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Coastal management involves human intervention to protect coastlines from erosion, flooding and habitat loss. At A-Level, you must understand the full range of management approaches — from traditional hard engineering to modern soft engineering and strategic planning through Shoreline Management Plans. Crucially, you need to evaluate these approaches critically, considering their effectiveness, sustainability, cost and social/environmental impacts.
Coastal management is driven by the need to protect:
However, coastal management also involves difficult decisions about where to invest limited resources and what trade-offs to accept. Not every section of coast can be protected, and protection in one area can create problems elsewhere.
Hard engineering involves the construction of physical structures to resist or control natural processes. These approaches are typically expensive, require ongoing maintenance, and can have unintended consequences on adjacent coastlines.
| Feature | Detail |
|---|---|
| Description | Concrete or stone wall built at the base of a cliff or at the back of a beach |
| Purpose | Reflects wave energy; prevents cliff retreat and overtopping |
| Cost | £5,000-£10,000 per metre (curved/recurved walls are more expensive) |
| Lifespan | 30-50 years (requires maintenance) |
| Advantages | Effective at preventing erosion directly behind the wall; protects property and infrastructure |
| Disadvantages | Very expensive to build and maintain; reflected wave energy scours the beach in front (reducing natural protection); prevents cliff erosion that supplies sediment to the system; visually intrusive; can fail catastrophically in extreme storms |
Example: The sea wall at Scarborough (North Yorkshire) protects the town's promenade and tourist infrastructure. The original Victorian wall has been rebuilt and strengthened multiple times, most recently after storm damage in 2012, at a cost of over £7 million.
| Feature | Detail |
|---|---|
| Description | Timber, rock or concrete barriers built perpendicular to the shore, extending across the beach |
| Purpose | Trap sediment transported by longshore drift, widening the beach on the updrift side |
| Cost | £5,000-£10,000 per groyne (timber); up to £20,000 (rock) |
| Lifespan | 20-30 years (timber); 50+ years (rock) |
| Advantages | Effective at building up the beach, which provides natural wave energy absorption; relatively simple to construct |
| Disadvantages | Starve beaches downdrift of sediment (terminal groyne effect); require regular replacement (timber rots); create discontinuous beach |
Example: At Mappleton, Holderness (1991), two rock groynes and rock armour were installed at a cost of £2 million to protect 80 properties. The groynes successfully trapped sediment and built up the beach locally, but cliff erosion doubled at the unprotected village of Cowden 2 km to the south, which lost its access road and several properties.
Key Definition: The terminal groyne effect is the accelerated erosion that occurs downdrift of a groyne field, caused by the interception of sediment that would naturally have been transported along the coast by longshore drift.
| Feature | Detail |
|---|---|
| Description | Large boulders (typically granite or basalt, 5-10 tonnes each) placed at the base of a cliff or sea wall |
| Purpose | Absorb and dissipate wave energy before it reaches the cliff or wall |
| Cost | £1,000-£3,000 per metre |
| Lifespan | 20-30 years |
| Advantages | Effective at reducing wave impact; relatively cheap compared to sea walls; can use locally sourced rock; permeable (allows water to drain through) |
| Disadvantages | Visually intrusive (large, angular boulders look unnatural); can be dangerous to walk on; may need replacing after storm displacement; restricts beach access |
| Feature | Detail |
|---|---|
| Description | Wire cages filled with rocks, placed at the base of a cliff |
| Purpose | Absorb wave energy; support the cliff face |
| Cost | £50-£100 per metre |
| Lifespan | 5-10 years (wire corrodes in salt water) |
| Advantages | Very cheap; easy to install; can be effective short-term |
| Disadvantages | Short lifespan; look unattractive; wire cages can break and become hazardous; limited effectiveness against high-energy waves |
| Feature | Detail |
|---|---|
| Description | Walls of rock or concrete blocks built offshore, parallel to the coast |
| Purpose | Force waves to break before reaching the shore, reducing energy; encourage sediment deposition in the calmer water behind |
| Cost | £3,000-£5,000 per metre |
| Lifespan | 30-50 years |
| Advantages | Reduce wave energy reaching the shore; can promote beach growth in their lee (creating tombolo-like features) |
| Disadvantages | Very expensive; can alter sediment transport patterns; hazard to navigation; visually intrusive from shore |
| Feature | Detail |
|---|---|
| Description | Sloping structures built along the cliff base, typically of timber, concrete or interlocking blocks |
| Purpose | Absorb and dissipate wave energy; prevent undercutting |
| Cost | £1,000-£4,000 per metre |
| Lifespan | 20-30 years |
| Advantages | Less expensive than sea walls; permeable designs (e.g., open timber revetments) allow water to drain through, reducing wave reflection |
| Disadvantages | Require maintenance; can restrict beach access; timber rots; concrete can crack |
Soft engineering works with natural processes rather than against them. These approaches are generally cheaper, more sustainable, and more environmentally sensitive than hard engineering.
| Feature | Detail |
|---|---|
| Description | Adding sand or shingle to a beach, usually dredged from offshore or transported from elsewhere |
| Purpose | Widen the beach, increasing its capacity to absorb wave energy and protect the coast behind |
| Cost | £3,000-£5,000 per metre (initial); requires repeat applications every 3-10 years |
| Advantages | Looks natural; maintains beach amenity value for tourism; provides natural wave defence; does not disrupt sediment transport along the coast |
| Disadvantages | Expensive over the long term (sediment is continuously removed by longshore drift and storms); dredging can damage offshore habitats; nourishment sand may not match native beach material in colour or grain size |
Example: The Bournemouth Beach Management Scheme (2006-2010) involved pumping approximately 1 million m³ of sand from Poole Bay onto the beaches. The scheme cost £22 million and widened beaches by up to 60 m, significantly improving both coastal defence and the tourism economy (worth over £500 million/year to the local area).
| Feature | Detail |
|---|---|
| Description | Bulldozing existing beach material to create a steeper, higher beach profile |
| Purpose | Increase the beach's effectiveness as a wave barrier |
| Cost | £5-£20 per metre (very cheap) |
| Advantages | Very inexpensive; no imported material needed; quick to implement |
| Disadvantages | Temporary — storms quickly return the beach to its natural profile; only works with existing sediment |
| Feature | Detail |
|---|---|
| Description | Planting marram grass, installing sand fences, and managing public access to encourage dune growth |
| Purpose | Build up and stabilise sand dunes as a natural barrier against flooding and erosion |
| Cost | £200-£2,000 per metre |
| Advantages | Creates natural, self-sustaining defence; enhances biodiversity; relatively cheap; attractive landscape |
| Disadvantages | Takes time to establish (years); vulnerable to storm damage during early growth; requires ongoing management of public access (boardwalks, fencing) |
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