Case study - Nile delta Flashcards
Low energy coastal environment - compare with Flamborough Head (31 cards)
River Nile - describe as it reaches Mediterranean Sea
- Slows down, widens, forms vast delta
- 150 miles coastline
River Nile - give importance to people
- Fisherman
- Farmers irrigate land - area of intense farming
- most Egyptians live along the River Nile, delta densest area (2/3 of Egypt’s population)
Nile Delta - locate it
- North Eastern Africa
- Egypt, leading into the Mediterranean Sea
Nile Delta - name main geographical process
Landscape erosion / recession
- balance of processes has changed
- erosion now dominant due to Aswan Dam trapping sediment
Nile Delta - measures taken to farm the land
- Fresh water pumped in (rainfall was enough)
- Sand bags to lay on top of salty ground
- Expensive compared to previously just plant seeds
Nile delta - predicted rising sea level
1.2mm per year sea level rise
- reduced delta size over last 4000 years
- Many experts predict 1 metre this century
- cities like Alexandria in trouble - ancient city, 40 buildings per year collapse
Nile delta - changes to human environment
- Deteriorating
- Harder for people to make a living
Nile Delta - changes to farmland
- used to be fertile
- increasing salinity from rising sea levels
- ## salt water infiltrate soil from below
Nile Delta - impact of changes to farming land
- Ecological disaster - delta is dying
- Economic disaster - poverty and hunger
- Wider lack of food as most grown in the delta area
Nile Delta - how decline impacts local population
- potential climate refugees
- poor people / farmers and fishermen most affected
Nile delta - decline impact on ecosystem
- delta is fertile, surrounded by desert
- salty land develops thick salt crust, no plant life can grow except specific adaptations
Aswan High Dam - locate it
- Egypt
-1 100 km from river mouth
Aswan High Dam - give impacts of construction
- disrupt flooding deposit of silt and sediment
- survival of delta ecosystem - have to bring in fertilisers to keep land as fertile as used to be
- delta no longer recieves annual supply of nutrients and sediments from upstream
Nile Delta - impact of global warming
- delta swallowed up by global warming / waves eroding deposited material
- predicted sea level 30cm rise in last 4 years, flood 200 km squared of land
- salinity affecting land fertility
Nile delta - give shape
- marine arcuate delta
Nile delta - explain formation
- Sediment materials carried down by river deposited
- river loses energy as meets the sea, can’t carry as much
- coarser materials fall first, finer sediments deposited further out towards the sea
- formed new, finer river channels, spread out to meet the sea
Nile delta - impacts of coastal erosion
- Outer edges / frontal plane of delta eroded by waves
- Coastal lagoons on the outside of the delta increase in salinity
- Increased connection between fresh river water and the sea
Nile delta - changes in vegetation
- Really well established
- alluvial deposits (river) make highly fertile land
- soils on flood planes become poorer since construction Aswan High Dam
Nile delta - reasons for size change
shrinking - some places lose land at rate of 100 yards per year
- global warming = erosion
- Aswan High Dam = lack of deposition
- accelerated sediment retreat up to 140mm per year
Nile delta - human causes of issues
- fisheries
- increased salt production
- heightened agricultural production
- natural population increase
- dam building
Nile delta - tidal range
Mediterraean sea has very small tidal range
- not much water go in and out
Nile delta - geology / land relief
- low
- flat
- mud and sand
Nile delta - budget and sources
- huge fluvial load gave acretion of 120mm annualy, rapid reduction to trace amounts
- AHD stops sediment reaching delta, not enough input to fight output
Nile delta - promentaries
- Over past 4 000 years, build by deposition into North Sea
- Rosetta - eastward distributary
- Damietta - westward distributary
