IV. Retreating Shorelines
305
3
The Beach/Dune System
Beach sand is stored in various coastal indentations, lagoons, off-shore areas, and
in massive dunes. But using dune sand may have nefarious effects " exposing
areas to flooding.
It requires thus a careful local analysis before using such sand for any purpose.
Dune sand, furthermore, being too fine, is seldom suited for beach recharge.
The dune and beach system has gained considerable importance as travel became
easier and more readily accessible to persons with modest incomes. If the
seasonal occupation of the system exerts a serious stress on that environment,
including but not limited to trampling of cf.dlings and plants, dune buggies runs,
creation of passages, or even walkways, which facilitate the invasion of storm
water and establish wind breaks, viz. blowing channels, the building of villas,
hotels and other development structures, has led to dune modification, even
bulldozing, and outright disappearance.
3.1
Regional Development
Often constructions have been lined up too close to the shoreline and the
literature is replete with cases of houses that tumbled in the water. Flood and
storm insurance used to compensate owners in the United States ; this has been
discontinued and a strict construction line established along all coasts. In some
cases the policy of "let us not interfere any longer with nature" is not
economically conceivable. The value of property in numerous areas, including
hostelries and tourist facilities, is simply too high not to try to protect it.
There are of course various approaches : positioning of hard structures, or
favoring nature's work. Dams erected across rivers reduce in many cases delivery
of sediment to the beach ; so can electricity generating stations calling upon tidal,
wave or current power. The first effect -river dams- has e.g. caused major erosion
on the coast of Nigeria. On the other hand construction of the tidal power barrage
across the Rance River near St Malo, France, has not had, according to official
reports, negative environmental impact.
305
3
The Beach/Dune System
Beach sand is stored in various coastal indentations, lagoons, off-shore areas, and
in massive dunes. But using dune sand may have nefarious effects " exposing
areas to flooding.
It requires thus a careful local analysis before using such sand for any purpose.
Dune sand, furthermore, being too fine, is seldom suited for beach recharge.
The dune and beach system has gained considerable importance as travel became
easier and more readily accessible to persons with modest incomes. If the
seasonal occupation of the system exerts a serious stress on that environment,
including but not limited to trampling of cf.dlings and plants, dune buggies runs,
creation of passages, or even walkways, which facilitate the invasion of storm
water and establish wind breaks, viz. blowing channels, the building of villas,
hotels and other development structures, has led to dune modification, even
bulldozing, and outright disappearance.
3.1
Regional Development
Often constructions have been lined up too close to the shoreline and the
literature is replete with cases of houses that tumbled in the water. Flood and
storm insurance used to compensate owners in the United States ; this has been
discontinued and a strict construction line established along all coasts. In some
cases the policy of "let us not interfere any longer with nature" is not
economically conceivable. The value of property in numerous areas, including
hostelries and tourist facilities, is simply too high not to try to protect it.
There are of course various approaches : positioning of hard structures, or
favoring nature's work. Dams erected across rivers reduce in many cases delivery
of sediment to the beach ; so can electricity generating stations calling upon tidal,
wave or current power. The first effect -river dams- has e.g. caused major erosion
on the coast of Nigeria. On the other hand construction of the tidal power barrage
across the Rance River near St Malo, France, has not had, according to official
reports, negative environmental impact.