COASTS Flashcards
Outline the sinks in the Holderness coast sediment cell
- Locations where the dominant process is deposition; depositional landforms are created
Outline the sources in the Holderness coast sediment cell
- Where sediment is eroded from cliffs/sand dunes (e.g., Flamborough Head’s chalk). Sources can be offshore bars or river systems.
Outline the transfer systems/zones in the Holderness coast sediment cell
- Places where sediment is moving across the coast by LSD and offshore currents, beaches, parts of dunes and salt marshes (Humber estuary)
What is the average annual erosion along the Holderness coast?
Average annual erosion is around 1.25m per year, but there are wide spatial variations from 0-6m a year
Why are there spatial variations in average annual erosion along the Holderness coast?
- Coastal defences in Hornsea, Mappleton and Withernsea.
- Starvation of sediment
- Variations in cliff height and the susceptibility
- Mass movement increases susceptibility in some locations
Why do erosion rates vary along the Holderness coast?
- Winter storms
- Storms are rare in the summer months (seasonality)
- NE storms cause most erosion because of the long fetch along the North Sea
How high is the highest point in the Maldives?
2.3m above sea level
What is the population of the Maldives and how many islands are there
- Population of 400,000 spread out across 1200 islands (although many are uninhabited)
Outline the threat posed to the Maldives
A sea level rise of 50cm by 2100 would mean that the Maldives loses 77% of its land area, and the areas above sea level would become prone to storm surges and erosion
Are there any coastal defences in Mali?
- Yes, but only in the form of a 3m high sea wall bordering the capital Male
Why is Bangladesh especially vulnerable to the impacts of tropical cyclones?
- Low-lying river delta
- Incoming storm surges meet outflowing river discharge in the Ganges
- Intense rainfall from tropical cyclones
- Almost all of the coastline consists of unconsolidated delta sediment
- Deforestation of coastal mangrove forests
- Triangular shape of the Bay of Bengal concentrates a cyclone storm surge
Outline what happened at the South Devon Mainline Railway at Dawlish
- Collapse due to the erosion in February 2014
- Railway links Exeter and Plymouth to London and Bristol
- Estimating the cost was put between £60mnn and £1.2bn
- Huge further economic costs
Evaluate sustainable management in the Maldives
- Risk that sustainable management of traditional income sources and resources is often overlooked
- Money spent protecting the capital and creating new artificial islands means that isolated islands are often ignored
Outline coastal decision making in Hornsea and Mappleton
Hornsea: Hold the line
- regional economic centre
- important historical sites
- Hornsea Mere (bird habitat)
Mappleton: protect for the time being, but it is a vulnerable area which erosional effects are inevitable, leading to outflanking of its defences. This means that properties would be difficult to sell and their value would significantly decrease.
How did the Aswan High Dam on the River Nile cause erosion?
- The delta was starved of sediment down-stream
