Chapter 5: Coastal change and Conflict (Part 2)

Chapter 5: Coastal change and Conflict (Part 2)

1. People + coastal retreat

   • Sue Earle, farmer - Hornsea, East Yorks
     • 1994 - watched her home of 25 years be demolished - lost battle against north sea waves
       • Farm 39 years earlier 150m away form sea
         • erosion has accelerated when sea defences were built at Mappleton
   • Norcliffe family - Barmston, north of Hornsea
     • 2004 - home was 1.5m away from edge
       • no defences against waves
         • The Humber estuary Coastal shorline management plan - 'do nothing' - potential economic damage to caravan parks + isolated farms - not enough to justify defences
           • a rollback policy for caravan parks but not homes

2. Holderness, East Yorkshire

   • 60km long stretch of low cliffs (20-30m)
     • cliff line retreating - 2m a year - fastest in Europe
       • erosion takes place in storms + tidal surges (6m lost in a storm in 1967)
         • over 4 km lost since Roman times
   • what's the problem?
     • cliffs made of soft glacial clay
       • coast very exposed - waves have long fetch over north sea
         • sea level rise - more attack
           • destructive waves
             • Beaches are narrow due to longshore drift - little protection
   • conflicting views
     • The eldery - lived here whole lives - too old to move
     • Farmers - lost valuble land - no compensation
     • Caravan park owners - whole business threatened - cannot afford to buy more land
     • Politicians - not economically justifiable as the edges are not densely populated
     • Chief engineer - an inevitable natural process - impossible to protectwhole coast

3. Shoreline Management plans

   • 1. Do nothing
     • 2. Advance existing defence line by more hard engineering
       • 3. Hold existing defence line by maintaining/ improving standard of protection
         • 4. Retreat existing defence line (strategic realighnment)
   • strategies are expensive to put in place
     • so a cost-benefit analysis is done -
       • + how sustainable
   • Costs
     • loss of farmland
       • loss of caravan parks + holiday chalets
         • cost of sea defences
           • loss of houses
             • loss of roads
   • Benefits
     • no loss of homes or businesses
       • erosion of cliff stops
         • no loss of land or farms
           • coastline is stabilised

4. Coastal Management

   • Hard engineering
     • Sea wall
       • + protects cliffs and buildings
       • - Expensive
     • Groynes
       • + prevents sea removing sand
       • - exposes other areas of coastline
     • Rip rap
       • + rocks absorb wave energy
       • - expensive
     • Off-shore reef
       • + waves break on reef and lose power
       • - interfere with boats and fishing
   • Soft engineering
     • Beach replenishment
       • + sand reduces wave energy and maintains tourism
       • - expensive
     • Managed retreat
       • + people and activities avoid erosion by moving inland
       • - expensive and disruptive
     • Cliff regrading
       • + mass movement less likely
       • - foot of cliff still needs protection from waves
   • Integrated coastal zone mangement
     • the system of dividing the UK coastline into zones that can be managed holistically
       • reduces damage to environment

5. Case study of traditional coastal engineering structures

   • Durlston Bay, Dorset
     • erosion mainly occured at one particular point - major weakness in rock
       • safeguard houses + apartments on cliff top
     • Regrading cliff - extended forward at base - slope longer - therefore less steep
       • Installing drainage - remove excess water - slope not as heavy or lubricated after rain
         • Rip rap - large granite boulders (8 tonnes each) at base - resist wave attack
   • Swanage Bay, Dorset
     • erosion occured on a considerable length not just one point
       • safeguard houses and hoteld (e.g. Grand Hotel) gardens
     • Sea wall - built in 1920s - provided promenade and a barrier to wave attack
       • Cliff regrading - series of steps in cliff - lower slope angles
         • Groynes - timber groynes in 1930s - 18 recently replaced- reduced long shore drift - beach for protection
           • Beach replenishment - 90,000m3 from studland bay
             • cost of groynes and replenishment - £2 million