unit 3 definitions

Question 1

remote sensing

Answer 1

It is the acquisition of information about an object or phenomenon without making physical contact with the object

Question 2

passive sensors

Answer 2

absorb energy reflected or emitted

Question 3

active sensors

Answer 3

provide the source of energy that is measured

Question 4

spatial scale

Answer 4

the location and extent of features on Earth’s surface can be identified, measured and mapped (at a range of scales)

Question 5

spectral scale

Answer 5

by looking at a range of wavelengths, different types of land cover can be identified and mapped, as well as the consequences of any land cover changes (e.g. degraded forests, silting in waterways)

Question 6

temporal scales

Answer 6

due to the frequent repeating cycle of images being collected the rate and nature of change over time is easily identified and can be measured

Question 7

land cover change modelling

Answer 7

Where scientists take images of existing land covers and, using computer software analyse the effects of a range of future scenarios to predict how land cover might change in the future

Question 8

environments

Answer 8

The living and non-living elements of the earth’s surface

Question 9

natural biomes

Answer 9

A community of life forms adapted to a large natural area

Question 10

anthropogenic biomes

Answer 10

A global ecosystem unit defined by patters of sustained human interaction with ecosystems, creating a description of the terrestrial biosphere in it contemporary, human alters form

Question 11

ecosystem

Answer 11

A description of the organisms (biotic) and physical (abiotic) features of environments including the amount and distribution of nutrients in particular

Question 12

ecosystem dynamics

Answer 12

Are the network of interactions WITHIN the ecosystem community

Question 13

affluence

Answer 13

Affluence is having increasing amounts of money or wealth

Question 14

deforestation

Answer 14

The permanent removal of trees and often their associated vegetation for non-forest uses

Question 15

expansion of agriculture

Answer 15

The expansion of agriculture refers to increasing the amount of land available which can be used for agricultural purposes

Question 16

intensification of agriculture

Answer 16

Agricultural intensification is the increase of the productivity of land already used for agriculture through more inputs (such as fertilisers, machinery, labour, technology) in hope of increasing the outputs received from it

Question 17

rangelands

Answer 17

Rangelands are ecosystems dominated by natural grasses, shrubs and some trees that are grazed by herbivores, such as grasslands, woodlands, wetlands and deserts that are grazed by domestic livestock or wild animals

Question 18

land and soil degradation

Answer 18

The process by which the value of the land and soil is negatively affected by human induced changes

Question 19

irrigation

Answer 19

the watering of land for agriculture

Question 20

land drainage and reclamation

Answer 20

Land drainage involves water being removed from water logged land near lakes, rivers and deltas so that land can be used for other purposes. Reclamation often goes one step further creating new land from oceans, rivers etc

Question 21

urban growth

Answer 21

Urban growth or urban sprawl refers to the outwards expansion of the urban area – usually in low density and often uncontrolled manner e.g. slums

Question 22

mining

Answer 22

Mining is the process of extracting ore or minerals from the ground (such as coal or iron ore)

Question 23

government policy

Answer 23

Governments can directly affect land use and land cover through the establishment of laws, regulations and policies

Question 24

land degradation

Answer 24

Land degradation is the deterioration or loss of productive capacity of the soils for present and future

Question 25

habitat destruction

Answer 25

the elimination or alteration of the conditions necessary for animals and plants to survive

Question 26

urban heat islands

Answer 26

An urban heat island is a localised climate change – a metropolitan area that is significantly warmer than its surroundings

Question 27

afforestation

Answer 27

Afforestation is largely a phenomenon of advanced industrial societies, which are both affluent and have high technological capacity and energy efficiency

Question 28

spectral signature

Answer 28

the unique combination of wavelengths of energy reflected from that particular land cover

Question 29

eutrophication

Answer 29

Caused by the release of excess nutrients into waterways from fertilisers dissolved in runoff from urban gardens and agricultural areas

Question 30

heat budget

Answer 30

Refers to the balance between energy from the sun and the outgoing terrestrial energy lost to space

Question 31

natural greenhouse effect

Answer 31

A phenomenon created by the energy radiated by the sun, the heat emitted from the Earth’s surface and greenhouse gases normally present in the atmosphere

Question 32

enhanced greenhouse effect

Answer 32

Increasing the concentrations of the greenhouse gases due to human activities has led to increase in temperature

Question 33

carbon cycle

Answer 33

the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth

Question 34

carbon sinks

Answer 34

Natural store of carbon in rocks, oceans, biomass etc are relatively stable over long periods of time but can vary with changing conditions which have the ability to change climate

Question 35

atmospheric circulation system

Answer 35

the large-scale movement of air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth

Question 36

hydrological cycle

Answer 36

The continuous movement of water through Earth’s environments, in the form of liquid water, gaseous water vapour or solid snow/ice

Question 37

evaporation

Answer 37

change of state from a liquid to gas and occurs over water bodies but also from land surface

Question 38

transpiration

Answer 38

loss of water vapour from plants through leaf pores

Question 39

advection

Answer 39

movement of water as water vapour and clouds in the atmosphere blown by winds

Question 40

condensation

Answer 40

process where gaseous water vapour changes to liquid water droplets once the dewpoint is reaches

Question 41

sublimation

Answer 41

change of state from gas to solid or vice versa, without passing through a liquid phase (snowflakes from in atmosphere)

Question 42

precipitation

Answer 42

movement of liquid or solid water from the atmosphere back to the Earth’s surface

Question 43

convectional rainfall

Answer 43

results from hot energy from earth’s surface transferred to air above, which becomes less dense as it rises creating low pressure. As it rises, it cools and the water vapour contained in the air condenses to form

Question 44

frontal rainfall

Answer 44

associated with sub-polar lows where converging air masses meet. Warmer air is displaced by cold air, eventually cooling as it rises, condensations of water vapour, clouds and rain follow the front

Question 45

orographic rainfall

Answer 45

moist air is forced to rise due to the presence of a physical barrier. Mountain ranges block the flow of air masses, forcing air to rise to pass over mountains. The rising air cools, condenses, clouds form and rain falls on the windward side of the mountain. The air that passes over is relatively dry and results in a rain-shadow on the inland side

Question 46

surface runoff

Answer 46

water that falls on the lands surface and flows along the surface, downhill, collecting in streams, rivers, lakes and ultimately flows back to the ocean

Question 47

infiltration

Answer 47

infiltration is the water soaking into the soil surface, percolations refers to deeper downwards movement of water through the soil profile

Question 48

groundwater flow

Answer 48

flowing and stored groundwater underground within the layers of soil and rock – stored in aquifers (Leederville aquifer) and often slowly flow back to ocean

Question 49

climate change

Answer 49

Climate change is a long-term shift in global or regional climate patterns or average atmospheric conditions

Question 50

ice age

Answer 50

permanent ice on land

Question 51

glacial-interglacial cycles

Answer 51

Within an ice age, individual pulses of extra cold (glacial) and warmer (inter-glacial) periods exist

Question 52

obliquity

Answer 52

Refers to the degree to which Earth is tilted on its axis and 41,000 year cycle between 22° to 24°

Question 53

precession

Answer 53

Refers to the way in which the Earth wobbles on its axis like a spinning top and 26,000 year cycle

Question 54

eccentricity

Answer 54

Refers to regular changes in the shape of the Earth’s orbital path around the sun and 100,000/400,000 year cycle

Question 55

urban heat island effect

Answer 55

Local scale climate change (heating of urban areas relative to surrounding rural areas) due to physical differences between land cover

Question 56

albedo

Answer 56

Albedo is the proportion of light (insolation) that is reflected by the Earth’s surface