The North East Coastline of Scotland
29
Sustainability of the Beach/Dune Resources
Throughout the region it would appear that extensive glacial and fluvioglacial deposits
on the continental shelves are the ultimate sources of beach and sand dunes. It is also
of interest that there are higher shell sand contents on beach sands between Rosehearty
and Peterhead. It has not been possible so far to estimate the contribution being
received from current processes such as cliff erosion or river discharge. Similarly it has
proved impossible to determine whether or not the coastal dunes are at a stage of net
retreat or net advance. Examination of the detailed morphological evidence suggests
that the steep, undercut dune face is most common especially on the North Sea coast of
North East Scotland so that the balance of opinion favours coastline retreat.
Nevertheless, there are significant areas of accretion especially near the river outlets, at
places between Fraserburgh and Peterhead and in the Inner Moray Firth west of Spey
Bay. In the last named area, however, it is thought that erosion along one section of the
coast is balanced by redeposition further along the coast.
On both coasts there are good examples of the problem of differentiating
between long-term changes and short, violent events. In January 1978, for example, a
particularly severe storm coincided with elevated sea levels produced by a small North
Sea surge and several hundred thousand pounds worth of erosion damage occurred
between Spey Bay and Peterhead. Significant local changes in beach and dune
morphology were also produced by this storm. It is important to stress that these
'exceptional' storms and high water levels occur with a high statistical frequency.
Research programmes, which have been undertaken as design studies for offshore
North Sea oil and gas installations, have calculated that the 'ten-year' storm or the
'hundred-year' high water level may produce wave heights several metres above the
average along any part of the northeast coastline.
Weather changes have the same degree of variability. Precipitation, for
example, has varied from near drought in summer 1976 to excessively high winter
values in 1977. River discharges vary accordingly and cause significant changes to
occur on adjacent spit and beach features as for example at Speymouth, Banff Bay or
Donmouth. Similarly the characteristic winter flooding which converts most of the
low-lying links and dune areas to temporary lakes varies both in timing and depth of
flooding. This seasonal flooding has important physiographic and ecological effects.
As explained earlier in the chapter, the dunes and links are generally more
stable on the north coast. There are presently no expansive bare sand waves
comparable to the great spreads of bare sand that are found between Strathbeg and
Aberdeen. To some extent this contrast is explained by different land use. Culbin and
Burghead Bay, for example, were described as consisting of extensive migrating bare
sand dunes well into the 20th century, but with afforestation they are now fixed
landforms.
Morphological evidence suggests that the dunes between Fraserburgh and
Aberdeen are more active than those elsewhere in the region. Erosion forms are more
frequent and the landforms are higher and steeper than those found on the Moray Firth
coast. Free-standing dune ridges and sandhills attaining more than 16 m. O.D. are
29
Sustainability of the Beach/Dune Resources
Throughout the region it would appear that extensive glacial and fluvioglacial deposits
on the continental shelves are the ultimate sources of beach and sand dunes. It is also
of interest that there are higher shell sand contents on beach sands between Rosehearty
and Peterhead. It has not been possible so far to estimate the contribution being
received from current processes such as cliff erosion or river discharge. Similarly it has
proved impossible to determine whether or not the coastal dunes are at a stage of net
retreat or net advance. Examination of the detailed morphological evidence suggests
that the steep, undercut dune face is most common especially on the North Sea coast of
North East Scotland so that the balance of opinion favours coastline retreat.
Nevertheless, there are significant areas of accretion especially near the river outlets, at
places between Fraserburgh and Peterhead and in the Inner Moray Firth west of Spey
Bay. In the last named area, however, it is thought that erosion along one section of the
coast is balanced by redeposition further along the coast.
On both coasts there are good examples of the problem of differentiating
between long-term changes and short, violent events. In January 1978, for example, a
particularly severe storm coincided with elevated sea levels produced by a small North
Sea surge and several hundred thousand pounds worth of erosion damage occurred
between Spey Bay and Peterhead. Significant local changes in beach and dune
morphology were also produced by this storm. It is important to stress that these
'exceptional' storms and high water levels occur with a high statistical frequency.
Research programmes, which have been undertaken as design studies for offshore
North Sea oil and gas installations, have calculated that the 'ten-year' storm or the
'hundred-year' high water level may produce wave heights several metres above the
average along any part of the northeast coastline.
Weather changes have the same degree of variability. Precipitation, for
example, has varied from near drought in summer 1976 to excessively high winter
values in 1977. River discharges vary accordingly and cause significant changes to
occur on adjacent spit and beach features as for example at Speymouth, Banff Bay or
Donmouth. Similarly the characteristic winter flooding which converts most of the
low-lying links and dune areas to temporary lakes varies both in timing and depth of
flooding. This seasonal flooding has important physiographic and ecological effects.
As explained earlier in the chapter, the dunes and links are generally more
stable on the north coast. There are presently no expansive bare sand waves
comparable to the great spreads of bare sand that are found between Strathbeg and
Aberdeen. To some extent this contrast is explained by different land use. Culbin and
Burghead Bay, for example, were described as consisting of extensive migrating bare
sand dunes well into the 20th century, but with afforestation they are now fixed
landforms.
Morphological evidence suggests that the dunes between Fraserburgh and
Aberdeen are more active than those elsewhere in the region. Erosion forms are more
frequent and the landforms are higher and steeper than those found on the Moray Firth
coast. Free-standing dune ridges and sandhills attaining more than 16 m. O.D. are