Physical Geography Case Study

• A Level view of coasts as a landscape is how the overall landscape is created, how the coast can be viewed as a system, flows of energy/material and how the landscape is used and managed.
• Landforms of erosion - cracks, caves, stacks, stumps, wave-cut platforms, blowholes
• Landforms of deposition - beaches, spits, tombolos, sand dunes, salt marshes
• Coastal management strategies include hard engineering (sea walls) and soft engineering (beach nourishment)
• Marine Inputs - waves, tides sea spray and currents
• Kinetic energy - waves and wind
• Thermal energy - sun
• Potential energy - material on cliffs/slopes and material rom processes of weathering, mass movement, erosion and deposition
• Atmospheric - climate, wind speed/direction, precipitation, weather and climate change
• People - urban planning, housing, industry, coastal management/defences, leisure
• Coastal Transfers - Longshore drift
• Sediment cell - area along the coastline and in the nearshore area where the movement of material is largely self-contained . They can be considered as a closed coastal sub-system.
• The boundaries of sediment cells tend to be headlands and peninsulas which act as natural barriers to stop the further movement of the sediment.
• Sediment sinks occur at the boundaries of sediment cells, where there is an accumulation of sediment as transport paths meet
• There are 11 large sediment cells in England and Wales
• Human intervention in a coastal system, in the form of coastal defenses, are likely to have repercussions elsewhere in the system.
• A positive sediment budget is when there are more inputs than outputs to the system
• A negative sediment budget is when outputs are higher than inputs.
• Output changes - Human intervention, such as removing large amounts of sand from an area for industril or coastal use.
• Input changes - Volume of fluvial material being deposited into the coastal system and the impact that human intervention can have on that.
• Wave action is a source of energy for coastal erosion and transportation of sediment
• Tidal range is the difference between high tide and low tide
• Coastal Energy sources consist of Waves, Tides, Geology and Ocean Currents
• Storm Surge occurs during tropical cyclones where the pressure gradient increases rapidly causing sea levels to rise dramatically
• An example of a low energy coastline is the Mississippi Delta
• The Mississippi river is the third longest river system in the world
• The length of the river increases and decreases over time due to the erosion and deposition rates fluctuating at the coast
• The width of the river changes through its course as expected, it changes from 6 metres to 17,700 metres wide throughout the course.
• The Mississippi catchment area includes all or part of 31 states and 2 Canadian provinces (Alberta and Saskatchewan)
• The Mississippi river is made up of - 40% Silt, 30% Clay and 30% Fine sand
• The Mississippi delta was formed over the last 7,000 years in a dynamic process known as the delta cycle