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level: Coastal Change and Conflict

Questions and Answers List

level questions: Coastal Change and Conflict

QuestionAnswer
What are two advantages and disadvantages of dune regenoration?It is cheap and maintains coastal habitats. It is a long process and can hinder tourism.
What is soft engineering?Natrual process that protects coasts
What is soft engineering?Natrual process that protects coasts
What are concordant coastlines?Coasts that are made up of the same type of rocks. They can lead to coves.
What are discordant coastlines?Coasts that are made up of different types of rocks. They can lead to bays and headlands.
What type of rock is chalk?It is a strong sedimentary rock that is more resistant. It produces steep cliffs like the ones in Dover, southeast, and is pure white.
What type of rock is granite?It is an igneous rock and is resistant to erosion. It produces steep cliffs and little beach material. It can be found in Cornwall.
What type of rock is unconsolidated soft rock?It is a sedimentary rock that is a mixture of sands and boulder clay. As a result of a lack of heat and pressure, it erodes quickly.
Which country has the longest beach?Bangladesh - Cox Bazar which is 150 miles.
What is the length of UK's coastline?7723 miles.
What is a tide?The rising and falling of ocean levels, caused by the gravitational pull of the moon (and sun), and the rotation of the Earth.
How much more power does the moon exert than the sun on tides?It exerts 2.2x more power. If it is above us, it creates high tide, and if it's on our side, it created low tide.
What happens to the tide if the sun and moon are directly inline?A tide is created higher than usual. These are called spring tides.
What happens to the tide if the sun and moon are at a right angle?A tide is created lower than usual. These are called neap tides.
Explain the formation of tides (4 marks)Tides are caused by the gravitational force of the moon. This causes the sea to bulge out towards the moon. It also happens on the opposite sides of the Earth since it's being pulled towards the moon and away from the water on the far side. This creates high tide. The sun also has an influence on the tides, but the moon is 2.2x stronger.
What is a wave?A circular arch of water that's created when the wind blows over the surface of the sea or ocean. They form from the transfer of energy.
What is the swash?The wave that approaches the coast at an angle (45°).
What is the backwash?The wave that pulls back back from the beach at 90° angle.
What are the south west winds?Strong winds that have been blown from a great distance.
What is the fetch?The distance the wind travels across the wave or water.
What are destructive waves?Waves that remove beach material because their backwash is stronger than its swash due to having lots of leftover energy. It has high rates of erosion.
What are constructive waves?Waves that deposit sediments because their swash is stronger than its backwash since it has little energy that's used up straight away.
What is longshore drift?The movement of sediment along the coastline.
What is the process of longshore drift?The prevailing wind pushed the wave up the beach at a 45° angle. The backwash pulls sediment down the beach at the direction of gravity, so at a 90° angle. The process then repeats in a zigzag pattern, pulling sediment along the coast.
What is a spit and how is it formed?A spit is an extended stretch of beach material that projects into the sea. It's formed by the deposition of sediment from longshore drift. An example is Spurn Head along the Holderness Coast in Humberside.
What is a bar and how is formed?A bar is an extended stretch of beach material that has joined two headlands together due to the deposition of material - a spit.
How is a bay formed?Bays are formed when soft rock is eroded quicker than hard rock. This causes an inward curve within a beach, in-between headlands.
What is a lagoon and how is it formed?A lagoon is a bay that has been closed off by a bar.
What is a tombolo?A tombolo is formed when an island is connected to the beach by a spit.
What is a salt marsh and how is it formed?A salt marsh is formed behind the recurve of a spit. The water there is protected from storms and tides so vegetation grows.
Explain the formation of a spit (4 marks)Spits are formed by the transportation and deposition of material along a coastline. Longshore drift carries material in the direction of the prevailing wind. When there's a break at the coast (a river mouth) or the coast changes direction, the process builds a long narrow ridge of material, incurved at a distance from the coast due to winds or waves in different directions.
What are rising sea level estimates?30cm to 1 metre.
What will happen to the temperature of waters if there is an increased frequency of storms?It will create warmer waters, creating low pressure systems.
What are storm surges?Flooding from the sea.
What is thermal expansion?When water becomes warmer and expands, increasing the relative volume.
What are some examples of sub-aerial processes?Weathering - freeze thaw. Mass movements - cliffs collapsing.
How is a stump formed?A large crack in the cliff is created due to hydraulic action, which is when water gets into the cracks in cliffs, and the air pressure widens the crack. It's then widened into a cave by hydraulic action and abrasion. The cave continues to become larger until it breaks through the headland to make a natural arch. The arch is eroded and collapses, leaving a tall rock called a stack. The stack is eroded and turns into a stump.
What are 5 key factors that affect coastlines?Settlements, tourism, infrastructure, construction and agriculture.
How does construction influence coastal landscapes?Dredging removes sand and gravel from the system. In 1897, over 600,00 tonnes of sand and gravel from the sea bed was moved to Plymouth Docks in Devon, and the 5m each protecting Hallsands Village was destroyed in 1917 storms.
How does settlements influence coastal landscapes?Over 20 million people live on the coastal zone in the UK. At the Holderness coast over 29 villages have been lost due to coastal erosion in the past 1,000 years.
How does infrastructure influence coastal landscapes?Many buildings like roads, railways and oil refineries are on the coast. Due to their high economic value like the one in Southampton, handling 2,000 ships annually, the coast can't change naturally.
How does agriculture influence coastal landscapes?Rising sea levels and increased coastal erosion has led to a loss in farmland and can affect the fishing industry. The land has low economical value and is normally not protected, so the coast naturally erodes and grows like the Exe Estuary in Devon.
Summarise the Dorset coast case study.Swanage Bay is an important tourist resort with sea defences like groynes and sea walls, which were built to protect the beaches and town.
Identify one type of hard engineering used to protect this coastline. (1 mark)Groynes.
What is soft engineering?Natural process that protects coasts from erosion and flooding.
What is hard engineering?Artificial, mad-made structures that absorb the energy of waves, preventing erosion and flooding.
What is managed retreat?Monitoring coastline erosion in case of dramatic change or danger.
What is a sea wall?Concrete walls that act as a barrier by reflecting wave energy to the sea.
What is rock armour/ rip raps?Large boulders that absorb wave energy.
What are gabions?Wired cages with rocks that can be built up to provide a buffer against the sea and wave energy.
What are groynes?Wooden barriers built out into the sea to stop longshore drift, making the beach grow.
What is beach nourishment?The addition of material to a beach to make it wider.
What is reprofiling?The redistribution of sediment from a lower to a higher section, increasing the gradient.
What is dune regenoration?Building dunes, marram grass, fencing or boardwalks to increase vegetation.
What are two advantages and disadvantages of sea walls?They are very effective and are promenades for tourists. They are ugly and expensive.
What are two advantages and disadvantages of rock armour/ rip raps?They are effective and have easy maintenance. They are ugly and expensive to transport.
What are two advantages and disadvantages of gabions?They are cheap and are flexible to place. They are ugly and only last 5-10 years before rusting.
What are two advantages and disadvantages of groynes?They are relatively cheap and create wider beaches. They starve beaches further along of sediment and only last 25 years.
What are two advantages and disadvantages of beach nourishment?It is relatively cheap and increases tourism. It needs replenishment regularly and groynes can be used instead.
What are two advantages and disadvantages of reprofiling?It is cheap and it reduces wave erosion/ energy. It needs regular redoing and only works when wave energy is low.
What are two advantages and disadvantages of dune regenoration?It is cheap and maintains coastal habitats. It is a long process and can hinder tourism.
Where is the Holderness Coast?On the east coast of England.
How many metres per year does the Holderness Coast erode?1-2 metres per year.
What is the main physical cause of erosion on the Holderness Coast?Geological erosion.
What is the geology of the Holderness Coast, and how is it eroded?It's a mixture of bulldozed clays. The boulder clay on cliffs become saturated with rainwater and become unstable. The cliff is too steep, and eventually collapses. The cliff failure reduces the angle, reducing the prevention of erosion. Large waves reduce sediment through longshore drift.
What are 4 holistic management strategies?Holding the line; Advancing the line; Strategic retreat/ realignment; Doing nothing.
What are holistic approaches?Approaches that consider the whole coast line.
What is holding the line and is it expensive?Using sea defences to stop erosion, so the coast stays where it is. It's expensive.
What is advancing the line and is it expensive?Using sea defences to move the coast into the sea. It's very expensive.
What is strategic retreat?Gradually letting the coast erode, but moving houses and business from areas of risk.