Complex relationships exist among offshore conditions, beach
sediment transport and morphology, and till cliff erosion. Modelled
and measured sediment transport rates established for the Holderness
coast are similar to those on comparable coasts elsewhere. The
direction of sediment drift depends on wave approach, and determining
sediment transport rates, cliff composition and cliff retreat
rates allows a sediment budget to be prepared. The beach response
predicted by the sediment budget was confirmed by field observations,
with budget surpluses and deficits coinciding with full and depleted
beach profiles respectively. The area of deficit in the north of the
study area was associated with the reduced sheltering effect of
Flamborough Head on sediment drift.
At most profiles, especially those with a sediment deficit, high
energy waves may remove the sand veneer completely, leaving the
till platform exposed. These bare till patches which elsewhere have
been called ords and have been regarded as unique, were thought, in
the present study,to represent a normal beach response to limited
sediment supply and prevailing offshore conditions.
Beach evolution was also modelled formally, the range of beach
profiles exhibited on the Holderness coast being grouped into a
number of distinct types, and evolution among them described and
predicted by a first-order Markov model. This can be refined to
provide different models for "winter" and "summer". Different modal
types occur at different locations, and certain types of transitions
between classes can be associated with particular ranges of wave
conditions.
Beach Development, Sediment Budget and Coastal Erosion at Holderness
Susan J. Mason.
Till cliff retreat at Holderness is extremely variable, both
spatially and temporally, being influenced by beach level, energy
conditions, cliff moisture content and the actions of man.
The sediment transport rates, cliff retreat data, sediment
budget and beach behaviour model are all essential elements of a
research programme currently being undertaken to find a cheap
method of protecting this coast.