Holderness

• Holderness coast


  Located on the east coast of England, a dynamic coastal system subject to a range of physical processes
• Fundamental coastal processes at the Holderness coast


  1. Erosion

  2. Transportation

  3. Deposition
• Erosion


  • Most dominant process, driven by powerful waves generated by strong prevailing winds from the northeast
  • Removes material and causes the coast to retreat at a rate of approximately 2 metres per year
  • Exacerbated by the geology of soft, easily eroded materials such as clay and sand
• Transportation


  • Driven by longshore drift, the movement of sediment along the coast in a zigzag pattern
  • Responsible for the formation of spits and beaches, and the transportation of sediment away from eroding cliffs
• Deposition


  • Responsible for the formation of features such as beaches, sand dunes, and spits
  • Occurs when sediment carried by longshore drift is deposited in areas where the energy of the waves is lower, allowing sediment to accumulate and form new landforms
• Geology of Holderness


  • Primarily composed of soft, easily erodible materials such as boulder clay, silt, and sand
  • Highly susceptible to erosion from wave action, the dominant process shaping the coast
• The combination of soft geology and powerful wave energy leads to high rates of erosion along the coast, with an average rate of retreat of approximately 2 metres per year
• In some areas, erosion rates can be even higher, with cliffs receding by up to 10 metres per year
• Rotational slumping


  A common feature along the Holderness coast, caused by the soft, unconsolidated sediments prone to slumping and landslides, leading to large-scale collapse of the cliffs
• The distinctive landscape of the Holderness coast is characterized by eroding cliffs, long stretches of beaches, spits, and sand dunes
• The rate of erosion and the dynamic nature of the coastal system mean that the landscape is constantly changing, and management strategies are required to protect local communities and infrastructure
• Holderness Coastline


  • Faces significant challenges in terms of sustainable management
  • High rates of erosion
  • Dynamic nature of the coast
  • Human activities taking place in the area
• Erosion rate


  Average retreat rate of 2 metres per year
• The Holderness Coastline is one of the most rapidly eroding coastlines in Europe
• Coastal processes


  • Wave action
  • Longshore drift
  • Tidal currents
• The dynamic nature of the coast makes it difficult to predict how the coast will change over time
• Human activities in the area


  • Agriculture
  • Tourism
  • Coastal development
• Human activities can exacerbate the erosion problem and impact the natural habitats and biodiversity of the area
• Stakeholder engagement


  • Local communities
  • Landowners
  • Government agencies
• Balancing the needs and interests of stakeholders while ensuring sustainable management of the coastline can be challenging
• Managed realignment


  1. Allow areas of the coastline to erode naturally

  2. Create new habitats and flood defences further inland
• Managed realignment can be more sustainable than hard engineering solutions but may be challenging to implement due to issues around land ownership and stakeholder engagement
• Beach nourishment


  1. Add sand and sediment to the beach

  2. Reduce the impact of wave energy and erosion
• Beach nourishment can be effective in the short term but requires ongoing maintenance and may impact natural habitats
• Coastal defences


  1. Sea walls

  2. Groynes
• Hard engineering solutions can be expensive, impact natural habitats, and may only provide temporary protection
• Stakeholder engagement


  • Education and awareness-raising about the challenges facing the coastline
  • Involving stakeholders in decision-making processes
• Engaging with local communities and other stakeholders is essential for sustainable management of the coastline
• East Riding of Yorkshire coast


  • Provides some of the most variable coastal features in a 70km stretch of contrasting landscapes and coastal processes
  • Features of erosion dominate the northern sections
  • The most rapidly eroding coast in Europe occupies the central plain of Holderness
  • The southern end has a distinctive profile with the growing spit of Spurn Point extending into the Humber estuary and sheltering the mudflats and saltmarshes of the Humber Estuary behind
• Spatial factors


  Factors responsible for the contrasting coastal landscapes that extend over space
• Temporal factors


  Factors responsible for the contrasting coastal landscapes that extend over time
• Lithology and rock structure


  • At the northern end there are thick layers (over 300m) of Upper Cretaceous chalk that originated in warm tropical seas around 75 million years ago
  • The chalk layers are gently dipping on a north west/south east axis, outcropping at their highest at Bempton cliffs 4 km north of Flamborough Head and gently shelving until they disappear under glacial deposits at Bridlington
  • The layers of chalk are largely undisturbed for the most part, exposed at right angles to the cliff face and, consequently, forming vertical cliffs over 100m. high (the highest sea cliffs on the east coast of Britain)
  • At Flamborough Head the chalk has been subject to tectonic movement with extensive faulting and folding at Selwick's Bay that have fractured the chalk more fully, allowing agents of weathering and marine erosion to erode bays into the promontory
  • Weaknesses in the chalk have enabled distinctive features of erosion to develop around Flamborough Head in contrast with the relatively massive beds of more undisturbed, resistant chalk just north at Bempton
  • Caves, arches, stacks and blow-holes are common and lateral erosion of chalk promontories by wave refraction have indented the coast at this point even further
  • There are extensive wave cut platforms in the small coves and bays of Flamborough Head denoting cliff retreat over thousands of years
• Sediment transfer

  • The prevailing north easterly winds drive onshore waves that generate longshore movement of sediment from north to south along the coast
  • Chalk debris from Flamborough Head is deposited all along the coast as far as Spurn Point in the south
  • From a zone of net erosion and sediment loss in the north, the sediment budget changes to net deposition and sediment gain in the south in the form of the spit Spurn Head
  • The River Humber, one of Britain's largest drainage systems capturing over 20% of British river water, enters the North Sea and deposits far more sediment into the sub-cell than is provided just from coastline mass movement and marine erosion
  • The combination of this river sediment encountering the southward littoral movement of marine sediment has enabled a larger spit to form than otherwise would have been the case
  • The turbulence between the two currents meeting at right angles deposits river and marine sediment at the end of the 4.8km. long spit, continuously extending its length
  • Behind (to the west) of the spit the calm tidal waters of the Humber estuary have created large mudflats that develop into saltmarsh successions closer to the shore
• Ancient processes


  1. The deposition of the shells and skeletons of marine sea creatures 75m. years ago and subsequent uplift of the lithified sedimentary rock 15m. years later are responsible for the basic structure of the northern part of the East Yorkshire coast

  2. The chalk has been subject to erosion at various phases since then
• Quaternary processes


  1. The last major advance of ice during the Pleistocene era (began 2.5m years ago) came to an end 18 000 years ago

  2. The rapidly melting ice sheets left a layer of glacial till over the entire region, plastering the exposed chalk and depositing boulder clay to such an extent that it became the Holderness Plain as ice sheets retreated

  3. As sea levels rose rapidly around 10 000 years ago this unconsolidated material became the new coastline of the region

  4. Rapid coastal retreat has occurred ever since and continues today

  5. With an average retreat of 1.6m of coast each year, over 2km have been lost since Roman times and the constant slumping and removal by littoral drift is the key characteristic of the mid-section of the East Yorkshire coast
• Century cycles


  1. The development of the Spurn spit operates on a 350-year cycle of development, growth, extension, breaching at the neck and washing away, before a new cycle of growth begins at the new position of the retreated coastline

  2. The current spit is thought to be reaching the end of the cycle: the neck is regularly breached and the lifeboat families that lived at Spurn Head have now been permanently moved off the spit
• Short term cycles


  1. The tidal range of the Humber estuary varies from 2.8m at average neap tide to 5.7m at average spring tide, contributing to the extensive development of mudflats on the north bank of the Humber estuary

  2. Sea level rise is expected to inhibit the development of saltmarsh successions that would otherwise be expected to take place

  3. Managed retreat developments are taking place near Paull to the east of Hull which are creating human-induced saltmarsh habitats in an effort to contain rising sea levels and absorb periodic flooding