aqa gcse geography - uk physical landscape

relief

relief

the shape of the land

highland

area of high/mountainous land

lowland

area of land where the land is at, near or below sea level

gradient

steepness of a slope

hydrological cycle

water cycle

source

where the river starts

mouth

river flows into lake/sea/ocean

estuary

tide meets river

tributary

smaller river joins another

confluence

place where 2 rivers meet and flow into one

watershed

edge of drainage basin, imaginary line separating drainage basins

drainage basin

area of land that is drained by a river and its tributaries

vertical erosion

erosion downwards

lateral erosion

erosion across

long profile

river journey

upper course

steep, waterfalls and rapids / steep valley, v shaped, gorges / interlocking spurs, v-shaped valleys, waterfalls, gorges / vertical erosion

middle course

gentle gradient, much smoother / lower, more gentle slopes, flood plain on valley floor / meanders, slip-off slopes, river cliffs / lateral erosion, deposition

lower course

very gentle gradient, almost flat / wide, flat valley bottom / ox-bow lakes, mudflats, estuaries, delta / no erosion

abrasion

sandpaper! grinding of rocks on the river bed and banks

solution

some rocks dissolve, chemical reaction, e.g. chalk

attrition

hit! rocks against rocks = wear away

hydraulic action/power

water force, water smashes rock

traction

large particles lie boulders are pushed along the river bed by the force of the water

saltation

pebble-sized particles are bounced along the river bed by the force of water

suspension

small particles like silt and clay are carried along in the water

solution

soluble materials dissolve in the water and are carried along

waterfall

a geological formation where flowing water rapidly drops in elevation as it flows over a steep region or cliff

causes of flooding

deforestation, agriculture, relief, land use, geology, urbanisation

deforestation

trees are removed = water more available = no water temporarily stored or transpired

land use

deforest for space/plough the land/plant crops = no trees = no shelter = no interception = no surface runoff

relief

v-shaped valleys = more surface run off OR flat land = water can't run off and gets oversaturated

agriculture

soil is left unused and exposed = more surface run off = doesn't soak in

geology

hard rock e.g. granite = prevents infiltration so surface water builds OR soft rock e.g. clay = some water soaks in

urbanisation

building on floodplains = impermeable surfaces = water can't sink in

groynes (HARD)

• cost up to £5000/m

• timber/rock structures built out to sea. trap sediment moved by LSD and broaden beach = reduce waves attack on coast

• adv: bigger beach = more tourists, not too expensive, useful for fishing

• disadv: unnatural/unattractive, stops other beaches from getting sediment

rock armour (HARD)

• cost: £1000-4000/m

• piles of large boulders dumped at foot of cliff. rock forces wave to break = protects cliff

• adv: fairly cheap, easy to maintain

• disadv: expensive to transport, can block views

dune regeneration (SOFT)

• cost: £2000/100m

• sand dunes are effective buffers = maram grass stabilises

• adv: maintains natural coastal environment, relatively cheap, popular w/ people & wildlife

• disadv: time consuming, can be damaged by storms

managed retreat (SOFT)

• cost: £5000-10000/h

• involves allowing low lying coastal areas to be flooded by sea = salt marsh = affective barriers to the sea

• adv: cheap, no maintenance, creates habitats

• disadv: land is lost, farmers need to be compensated

sea wall (HARD)

• cost: up to £6mil/km

• concrete/rock barrier placed on foot of cliffs

• adv: effective at reducing erosion, often have walkways

• disadv: expensive, can be obtrusive, hard to maintain

beach nourishment (SOFT)

• cost: £3,000/m

• addition of sand/shingle to make beach wider

• adv: cheap, increased tourism, blends in

• disadv: needs constant maintenance

gabions (HARD)

• cost: £350/m

• cages of boulder built into cliff face = absorbs wave energy

• adv: effective with severe erosion, cheap

• disadv: environmentally ugly

wooden revetment (HARD)

• cost: £1000/m

• similar to groynes, wooden structure breaks wave energy

• adv: creates bigger beach, effective

• disadv: ugly, does not protect cliff, may need replacing

sustainable management

long term management that does not harm people/environments