280
R.H. Charlier and Chr. P. De Meyer
D.E. Newman (1976, Beach Replenishment : sea defenses and a review of the
artificial beach replenishment : Proc. lnst. Civ. Engrs., I, 60, 445-460)
recommends, however, a mean grain diameter size (D5o) of at least 1.5 times that
of the original sand, in quantities sufficient to establish an ultimate slope
compatible with the wave climate. Topping-up should be carded out as need
arises.
The following steps are suggested in the establishment and management of
artificial beaches : establishment of various conditions affecting the beach under
consideration and choice of the size and methods for the project, assessment of
the environmental conditions, detailed facilities design, implementation and,
after completion, beach administration.
The survey program related to a beach nourishment scheme involves bathymetric
soundings, beach evolution (eventually by remote sensing) and monthly
terrestrial measurements (beach profiling). At least once a year sampling should
be carded out on the beach, the nearshore and the seabed. Winds, littoral drift
and tides affect sediment transport and effects must be measured. The survey
requires hence the gathering of tides, waves, currents and winds data.
Tables 2 and 3 illustrate a far from comprehensive review of major beach
nourishment projects, and the Japanese step-by-step approach to planning,
design, construction and care.
In their report on impact T.E. Lanford and B.J. Baca (1989, Comparative
environmental impacts of various forms of beach nourishment : Coast. Zone '89,
II, 2046-2059) showed that impacts resulting from nearshore turbidity, organisms
direct burial and severe habitat alterations at deposition site, were of short
duration no matter which method was used. More serious consequences are noted
for the "source" sites, especially related to hard-bottom communities ; far less
impact was observed for near-shore, dune and onshore borrowing sites than for
offshore locations. The nourishment methods considered were of short duration
no matter which method was used and were upland borrow, offshore pits
dredging, inshore dredging (harbor or waterway), intertidal shoal inlet relocation
scraping, inlet relocation or -stabilization.
3.8
Sand By-Passing and Compensation Dredging
Whether sand by-passing should be considered a "soft" coastal protection system
or a concomitant method with other schemes is open to discussion. What is sure
is that it is quite useful in many cases where for one reason or another a beach is
starved (cf. 3.1.3).
R.H. Charlier and Chr. P. De Meyer
D.E. Newman (1976, Beach Replenishment : sea defenses and a review of the
artificial beach replenishment : Proc. lnst. Civ. Engrs., I, 60, 445-460)
recommends, however, a mean grain diameter size (D5o) of at least 1.5 times that
of the original sand, in quantities sufficient to establish an ultimate slope
compatible with the wave climate. Topping-up should be carded out as need
arises.
The following steps are suggested in the establishment and management of
artificial beaches : establishment of various conditions affecting the beach under
consideration and choice of the size and methods for the project, assessment of
the environmental conditions, detailed facilities design, implementation and,
after completion, beach administration.
The survey program related to a beach nourishment scheme involves bathymetric
soundings, beach evolution (eventually by remote sensing) and monthly
terrestrial measurements (beach profiling). At least once a year sampling should
be carded out on the beach, the nearshore and the seabed. Winds, littoral drift
and tides affect sediment transport and effects must be measured. The survey
requires hence the gathering of tides, waves, currents and winds data.
Tables 2 and 3 illustrate a far from comprehensive review of major beach
nourishment projects, and the Japanese step-by-step approach to planning,
design, construction and care.
In their report on impact T.E. Lanford and B.J. Baca (1989, Comparative
environmental impacts of various forms of beach nourishment : Coast. Zone '89,
II, 2046-2059) showed that impacts resulting from nearshore turbidity, organisms
direct burial and severe habitat alterations at deposition site, were of short
duration no matter which method was used. More serious consequences are noted
for the "source" sites, especially related to hard-bottom communities ; far less
impact was observed for near-shore, dune and onshore borrowing sites than for
offshore locations. The nourishment methods considered were of short duration
no matter which method was used and were upland borrow, offshore pits
dredging, inshore dredging (harbor or waterway), intertidal shoal inlet relocation
scraping, inlet relocation or -stabilization.
3.8
Sand By-Passing and Compensation Dredging
Whether sand by-passing should be considered a "soft" coastal protection system
or a concomitant method with other schemes is open to discussion. What is sure
is that it is quite useful in many cases where for one reason or another a beach is
starved (cf. 3.1.3).