Geography Distinctive Landscapes (+ Costa Rica case study from sustaining ecosystems)

How much of the world’s biodiversity does costa rica contain

6%

how many tourists does costa rica attract

over 2 mil per year

Costa rica location

small country in central america

When did costa rica begin to experience rapid deforestation & why was this

1960s

it was due to cattle ranching and agricultural development

how much forest was deforested at the highest point in costa rica

32k hectares a year

What did the government of costa rica do to combat deforestation

• established protected areas of forest throughout the country

• passed laws to stop deforestation

• paid landowners to keep land as forest rather than cutting it down (financial incentive)

how much of costa rica’s land is protected today

24%

agroforestry

trees and crops are grown together, so that crops benefit from shelter of the canopy, trees prevent soil erosion, and crops benefit from nutrients in leaf litter

selective logging

trees are only felled when they reach a certain height - young trees ensure that the height of the canopy is maintained

afforestation

trees are planted to replace those cut down (but it lacks biodiversity as species have to re-establish)

monitoring

sattelites & photos ensure that no illegal activites are taking place in forests

ecotourism

a type of sustainable development that aims to create local employment while conserving the natural environment

• doesn’t damage natural environment

• relatively small scale

• consults with local community about developments

• infrastructure improvements benefit local people too

example of an ecotourism resort w/ psd x 4

monteverde cloud forest

• 10,000-hectare wildlife reserve

• 3,000 plant species

• 400 bird species

• 100 mammal species

how does Monteverde protect the environment

• controlled tourist access with unpaved roads only accessible with 4×4s

• info & guidlines for tourists on minimising environmental impact e.g. specific trails, respecting wildlife, limiting noise, no flash photography

school that works with monteverde resort

santa elena high school

• integrates monteverde ecology into curriculum

• promotes conservation

• promotes skills for ecotourism jobs

• school-run santa elena reserve helps disperse tourist crowds

sucesses of monteverde resort

• attracts 250k tourists each year with minimal environmental impact

• benefits the economy

• harmonious coexistence between humans and wildlife

challenges of monteverde resort

• increasing tourists = more facilities = less forest/land

• inevitably some environmental damage occurs

landscape

an area of land with a particular appearance

it can be any scale, and may be physical, human, or a combination of both

relief

the way the landscape changes in height

uplands

areas that are high above sea level and often mountainous

lowlands

areas that are not very high above sea level and often flat and rolling

examples of natural / physical elements of landscapes

• mountains

• coastlines

• valleys

• plains

• rivers

• lakes

• soils

• geology

examples of biological elements of landscapes

• vegetation

• marshes

• wildlife

• habitats

• plants

examples of human elements of landscapes

anything made by humans

• infrastructure

• communications

• industry

• farmlands

• paths

examples of variable elements of landscapes

temporary things / things that change

• weather

• smells

• sounds

• season

glaciated upland areas

upland areas formed through glaciation, where glaciers erode the surface of the land

non glaciated upland areas

upland areas formed through river erosion and weathering (often made of limestone / sandstone)

sometimes found in areas also formed through glaciation

glaciated lowland areas

glaciers have created fertile plains and rolling landscapes, providing an opportunity for settlements and farming

non glaciated lowland areas

areas of flat land formed by deposition, often marshy and found near the coast

characteristics of glaciated landscapes

• u-shaped valleys

• rolling, fertile plains

• steep mountain peaks

• ridges

human activities in glaciated landscapes

• farming in the fertile land created

• building settlements in the rolling plains

igneous rock

formed from molten rock at depth or that reaches the surface as lava

granite, basalt

sedimentary rock

formed from sediments carried by rivers to the sea and deposited in layers called beds

clay, sandstone, limestone

metamorphic rock

rock that is changed by heat and/or pressure when mountains are formed as tectonic plates collide

slate, schist, marble

mechanical weathering

aka freeze-thaw weathering

caused by large temp changes between night and day

rainwater collects in cracks in rocks, water freezes into ice and expands, repeated freezing and thawing makes the crack bigger, crack widens enough for the rock to split apart

chemical weathering

can happen with acidic rain - rain dissolves carbon dioxide in the air, making rainwater acidic. when it falls it causes chemical weathering

limestone and chalk are more easily effected

can form limestone pavements (see image)

biological weathering

caused by plants and animals e.g:

• tree roots force into rocks, splitting them apart

• small plants (e.g. moss) grows on the surface of rock, making it crumble

• animals burrow into softer rocks

• animals can trample with their feet

erosion: hydraulic action

waves crash against the coast, forcing air into cracks and breaking up rock

erosion: attrition

pebbles are picked up by waves and bash into each other, wearing down into smaller, rounder pieces

erosion: abrasion

waves pick up rocks from the seabed and smash them against the coast, wearing it away

erosion: solution

some rocks like limestone slowly dissolve in water

transportation: traction

boulders and large stones are dragged along the river/sea bed

transportation: saltation

pebbles and small stones are picked up and dropped further along

transportation: suspension

tiny particles of sand and silt are carried in the water

transportation: solution

some rocks dissolve and are carried by the water, invisible to the naked eye

deposition

the dropping of material on land when the water no longer has enough energy to carry it

mass movement: sliding

sudden movement of large volumes of rock/soil along a zone of saturated soil

mass movement: slumping

rapid mass movement of permeable rock & soil (e.g. clay) that has become heavily saturated, lying on top of impermeable material

mass movement: rock falls

free-fall movement of rock fragments due to gravity. increased by mechanical weathering

coast definition

a narrow zone where the land and sea overlap and directly interact

its development is affected by the interaction of physical and human pocesses

beaches

the main depositional landform found at the coast

material has built up between high and low mark. beach material can be brought from the swash of waves, landslides on cliffs, and rivers transporting sediment to estuaries

swash (of a wave)

the water washed up the beach

backwash (of waves)

the water that runs back down the beach

destructive waves

waves that erode the beach

• high wave in proportion to length

• tall breaker that breaks downwards with great force

• strong backwash

• weak swash

constructive waves

waves that deposit sediment and create beaches

• low wave in proportion to length

• strong swash

• weak backwash

• deposits sediment due to its strong swash, and doesn’t have enough backwash to take it away

headland

a hard piece of rock that sticks out into the sea

bay

an area of coastline which has receded backwards, usually with beaches

concordant coastlines

has the same type of rock along its length, creates fewer bays and headlands

discordant coastlines

bands of rock type run perpendicular to the coast

differing erosion speeds between softer & harder rock leads to the formation of headlands & bays

formation of cracks, caves, arches, stacks & stumps

1. crack is opened by hydraulic action

2. crack eroded & grows into a cave

3. cave is eroded until water breaks through the back to form an arch

4. after more erosion the unsupported top of the arch collapses, forming a stack

5. stack is eroded around the base and falls, forming a stump

longshore drift

the movement of beach material by the sea along the coast

direction is determined by the direction of the prevailing wind

spits

an extended stretch of beach that projects out to the sea and is joined to the mainland on one end

ususally found at the mouth of a river

over time can develop a hook if the wind direction changes further out

waves can’t get past it, forming a sheltered area where silt is deposited - salt marshes

hard engineering

using man-made structures to stop waves in their tracks

more expensive but more effective

used in front of high-value land

soft engineering

smaller, more natural structures to reduce energy in waves to protect in a more natural way

less expensive but less effective

sea walls

hard engineering

walls of concrete placed at the foot of cliffs / top of beach to prevent erosion

good at protecting valuable land but expensive (up to £5k per meter)

groynes

hard engineering

wooden fences running at right angles to the beach & go out to sea to interrupt longshore drift by trapping sediment. also absorb wave energy, reducing erosion

result in a larger beach but are expensive (up £10k each) & can starve other beaches of sediment

rock armour / rip-rap

hard engineering

dumping large boulders of rock at the base of a cliff / sea wall that help the wave break & absorb its energy

relatively cheap (£300 / meter) & can look more natural but can be hard to transport & make accessing the beach harder

offshore reefs

soft engineering

sandbanks built parallel to the coast out to sea that force the waves to break before they reach the shore

don’t spoil the look of the beach but are very expensive (£1.3mil each) & hard to maintain

beach nourishment

soft engineering

adding additional beach material to the beach to make it higher & wider

cheap (£3k / km) & blends with the beach but needs constant replacement & doesn’t stop waves

managed retreat

soft engineering

controlled flooding of low-lying, low-value areas to take away risk of damage to other areas

cheaper compared to other defences but land is lost & landowners need to be compensated

chesil beach in jurrasic coast

• 18 miles long

• from west bay to isle of portland

• can get up to 15m high and 200m wide

• pebbles of flint & chert

mudeford spit in jurrasic coast

• lots of longshore drift (south → southwest winds)

• beach recharge used because no erosion from beaches further up so no sediment

• made of boscombe sands

temp of jurrasic coast

• warm, dry summers (21’)

• mild, wet winters (min 3’)

• freeze-thaw weathering is rare

• salt weathering is prominent

wind in jurrasic coast

• southwest winds can bring storms from the atlanctic

• winds bring high energy destructive waves that increase erosion

• unstable cliffs mean mass movement

rainfall in jurrasic coast

• relatively low rainfall but can be heavy during storms

• soil saturates, causing slumping

• chemical weathering of chalk cliffs

geology of jurrasic coast & geomorphic processes

• both concordant and discordant coastlines

• headlands

• rock is vulnerable to solution

human activity in jurrasic coast

quarrying: limestone quarried on isle of portland, exposing rock & making them vulnrable to chemical erosion

tourism: tourists erode footpaths & trample vegitation, exposing underlying soil to weathering & erosion

management strategies: costal defences change the natural landscape & alter costal processes

headlands & bays in jurrasic coast

• the area around swanage is made up of bands of harder rock (chalk & limestone) & softer rock (clay & sands)

• studland & swanage bays

• durston head & ballard point (headlands)

old harry rocks in jurrasic coast location

2 miles northeast of swanage & 1 mile east of studland, on the eastern edge of the isle of purbeck

impact of climage change on jurrasic coast

• warming temps = higher sea levels: sea around uk expected to rise by 600mm by 2100

• warmer atmosphere = more likely intense storms = more powerful waves = more erosion

• more intense rainfall = greater weathering of cliffs & more mass movement & rockfalls

jurrasic coast: hold the line

shoreline management plan based around swanage

aims to protect swanage from erosion & improve features for residents & visitors

plan is to build 19 groynes to replace 75yo ones & replenish beach with 160k tons of sand

sea walls in jurrasic coast

some put in place in south in swanage in late 1800s & extension added in 1920s

beah reacharge in jurrasic coast

90,000m³ of sand deposited in 2005

now the beach will need to be recharged with around 40,000m³ every 20 years

groynes in jurrasic coast

some put in south of swanage in late 1800s & more added in 1920s

scheme extended in 1960s as it starved other beaches of sediment

groynes replaced in 2005

upper course of rivers

common features: waterfalls, v-shaped valleys, steep relief

source found in mountains, starting off tiny but tributaries feed into it & increase the size

vertical erosion takes place, creating a V-shaped side profile as the river erodes downwards

middle course of rivers

common features: meanders, oxbow lakes, flat land, floodplains

both erosion & deposition take place

side profile is less steep as lateral erosion starts taking place

lower course of rivers

common features: very wide river, river mouth / estuary, industry on banks, marshy flat land, floodplains

deposition & lateral erosion

waterfalls

forms when more resistant rock lies on top of less resistant rock

1. water erodes less resistant rock (hydraulic action & abrasion) forming an undercut & plunge pool

2. more resistant rock on top doesn’t erode, forming an overhang

3. eventually unsupported overhang collapses into plunge pool

4. process repeated & waterfall retreats upstream to form a gorge

waterfalls form because of differential erosion

v-shaped valleys

1. river vertically erodes straight down

2. steep sides of river weaken (due to precipitation & weathering)

3. eventually sides break & fall into river channel, creating a v-shape

interlocking spurs

ridges of rock extending alternately, with a stream/river running between

formed because of river winding & bending to find the areas of least resistance. non-resistant rock erodes more quickly, creating uneven appearance

meanders

bends in a river formed because of river curving because of naturally uneven land

water moves fastest on the outside of the bend & slowest on the inside

where it moves fastest on the outside it erodes, forming river cliffs

where it moves slowest on the inside it deposits, forming a slip-off slope

meanders become larger over time

oxbow lakes

still, curved bodies of water near a river

formed through meanders changing shape over time so that the ends of the beds end up joining. the water takes the easiest route, cutting off the bend.

floodplains

the areas of land on either side of a river that are covered in water when the river floods

very fertile because of the minerals deposited when the river floods

alluvium: the fine sediment & minerals deposited on the floodplain when the river floods

often used for farming because of the fertile soil

levees

extended banks of deposited material on the sides of rivers

when the river floods, sediment is deposited across the floodplain with the largest material being deposited first, closest to the river. after many floods this builds up

flooding definition

when a river overflows its banks onto the surrounding land

discharge

the amount of water in a river

river drainage basin

the area of land surrounding a river

surface run-off

water that runs over the surface of the ground towards a river

infiltration

when rainfall moves down into the ground

causes of flooding

physical:

• weather (rainfall, surface run-off)

• soil (surface run-off if soil is full of water)

• geology (impermeable rocks = surface run-off)

• relief (fast travel on steep relief)

• drainage basins (circular = more risk as all water takes the same time to reach the river)

human:

• urbanisation (impermeable ground surfaces, sloped roofs, drains)

• deforestation (trees intercept water so no trees = more water)

• river mismanagement (e.g. river straightening can increase flood risk downstream)