The byproduct of sericulture in different industries.pptx
Coastal management integrated and sustainable management
1. The Holderness Coast, NE
England
Aims:
Why is the Holderness Coast at risk from coastal
erosion?
What management strategies can be used to protect
it?
How successful are these management strategies
2. 1. Geology
What factors put this
coastline at such risk?
2. Fetch
3. Processes
What are / could be
the effects of this
coastal erosion?
3. Holderness Coast: N.E England
Most rapidly eroding coast in (29 villages lost since Roman times)
Rapid coastal erosion (~2m /yr)
•Geology: (soft Boulder Clay) this is also a problem as it erodes to form
small clay particles which are transported out to sea rather than
forming beaches to protect the coast. (Although more resistant chalk at
Flamborough Head to the North)
•Fetch: Currents circulate around the North Sea from the . This
5000km fetch produces high energy destructive waves. The North Sea
is also enclosed and deep which means waves reach cliffs without being
weakened by friction from shallow beaches and have no where to
disperse there energy.
•Processes: Cliff foot (marine erosion/ transportation / deposition) and
sub-aerial process (mass movement and weathering) erode the coastline.
4. Hard engineering
•Hard engineering options tend to be expensive and short-term options.
They may also have a high impact on the landscape or environment. The
table shows the most common hard engineering solutions
5. Soft engineering
Soft engineering options are often less expensive than hard engineering
options. They are usually also more long-term and sustainable, with less
impact on the environment. There are two main types of soft engineering.
1. Beach nourishment
• This replaces beach or cliff material that has been removed by
erosion or longshore drift.
• The main advantage is that beaches are a natural defence against
erosion and coastal flooding. Beaches also attract tourists.
• While it can be a relatively inexpensive option it requires constant
maintenance to keep replacing the beach material as it is washed
away.
2. Managed retreat
• This is where areas of the coast are allowed to erode and flood
naturally. Usually this will be areas considered to be low value.
• The advantages are that it encourages the development of beaches
(a natural defence) and salt marshes (important for the
environment) and cost is low.
• While this is a cheap option, it will not be free as people will need
to be compensated for loss of buildings and farmland.
•
6. How are these management decisions
made?
•
•
•
•
•
Cost Benefit Analysis:
Environmental Impact Assessment:
Feasibility Study:
Risk Assessment:
Shoreline Management Plan:
8. Coastal management along the Holderness
Coast?
Integrated Coastal Management
•
•
Means that sections of the coast are managed as a whole, rather than by
individual towns or villages. Coastal engineers now realise that actions in one
place have effects in other areas.
Shoreline Management Plans (SMPs) are used to manage smaller sub cell area.
All local interest groups are consulted before taking one of the following options.
1. Do Nothing: e.g. let existing defences collapse
2. Hold the Line: e.g. keep the coastline where it is by using hard
engineering
3. Advance the Line: e.g. build coastal defences further out to sea –
breakwaters
4. Retreat the Line: e.g. allow the coast to erode back to a defined line
The SMP for the Holderness Coast is:
•
•
Hold the line in places of economic value – e.g. Gas pipe terminal at
Easington and towns at Bridlington and Hornsea
Do nothing in areas where nothing is worth protecting from erosion.
Unprotected areas will eventually from bays. These will become more
sheltered, and erosion should stabilise
9. Coastal management along the Holderness
Coast?
What are the positives and negatives of Integrated Coastal Management
Positives
•Combines hard engineering (for places
of economic value needing a strategy of
hold the line) with soft engineering
which is more sustainable and long term
for areas of lower value or with valued
eco-systems.
•They manage the coastline (sediment
cell) as a whole so consider any
consequences of management schemes
on different areas of the coastline.
•They take into account the views of
many local interest groups, so should be
of benefit to most.
Negatives
•It can be difficult and time consuming
to consult lots of different players,
with different priorities.
•Hard engineering (holding the line) is
expensive and can be short term.
•Holding the line in one place can have
increased impacts in other areas. E.g.
Mappleton – rock groynes leading to
increased erosion in Great Cowden.
•Managed retreat (do nothing) is often
unpopular, it can be seen as an ‘easy opt
out’ and can be politically difficult to
execute.
10. Sustainable coastal management: Abbotts
Hall Farm, Thames Estuary
Sustainable Coastal Management
•
•
•
•
Sustainable coastal defence/management attempts to accommodate,
copy or work alongside natural systems and processes, with ecosystems
often playing a key role.
Typically such approaches are small scale, localised and bottom-up or
community driven.
They have the advantages of being environmentally friendly, sometimes
cheaper and longer-lasting. Consideration needs to be taken so that
schemes are compatible with adjacent coastal areas. E.g. Thames
Estuary, Abbotts Hall Farm, Essex
Coastal Realignment can be controversial – as existing sea defences are
left to collapse (do nothing approach).
– Salt marsh ecosystems are encouraged. This deliberate flooding helps
create valuable habitats and can provide a natural defence to flooding
– It also saves expenditure on failing sea walls
11. Sustainable coastal management: Abbotts
Hall Farm, Thames Estuary
What are the positives and negatives of Sustainable Coastal Management
Positives
•Ecosystems playing a key role. E.g. Salt
marshes are allowed to develop. This provides
an ecosystem / habitat
•Typically such approaches are small scale,
localised and bottom-up or community driven.
Therefore local people have ownership over
the schemes.
•They are environmentally friendly.
•Often cheaper (it costs very little to retreat
the line – i.e. just the cost of low value farm
land)
•Often longer-lasting. E.g. with rising sea
levels the area will eventually flood.
Introduction of salt marshes provide a longer
term, natural solution to this
Negatives
•Coastal realignment may be controversial. It
involves ‘retreating the line’ and is often
viewed by local residents as the do-nothing
and easy opt out. Politically can be difficult to
execute.
•Consideration needs to be taken so that
schemes are compatible with adjacent coastal
areas.
•Can only be used in areas of low value land as
it does not hold the line. E.g. protect
property.
•It is often only small scale so does not
contribute to large areas of the coast.