dune

Aberlady dunes

Aberlady succession

Aberlady links

Aberlady processes

Aberlady salt marsh

Aberlady Sands

Aberlady slacks

Aberlady Bay: current processes

The landforms of coastal deposition around Aberlady Bay are being reshaped by a range of processes:

  • wave action, which is eroding older dune systems, transporting sand southwards by alongshore drift and depositing this sands at the mouth of Aberlady Bay.
  • wind action, which is eroding , transporting and depositing sand within the beach and dune system
  • river action, which is bringing small volumes of fine-grained debris into the estuary
  • human action, which is modifying the dune geomorphology and altering the dune and marsh ecosystems

The beach is prograding south-westwards into Aberlady Bay. New berms are forming parallel to the shoreline close the low water mark. Sand transported south along the beach by a dominant southerly alongshore drift is forming a new spit or spits, with a tip that curves into Aberlady Bay under the secondary influence of easterly winds.

The area of dunes is advancing in the area of the new spit. Embryo dunes are colonised by sea couch grass, allowing low ridges to form. In the area of the outfall pipe the dunes appear to be growing in height, as small dunes are developed on top of the main dune ridges. Further north, however, the dune front may have receded a little in recent years as the foot of the main foredune is undercut. Blow-outs in the dune ridges also point to significant and continuing reorganisation of the original ridges into a series of west-east oriented sand hills. The sand removed from the blow-outs forms sand spreads and ridges downwind of the hollows.

The salt marsh is gradually extending into the estuary of the Peffer Burn from both shores. This growth is most noticeable in the intertidal muds west of the footbridge, and may in part be related to the southwards movement of the Peffer Burn channel revealed by old maps.