Hard Engineering
- Sea Walls. Sea walls aim to protect the coast by by shielding it with concrete, steel and stone. Some sea walls are...
- Coastal Barrages. These structure are sometimes constructed in bays and estuaries. Coastal barrages are partly submerged...
- Rock Armour. Rock armour or rip-rap involves placing large boulders in front of a cliff or sea wall to absorb the...
What are hard engineering techniques used for coastal protection?
Hard engineering techniques are typically used to protect coastal settlements. They are used to deflect the power of waves. These are highly visible solutions which help reassure coastal communities.
What are some hard engineering strategies at Holderness coast?
The image below shows a range of hard engineering strategies at Hornsea, Holderness Coast. Groynes are wooden barriers constructed at right angles to the beach to retain the material. The beach material, including sand and pebbles, are trapped between groynes and cannot be transported away by longshore drift.
What is hard engineering and why is it important?
Hard engineering involves building artificial structures which try to control natural processes. Each engineering strategy has its advantages and disadvantages. Concrete walls that are placed at the foot of a cliff to prevent erosion. They are curved to reflect the energy back into the sea.
What are the disadvantages of hard engineering coastal management?
Hard engineering approaches to coastal management tend to be expensive, last only a short amount of time, are visually unattractive and unsustainable. They often increase erosion in other places further down the coast.
What are the benefits of hard engineering?
AdvantagesOften more effective at preventing flooding than Soft Engineering options.Dams and reservoirs provide oportunity for Hydroelectric power.Job opotunities (e.g in builing artifical levees/dams)Building flood banks is relatively cheap.
How does hard engineering affect the coast?
Hard engineering can cause unintended environmental consequences, such as new erosion and altered sedimentation patterns, that are detrimental to the immediate human and natural environment or along down-coast locations and habitats.
What are hard engineering coastal management strategies?
Hard engineering strategies act as a barrier between the sea and the land. Artificial structures are used to change or disrupt natural processes. Examples of hard engineering strategies include sea walls, groynes, revetments, rock armour (rip rap), gabions and offshore breakwaters.
How soft engineering can be used to protect the coastline?
Soft engineering is where the natural environment is used to help reduce coastal erosion and river flooding. At the coast soft engineering is where a beach is used to absorb wave energy and reduce erosion.
Why are hard engineering approaches still used to protect some coastal environments?
Hard engineering techniques are typically used to protect coastal settlements. They are used to deflect the power of waves. These are highly visible solutions which help reassure coastal communities.
What are the advantages and disadvantages of hard engineering at the coast?
Hard engineering options tend to be expensive, short-term options....Gabions.AdvantagesDisadvantagesAbsorb the energy of waves. Allows the build-up of a beach.They can be expensive to obtain and transport the boulders. Can also look unattractive.
What Defences can be used to protect the coast?
Coastal defences3.1 Groynes.3.2 Sea wall.3.3 Revetments.3.4 Breakwaters.3.5 Gabions.
How does hard engineering prevent flooding?
Examples of hard engineering strategies include artificial embankments or levees, channelisation, diversion spillways and dredging. These are larger than natural levees and are usually made of erosion-resistant concrete. They allow more water to flow in the river at a greater height so flood risk is reduced.
What are the hard engineering schemes to prevent flooding?
Dams are the classic hard engineering solution to flooding problems. A dam is a giant wall built across a river's channel to impede its flow. Water builds up behind the dam and forms a reservoir which can then be steadily drained at a controlled rate over time.
Is hard engineering more effective than soft engineering?
Soft engineering is better because it is low cost, long term and sustainable it also incorporates habitats for fish and wildlife and tries to reduce erosion and other environmental impacts.
How does hard engineering affect erosion?
By trapping sediment it starves beaches further down the coastline, increasing rates of erosion elsewhere.
What does hard engineering mean in geography?
Erosion is a natural process which shapes cliffs . Over time, erosion can cause cliff collapse – therefore the coastline needs to be managed. Hard engineering involves building artificial structures, which try to control natural processes at a local scale.
Revetment
Open slanted concrete or wooden facing/fence offering partial resistance but letting some seawater to pass through
Tetrapods
Moulded multi-angular concrete shapes formed on site and tipped onto beach to form interlocking components
Groynes
Wooden (or less often, boulder) ‘breakwaters’ at right angles to a beach extending into the sea designed to capture longshore drift sediments to build up beach width and height
Offshore reefs
Artificial sand/gravel offshore deposits designed to intercept destructive wave action
Coastal management
Hard engineering management involves using artificial structures, whereas soft engineering management is a more sustainable and natural approach to manage coastal erosion.
Sea walls
Concrete walls that are placed at the foot of a cliff to prevent erosion. They are curved to reflect the energy back into the sea.
Rock armour
Large boulders placed at the foot of a cliff. They break the waves and absorb their energy.
What is hard engineering?
Hard Engineering. Hard engineering techniques are typically used to protect coastal settlements. They are used to deflect the power of waves. These are highly visible solutions which help reassure coastal communities. However, they are are expensive to install and maintain.
Why are coastal barrages important?
They help provide a more consistent level of water. An example can be found in Cardiff Bay, Wales. Coastal barrages can also be used to generate hydro-electricity. Their environmental impacts are considerable due to their impact on tides and are very expensive to construct and maintain.
What is the purpose of a preserved beach?
The preserved beach helps slow waves and reduce their energy which provides protection from flooding and erosion. A groyne at Hornsea, Holderness Coast.
What are the disadvantages of sea walls?
The disadvantages of sea walls are that they are expensive to construct and maintain. They also create a strong backwash which can erode under the wall. Scarborough sea defences from Anthony Bennett on Vimeo. Scarborough sea defences. from Anthony Bennett. Play.
What is the purpose of sea walls?
Sea walls aim to protect the coast by by shielding it with concrete, steel and stone . Some sea walls are recurved, like the one shown in the video of Scarborough sea defences below. The aim of the lip is to deflect the energy of the wave.
Where are coastal barrages located?
They help provide a more consistent level of water. An example can be found in Cardiff Bay, Wales.
Is rock armour cheaper than seawalls?
Rock armour is a cheaper solution than seawalls to deflect the wave energy. The video below shows a combination of rock armour in the form of large rocks and accropodes (x shaped concrete structures) at Scarborough, North Yorkshire. This opens in a new window. Gabions work in a similar way to rock armour.
What is hard engineering?
Hard engineering involves building artificial structures, which try to control natural processes at a local scale. Each engineering strategy has its advantages and disadvantages.
What is the difference between hard engineering and soft engineering?
Traditionally, hard engineering management involves using artificial structures, whereas soft engineering management is a more modern day technique which is often a more sustainable way to manage the effects of coastal erosion and flooding. Part of. Geography. Coastal hazards and their management.
How do coral reefs help the shoreline?
Adding to those benefits, coral reefs can protect the shoreline from erosion by helping to build up sediment deposits (Morris et al, 2017). This fixes a major problem of seawalls and levees. Reefs will not stop the effects of sea level rise and ocean warming, but they can mitigate its effects.
What is soft engineering?
The other option, Soft Engineering , involves using natural defenses to protect the coastline. For example, coral reefs are some of the most effective barriers to coastal damage and erosion. They cost less than seawalls and provide roughly equivalent (or even superior) defensive capabilities (Carey, 2014) (Morris et al, 2017).
What is the purpose of jetties?
Army Corps of Engineers help ocean-going vessels move between coastal rivers and the Pacific Ocean. Simply put, jetties are rock fingers which stretch out into the ocean from the beaches, essential ly extending the mouths ...
Why are coral reefs important?
In addition to this, coral reefs have numerous ecological and commercial benefits, providing habitat for thriving fisheries and money for local tourist industries (Morris et al, 2017). However, natural defenses are restricted by environmental factors and often difficult to control and manage.
What are the most important hard structures?
The most important hard structure types are dikes (levees), seawalls, breakwaters, groins, and jetties. The following descriptions are taken directly from the USACE Coastal Engineering Manual, the primary reference for coastal structure design in the U.S.
Why are coastal structures important?
Coastal structures are frequently constructed to prevent erosion of coastal landscapes and infrastructure and mitigate the risks to the populations and economic activities dependent on the coastal zone. Coastal structures, sometimes referred to as “hard” structures, are usually built using materials (at least for certain coasts and beaches) ...
What are coastal structures?
Coastal structures, sometimes referred to as “hard” structures, are usually built using materials (at least for certain coasts and beaches) that do not form naturally, such as of concrete, large armor stone, steel, or timber, are relatively permanent (typical 50-yr design life), and are spatially-fixed within an otherwise dynamic coastal zone.
What are the advantages and disadvantages of sea walls?
Advantages: > They are effective in protecting the cliff from further erosion and act as a barrier to protect the shore from flooding. Disadvantages: > They are large, ugly structures that are not appealing for seaside. > Sea walls are very costly and need constant maintenance to prevent them from failing when needed.
Why are sea walls built?
Sea walls are huge barriers that are built along the coastline, shielding it with concrete, steel and stone, aiming to reduce erosion and protect from flooding.
What is a cliff revetment?
Revetments. Revetments are large concrete, wooden or rocky structures built along the base of a cliff, not too dissimilar to sea walls. The cliff is protected from sea erosion as the waves break upon the revetments, absorbing all the energy.
Sea Walls
- Seawalls are usually built along the front of cliffs to protect settlements or another land of high economic importance. They are often recurved which means waves are reflected back on themselves. This can cause the erosionof material at the base of the seawall. The video below s…
Coastal Barrages
Rock Armour
Groynes
Cliff Fixing
- These structure are sometimes constructed in bays and estuaries. Coastal barragesare partly submerged structures containing sluice gates that control the tidal flow of the sea and river water from land. They help provide a more consistent level of water. An example can be found in Cardiff Bay, Wales. Coastal barrages can also be used to generate hydro-electricity. Their environmenta…
Off- Shore Reefs
- Rock armouror rip-rap involves placing large boulders in front of a cliff or sea wall to absorb the energy of waves. Rock armour is a cheaper solution than seawalls to deflect the wave energy. The video below shows a combination of rock armour in the form of large rocks and accropodes (x shaped concrete structures) at Scarborough, North Yorkshire. Gabionswork in a similar way to r…