Hydrosphere: Global Hydrological Cycle and Drainage Basins

Question 1

storage

Answer 1

lakes, oceans glaciers and underground aquifers store water

Question 2

overland flow

Answer 2

• also called surface runoff
• water from rain or snowmelt that flows over the land

Question 3

aquifer

Answer 3

porous rock or sediment that is saturated with groundwater

Question 4

stream flow

Answer 4

the flow of water in streams and rivers back to the ocean

Question 5

soil moisture flow

Answer 5

• also called through flow
• the movement of water horizontally in the soil beneath the surface

Question 6

interception

Answer 6

when precipitation falls on leaves & branches before reaching the ground

Question 7

infiltration

Answer 7

when water is absorbed into the soil

Question 8

percolation

Answer 8

when water flows through porous, permeable rock to go further underground than the soil level

Question 9

water table

Answer 9

• also called groundwater
• the level at which soil or rock is saturated with water

Question 10

groundwater flow

Answer 10

• also called base flow
• the slow process of water flowing underground back to the sea

Question 11

tributary

Answer 11

a smaller river feeding into the main one

Question 12

confluence

Answer 12

when two rivers meet

Question 13

watershed

Answer 13

the boundary between two drainage basins

Question 14

input

Answer 14

water arriving into the drainage basin

Question 15

transfer

Answer 15

the flow of water through the drainage basin system without stopping

Question 16

output

Answer 16

ways in which water leaves the drainage basin system

Question 17

human factors affecting the hydrological cycle (6)

Answer 17

• deforestation
• afforestation
• irrigation
• urbanisation
• mining
• construction of dams and reservoirs

Question 18

how does deforestation affect the hydrological cycle?

Answer 18

• felling of trees decreases interception
• this increases overland flow, increasing soil erosion
• evapotranspiration decreases, reducing cloud formation and rainfall
• less interception and water storage in trees means more water in rivers

Question 19

how does irrigation affect the hydrological cycle?

Answer 19

• taking water from rivers/aquifers reduces the flow of rivers and lowers water tables
• storing water in surface stores increases evapotranspiration
• in arid places, irrigation may wash out salts from below the level of roots
• capillary action may bring salts up to the roots and kill plants

Question 20

how does urbanisation affect the hydrological cycle?

Answer 20

• the replacement of vegetation with impermeable surfaces like concrete means that soil cannot absorb precipitation
• this results in more overland flow, a rise in river levels and therefore more risk of flooding
• lack of absorption also reduces the amount of water in groundwater storage, lowering the water table

Question 21

how does mining affect the hydrological cycle?

Answer 21

• clearance of land for mining reduces vegetation
• this causes increased overland flow and more evaporation and therefore more clouds, altering rainfall patterns
• this can cause silting up of storage, reducing water storage capacity

Question 22

how does the construction of dams/reservoirs affect the hydrological cycle?

Answer 22

• storage of water like this increases its surface area, increasing evaporation
• also increases the water table

Question 23

how does afforestation affect the hydrological cycle?

Answer 23

• increase in interception
• water will be stored in trees, reducing rates of overland flow
• evapotranspiration increases, forming more clouds and bringing more rain