Coastal Processes Flashcards
What are the inputs into the coastal system?
Sediment from landforms/cliffs Geology of the coastline Sea level change Tides Wind energy Wave energy
What are the outputs of a coastal system?
Sediment taken above the tidal system (usually by wind or storms)
Sediment taken to a sediment sink (out of the sediment cell)
Dissipation of wave energy
What are the stores of the coastal system?
Erosional landforms and landscapes (cliffs, stacks, arches)
Depositional landforms and landscapes (spits, beaches, tómbolas)
What are the flows/transfers of a coastal system?
Longshore drift
Erosional processes (wave quarrying, abrasion/corrasion, hydraulic action, solution, attrition)
Wave transport (traction, saltation, suspension, solution)
Aeolian/wind transport (saltation, suspension)
What is an example of negative feedback in a coastal system?
Waves erode a cliff Cliff collapse occurs The debris at the base of the cliff Absorbs the wave energy Reducing erosion of the cliff
What is an example of positive feedback in a coastal system?
Wave erodes a cliff Cliff collapse occurs Debris at the base of the cliff Is picked up by the waves And used for corrasion Increasing erosion of the cliff
What are the sources of energy at a coastline?
Wave energy
Tidal energy
Wind energy
Sea currents
Which factors affect wave energy?
Fetch
Strength
Duration of wind
What is the definition of wind?
Movement of air from one place to another (due to air moving from a high atmospheric pressure to a lower atmospheric pressure)
How does wind affect sediment?
Agent of erosion (picks up sand and uses it to erode other landforms by abrasion) Moves sediment (picks it up and drops it elsewhere)
What are the three different types of currents?
Longshore currents (also known as littoral drift)
Upwelling
Rip currents
What do longshore currents do?
Moves water (and transports sediment) parallel to a shoreline
What is the definition of rip currents?
Strong localised currents that move water away from the shoreline (occur on some beaches)
What is the definition of upwelling?
Movement of cold water from deep in the ocean towards the surface
What does upwelling do?
Forms part of the pattern of the global circulation system
What are the characteristics of a high energy coastline?
Powerful waves
Long fetch and strong prevailing winds= high energy waves
Often dynamic equilibrium
More erosion than deposition= erosion landforms
Often Atlantic Ocean facing (Cornwall)
What are the characteristics of a low energy coastline?
Less powerful waves
Wave energy is low
Often stable equilibrium
More deposition than erosion = deposition landforms
Often in sheltered bays or estuaries (Lincolnshire)
What are the opportunities for human development in Odisha?
Has potential for offshore wind energy, or offshore oil and gas
Large fish stocks, so people can be fishermen, or work in aquaculture
Chilika Lake has over 150 species of birds so attracts tourists
People in forests can work with coir (coconut husk) in textile industries
Alternative industry of poultry farming (away from coastline)
What are the risks for human occupation in Odisha?
Coastal erosion and flooding have increased as sea levels are rising
Storm surges and tsunamis makes coastal communities particularly vulnerable
The majority of Odisha’s population live on or near the coast
Rising sea levels, storm surges, and tsunamis are all increased by climate change
Any attempt to stop coastal erosion will only increase it elsewhere
What are examples of human resilience in Odisha?
Replanting mangroves, and rebuilding buildings after storms
What are examples of mitigation in Odisha?
Before 2013 tropical storm:
- 1 million people were evacuated
- warnings were broadcast to the most vulnerable areas
Multi-purpose cyclone shelters have been built
Mangroves have been planted to try to slow coastal erosion
What are examples of adaptation in Odisha?
Mangroves have been planted
Industry has been diversified (people becoming poultry farmers which can be done further inland)
What is the aim of the Integrated Coastal Zone Management?
Coordinate activities of all the stakeholders into an integrated approach to use the natural resources of the coast sustainably and maintain the natural environment
What is the aim of the Shoreline Management Plans?
To consider the entire coastal zone and achieve a balance between natural processes and human needs
