Coastal management

Coastal counseling mental institutionThis report studies the concepts ring sliding boardal forethought. It accommodates the memorial of the British coast stock in varianceicular the eastbound Anglian coast, the genuine theories of coastal aegis and the challenges that pull up s pull in ones hornss be faced in the time to come as a result of possible climate change. The report in any case describes the different responsibilities and roles that Goernment funded organisations such(prenominal) as The environment Agency induce in coastal protection management.The report focuses on coastal eroding and protection schemes in the eastbound Anglian region.The History Of The vitamin E Anglian CoastlineThroughout history Britains coastline has been under attack from the forces of the ocean. This has lead to some signifi sackt changes in the coast over the last two thousand years or so. heretofore these changes w atomic number 18 not been constant. Fluctuations in temperature o ver hundreds of years take for modify climates create ocean levels to alter, changes in levels of precipitation and varying probabilities of the occurrence of assail surges.As expound by Cracknell (2005) eastern Anglias coast has changed signifi contributetly in the last two thousand years. This is sh experience in figure 1. interpreted from Cracknells (2005) usurious Waves. The lay out shows how the city of Dunwich, a settlement on Suffolks coast, has been gnaw at over the last seven hundred years. The map clearly shows how the ocean piecemeal erode the city of Dunwich taking with it galore(postnominal) important buildings such as the Chapel of Francis.The past destruction of some of East Anglias coastline pile be stray dispirited to attack surges, which brook cause a plumping total of eating away in a very shout derive of time. The scale of destruction passelnot be seen over a long timescale, such as in figure 1 as averages be taken of the distance of land e roded.The East Anglian coastline has not only been washed-up by coastal cognitive operatees but as well as new land has been created as a result of them. For example the now named Scolt Head Island off the coast at Brancaster has formed. This innate forming sand bar is now a born(p) ocean defence protecting the local anaesthetic villages from possible erosion.Others villages on the new(prenominal) communicate behave not been that lucky with many of them falling victim to coastal erosion in the last hundred years or so. These include such settlements as Sidestrand, Slaughden and Eidesthorp.As stated by Cracknell (2005) East Anglia is unconnected many other parts of the British coastline as it is still macrocosm eroded to this day, at a signifi force outt rate. This is principally due to its geology of mainly clay and soft rocks. It is also believed to be due the isostatic readjustment of the fall in Kingdom caused by the melting of the grouch caps by and by the last i ce age. The resultant outcome from this dish is that East Anglia is sinking beneath sea level. This is shown at Potter Heigham where a bridge built in 1385 has been disappearance under the urine level.Coastal ProcessesCoastal Processes IntroductionCoastal processes be made of inputs, outputs, transfers and stores. These ideas be used when targeting new coastal management schemes, as it is vital for engineers not to architectural plan a scheme which depart have a negative impact on the coastline.Coastal wearingThere atomic number 18 four main processes touch on in the erosion of the coastline. The first is hydraulic action this involves water compressing air at heart small cracks in the cliff and causing the rock to fracture. The process also involves the actual force of the waves on the cliff face. The wink process mired in coastal erosion is abrasion also known as corrosion. This reference of erosion involves eroded veridical hitting the coastline. The hearty is carried by the forces knotty in wave action. The third process is corrosion, which is a process whereby a chemical reaction takes place causing the coastline to erode. This process is not usually associated with East Anglias coastline as it predominantly involves the chemical reaction amid sea water and limestone. Attrition is the final process and is when already eroded material is worn down further by contact with other material.Long Shore DriftLong shore drift is the process when eroded material is transferred down the coast by the sea. It principally acts in only one bearing along the coastline and is a main factor in when designing coastal defences. By altering this process eroded material can be prevented from being deposited further down the coast, thereby exposing the coastline to much(prenominal) coastal degradation.Natural sea Defences brimesNatural sea defences ar normally a result of the transfer a deposition of eroded material. The some common natural sea defen ce is the beach. These form when eroded material is either deposited straight below the place of erosion or whereby eroded material is transported along the coastline by the process of long shore drift. onshore land formsOffshore land forms be created when the forces involved in carrying eroded material by long shore drift dumbfound in any case small and material is deposited on the sea floor. These land forms create natural barriers against wave action and significantly cut out the amount of energy the waves have when they reach the coastline.Coastal Management To DateCoastal Management IntroductionThe English coastline is soundly 3000 kilometres long. Nearly two thirds of this coastline is protected by semisynthetic sea defences put in place to protect against both coastal erosion and sea implosion therapy. The East Anglian is however heavily protected as it is much more prone to coastal processes compared to other stretches of the English coastline.Bodies involved in Coas tal ManagementFour main bodies are involved in the coastal management of East Anglias coastline. The first is The milieu Agency, which has no accountability to protect the coastline from erosion. in time it is responsible to protect the land against flooding from the sea. This role comprises of designing and creating coastal flood defences, but also includes producing flood-warning systems.The second group involved in coastal protection is the local authorities, which have the power to protect the land from coastal erosion. Local authorities and The environs Agency are both funded by DEFRA (Department for Environment Food and campestral Affairs). DEFRA is a government body which funds coastal schemes. Before these schemes are funded they have to go through rigorous assessment. This is done to prioritise the schemes for funding. individual(a) landowners are the final group responsible for coastal protection. This group includes problem which can afford to fund there own coastal management schemes. These do however have to be authorized by the local chest to work out sure they comply with planning regulations. establishment PoliciesThe Government has four main policies concerning the protection of East Anglias coastline. These are shown in the disconcert below. These policies are depute to different stretches of the coast. The coast is split up into units and depending on the assessment made of the value of the land they pass on be put under the four different policies.Policy NameAction to be takenDo nothingNo action to be taken to prevent the natural erosion of the coastHold the line nominate a defence to keep the coastline as it isAdvance the line rear a defence seaward of the current coastline defenceManaged retreat take the sea to erode the coastline and create defences further inlandCurrent SchemesEast Anglias coast is split into four separate units. each section has its own specific SMP (Shoreline Management Plan), which has been put together by the local authority and The Environment Agency. These are shown on the adjacent map taken from http//www.essex-estuaries.co.uk/EastAnglianStrategies/Coastal.htmEach unit is made up of many sub units, which have been assessed and assigned a coastal defence insurance policy (eg. Hold the line).Map of East Anglias 4 different SMP units. http//www.essex-estuaries.co.uk/EastAnglia nStrategies/Coastal.htmTypes of DefenceThere are two categories of sea defence which are used on the East Anglian coastline. These are lumbering defences and soft defences, each work in different ways to belatedly coastal degradation. Hard defences are constructed to create a static line of coastal protection. Whereas soft defences are designed so they are responsive to sea processes.Both categories of defence need to be designed with study on how local sea processes may react with their manifestation. Much interrogation is carried out to find how the local tides, wave action and other factors willing be affected by the introduction of new defences. This research may include scaled down models of the coastline and use of computer models.Hard DefencesSea WallsSea walls have been used for many years now, in the protection of the East Anglian coast. The sea wall is mainly used as part of the hold the line coastal management policy. The walls are designed to forget the wave energy away from the coastline. Early sea walls were vertical, but these designs were slowly damaged and had to be repaired frequently. For example at Sheringham, where the sea wall had to be replaced after only five years. The reason these sea walls are no longer used is that they absorb most of the waves energy rather than exclude it like new sea walls. New sea walls are constructed with a curve to channel the waves energy back on itself. This however can have a negative effect on the beach, as it can cause more erosion to take place. The erosion can shop the foundations and eventually lead to the collapse of the sea wall.typical sea wall design taken from http//www.northnorfolk.org/coastal/microsite/documents/Coastal_Environment_002.pdf. Sea walls need foundations to provide stableness to the structure. In this design piles have been used as they can penetrate deep into the ground to reach a suitable subsoil. A wave step constructed out of concrete has been incorporated into the design to decease up the energy of the waves. A rubble drain is situated rear end the step so that water does not build up and step down the sea wall.Sea walls are very expensive compared to other sea defences. The main reason for the costs ranging from 2000-5000 per metre is that they can be rather complicated to construct. The need for pilling and large amounts of concrete makes the design very costly. However sea walls can last up to 30 years do them more cost effective.Groynes are used to slow down the process of long shore drift along the coastline. The groynes are built perpendicular style to the c oast so they catch sediment which is being carried by the sea. The construction of the groynes helps to increment the size of the beach and therefore creates a better natural defence against coastal erosion. Groynes are designed according to the strength and direction of long shore drift on the coastline. If badly designed groynes can stop the supply of sediment further along the coast. This has lead to the design of a new semi permeable groyne, which allows some sediment to run low through the groyne and travel along the coast.Figure 5 shows the more common impermeable groyne design. Most groynes are constructed from tropical hardwoods as they are resistant to erosion processes and marine animals which might try to dig into the groynes. The groynes are financial supported by timber and steel piles to make sure they can withstand the forces of the sea.Diagram of impermeable groyne design. taken from http//www.northnorfolk.org/coastal/microsite/documents/Coastal_Environment_002. pdfRevetmentsRevetments are used in the place of sea walls. They are normally used at the bottom of cliffs which are at the chance of collapse. The revetments act as sloping barrier to the sea, reflecting and absorbing the energy. Timber revetments are much cheaper than sea walls and have become a real substitute as they cost only 1200 per metre. However they are prone to rapid degradation as seen at Weybourne cliffs.They are constructed using piles or a concrete apron to give the structure enough support to withstand forces during high tide events. Revetments are built so they are permeable structures, thus allowing sediment to build up behind it. This creates an supererogatory protection at the foot of the cliff. However this can have its disadvantages, it can cause the foundations of the revetments to become exposed and ultimately undermine its structural integrity.They can be built from timber and pebbles, but recently there has been a tendency to design them using different sized rocks. This sort of design named rip rap has become more popular recently as it is seen as more aesthetically pleasing.Offshore BreakwatersOffshore reefs or breakwaters are used as a way to significantly reduce the amount of wave energy reaching the coast. By altering where the waves break on the coastline the size of beaches can be changed. Offshore breakwaters at Sea Palling have been very successful. The Environment Agency installed 9 reefs to protect the coastline. The diagram below shows how the breakwaters can significantly increase the size of the beach. However this success comes at a cost of several million for each reef.Soft DefencesBeach NourishmentBeach nourishment is used where a beach is excessively small to act as a sufficient barrier against the coastal processes. It may involve the dredging of sediment from offshore stores which is then added to the beach. Another natural selection is to collect and transport sediment from somewhere along the coastline whic h is in well-situated supply. Dredging is favoured as it does not involve the mixing of two sediment types which is believed to be less pleasing to the eye. Dredging can involve high pressure hoses which are used to spray sediment onto the beach.Managed RetreatManaged retreat is policy whereby a stretch of coastline is allowed to erode to a point where another line of coastal protection has been constructed. This enables a natural beach or other type of coastal landform to form creating a second line of defence. This sort of policy is becoming more popular with the realisation that not all of East Anglias coastline can be saved.Future mode ChangePast Climate ChangeOver the last thousand years or so Britains climate has changed many times. It has seen a small ice age and many fluctuations in temperature. With these changes there have been transformations in sea levels as well. It is described in Cracknells (2005) Outrageous Waves a period of time known as the chivalric warm perio d which saw a large number storm surges. These storms are connected in Cracknells book to the warm period the united Kingdom experienced from 1300 to 1600. In which a number of coastal settlements were destroyed due to coastal erosion. This period was then followed by a period named the little ice age by Cracknell (2005) where the temperature decreased to the lowest in the last millennium in the 17th century. Then was followed by an increase to the temperature we have today.Predictions of Future Climate ChangeIt is predicted by Cracknell (2005) that sea levels will rise significantly in the next century. Figure 7 shows a map of Britain with forecast sea levels in 2100 taken from Outrageous Waves, Cracknell (2005). This map shows the sea levels Cracknell believes to be most probable in 2100. The map shows how in East Anglia the sea level is predicted to rise as much as 69.6 cm by 2100. This sudden rise is said to be down to two factors by Cracknell (2005). Firstly due to the isotsta tic readjustment of Great Britain. This is caused by ice melting and reducing the weight on earths crust causing some areas to rise and others sink. Secondly to the increased volume amount of water in the worlds oceans due to ice melt.Map of Britain with forecast sea levels in 2100 taken from Outrageous Waves, Cracknell (2005)It is suggested by Cracknell (2005) that the effects on the climate caused by global warming may only become apparent after a lag time. Cracknell states that this lag time maybe due to an speedup of climatic changes as time progresses. He implies there will be more significant changes towards the end of the 21st century.Future Management Of The East Anglian CoastlineIt is stated in Making set for water a extension coif from DEFRA that a new coastal management strategy is ask to tackle the forecast climate changes. It also identifies that a significant likeness of Englands GDP is dependent on industry on the coast. This and other change factors have lead t o DEFRA putting together a new and change set of possible guidelines to prevent the degradation of Englands coastline.In Making space for water the possibility of changing roles of different bodies involved in coastal protection are argued. It is suggested that a new national authority could take control of all coastal protection. However this seems unlikely to happen, as it would reduce the amount of European funding coastal schemes could claim.It identifies in the DEFRA consultation exercise the need for sustainable development on the coast. It suggests that new developments in coastal regions need to be regulated better to ensure that they can be sustainable. This includes better planning guidelines to whether new developments built on flood plains and on eroding coasts should be protected with defences paid by the government or whether they should be built at all.It appears the idea of cost-benefit analysis is bound to hide to take an important role in the future of coastal ma nagement. This will be essential in deciding which areas of coastline need protecting in the future. However with the increasing realisation that the coastline is a natural landform, it is becoming more and more apparent that a policy of managed retreat will become more common.This policy is destined to become more popular as the cost of more complicated sea defences exceeds the value of the land they are meant to be protecting.I think it is clear from researching the current coastal policies in East Anglia and the possible consequences of predicted climate change that there will be significant changes in the coastline of Great Britain in 100-200 years. Moreover I aspect that East Anglias coastline could change the most compared to others of coasts, mainly due to the fact it seems to be experiencing nearly all of the problems associated with coastal erosion. If not tackled effectively in the near future I envision East Anglia will face permanent economic, environmental and social problems.ReferencesCRACKNELL, B., 2005.Outrageous Waves. Chichester Phillimore CO. LTDSAMPSON, A., 1998. Processes affecting North Norfolks cliffs and coastal defences. Sheringham Sheringham Museum TrustDEFRA (Department for Environment Food and Rural Affairs)., 2004. Making space for water, A consultation exercise. capital of the United Kingdom Defra PublicationsENVIRONMENT AGENCY. Essex Estuarine Strategies. in stock(predicate) at http//www.essex-estuaries.co.uk/EastAnglia nStrategies/Coastal.htm on (5/01/2007)ALUN WITHERS, 2001. Document 2-Coastal testimonial in North Norfolk. Available at http//www.northnorfolk.org/coastal/microsite/documents/Coastal_Environment_002.pdf. on (5/01/2007)DEFRA (Department for Environment Food and Rural Affairs), 2002.Soft Cliffs Manual for Managers. London Defra Flood Management Division. Available at http//www.defra.gov.uk/environ/fcd/cliffsrepfinal2.pdfDAVID RAYNER BEAGLE GRAPHICS (GeoResources), 2001. Coastal Management. Available at http//ww w.georesources.co.uk/coastman.htmL1 on (6/01/07)DOVER DISTRICT COUNCIL. Coast protection. Available at http//www.dover.gov.uk/coast/constructing-coast-defences.asp on (5/01/07)