Landscapes and Physical processes Flashcards
upland
a landscape that is hilly/mountainous
lowland
an area that is lower than the land around it
what factors make a landscape distinctive?
geology, people and culture, vegetation, land use
Snowdonia, distinctive landscape example
diverse upland landscape shaped by volcanic eruptions, variety of animal and plant life, rich cultural history with many world heritage sites, landscape been shaped by slate mining and large areas of agriculture.
Positive human impacts on the environment
visitors to countryside bring benefits to rural economies
negative human impacts on an environment
visitor pressure may adversely affect the local communities and landscape
Honeypot site
area of interest to tourists
carrying capacity
maximum population an environment can sustain
strategies to manage landscapes
designated paths, clearly marked car parks, strict control over planning and building within area
Drainage basin
land that is drained by a river and its tributaries
interception
when precipitation is blocked from reaching the ground by obstacles like trees
infiltration
the movement of water going into soil
Throughflow
flow of water through the soil
overland flow
the flow of water across the ground/surface
groundwater flow
flow of water through rocks
transpiration
water given off by plants into the atmosphere
stem flow
movement of water that has been intercepted and is flowing down the stem of a trunk/plant etc.
percolation
movement of water from the soil into the bedrock
what does the speed of water movement through drainage basins depend on?
type and quantity of rainfall/vegetation cover, size and shape of drainage basin, steepness of slopes, geology and soil type within drainage basin
why do rivers flood?
climate, vegetation, geology, urbanisation
what does a hydrograph show?
discharge of a river over a period of time. It shows the total rainfall amount w/ a bar graph and the river discharge as a line graph
features of hydrographs
peak discharge, peak rainfall, baseflow, lag time, falling limb, rising limb
lag time of a hydrograph
time between peak rainfall and peak discharge in a river
factors that effect hydrographs
urbanisation (decrease lag time, steep rising limb), porous rocks (increase lag time, gentle rising limb), impermeable rock (decreases lag time , steep rising limb)
hard engineering strategies for river and drainage basin management
dams, levees/embankments, channelisation, gabions, dredging river channel, creating flood relief channel
soft engineering strategies for river and drainage basin management
restrict building on flood plains, afforestation, ecological flooding, warning systems,
land-use zoning strategies for river and drainage basin management
planning land use within a river basin less valuable land is in danger to flooding. housing and key services usually built on higher ground to avoid flooding.
fluvial
referring to rivers and their landforms
erosion
the weathering away of land
transportation
the movement of material via water flow
deposition
The dropping of the material carried by the river
bed load
The material carried by the river being bounced or rolled along its bed
what are meanders
a bend in a river formed by lateral erosion
factors in the erosion process of a river channel
Abrasion (material hitting river bed and banks), hydraulic action (sheer force of water against bed and bank), solution (slightly acidic water dissolves chalk and limestone rocks)
factors in the erosion process of the river bed
Attrition - stones carried by river collide and brake down becoming rounder and smaller
Abrasion - material travelling hitting river bed and bank become eroded
how does the river transport its load
solution (minerals dissolved in water, solute load), suspension (light material held up and carried by water, suspended load), traction load (large rocks rolled along river bed, Bedload), saltation (small rocks bounced along bed)
when does a river deposit material
when the speed of flow is too slow
what causes a river to deposit material
a lack of rainfall, inside of a meander as majority of water flowing on outside of bend so inside flow is slower, at mouth of river when flowing against direction of sea.
gorge
steep-sided narrow valley formed by retreating waterfall
interlocking spurs
hard, resistant rocks that rivers can’t easily erode so goes around
plunge pool
deepened part of the river bed at base of waterfall
what are the two ways a waterfall can form
glacial erosion or differential erosion
what is glacial erosion
where waterfalls have formed due to erosive power of a glacier during ice age. Glaciers carved steep valleys which melted glaciers drained into
what is differential erosion
where waterfalls are formed due to a change in rock structure leading to the river bed being eroded at different rates
how is a waterfall formed by differential erosion
river bed crosses from hard rock to soft rock which is eroded faster making a step. As water falls hydraulic action keeps eroding the rock underneath the hard rock. As soft rock is eroded further overhang becomes to heavy and collapses making waterfall move upstream.
how is a plunge pool formed
the sheer force of the water hitting the river bed and abrasion caused by rocks from overhang falling.
how is a gorge formed
when a waterfall collapses and retreats upstream
slip-off slope
A bank of gently sloping deposited materials on inside bend of a meander
how are meanders formed
erosion on outside of river and deposition on inside of river
where in the river are meanders usually found
middle and lower courses of a river valley, when on a flood plain.
slop processes
the processes involved in moving material from the cliffs onto the beach
weathering
the breakdown of rocks in place by elements of the weather
freeze-thaw action
the breakdown of rocks to due to water entering cracks and repeatedly freezing and thawing
carbonation
where chemicals in rainwater react with chemicals in rock
mass movement
when soil, rocks, or stones move down a slope
types of weathering
Physical, biological, chemical
how does salt crystal growth cause weathering
seawater left on rocks evaporates, salt crystals grow and exert pressure on rock making it break.
how do plant roots cause weathering
plants grow on top of cliffs, roots push into cracks in rocks making it break
how does carbonation cause weathering
rainwater enters cracks, weak acid reacts w/ carbonates in lime stone, cracks get bigger
what processes erode cliffs
hydraulic action (force of waves), abrasion (sand and pebbles thrown against cliffs), solution (salt water dissolves rock)
processes that erode beach material
Abrasion and attrition
long shore drift
the process which moves sediment along the beach
how does long shore drift move sediment up beach
sediment is pushed onto beach at angle in swash of wave, pulled back into sea by backwash
headland
area of land that juts into sea
bay
a recesses area of coastline often between two headlands
wave-cut platform
a coastal landform made of rocky shelf in front of cliff
wave-cut notch
a slot with overhanging rocks that has been cut into the bottom of a cliff by wave action
bedding plane
clearly seen layers of rock in a cliff face
how are headlands formed
made of harder, more resistant rock that erodes slower than surrounding areas
how are bays formed
formed between two headlands due to a softer, less resistant rock that erodes quicker than surrounding areas, beaches often form in sheltered bays
how is a cliff pushed backwards/ wave-cut platform made
hydraulic action makes a wave-cut notch, continuous erosion eventually leads to collapse, material from cliff gets moved to sea and while doing so abrasion smooths the surface
when are beaches and pits formed
when the swash is stronger than the backwash
swash
the movement of water up the beach as a wave breaks
backwash
the flow of water back into the sea after a wave has broken
how is a spit formed
longshore drift transports material up the coast, when the coast changes direction, it is carried out to sea creating a strip of land
how is an offshore bar formed
an area of deposition slightly off the coast transported at the river mouth.
factors that effect how fast a landform changes
geology, climate and human activity
How does geology effect the rate of landform change
different materials erode at different speeds
how does the climate effect rate of landform change at coasts.
winds affect teh angle waves break at, so also direction of erosion and transportation.
how does the climate effect the rate of landform change at rivers.
the more water flowing, the higher erosion rates will be, higher in winter months when there’s more rainfall
how do extreme weather events alter the landscape
more sever storms create more destructive waves. increased by wind and fetch (distance travelled before breaking), worst storms come from south-east as its the largest distance of open water,
intended human activity impact on landscapes.
management strategies to reduce erosion, e.g. on meanders with building on outside bend. Gabions used. human settlement vulnerable on coast cliffs.
