The Holderness Coast Case Study

• The Holderness Coast is located on the East coast of England in Yorkshire.
• The Holderness coast is currently eroding at 2 metres per year.
• The Holderness coast is eroding because: it suffers from rotational slip, heavy rain saturates the cliff and soaks through, adding weight, the cliff is then too heavy and collapses, causing large chunks of rock to slip down (rotational slip). The cliff's weight is added to by the houses and trailer park located on top of it. It is also eroded by sub-ariel processes like weathering. The base of the cliff is eroded by marine processes, e.g. attrition and abrasion.
• A long fetch and soft boulder clay, makes the waves erode the Holderness coast quickly.
• The Holderness coast consists of boulder clay, making it vulnerable to erosion as the soft rock is easily eroded. There is a large fetch as the waves come from the North sea, causing the waves to have a strong erosive backwash. Climate change is also affecting the coast as it causes storm surges and sea level rise.
• Hard engineering is human made structures that help to manage coastal erosion. They are man made and expensive. Work against nature.
• Soft engineering is adaptations that work with nature to manage coastal erosion, often cheaper than hard engineering.
• Strategies of managing the coastline include: groynes, gambions, recurved sea walls, sea walls, beach nourishment, managed retreat, riprap, and rock armour.
• The types of management plans include: hold the line, advance the line, no active intervention and strategic retreat.
• Groynes prevent longshore drift by trapping sediment. They 10 - 100 k each and 5 are needed per kilometre. Advantages of groynes are they prevent longshore drift and dissipate energy. A disadvantage of groynes is they may increase erosion downdrift - terminal groyne syndrome.
• Sea walls allow waves to crash against the wall and reflect back out to sea, they cost up to £ 5000 per metre. Advantages of sea walls are they can reflect waves back out to sea. Disadvantages are they can prevent easy access to the beach and can suffer from wave scour, where the waves attack at the sea wall's foundations.
• Rock armour, also known as rip rap absorbs the energy of waves, it can cost up to £ 6000 per metre. Advantages are that rip rap dissipates energy and looks natural for tourists. Disadvantages are the cost depends on the location and it is more expensive if it is built in the sea.
• Planting vegetation / slope stabilisation is where plants are used to make the cliff more stable. Advantages of this include it is cheap (20 - 50 per square metre) and it looks natural for tourists. However, it is not particularly effective.
• Beach nourishment is where sand is pumped into the beach to increase its size, it costs up to £ 2000 per square metre. Advantages of this include: it looks natural for tourists. However, it eventually erodes anyway.
• On the Holderness Coast, Wilthemsea has sea walls, rock armour and groynes, however just south of Wilthemsea is Holmpton, which has no protection and has the highest erosion rates along the Holderness Coast due to terminal groyne syndrome.
• Holistic management takes into account the needs of different people, the amount of money needed and the environmental impacts.