large, steep waves. These waves carry large quantities of sand from the
beach to the nearshore bottom. Land structures, inadequately protected
and located too close to the water, are then subjected to the forces of
waves and may be damaged or destroyed. Low-lying areas next to the océan,
lagoons, and bays are often flooded by storm surge. Storm surges are
especially damaging if they occur concurrently with astronomical high tide
Beach berms are built naturally by waves to about the highest élévation reached by normal storm waves. Berms tend to absorb the wave energy;
however, overtopping permits waves to reach the dunes or bluffs in back of
the beach and damage unprotected upland features.
When storm waves erode the berm and carry the sand offshore, the protective value of the berm is reduced and large waves can overtop the beach
The width of the berm at the time of a storm is thus an important factor
in the amount of upland damage a storm can inflict.
Notwithstanding changes in the beach that resuit from storm-wave
attack, a gently sloping beach of adéquate width and height is the most
effective method known for dissipati'ng wave energy.
1.48 BEACH STABILITY
Although a beach may be temporarily eroded by storm waves and later
partly or wholly restored by swells, and érosion and accretion patterns
may occur seasonally, the long-range condition of the beach - whether
eroding, stable or accreting - dépends on the rates of supply and loss
of littoral material. The shore accretes or progrades when the rate of
supply exceeds the rate of loss. The shore is considered stable (even
though subject to storm and seasonal changes) when the long-term rates
of supply and loss are equal.
1.5 EFFECTS OF MAN ON THE SHORE
1.51 ENCROACHMENT ON THE SEA
During the early days of the United States, natural beach processes
continued to mold the shore as in âges past. As the country developed,
activity in the shore area was confined principally to harbor areas.
Between harbor areas, development along the shore progressed slowly as
small, isolated, fishing villages. As the national economy grew, improvements in transportation brought more people to the beaches. Gradually, extensive housing, commercial, recreational and resort developments
replaced fishing villages as the prédominant Coastal manmade features.
Examples of this development are Atlantic City and Miami Beach.
Numerous factors control the growth of development at beach areas,
but undoubtedly the beach environment is the development’s basic asset.
The desire of visitors, residents, and industries to find accommodations
as close to the océan as possible has resulted in man’s encroachment on
the sea.
1-13
beach to the nearshore bottom. Land structures, inadequately protected
and located too close to the water, are then subjected to the forces of
waves and may be damaged or destroyed. Low-lying areas next to the océan,
lagoons, and bays are often flooded by storm surge. Storm surges are
especially damaging if they occur concurrently with astronomical high tide
Beach berms are built naturally by waves to about the highest élévation reached by normal storm waves. Berms tend to absorb the wave energy;
however, overtopping permits waves to reach the dunes or bluffs in back of
the beach and damage unprotected upland features.
When storm waves erode the berm and carry the sand offshore, the protective value of the berm is reduced and large waves can overtop the beach
The width of the berm at the time of a storm is thus an important factor
in the amount of upland damage a storm can inflict.
Notwithstanding changes in the beach that resuit from storm-wave
attack, a gently sloping beach of adéquate width and height is the most
effective method known for dissipati'ng wave energy.
1.48 BEACH STABILITY
Although a beach may be temporarily eroded by storm waves and later
partly or wholly restored by swells, and érosion and accretion patterns
may occur seasonally, the long-range condition of the beach - whether
eroding, stable or accreting - dépends on the rates of supply and loss
of littoral material. The shore accretes or progrades when the rate of
supply exceeds the rate of loss. The shore is considered stable (even
though subject to storm and seasonal changes) when the long-term rates
of supply and loss are equal.
1.5 EFFECTS OF MAN ON THE SHORE
1.51 ENCROACHMENT ON THE SEA
During the early days of the United States, natural beach processes
continued to mold the shore as in âges past. As the country developed,
activity in the shore area was confined principally to harbor areas.
Between harbor areas, development along the shore progressed slowly as
small, isolated, fishing villages. As the national economy grew, improvements in transportation brought more people to the beaches. Gradually, extensive housing, commercial, recreational and resort developments
replaced fishing villages as the prédominant Coastal manmade features.
Examples of this development are Atlantic City and Miami Beach.
Numerous factors control the growth of development at beach areas,
but undoubtedly the beach environment is the development’s basic asset.
The desire of visitors, residents, and industries to find accommodations
as close to the océan as possible has resulted in man’s encroachment on
the sea.
1-13