Coastal management Flashcards
Soft management - Where is Formby Point?
Formby point can be found along the Sefton coast, North of Liverpool. It has the largest dune area in England at 17 KM long
Why did the Sefton Coast need management?
- It had been experiencing continual erosion and lost
700m between 1920 to 1970. The dunes were
particularly at risk due to use of off road vehicles
and human access destroying the dunes. Periodic
storms causing high tides and dredging of beach
material for the glass industry also made the coast
more vulnerable to erosion - the area attracts large amounts of visitors to the
beaches, sand dunes and pine forests which locals
earn income from - There are local populations of rare wildlife such as
Red squirrels and Natterjack toads who are also an
attraction and rely on the area as a habitat - Climate models suggest that the average sea level
could rise by 0.3m over the next 60 years - could
lead to an increase in maximum wave height
leading to significantly increased erosion. Dunes
could be vital to defend to coast and for mitigating
flood risks from this and so need protecting. - Without The dunes, buildings would at risk to floods, as the coast becomes straighter, it will cause more sediment to be transported north and south, the deposited, which can bury footpaths in sand.
Management scheme at Sefton coast.
- Areas of the dunes were fenced off to restrict Pedesrian access
- Wooden posts were places in front of the dunes to encourage regeneration and to protect them against tides.
- Off road vehicles were banned from the dunes.
- The extraction of sand for commercial purposes is now controlled
- ranger services were brought into schools to educatee children about the protection and conservation of dunes.
- Broad walks were built to stop people trampling the dunes, signage was used to direct them down routes to avoid the dunes.
- A debate also occured about the impact the pine plantation has on the dune system and if removing it would encourage a broader variety of habitats. (it would mean loosing the rare species)
Hard Management example - Where is Heysham and Morcambe Bay?
Heyshame and Morcambe bay is located in Lancashire, West of Leeds.
Why did Heysam need management?
- Very close to the shoreline existed Morcambe’s town centre, with many seaside resort facilities, hotel and guest houses that line a promenade along the beach. Without this protection, a major source of income from tourism would be lost.
- In Heysham a nuclear power plant and port were at risk, again major sources of income and energy.
- Residential areas were at risk and so people could have been displaced.
- There is a major A road that exists near the promenade and extends the full length of the coast (except round Heysham head)
Management scheme at Heysham
Many hard engineering tactics were used, choosing to hold the line mostly apart from doing nothing at the sandstone cliffs of Heysham head which was a site of historical and ecological importance.
- 10 breakwaters and rock groynes were installed at intervals in front of the town. Under a million locally sourced limestone boulders were used.
- Rock armour was places along the majority of the existing sea wall and promenade along one kilometre of the town. Rock again was locally sources.
- Much of the length of the promenade in front of both Heysham and Morcambe had existing traditional re-curved sea walls, these were repaired and reinforced.
Was the management scheme at Heysham sustainable? Will it help against climate change?
It was made sustainable through designing the defences to be sympathetic to Morcambes bay as a Site of Special Scientific Interest and Special Area of Conservation.
- Any rock armour or breakwaters put in place were locally sourced from quarries and were limestone which meant it was the same geological origin as the rocks of the coastline.
- The quarries were located 10 KM away from the beach which reduced the carbon footprint caused by transportation .
- The placement of rock groynes and breakwaters were placed strategically to create a series of small bays to encourage beach formation to act as a soft engineering strategy to reinforce hard defences.
- Beach nourishment was used placing 89,000 tonnes of sand between Heysham and the Eastern end of the promenade.
- in total cost £ 28 million
ICZM (integrated coastal zone management plan) Where are the Sundarbans?
The Sundarbans is a caostal zone and occupies the worlds largest delta. It is located to the South west of Bangladesh and spreads over to India. It is located on the Bay of Bengal.
Coastal Processes in the Sundarbans
- Tidal action is the primary natural process
- a well developed, dense network of inter connecting river channels flow across the clay and silt deposits.
- Usually the location of the network of main channels remained relatively static due to the silts and clays being quite resistant to erosion
- Larger channels are generally straight and up to two or more kilometres wide, flowing generally north to south due to strong tidal currents
- Smaller interconnecting channels drain the land with each powerful ebb tide.
- Non cohesive sediment such as sand are washed out of the delta and deposited on banks (aka chars) at the river mouths where the strong south westerly monsoon winds then blow them into large ranges of sand dunes.
- With the protection of sand dunes, finer silts washed into the bay are deposited where wave action then adds and shapes further deposits of sand to form new islands.
- Vegetation established itself and eventually, if natural succession can proceed, dense mangrove forests form.
Challenges in the Sundarbans
Physical
- Coastal flooding
- cylones
- High levels of salinity in the soil
- Instability of the island
- Remoteness and accessibility
Human
- Over exploitation of coastal resources from vulnerable habitats.
- conversion of wetlands to intensive agriculture and settlements
- lack of awareness of coastal issues by decision makers
- lack of awareness of the environmental and economic importance of the region.
Opportunities in the Sundarbans
Goods
- construction materials - timber, poles, thatch
- household items - furniture, glue, wax
- food and drink - honey, cooking oil, leaves and fruits
Services
- maintenance - regulation of ecosystem processes and functions, organic matter and fertility, water catchment and ground water recharge.
- value - educational and scientific information, recreation and tourism
Human response to challenges of the Sundarbans
The mangrove forests in the Sundarbans covers a toatl of 10,000 KM squared of land. These forests provide a high level of resilience to the residents as they provide significant protection and shelter against:
- storm winds
- floods
-tsunamis
- coastal erosion
It is said that a density of 30 trees per 0.01 hectares can reduce up to 90% of the destructive force of a tsunami.
- The fertility of the soil and ecological diversity also provided a plentiful supply of a large range of nutritious foods.
- The mangroves have economic value - est. annual economic value of just one hectare is $12,000. Gives resilience against poverty and opportunities for sustainable economic development.
Mitigation of challenges of the Sundarbans
- The threat of natural disasters has meant that the
Sundarbans has attracted significant investment in
the physical infrastructure e.g. schools, telecoms,
hospitals and flood protection, roads, these help
mitigate the risks they face. - allows help from NGOs
to quickly send help after disasters as accessibility is
increased. - Many communities in the Sundarbans have good
levels of social capital from legal frameworks and
services provided by the formal government and
NGO organisations. Allow them to invest further into
protection. - Due to the area containing economic value and
resources, some communities in the Sundarbans
have a better economic safety net than other groups.
Resilience, however have been decreasing due to - shrinking of open access resources
- degradation of ecosystems
- corruption of both local and national political institutions.
Adapting to the Sundarbans
Challenge - Permanent embankments built by the commercial shrimping industry are encouraging the deposition of silt, thus raising water levels in rivers.
Adaptation - USAID trains communities to become more resilient to future climate shocks, 30,000 people have received training on improving agricultural techniques.
Challenge - rising temperatures contribute ti increased salinity levels of the soil
Adaptation - New salt tolerant rice varieties that can survive being submerged in sea water for over two weeks are being planted.
Challenge - Flood Waters remaining for longer and there is increased intensity and frequency of floods
Adaptation - NGOs provide education and training for community level preparation for natural disasters - planning and preparation can significantly mitigate the impacts of natural disasters.
Challenge - changes to seasonal patterns to rainfall
Adaptation - Installing storage tanks for rain water at most risk from inundation by salt water. Water tight containers to store important belongings and papers during floods are given out.
Opportunities fro sustainable development in the future
- the region has many international and national designations already in place
- there are opportunities for eco tourism in the mangrove forest and wetland areas
- There has been recent investment to improve communications in the region.
