sediment cells

• sources of sediment at coast:

  • rivers
  • cliff erosion
  • longshore drift
  • glaciers
  • wind
  • offshore
• a sediment cell is a stretch of coastline boarded by two prominent headlands where movement of sediment is self-contained (stays there)
• inputs (sources) of a sediment cell:

  • rivers
  • coastal erosion
  • offshore sources e.g bars , banks
• transfers (flows) of sediment cell:

  • littoral drift
  • onshore processes
  • offshore processes (rip currents)
• stores (sinks) of sediment cells:

  • beaches
  • sand dunes
  • offshore deposits (bars)
• UK has 11 key sediment cells and sub-cells
• positive sediment budget


  more sediment enters than leaves - coastline builds outwards
• factors causing positive sediment budget

  • beach nourishment
  • deforestation along coast
  • sea level rise
• factors causing negative sediment budget


  • dam built along river
  • dredging of a river
  • creation of a seawall
• negative sediment budget


  more sediment leaves than enters - coastline retreats