Soft engineering coastal protections

The reason for coastal management is obvious, to protect homes and businesses from being damaged and even destroyed by coastal erosion or flooding. Failure to do so can have severe economic and social effects, especially along coastlines which are used for tourism and industry pretty much all of them. Hold the line - Where existing coastal defences are maintained but no new defences are set up.

Soft engineering coastal protections

Groyne Groynes are barriers or walls perpendicular to the coastline, often made of greenharts, concrete, rock or wood. Material builds up on the downdrift side, where littoral drift is predominantly in one direction, creating a wider and a more plentiful beach, thereby protecting the coast because the sand material filters and absorbs wave energy.

However, there is a corresponding loss of beach material on the updrift side, requiring another groyne there. Groynes do not protect the beach against storm-driven waves and if placed too close together create currents that carry material offshore.

Groynes are cost-effective, require little maintenance and are one of the most common defences. However, groynes are increasingly viewed as detrimental to the aesthetics of the coastline and face opposition in many coastal communities. Groyne construction creates a problem known as terminal groyne syndrome.

The terminal groyne prevents longshore drift from bringing material to other nearby places. This is a problem along the Hampshire and Sussex coastline in the UK; e.

Beach nourishment

Seawall Walls of concrete or rock, are used to protect a settlement against erosion or flooding. Older-style vertical seawalls reflected all the energy of the waves back out to sea, Soft engineering coastal protections for this purpose Soft engineering coastal protections often given recurved crest walls which increased local turbulence, and thus increased entrainment of sand and sediment.

During storms, sea walls help longshore drift. Modern seawalls aim to re-direct most of the incident energy in the form of sloping revetments, resulting in low reflected waves and much reduced turbulence.

Coastal management - Wikipedia

The location of a seawall, must consider the swept prism of the beach profile, the consequences of long-term beach recession and amenity crest level, including cost implications.

Sea walls can cause beaches to dissipate. Their presence also alters the landscape that they are trying to protect. Modern examples can be found at Cronulla NSW,[10] Blackpool —[11] Lincolnshire — [12] and Wallasey — Revetments Revetments are slanted or upright blockades, built parallel to the coast, usually towards the back of the beach to protect the area beyond.

Coastal Protection and Management - Hard Engineering - A Level Geography Select Page Hard Engineering Hard engineering techniques are typically used to protect coastal settlements.
Cliff stabilisation Groyne Groynes are barriers or walls perpendicular to the coastline, often made of greenharts, concrete, rock or wood. Material builds up on the downdrift side, where littoral drift is predominantly in one direction, creating a wider and a more plentiful beach, thereby protecting the coast because the sand material filters and absorbs wave energy.
Select Page Coastal Protection and Management — Soft Engineering Soft engineering techniques involve working with nature to manage the coastline.

The most basic revetments consist of timber slants with a possible rock infill. Waves break against the revetments, which dissipate and absorb the energy.

The shoreline is protected by the beach material held behind the barriers, as the revetments trap some of the material.

They may be watertight, covering the slope completely, or porous, to allow water to filter through after the wave energy has been dissipated. Most revetments do not significantly interfere with transport of longshore drift.

Since the wall absorbs energy instead of reflecting, the surf progressively erodes and destroys the revetment; therefore, maintenance is ongoing, as determined by the structural material and product quality.

Riprap Rock armour is large rocks placed at the sea edge using local material. This is generally used to absorb wave energy and hold beach material. Although effective, this solution is unpopular for aesthetic reasons. Longshore drift is not hindered.

Rock armour has a limited lifespan, is not effective in storm conditions and reduces recreational values. Gabion Boulders and rocks are wired into mesh cages and placed in front of areas vulnerable to erosion: When the ocean lands on the gabion, the water drains through leaving sediment, while the structure absorbs a moderate amount of wave energy.

Gabions need to be securely tied to protect the structure. Downsides include wear rates and visual intrusiveness. The waves break further offshore and therefore lose erosive power. This leads to wider beaches, which further absorb wave energy. Dolos has replaced the use of concrete blocks because it is more resistant to wave action and requires less concrete to produce a superior result.

Cliff stabilization Cliff stabilization can be accomplished through drainage of excess rainwater of through terracing, planting and wiring to hold cliffs in place. Entrance training walls[ edit ] Main article: Training civil Training walls are built to constrain a river or creek as it discharges across a sandy coastline.

The walls stabilise and deepen the channel which benefits navigation, flood management, river erosion and water quality, but can cause coastal erosion by interrupting longshore drift.

Coastal management - Wikipedia

Floodgate Storm surge barriers, or floodgateswere introduced after the North Sea Flood of and prevent damage from storm surges or any other type of natural disaster that could harm the area they protect. They are habitually open and allow free passage, but close under threat of a storm surge.

Soft engineering coastal protections

The Thames Barrier is an example of such a structure.Coastal management is defence against flooding and erosion, and techniques that stop erosion to claim lands. [1] Coastal zones occupy less than 15% of the Earth's land area, while they host more than 45% of the world population.

When engaging in coastal management, there’s four key approaches that can betaken: Like most engineering schemes in geography, there’s hard and soft coastal engineering.

As usual, hard engineering techniques are high technology, high cost, human made solutions. They do little to work with nature and sustainability is a key issue with.

Hard engineering coastal protection (erosion) These traditional strategies aim to slow down or prevent further erosion of the coastline taking place, usually by placing an artificial, more resistant barrier between wave action and the coast.

An Xbloc is an interlocking concrete block (or "armour unit") designed to Concrete armour units are generally applied in breakwaters and shore protections. The units are placed in a single layer as the outer layer of the coastal structure.

Innovative and Unconventional Coastline Protection Methods, Coastal Engineering section, Delft.

Coastal Barrages

Coastal protection soft engineering 1. Soft EngineeringUse of ecological principles and practices to reduce erosion and achieve the stabilization and safety of shorelines and the area surrounding rivers, while enhancing habitat, improving aesthetics, and saving money.

Hard engineering coastal protection (erosion) These traditional strategies aim to slow down or prevent further erosion of the coastline taking place, usually by placing an artificial, more resistant barrier between wave action and the coast.

Xbloc - Wikipedia