Case Studies Flashcards
What are the case studies for this topic?
- Odisha
- Swanage and Studland
Where is Odisha?
It is a state on the south-east coast of India, bordering the Bay of Bengal
Facts about Odisha’s size in relation to other Indian states
- It is India’s 9th largest state by area
- It is India’s 11th largest state by population
What is the coastline of Odisha like?
It is relatively straight, with few natural inlets and harbours
How long is Odisha’s coastline?
480km long
How many major deltas are there on the Odisha coast?
6 major deltas
How much mangrove forest can be found along the Odisha coast?
1435 km squared
What are the 3 major coastal ecological environments on this stretch of coastline?
- the 6 deltas
- the lagoon (Chilika lake)
- the 1435 km squared of mangrove forest area
Chilika lake
A brackish, salty lagoon, covering an area of 1,165 km squared with a water volume of 4 km cubed.
What is Chilika lake a good example of?
A temporary store in the water cycle
When is the monsoon season in India?
From June - September
What happens to Chilika lake in the monsoon season?
It becomes less saline, being diluted by the freshwater rainfall and it occupies a larger area than the rest of the year.
What does ICZM stand for?
Integrated Coastal Zone Management
How many species are in the mangroves found in Odisha?
More than 82 species
What is the Odisha coast subject to?
Severe weather events, such as cyclones and super-cyclones
What extreme weather events affect the Odisha coastline?
Cyclones and super-cyclones
How much of the mangrove ecosystem has been lost globally?
Around 35% of mangrove forests have disappeared in the last 30 years.
How many species are found in the Chilika lake bird sanctuary?
Over 150 species of birds
Does Odisha receive lots of rainfall and what is the effect of this?
Yes, resulting in huge waves (leading to coastal flooding) and strong winds
Why are tropical storms getting more frequent and intense?
Because of climate change
How many tropical fish are born in mangroves?
3/4 of all tropical fish
What is coral reef health dependent on?
Mangroves
What do mangroves have a symbiotic relationship with?
Coral reefs
How do mangroves and coral reefs have a symbiotic relationship?
- mangroves take out toxic things
- coral reefs are sensitive and require really pure water
- mangroves take things out so coral reefs can survive
What type of water is needed by coral reefs?
Really pure water
What do coral reefs need?
Mangroves, although this isn’t necessarily the other way around
What is Odisha a vulnerable community towards?
Storm surges and climate change
What is the Odisha coast becoming more susceptible to?
Erosion
Why is the Odisha coast becoming more susceptible to erosion?
Because when you put management in one place, the problem often shifts down the coastline
Where is the main area of erosion in Odisha?
In the south
Where is the main area of accretion/deposition in Odisha?
In the Bay of Bengal (more north-east?)
Give some organisations who are trying to make the coastline of Odisha more resilient to climate change
- The Union Ministry of Environment, Forestry and Climate Change
- The World Bank
- the government of Odisha
What cyclone was Odisha affected by in October 2013?
Cyclone Phailin
When did Cyclone Phailin strike Odisha?
In October 2013
What did the wind speeds from Cyclone Phailin reach?
200 km/h
How many people were evacuated because of Cyclone Phailin?
Over one million people were evacuated from the areas deemed to be at greatest risk
How many people died in Odisha due to Cyclone Phailin?
44 people
How many agricultural crops were destroyed by Cyclone Phailin?
Around 500,000 ha of agricultural crops
What were the economic losses of Cyclone Phailin?
Close to $700,000
Why does replanting mangroves help to reduce the risk of coastal flooding?
- wind and swell waves are rapidly reduced as they pass through the mangroves, lessening wave damage during storms
- their above-ground, tangled roots reduce wave energy, meaning there is a natural barrier protecting against coastal flooding
- maintaining wide mangrove belts presents obstacles to incoming waves, therefore, lessening wave energy
Fact about mangroves reducing the height of waves after a short distance
A wave may be reduced to half its height after 100m passage through the mangroves
Fact about how mangrove belts several hundred metres wide reduce tsunami height
Mangrove belts several hundred metres wide have been shown to reduce tsunami height by between 5 and 30%, which lessens the impact on the land.
Population of Odisha (2014)
43.73 million
What does SMP stand for?
Shoreline Management Plan
How many sediment cells are there in England and Wales?
11
What are the 4 options within SMPs for any stretch of coastline in the UK?
- hold the line
- advance the line
- managed retreat
- no active intervention
Hold the line
Maintaining the current position of the coastline (often by using hard engineering methods)
Advance the line
Extending the coastline out to sea (by encouraging the build-up of a wider beach, using beach nourishment methods and groyne construction)
Managed retreat
Allowing the coastline to retreat in a managed way (e.g., creating salt-marsh environments by deliberately breaching flood banks that protect low-quality farmland)
No active intervention
Letting nature take its course and allowing the sea to erode cliffs, flood low-lying land and allowing existing defences to collapse
What do ICZMs do?
This is the process of bringing together everybody, they try to balance the conflicts and come up with strategies looking at the whole picture (don’t just look at costs)
What is Odisha’s coast subject to?
- extreme tidal variations. Sea levels have been known to rise by about 4m in certain stretches, inundating up to 3km of coastal land.
- a strong littoral drift, causing an estimated 1.5 million tons of sand to move from the southwest to northeast in a year.
What endangered species come to nest on some of Odisha’s beaches?
Olive Ridley sea turtles
What is being done to conserve the Olive Ridley sea turtles in Odisha?
- awareness is being raised among local people
- community members are being trained and armed to function as boatmen and guards to prevent poaching of the turtles
- there is a ban on fishing during the Olive Ridley breeding season
Aside from Olive Ridley turtles, give a species that the ICZM project is trying to increase in Odisha
Crocodiles
How much has the crocodile population risen in Odisha?
There has been a rise from 8 in 1975 to more than 1,600 today.
Shoreline Management Plan
A Shoreline Management Plan is a policy document that provides a strategy for coastal defence along a defined section of coastline
Where is Swanage and Studland located?
In the south of England
Is the coastline concordant or discordant in Swanage and Studland?
- concordant coastline on the south
- discordant coastline on the eastern side
Does Swanage or Studland have sand dunes?
Studland
What does the presence of sand dunes mean for the management strategies in Studland?
They have to be more natural
Does Swanage or Studland have more economic value?
Swanage, because of the towns there
What hard engineering features did Swanage used to have?
Groynes and a sea wall
Why were gabions implemented at Swanage?
Because the beach had basically disappeared, which wasn’t good for tourism
What features were put in place for Swanage?
- built 19 timber groynes along the sand
- replenished beach with 160,000 tons of sand
- stabilised erosion, leading to a bigger beach
Why wasn’t Swanage left as a No Active Intervention area?
Because it is a settlement and the value of the land is quite high
Where is Swanage close to?
Poole Harbour and Bournemouth
How many visitors do Studland’s beaches attract a day?
Up to 25 000
What percentage of visitors come to Studland by car?
90%
Are there problems with traffic congestion in Studland?
Yes, on busy days, car parks are often full by 11am
What is the biggest factor bringing people to Studland?
The beach (also popular because of Old Harry Rocks, it’s near Poole Harbour too)
Poole Harbour size
2nd biggest natural harbour in the world
How many boats can Poole Harbour get on a busy day?
Up to 300 boats
Give a reptile that can be found on the sand dunes at Studland
Adders (a type of snake)
When was Poole Harbour formed?
This is a large, natural harbour which is a drowned valley formed at the end of the last ice age. It is the estuary of several rivers, the largest being the Frome.
What is Europe’s largest natural harbour?
Poole Harbour
Has Poole harbour been reducing or increasing in size?
Reducing
Why has Poole Harbour been reducing in size?
Because of trapped sediment in mudflats and salt marshes
What is Swanage at risk from?
Erosion and land instability
How many properties would erosion and land instability affect in Swanage if no action was taken?
Around 100 properties
Where in Swanage is the town centre?
At the south end of the bay
Where is there protection in Swanage?
In Swanage, the town centre has protection in place (this is in the south end of the bay), but in the north end of the bay where there is agricultural land, there is no protection in place.
What has Swanage seen an increase of in the last 20 years?
Coastal flooding as a result of sea level rise and high tides overtopping the sea wall. This makes flooding of the lower high street commonplace.
What has the flooding of the lower high street in Swanage resulted in?
An increased cost to local people through loss of business
If sea level rises by 50 cm in Swanage, what are the cost of sea defences in this area thought to increase to?
£6-15 million/km
Give an example of when Studland suffered significant erosion
10m of cliff was lost on one night in February 2014
What is thought to happen by 2050 in Studland?
That the whole area to the North of Studland will be below sea level by 2050.
How many properties are at risk from flooding in Studland?
Just 8 properties, so there are no active sea defences in this area.
How much is Sandbanks receding at a year?
0.6 m/year
How much salt marsh captures how much carbon a year?
1 hectare of salt marsh captures 2 tonnes of carbon/year
How much carbon do the Studland salt marshes capture a year?
95 tonnes of carbon a year
