Coasta Flashcards
Describe a low energy coast.
Chesapeake Coast, East coast USA
Watershed stretches 524 miles from Cooperstown, New York, to Norfolk, Virginia
Meteor collided with Earth and formed a crater, rivers flow along the path is least resistance, so the depression caused by the meteor caused river valleys to converge, forming Chesapeake Bay
Prevailing wind during summer SW, 5-10mph
Describe the shoreline management plans for England and Wales
11 sediment cells
Each defines a distinct management zone for which an SMP was written
What is the Mekong delta?
A delta is a low lying plain, formed when a river deposits it’s sediment and splits into distributaries meeting the ocean
Lies in southern Vietnam
The transnational Mekong river sources from the Tibetan plateau and flows through 5 countries before reaching Vietnam and entering the South China Sea
18.4 million live on the delta
What are the opportunities that the Mekong delta brings
Makes up 25% of Vietnams agricultural land
Delta produces 55% of vietnams rice output and 90% of the National rice export valued at $2.85 million
Contributes to 2/3 of the National fishing outputs
Agricultural opportunities that the delta brought contributed to the annual growth of 11.7% for the first 10 years of the 21st century
Friendship bridges act as international borders between Myanmar Laos and Thailand, strengths relations
What are the global challenges that the Mekong delta faces?
Rising sea levels resulting in coastal flooding, most provinces will be affected by 2030. Tibetan glaciers are also melting which raises the flood water levels, this is worsened during the monsoon seasons. Increased intensity of TS will drive powerful storm surges. All caused by climate change.
What are the local challenges the Mekong delta faces?
Increased soil salinity is a consequence of rising sea levels, salinity is worded by over abstraction of groundwater resulting in saline intrusion. Soil salinity reduces the fertility of souls which affect harvests. This is worded by China damming and over abstracting water upriver, preventing it from reaching the delta. This has led to a decline of fish and they cannot migrate
By how much could rice production decline by, by 2100 in the Mekong delta due to the combination of the risks?
50% reducing food security of Vietnam
What are adaption strategies that can combat the challenges in the Mekong delta?
Crop patterns and rice species studied to see if they can survive harsh conditions such as salinity, drought etc
Coastal mangroves are being rehabilitated (living barriers against storm surges)
Research into contradiction of freshwater reservoirs for lengthy dry seasons
What are mitigation strategies that can combat the challenges in the Mekong delta?
Mekong river committee plans for the sustainable management of the river but the holistic approach is limited as China and Myanmar are limited
Vietnam signed up to the 2015 Paris agreement to reduce CO2 emissions by 8% by 2030
Migration has started placing economic strain in the community
Describe Holderness, England
61km of discordant coastline from Flamborough Head to Spurn head
Most cliff are made of boulder clay and is exposed to powerful destructive waves in the North Sea
What are the current problems at Flamborough Head?
Coastline has retreated by 4km, 30 villages have been lost
E.g. village of Skipsea is at risk and 80,000 m2 of farmland is lost each year which affects the economy and livelihoods
Loss of infrastructure, e.g. for example the gas terminal at Easington is only 25km off the edge
Loss of site sod special interests, e.g. the lagoons bear Easington provide habitats
Describe the hard engineering present at Holderness
11.4 of the 61km is being protected
Bridlington- 4.7km long sea walls and groynes.
Hornsea- sea wall, groynes, and riprap for a village
Withersea- groynes, sea wall and riprap that was damaged in a Storm
Easington gas terminal- revetments
Why is the hard engineering at Holderness unsustainable?
Groynes trap sediment and increase the epsilon of cliff down drift as less sediment is transported and deposited at the coastline, this offers less protection for example the Mappleton scheme has caused erosion of cliff south
Sediment produced along Holderness usually used to form tidal mudflats but a reduction of sediment increases risk of flooding
Protection of areas leads to formation of waves and this increases pressure on headland and cost of defences become too high
Describe vulnerability to sub-aerial processes
Colder places are more at risk of mechanical weathering, whereas warmer places are more at risk of chemical weathering
During freeze-thaw, how much can water expand?
10% in volume
