Coats case studes and exam questions

Question 1

Explain the impact of the construction of the Aswan Dam on the erosion rate in the Nile Delta

Answer 1

+Aswan dam has stopped the natural seasonal flooding of the Delta
+This stops the deposition of rich and fertile sediments (120 million tonnes a year to trace amounts today)
+Rising (eustatic) sea level means the salinity is increasing
+Impacting agricultural and industrial areas nearby
+Not enough sediment input means subsidence (sinking 0.1 inches per year)
+Little protection from sand dunes and brackish lakes

Question 2

What is the population density of Alexandria, a city on the Nile Delta

Answer 2

1000people /km squared

Question 3

What responses have there been to the threat of sea level rise at Nile Delta

Answer 3

+Some coastal defences built
+Land reclamation projects
+Both costly but more practical solutions than relocation
+Refuge mounds and embankments should be considered

Question 4

What’s happening in Kiribati?

Answer 4

+A nation of 33 widely spaced island could disappear underwater in the next 5 years (many places only 1m above sea level)
+Sea levels are rising due to melting polar ice sheets and thermal expansion

Question 5

What are some of the causes of flooding in Kiribati?

Answer 5

+Low lying atolls (ring shaped coral reef)
+Subsidence caused by the removal of sediment for farming
+Removal of water from underground aquafers also results in subsidence

Question 6

What are some of the consequences of flooding in Kiribati?

Answer 6

+Crops and water contamination
+Destruction of infrastructure
+Displacement, environmental refugees
+Higher temperatures and rainfall changes mean dengre fever is more prevelant

Question 7

What have been the responses to rising sea levels in Kiribati?

Answer 7

Mitigation:
+500,000 Mangroves planted
+Coral reefs built

Adaption:
+‘Migration with dignity’ policy- allowing people to apply for jobs in Fiji
+President Tong purchased 201km of land on Fiji

+Could lead to a lack of sovereignty

Question 8

What are the causes of coastal flooding in Bangladesh?

Answer 8

+Eustatic sea level rise
+Deforestation removes buffer zone between forest and sea
+Subsidence due to clearance of forested islands
+Less than 10m above sea level, on a low lying delta
+Bay of Bengal funneling cyclones towards Bangladesh= storm surges

Question 9

What’s the population of Bangladesh?

Answer 9

169 million (in 2015)

One of the world’s most densley populated countries

Question 10

How much have Bangladesh’s islands sunk by in the past 50 years?

Answer 10

1.5 metres

Question 11

How much is Bangladesh’s mangrove coastline retreating by?

Answer 11

Up to 200 m a year

Question 12

Explain the impacts of storm surges on low land coastal areas

Answer 12

+Occur when there is a short term change in sea level due to low pressure during a cyclone
+Storm Xavier in the UK (2013) coincided with high spring tides and and 80mph+ winds
+North Sea coastline narrows into a funnel shape for incoming storms

+1800 evacuations, economic loss of £100 million, two deaths

Question 13

How many people were killed by the 2007 storm surge in Bangladesh?
What other impacts did it have?

Answer 13

Estimated 3500+

900 freshwater wells destroyed and agricultural land damaged

Total damage: $1.7 billion

Question 14

Why might UK Govt coastal management policies vary from place to place?

Answer 14

Economic value of asset:
+Easington on Holderness coast is home to a natural gas terminal
+Hard engineering approaches like ‘hold the line’

Ecological value of land
+Nature reserves protected by soft engineering, like dune stablilisation
+Strategic realignment policies, working with the natural habitats
+Local stakeholders also have a say

Technical feasibility
+Hard engineering wouldn’t be appropriate for a dune heath environment

Question 15

igneous/ rocky coasts make up how much of the UK’s coastline

Answer 15

1000km mainly in the North and West

Question 16

Evaluate the view that coastal flood risk is increasing mainly because of rising sea levels

Answer 16

Other factors contribute (subsidence, management strategies, economic development, vegetation loss)
But scientific evidence shows eustatic changes will have effects globally.

1. state what eustatic changes are and why Sea level change is the primary risk as it’s long term and all encompassing
   Puts SIDS at risk (Kiribati’s many atolls)
   Socioeconomic losses, refugees etc.

HOWEVER natural variability means sea level rise isn’t uniform globally, Maldives is at relatively less risk than other SIDS. Factors out of human control, ocean currents = storm surges (cyclone sidr)
THOUGH sea level rise is the main risk as flooding and freak weather events become more frequent. Testing not only vulnerable nations, but USA Florida.

Subsidence is another factor. Jakarta, Indonesia 95% is expected to be submerged by 2050. Depletion of aquifers. Bangladesh too, reducing resilience. Salt water intrusion.
HOWEVER sea level rise is the main factor as its less region specific, subsidence can ultimately be manageable with embankments, sea level rise is hard to mitigate.
Amplifies existing issues.

Complexity of flood risk can’t be undermined.
Vegetation loss (mangroves, Bangladesh) contributes. 41% live on delta. Moreover we can adapt, Netherlands has dykes, despite 26% below sea level. THOUGH sea level rise will ultimately but a social, economic and political strain on everything.

Question 17

What did the IPCC report?

Answer 17

In the last century, sea levels rose by 15cm.

Question 18

What % of Jakarta is expected to be submerged by 2050?

Answer 18

95% of the north of the city.

Question 19

What % of the Netherlands is below sea level?

Answer 19

26%