514
J. Ojeda Zújar et al.
Recent Foredune Evolution (1979-1996)
The location of the study site in relation to the aforementioned hydrodynamic of
eastward littoral drift and the pressures of tourism, has meant that the processes which
have controlled its recent evolution can be summarized into two morphodynamically
distinct systems:
(i) Marine erosion: since their construction in the 1970s the jetties have been a total
barrier to longshore sediment transport. The study zone being immediately
downstream, has a definite sedimentary deficit and has been subjected to intense
marine erosion in which the dunes serve as a sediment reserve. The results are:
a) the foredune is subjected to intense erosion processes with significant
rates of foredune retreat and the duneface is effectively a cliff.
(ii) aeolian deflation: as can be seen in Fig. 4, the reactivation of deflation processes
throughout the dune complex were practically non-existent until the late 1980s.
Deflation increased throughout the 1990s linked to the increased tourist presence and,
above all, to the uncontrolled access to the beach by campers and other temporary
visitors from the nearby tourist facilities and villages. The destruction of sand-fixing
vegetation along the different paths across the foredune has led to the development of
blowouts. The morphological effects can be summarized as follows:
a)inland foredune migration because of blowouts
b)general lowering of foredune, increasing risk of inundation and the
destruction of pinewood in the inner dune complex.
c)weakening of the dune by the loss of fixing vegetation increases
vulnerability to marine erosion.
In general each morphodynamic system contributes to a typical landward migration of
the foredune with significant losses of sediment from this sector of the coastal dynamic
system, the destruction of vegetation and an increased risk of inundation.
b) the marine erosion begins at the western end and moves downdrift
c) there is a marked loss of sediment from the foredune which reduces its
role as a sediment reserve in storm events.
J. Ojeda Zújar et al.
Recent Foredune Evolution (1979-1996)
The location of the study site in relation to the aforementioned hydrodynamic of
eastward littoral drift and the pressures of tourism, has meant that the processes which
have controlled its recent evolution can be summarized into two morphodynamically
distinct systems:
(i) Marine erosion: since their construction in the 1970s the jetties have been a total
barrier to longshore sediment transport. The study zone being immediately
downstream, has a definite sedimentary deficit and has been subjected to intense
marine erosion in which the dunes serve as a sediment reserve. The results are:
a) the foredune is subjected to intense erosion processes with significant
rates of foredune retreat and the duneface is effectively a cliff.
(ii) aeolian deflation: as can be seen in Fig. 4, the reactivation of deflation processes
throughout the dune complex were practically non-existent until the late 1980s.
Deflation increased throughout the 1990s linked to the increased tourist presence and,
above all, to the uncontrolled access to the beach by campers and other temporary
visitors from the nearby tourist facilities and villages. The destruction of sand-fixing
vegetation along the different paths across the foredune has led to the development of
blowouts. The morphological effects can be summarized as follows:
a)inland foredune migration because of blowouts
b)general lowering of foredune, increasing risk of inundation and the
destruction of pinewood in the inner dune complex.
c)weakening of the dune by the loss of fixing vegetation increases
vulnerability to marine erosion.
In general each morphodynamic system contributes to a typical landward migration of
the foredune with significant losses of sediment from this sector of the coastal dynamic
system, the destruction of vegetation and an increased risk of inundation.
b) the marine erosion begins at the western end and moves downdrift
c) there is a marked loss of sediment from the foredune which reduces its
role as a sediment reserve in storm events.