Water Cycle

Question 1

Define Atmospheric Water:

Answer 1

Water found in the atmosphere mainly water vapour with some liquid water (cloud and rain droplets) and ice crystals.

Question 2

Define Cryospheric Water:

Answer 2

The water locked up on the Earth’s surface as ice.

Question 3

Define Hydrosphere:

Answer 3

A discontinous layer of water at or near the Earth’s surface. It includes all liquid and frozen surface waters, groundwater held in soil and rock and atmospheric water vapour.

Question 4

Define Oceanic Water:

Answer 4

The water contained in the Earth’s oceans and seas but no including such inland seas as the Caspian Sea.

Question 5

Define Terrestrial Water:

Answer 5

This consist of groundwater, soil moisture, lakes, wetlands, and rivers.

Question 6

Define Condensation:

Answer 6

The process by which water vapour changes into liquid water.

Question 7

Define Cryospheric Processes:

Answer 7

Those processes that affect the total mass of ice at any scale from local patches of frozen ground to global ice amounts. They include accumulation (the build-up of ice mass) and ablation the loss of ice mass).

Question 8

Define Drainage Basin:

Answer 8

This is an area of land drained by a river and its tributaries. It includes water found on the surface, in the soil and in near-surface geology.

Question 9

Define Evaporation:

Answer 9

The process by which liquid water changes to a gas. This requires energy, which is provided by the sun and aided by wind.

Question 10

Define Evapotranspiration

Answer 10

The total output of water from the drainage basin directly back into the atmosphere.

Question 11

Define Groundwater Flow:

Answer 11

The slow movement of water through underlying rocks.

Question 12

Define Infiltration

Answer 12

The downward movement of water from the surface into soil.

Question 13

Define Interception Storage:

Answer 13

The precipitation that falls on the vegetation surfaces or human-made cover and is temporarily stored on these surfaces. This water is then either evaporated or transferred to the ground.

Question 14

Define Overland flow:

Answer 14

The tendency of water to flow horizontally across land surfaces when rainfall has exceeded the infiltration capacity of the soil and all surface stores are full to overflowing.

Question 15

Define Percolation:

Answer 15

The downard movement of water within the rock under the soil surface. Rates vary depending on the type of geoglogy.

Question 16

Define Run-off:

Answer 16

All the water that enters a river channel and eventually flows put of the drainage basin.

Question 17

Define Saturated:

Answer 17

This applies to any water store that has reached its maximum capacity.

Question 18

Define Stemflow:

Answer 18

The portion of precipitation intercepted by the canopy that reaches the ground by flowing down stems, stalks, or tree bole.

Question 19

Define storm and rainfall event:

Answer 19

An individual storm is defined as a rainfall period separated by dry interval of at least 24 hours and an individual rainfall event is defined as a rainfall period separated by dry interval of at least 4 hours.

Question 20

Define Throughfall:

Answer 20

The portion of the precipitation that reaches the ground directly through gaps in the vegetation canopy and drips from the leaves, twigs, and stems. This occurs when the canopy-surface exceeds its storage capacity.

Question 21

Define Throughflow:

Answer 21

The movement of water down-slope through the subsoil under the influence of gravity. It is particularly effective when underlying permeable rock prevents further downward movement.

Question 22

Define Transpiration:

Answer 22

The loss of water from vegetation through stomata on their surfaces.

Question 23

Define Water Balance:

Answer 23

The balance between inputs (precipitation) and outputs (run-off, evapotranspiration, soil and groundwater storage) in a drainage basin.

Question 24

Define Bankfall:

Answer 24

The maximum discharge that a river channel is capable without flooding.

Question 25

Define Baseflow:

Answer 25

The representation of the normal day-to-day discharge of the river and is the consequence of slow throughflow and groundwater seeping into the river channel.

Question 26

Define Discharge:

Answer 26

The amount of water in river flowing past a particular point expressed as m^3s^-1

Question 27

Define Lag time:

Answer 27

The time between the peak rainfall and peak discharge.

Question 28

Define Peak discharge:

Answer 28

The point on a flood hydrograph when river discharge is at its greatest.

Question 29

Define Storm Flow:

Answer 29

Discharge resulting from storm precipitation involving overland flow, throughflow, and groundwater flow.

Question 30

Define Storm hydrograph

Answer 30

A graph of discharge of a river over the time period when the normal flow of the river is affected by a storm event.

Question 31

Define Water abstraction:

Answer 31

Demand on water exceeds the amount available and then have to be abstracted from an area to be used in another area.

Question 32

Define River regime:

Answer 32

The variability in its discharge throughout the course of a year in response to precipitation, temperature, evapotranspiration, and drainage basin characteristics.