Systems in physical geography: systems concepts and
their application to the development of coastal coast can be considered as an open (whilst coasts are open systems) the coast the coastal system is im
system acts as a closed system in some upon processes which o
landscapes – inputs, outputs, energy,
circumstances oceans of our planet and
stores/components, flows/transfers, positive/negative • it receives inputs from outside the
which they are part of
system .such as during scientific research and
feedback, dynamic equilibrium. The concepts of
coastline management planning
landform and landscape and how related landforms • transfers outputs away from the coast
and into other systems
combine to form characteristic landscapes.
.these systems may be terrestrial,
dyn
atmospheric or oceanic and can include the e.g. sediment cells
bala
rock, water and carbon cycles
energy • the movement of sediment is almost in a
contained
• power and driving force behind the •
transfers and flows in the system • flows of sediment act in dynamic
equilibrium
1. Wind inputs
•
2. Gravitational • material or energy inputs
3. Flowing Water include three main areas:
•
transfers
1. Marine: Waves, Tides, Salt Spray
• processes that link the inputs, outputs
2. Atmosphere: Sun, Air Pressure, Wind
and stores in the coastal system
Speed and Direction
short term factors classifying coasts
1. Wind-blown sand (aeolian transport)
3. Humans: Pollution, Recreation,
Settlement, Defences 2. Mass-movement processes
3. Longshore drift !!! dy
energy inputs from waves, tides, currents, long
4. Weathering
rivers, gravity and tectonics
OR i
long term factors classifying coasts 5. Erosion [Hydraulic Action, Corrosion,
can classify coasts as HIGH or LOW by n
Attrition, Abrasion]
ENERGY
6. Transportation [Bedload. In suspension,
Traction, In solution]
geology (=characteristics of the land,
stores/sinks
lithology - rock type/structure - 7. Deposition [Gravity Settling,
sediment inputs from waves and winds, arrangement of rock units) Flocculation] • stores and s
tides, currents, mass movement and
can classify coasts as estuarine, sandy or ● Beaches ● Sa
tectonic movement
rocky OR concordant (parallel to the coast) Headlands and B
can classify coasts as eroding or or discordant Wave-cut Notch
outbuildings outputs ● Stacks ● Stum
Bands and Bars
• material or energy outputs
sea level change (caused by tectonic 1. Ocean currents
coasts = narrow zone where land and sea overlap movement or climate change (eustatic,
2. Rip tides
isostatic change)) +F loop
coastal landscapes = sections of coastline - have a
3. Sediment transfer
, prevailing winds = rip
wind consistently longshore currents currents = general flow of water in one
gen
blowing from the direction
occurs when:
same direction > •
caused by:
causes higher • as waves hit beach at an angle
energy waves than • wind
generates what current?: >in
winds that change
• variations in wtr temp and salinity bet
direction frequently • current running parallel to the shore
move where: >>a
transports:
bey
• along the coast
• sediment along the shore
! ha
during storm
winds > created
events > higher
from air moving
pressure gradient strong winds =
from areas of high upwelling
(= differ. between powerful waves
pressure > to low
high + low generated occurs when:
pressure
pressure) > HIGH ENERGY COAST!
• Movement of cold water from deep in
stronger winds
the ocean towards the surface -
replaces warm surface water
Sources of energy in
coastal environments: generates what current?:
spring tides = where the Earth,
moon and sun are all in line > winds, waves • nutrient rich cold ocean currents
neap tides = where
causes large bulges of water (constructive and
the Earth, moon transports:
characteristics: and sun are destructive), currents
• cold water and nutrients from deep in
perpendicular and tides. Low energy
• highest monthly tidal range the sea bed
characteristics : and high energy coasts.
• occurs twice a month
area between • lowest monthly
HIGH
maximum high tide tidal range
and minimum low
• occurs twice a
tide > where most tides = periodic rise and fall of ocean
month
landforms are surface > created by gravitational pull
created and of moon and sun
destroyed HIGH ENERGY COAST!
fetch = maximum
high wind speed
wave height = distance if the
effect of wave on + long fetch =
affected by wind sea the wind has
tides affect the position where shore > depend higher and more
speed and fetch blown over - in
waves break on the beach > i.e. on wave’s height powerful waves
of the wave creating waves
higher tide = breaking higher on
the beach
wavelength
waves approaching the
wave crest
shore > they break >
friction with the sea bed
waves created by wind > wave trough
