R - Hydrological Cycle

Question 1

What is the hydrological cycle?

Answer 1

The process whereby water in it various forms is continually cycled between the land, sea and atmosphere

Question 2

What type of system is the global hydrological cycle? Why?

Answer 2

A closed system - there are no inputs or outputs

Question 3

What type of system is a drainage basin system?

Answer 3

An open system

Question 4

What are the four main processes in the hydrological cycle?

Answer 4

Interception, evapotranspiration, infiltration and precipitation

Question 5

What are the inputs of a drainage basin?

Answer 5

Precipitation

Question 6

What is precipitation?

Answer 6

All forms of moisture that reaches the Earth’s surface, including rain, snow and dew

Question 7

What are the storage things in a drainage basin?

Answer 7

Interception, vegetation storage, surface storage, groundwater storage and channel storage

Question 8

What is interception?

Answer 8

The prevention of precipitation from reaching the Earth’s surface by trees and vegetation

Question 9

What is vegetation storage?

Answer 9

Water being taken up by plants - it’s all the water contained in plants at any one time

Question 10

What is surface storage?

Answer 10

The total volume of water held on the Earth’s surface in lakes ponds and puddles

Question 11

What is groundwater storage?

Answer 11

The storage of water underground in permeable rock strata

Question 12

What is channel storage?

Answer 12

Water held in a river or stream channel

Question 13

What are the flows and processes in a drainage basin?

Answer 13

Surface runoff
Throughfall
Stemflow
Throughflow
Infiltration
Percolation
Groundwater flow
Baseflow
Interflow
Channel flow

Question 14

What is surface runoff?

Answer 14

Water flowing over the land surface as channel flow and overland flow. (aka surface flow and overland flow)

Question 15

What is throughfall?

Answer 15

Water dripping from one leaf (or plant) to another

Question 16

What is Stemflow?

Answer 16

Flow down plant trunks and stems following interception

Question 17

What is throughflow?

Answer 17

The movement of water downslope within the soil layer

Question 18

What if Inifltration?

Answer 18

The downward movement of water into soil surface

Question 19

What is percolation?

Answer 19

The gravity flow of water within soil

Question 20

What is goundwater flow?

Answer 20

The deeper movement of water through the underlying rock strata

Question 21

What is baseflow?

Answer 21

Water that reaches the channel largely through slow throughflow and from permeable rock below the water table

Question 22

What is interflow?

Answer 22

Water flowing downhill through permeable rock about the water table

Question 23

What is channel flow?

Answer 23

The movement of water within the river channel

Question 24

What are the outputs of a drainage basin?

Answer 24

Evaporation
Transpiration
Evapotranspiration
River discharge/River flow

Question 25

What is evaporation?

Answer 25

The transformation of water droplets into water vapour by heating

Question 26

What is transpiration?

Answer 26

Evaporation from plant leaves

Question 27

What is evapotranspiration?

Answer 27

The loss of water from a drainage basin into the atmosphere from the leaves of plants

Question 28

What is the water balance?

Answer 28

The balance between the inputs and outputs

Question 29

What happens to the water balance in wet seasons? What are the results?

Answer 29

Precipitation exceeds evapotranspiration - this creates a water surplus The ground stores fill with water so there more surface runoff and higher discharge - so river levels rise

Question 30

What is a surplus?

Answer 30

More than is needed

Question 31

What happens to the water balance in drier seasons?

Answer 31

Precipitation is lower than evapotranspiration Ground stores are depleted as some water is used (eg by plants & humans) and some flows into the river channel - but isn't replaced by precipitation

Question 32

What happens at the end of a dry season?

Answer 32

There is a deficit of water in the ground - the ground stores are recharged in the next wet season

Question 33

What is a deficit?

Answer 33

A shortage