4.1 Introduction to Water Systems

Question 1

Water Cycle/Hydrological Cycle

Answer 1

A (closed) system when considered on a global scale consisting of flows (transfers and transformations) and stores of water.

Question 2

Transfers in the water cycle

Answer 2

• Precipitation
• Water flowing down a stream
• Infiltration of water through the soil profile into the aquifer.

Question 3

Transformations in the water cycle

Answer 3

Evaporation, melting, freezing, condensation.

Question 4

Evaporation

Answer 4

Liquid to a gas (a transformation)

Question 5

Condensation

Answer 5

Gas to a liquid (a transformation)

Question 6

Precipitation

Answer 6

Water falling to the ground as rain, snow, hail etc (a transfer)

Question 7

Advection

Answer 7

Movement of clouds by the wind (a transfer)

Question 8

Infiltration

Answer 8

Water soaking into the ground

Question 9

Aquifer

Answer 9

Groundwater stored in a layer of porous rock

Question 10

Runoff

Answer 10

Water flowing across and impermeable surface (or a saturated soil)

Question 11

Transpiration/Evapotranspiration

Answer 11

A special kind of evaporation from plant leaves.

Question 12

Percolation

Answer 12

Filtering of liquid through porous material
Different from infiltration in that it occurs within the porous material. Infiltration is movement from the outside in to a porous material.

Question 13

Soil Moisture

Answer 13

Water in the pore spaces of the soil profile.
Not to be confused with an aquifer (which is a saturated layer of porous rock)

Question 14

Catchment

Answer 14

Used in the context of rivers.
Drainage area flowing into the same flow/output.

Question 15

Water Budget

Answer 15

A model accounting for the inputs and outputs of water in a system.

Question 16

Urban Water Cycle

Answer 16

The modified outcome of impervious roofs and roads funneling more runoff and inciting less infiltration or local retention following rain events.

Question 17

Stormwater Harvesting

Answer 17

A technique in which stormwater is captured stored and utilised locally rather than it flowing into the broader catchment following a rain event.

Question 18

Porous

Answer 18

Has holes/pored - like a sponge

Question 19

Impermeable/Impervious

Answer 19

Solid barrier restricting the infiltration of water leading to runoff

Question 20

Saturated/Saturation

Answer 20

When the pores in the soil profile are full and cannot soak up further rainfall, which runs off instead

Question 21

Run

Answer 21

Part of a river, characterised by smooth unbroken flow (as opposed to a riffle, which is fast, shallow flow over rocks)

Question 22

Riffle

Answer 22

A feature of a river characterised by fast shallow flow over cobbles or boulders, which break the water surface.
(As opposed to runs which consist of smooth, unbroken flow)