slips down the slopes and is carried away by the river This forms the distinctive V shape The collapsed material is used to abrade the river bed and so vertical erosion continues