R - Hydrological Cycle Flashcards Preview

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Flashcards in R - Hydrological Cycle Deck (33):
1

What is the hydrological cycle?

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

2

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

A closed system - there are no inputs or outputs

3

What type of system is a drainage basin system?

An open system

4

What are the four main processes in the hydrological cycle?

Interception, evapotranspiration, infiltration and precipitation

5

What are the inputs of a drainage basin?

Precipitation

6

What is precipitation?

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

7

What are the storage things in a drainage basin?

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

8

What is interception?

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

9

What is vegetation storage?

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

10

What is surface storage?

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

11

What is groundwater storage?

The storage of water underground in permeable rock strata

12

What is channel storage?

Water held in a river or stream channel

13

What are the flows and processes in a drainage basin?

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

14

What is surface runoff?

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

15

What is throughfall?

Water dripping from one leaf (or plant) to another

16

What is Stemflow?

Flow down plant trunks and stems following interception

17

What is throughflow?

The movement of water downslope within the soil layer

18

What if Inifltration?

The downward movement of water into soil surface

19

What is percolation?

The gravity flow of water within soil

20

What is goundwater flow?

The deeper movement of water through the underlying rock strata

21

What is baseflow?

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

22

What is interflow?

Water flowing downhill through permeable rock about the water table

23

What is channel flow?

The movement of water within the river channel

24

What are the outputs of a drainage basin?

Evaporation
Transpiration
Evapotranspiration
River discharge/River flow

25

What is evaporation?

The transformation of water droplets into water vapour by heating

26

What is transpiration?

Evaporation from plant leaves

27

What is evapotranspiration?

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

28

What is the water balance?

The balance between the inputs and outputs

29

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

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

30

What is a surplus?

More than is needed

31

What happens to the water balance in drier seasons?

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

32

What happens at the end of a dry season?

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

33

What is a deficit?

A shortage