EQ3 Flashcards
evaluate the contribution of geologically recent eustatic changes to the Uk’s coastal landscapes
Eustatic change describes a rise or fall in global sea level, with this occurring due to a variety of reasons and impacting on coastal landscapes, something that can be seen to be occurring within the UK
-One of the ways that eustatic changes are impacting the coastline in the UK can be seen with the increased frequency of storm events asa result of rising sea levels and global warming..this is impacting the coastal landscape mainly in short term changes such as….as well as greater erosive power also impacting on the landscape…
-However it could be said that it is the localised rise and fall of land relative to the say due to isostatic change that has most impacted the coastline of the UK. Isostatic change occurs much slower over many years, with the main way this is impacting the coast being seen in the emergence of both emergent and submergent landforms. An example of emergent landforms in the UK can be seen in the west of Scotland….raised beaches + relic cliffs..Submergent landforms can also be seen, rias are… as seen at the kings bridge estuary Devon….
-Another way it could be said that isostatic change is impacting the coastal landscape can be seen when looking at the differences in land level that are resulting in the north and south of the uk. North + west previously glaciated and so now rising…however south now sinking..thames estuary sediment..
-Although it must be said that the impact of eustatic rises in sea level are also impacting the coastline. These rising sea levels are mainly as a result of thermal expansion…and added ice melt…this can clearly be seen to be impacting the UK in the south where the risk of flooding is not only now heightened by the isostatic change but also arguably more rapidly being threatened by this rise in sea level….
Conclusion- It therefore can be seen that although clearly over the longer term the UKs coastal landscape is significantly being impacted upon by localised isostatic changes in land level, the more recent eustatic changes in terms of rising sea levels/storms could be said to be becoming more significant, especially into the future with the impact of coastal flooding within the south of the UK that is already been slowly sinking.
using examples, explain how contemporary sea level change is having an impact around the world (6 marks)
evaluate the influence of a country’s level of development in determining the impact of coastal flooding (20 marks)
level of development mainly looks at a countries level of economic development, mainly to do with infrastructure in place, services and governance within a country. This can be seen to often have a large impact on determining both the extent of coastal impacts as well as the type of impacts that occur, economically, socially and environmentally.
-Within the more developed regions it is often the case that due to economically them having advantages in terms of resources for preparation and mitigation, particularly the social impacts that occur (such as impact on people) are much reduced. An example of this can be seen with the impact on people and their livelihoods of the 2013 North sea storm surge which impacted on UK and Netherlands. Only 2 people were killed and although over a 1000 homes were flooded and transport services disrupted, these impacts are low considering the size of the area effected. This can be linked to the fact both regions are well developed when looking at the strategies that were in place, e.g. flood defences (thames barrier), sea wall, evacuation plans, and the Delta works in the Netherlands a large serious of tidal barriers/walls that stopped the tides from flooding the land. This itself cost over 2 billion euros, clearly showing that only well economically developed countries could afford this protection, but did mean no one was killed there. However when comparing this with a similar coastal flood event such as cycone sidr that arised in Bangladesh in 2007, the social impacts were much worse. Over 3000 people were killed, 1.5 million homes lost and large scale destruction of transport, land and communication. the economic cost was also much greater, at over 1.7 billion. this can be seen to be linked to development due to the lack of defences in place, lack of preparation and general lack of money to invest in something such as the Netherlands. This therefore does show there is a link.
-This level of development can also be seen to impact on individual countries own situations, looking at factors such as governance, management and day to day lives of people living in the region that can put some coastlines at much higher risk. This can be seen in bangladesh where the government have allowed mass deforestation of mangrove forests and coastal embankments that are leading the land to subside. much of banagladeshis economy is based on agriculture meaning this could be said to be more of a priority for the government than somewhere such as the Netherlands/Uk where protecting buildings etc on the mainland is much more important, more of an economic value and therefore more will be done to protect it. also the fact much of Bangladeshis population has to live on the coastal areas (is so densely populated), another factor putting it at risk.
-Although it must also be said that even in more well developed regions the effects of coastal flooding can still be severe, especially in terms of economic and longer time impacts. For example in Japan when it was hit by the 2011 tsunami although it did have a number of preparation techniques in place such as a 10 metre high sea wall as well as evacuation and management, economically the impacts cost over $240 billion. Also what could be even more significant when looking at somewhere such as Japan, the fact that it is well developed meant that it has infrastructure such as its nuclear power plant that was damaged by the tsunami, leading not only to immediate impacts in terms of radiation and evacuation of that region, but this is now still impacting people globally today. This is something that a country such as Bangladesh just wouldn’t have, showing that although socially and locally the coastal impacts were huge on bangladesh, Japans impacts could be said to be worse due to being so global and long lasting.
-However it cannot be said that level of development is only thing impacting a countries flooding impacts. Unlike the uk/Netherlands, Bangladesh is physically located in a very vulnerable position. it lies on low lying land, on the floodplain of 3 converging rivers, and within the bay of Bengal somewhere where high tides are common as well as monsoonal/heavy rainfall. therefore the impacts were always likely to be greater than other places. also as these events are more common, is less resilient than somewhere such as uk that events are more less frequent, perhaps impacting on its ability to prepare more long term solutions. This can be seen in the fact the last major storm surge effecting these areas was in 1953 + so netherlands especially was able to develop stringent delta networks that played a large role in reducing impacts.
conclusion- can be seen that level of development does play a large role, as somewhere like Bangladesh may not have had such large impacts if it had the resources to manage/prepare. however physical location plays a key role and can impact a countries ability to develop anyway.
assess the impacts of coastal flooding and storm surges globally (12)
Are becoming more of threat in developing countries with low lying land already at risk from coastal flooding, e.g. Bangladesh where 46% of coast is below sea level and islands beginning to subside, means more at risk
-Also evidence to show that due to climate change ocean temperatures are increasing leading to higher sea levels and stronger winds making storms more intense and frequent e.g. evidence that have increased to 16 per year from 11
-However could be said that many coastlines have always been at risk e.g. north sea UK storm surge in 1953 + 2013 so this isn’t increasing and the fact that evidence shows storm events in pacific + Indian oceans not increasing
-Overall can be seen that certain areas are becoming more at risk due to increasing sea level rise coupled with land falling
- the netherlands: DELTAWERKEN PROJECT
mega project costing around US$5 billion which is technically diffult and a usually a long-term project
AIMS: to shorten the dutch coastline to reduce the number of dykes that had to be raised when flood threatened. —> protection from flooding
- tuvalu and insurance ( HOLDERNESS)
evaluate the view that global warming is the greatest threat to coastlines and their communities (20 marks)
global warming is the gradual increase in the overall temperature of the earth’s atmosphere. Thereis evidence that global warming is going to cause massive problems for coastlines and the communities that live near coastlines but there are other factors that need to considered such as coastal management as well as lithology and geology which lead to threats to coastline
Paragraph 1 = Global warming
- Global warming can be a threat towards coastlines and their communities due to the rise in sea levels caused by thermal expansion that can wash away the islands
- EG = This is the case in the islands of Kiribati which is less than 10 metres below sea level
- MEANS = with the increased temperatures the sea levels will rise and then can force communities away from their land
- HOWEVER = policies that allow for people to apply for jobs in New Zealand due to the threat of global warming
- OVERALL = Global warming can threaten communities due to it potentially washing the islands away
- Paragraph 2 = coastal management
EG = Groynes at Mapleton had caused increased erosion rates at Cowden increasing their erosion rates from 2.5 to 3.8 metres per year
- MEANS = groynes being able to trap sediment which can increase erosion rates further along the coastline which can force people away from the area
- HOWEVER = coastal management at Mapleton had decreased the erosion rates there which would put communities at a lower threat of moving away
- OVERALL = Although coastal management can increase the threat to coastal communities global warming would have increased risks of storms which can further increase erosion on coastlines putting communities at risk
- Paragraph 3 = lithology and geology
- EG = Holderness cliffs that erodes at 2 metres per year
- MEANS = threaten communities because it may force people away from their land if the coastline retreats to much
- HOWEVER = this may not be as important compared to the threat of global warming which would be more significant in causing threats to communities
- Conclusion
- Global warming is important in the long term and globally which can threaten communities washing islands away. Coastal management can threaten communities due to the starvation of sediment causing high erosion rates elsewhere. Global warming would be the most important factor.
Evaluate how coastal flooding and storm surges have economic and social consequences for coastal communities in both developed and developing countries
the consequences of CL & SS socially and economically depends on whether its a developed or developing country.
- Developed regions → case due to economically them having advantages in terms of resources for preparation and mitigation → the social impacts much reduced.
+ Eg. impact on ppl/livelihoods of the 2013 North sea storm surge which impacted on UK and Netherlands.
+ Only 2 people were killed BUT over a 1000 homes were flooded and transport services disrupted →these impacts are low considering the size of the area effected.
- Bc both regions are well developed when looking at the strategies that were in place, e.g. flood defences sea wall, evacuation plans.
+ Netherlands a large serious of tidal barriers/walls that stopped the tides from flooding the land → cost over 2 billion euros → showing that only well economically developed countries could afford this protection → but did mean no one was killed there. - H/ comparing developing: coastal flood event such as cycone sidr that arised in Bangladesh in 2007 → the social impacts were much worse.
+ Over 3000 people were killed → 1.5 million homes lost → large scale destruction of transport, land and communication → the economic cost over 1.7 billion. this can be seen to be linked to development due to the lack of defences in place, lack of preparation and general lack of money to invest in something such as the Netherlands. This therefore does show there is a link.
This level of development can also be seen to impact on individual countries own situations → factors such as governance, management and day to day lives of people living in the region that can put some coastlines at much higher risk. Seen in Bangladesh → where the government have allowed mass deforestation of mangrove forests → leading the land to subside. much of Bangladeshi economy → based on agriculture meaning this could be said to be more of a priority for the government → than somewhere such as the Netherlands/Uk where protecting buildings etc on the mainland is much more important, more of an economic value and therefore more will be done to protect it. also the fact much of Bangladeshis population has to live on the coastal areas (is so densely populated), another factor putting it at risk
conclusion- can be seen that level of development does play a large role, as somewhere like Bangladesh may not have had such large impacts if it had the resources to manage/prepare. however physical location plays a key role and can impact a countries ability to develop anyway.
evaluate view that climate change is the most important factor influencing coastal risk (20) intro + 4 points + conclusion
Climate change is mainly leading to increasing temperatures, greater atmospheric water vapour and so is leading to variety of climatic changes + changing weather events adding to coastal risk
-climate change mainly can be seen to be increasing global ttemperatures, leading to the ocean surgaces and so leading to rising sea levels, something that clearly is putting many coastal areas at risk. an example of this can be seen along the coast of Bangladesh, where due to its physical characteristics such as low lying land, being on a floodplain, and one of the most densely populated countries in the world (with 46% of the population living below sea level), is at increasing risk as sea levels rise. not only is it at risk ffrom flooding as a resul of risnig sea levles, but also the increased frequency of storm events such as storm surges and cyclones, that due to warming temepratures are becoming much more frequent as a result of shifting climatic systems. this coupled also with the increasing ice melt from the himilayan mountains adding to the discharge levels of the converging rivers, with incrasing temeperatures it is clear to sea that the coastline of bangladesh is becoming more at risk, with all these factors being caused by the result of global rising temeperatures and so climate change. —-however it cannot be ignored that a number of significant human facotrs are influencing bangladesh coastal risk, with it possibly being that these could be having an even larger impact than that of climate change. for example, due to its rapid population growth, much of the land around the coast has been cleared and deforestatino has increased, leading to much of the land to start to sink and subside, with 1.5 metres already having sunk blow sea level. this is also as a result of coastal embankments built around theland that although aim to preent tidal flooding, are actually leading to the land to further subside due to the prevention of natural sedimnet transportaion. this therefore is leaving bangladesh at a much greater risk of coastal flooding, with these being as a result of human action, not that of climate change. -this also links to the management strategies implemented by coastal cities that may be facing rising sea levels as a result of climate change, as although to an extent this does put coastal regions at risk, strategies that are in place can play a alrge role in reducing this risk and overall vulnerability. for example when comparing the region of Odisha in india and that of bangladesh, although both physically located in similar regions and so also facing the rsiks of coastal flooding etc, due to a number of strategies implemented by odisha, such as replanting mangrove forests, adopting an ICZM, cyclone shelters etc, the resulting risk to the country and population could be seen to be much lower than bangladesh where only coastal embankments that are exarcibating the coastal risk have been put in place. -although it must also be said that without the impact of climate change and so subsequent increased storm frequency and rising sea levels, would these coastal regions even need to implement such strategies or the actions of bangladesh (such as land clearance etc) be such a problem? it could still be held that climate change is still the main factor playing a role in causing many areas to face increasing coastal risk, but that these other factors are playing an exenuating role too.
Assess the relative importance of factors which have led to rapid coastal erosion along a stretch of coastline (Holderness) (12)- 3 points
An example of a coastline that can be seen to be rapidly eroding is that of the Holderness Coastline, which currently erodes at up to 2m a year. There can be seen to be a number of reasons for this, with some being more significant than others.
-One of the main factors that contributes to such rapid erosion is the location of Holderness, being located along the North sea. Due to the coastline being exposed to strong winds and waves from the north east and from across the North Sea waves have relatively long fetch meaning when they reach the coast they have a large amount of energy making them more powerful and so erosive. This then is further caused by other physical factors along the coast. Currents circulate into the North Sea from the Atlantic, with these waves having a very long fetch and so add even more energy, meaning the waves most common are those of destructive nature, meaning erosion is the most dominant process. The North sea also regularly experiences winter storms producing localised high winds and high wave energy which then also add to erosion, with little slowing down of the waves due to the added factor of the sea floor being so deep reducing any chance of friction with the sea bed to help prevent as much erosion occurring. Due to how many different processes are operating along the coastline that cause waves to be so powerful, it can clearly be seen this plays a large role in the rate of erosion, especially with this meaning erosional processes such as hydraulic action etc therefore being more prominent and deposition occurring much less.
-There are also a number of other physical factors making this such a rapidly eroding coast, particularly the geology present.The majority is made up of boulder clay, a very structurally weak material that has very little resistance to erosion, with the influence being seen in many of the coastal landforms present such as that of Flambourough Head. This is then meaning that the beaches along the coast are very narrow, with much of the boulder clay just being transported along the coast via longshore drift. This means that the cliffs are then not protected from the erosional processes and much more exposed. This boulder clay then also experiences a number of sub-aerial processes, such as the mechanical weathering processes of freeze-thaw and wetting and drying, leading to regular slumping too. This is mainly due to the boulder clay absorbing a lot of water into cracks during wetter weather, adding weight into the cliff face leading it to weaken and so sliding downslope. This material is then just carried away again, further leaving the cliff more exposed and retreated. This shows just how significant the boulder clay is as it could be argued that if a more resistant material was present none of the other erosional processes would happen to such an extent. Although when looking at the location and subsequent such powerful waves, any material is still likely to experience a large degree of erosion regardless, although perhaps not so rapidly.
-However, it is not only physical factors impacting Holderness, it is also being impacted by human factors particularly those that are trying to protect the coastline. A number of hard engineering strategies have been implemented along the coast, such as groynes and sea walls, as in Hornsea. Although this has helped prevent erosion in Hornsea, much higher rates of erosion are now occurring downdrift such as in Mappleton as a result of Groynes preventing the transportation of sediment and so these areas are left very exposed. This is known as terminal groyne syndrome, leaving Mappleton to now experience erosion of up to 4m a year, with this continueing to occur and yet more defences being built. This can also be seen with sea walls that are reflecting waves away from certain areas but leading to more powerful waves downshore. Although it cannot be said that this alone is causing the rapid erosion rate along Holderness, when compared to before these defences were implemented, it seems to be occurring much more quickly than before.
Conclusion- It therefore can be seen that a number of different processes are leading to Holderness to experience such rapid erosion, however it cannot be ignored that recent human factors seem to be exacerbating the already powerful physical factors
