Soft engineering uses natural systems for coastal defence, such a beaches, dunes and salt marshes which can absorb and adjust to wave energy and tide energy. It involves manipulating and maintaining those systems, without changing their fundamental structure.
Advantages:
- Lower cost
- Retention of form and landforms of coast
- Natural appearance
- Limited reduction of amenity value.
Disadvantages:
- The need for regular maintenance
- The shifting nature of defences
- Less effective against storm events
Examples:
Beach nourishment eg Swanage Bay
Dune regeneration eg Seaton Sluice
Managed retreat eg St Margarets at Cliffe in Kent
Do nothing
Makes notes on these techniques and research examples.
See pages 109 - 113 for descriptions and case study material.
Research these examples and put them in the table below:
Beach nourishment
Dune regeneration
Managed retreat
Do nothing
Description of scheme |
Case study / example |
Advantanges |
Disadvantages |
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Read Geofile 508 Cuckmere Haven coastal management and see the Environmental Agency site and a summary of the options. Describe the coastal management proposed here. Consider all factors and viewpoints and decide on the best strategy for this area.
The Cuckmere River flows from its source to the north of Heathfield, through the Low Weald and on through the chalk landscape of the South Downs to Cuckmere Haven on the coast. Its estuary lies between Eastbourne and Seaford, south of the A259 at Exceat.
The area is enjoyed by thousands of visitors every year and is home to a wide variety of wildlife. It is used for farming and recreational activities like walking, cycling and canoeing.
The beauty of the Cuckmere Estuary and its importance to nature conservation are widely recognised. It is a Site of Special Scientific Interest, a local nature reserve and it forms part of the South Downs Area of Outstanding Natural Beauty, as well as being part of the national Heritage Coastline. The Estuary also lies within the boundary of the recently designated South Downs National Park
Shoreline Management Plans (SMP)
A key component in managing the coast has been the development of Shoreline Management Plans (SMP) which set out a strategy for the coastal management of a section of the coastline.
Each SMP covers an area of coastline known as a sub-cell within a littoral sediment cell, of which there are eleven on the England and Wales coastline.
A sediment cell is defined as a length of coastline, which is relatively self-contained as far as the movement of sand or shingle is concerned, and where interruption to such movement should not have a significant effect on adjacent sediment cells.
Each major littoral cell is divided into a number of sub-cells, based on the best available knowledge of large-scale processes.
In order to encourage improved co-operation between authorities a series of Coastal Groups have been established based on the littoral cell boundaries.
The production of each Shoreline Management Plans (SMP) involves the appointment of expert firms of consulting engineers to undertake a detailed study of all the issues affecting the coast such as land use, environmental protection, economics and the action of the coastal processes.
The final report establishes the management policy for the coast defences by dividing it into separate Management Units and making specific recommendations for each unit based on four alternative options:
1. Do Nothing - Carry out no coastal defence activity except for safety measures
2. Hold the Line - By intervention, hold the existing defence where it is
3. Advance the Line - By intervention, to move the existing defence seaward
4. Retreat the Line (Managed Retreat) - By intervention, to move the existing defence landward
Example 1 from the North Norfolk SMP: Management Unit No 3 Cley Coastguards to Stiffkey Marshes
Example 2 - Hold the Existing Line in the short term for Blakeney and Morston Defences.
Example 3 - Do Nothing at Blakeney Point - allowing the shingle ridge to evolve naturally
Research these examples
Read the Geo factsheet Coastal Management at Selsey in West Sussex - what factors influence the viability of managed retreat as a coastal management option?
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