IV. Retreatin[~ Shorelines
3
The Cell Theory
299
Mention should probably be made of the position that the sand budget being
irregularly distributed, redressing it would provide a viable solution to coastal
erosion. The proponent, following into the steps of work published by Collins in
1988, proposed at Bordomer '95, a "Coastal Cell Method".
According to Larcher's paper at that meeting, sand pockets, a.k.a, coastal cells,
are sites where beach profiles are healthy and keep wave energy away from
bluffs.
Erosion occurs between cells.
The length of coastline within a cell's boundaries determines whether it is a
micro-cell (less than 50 m or 164 ft long), a meso-cell (50 to 1,000 m or 164 to
3,280 fl long, or a macro-cell ( > 1,000 m).
The irregularity of coastal cells impedes parallel spreading of sediments along
coastlines. These cell's morphology determines two kinds of transits : one within
the cell, and one between cells. There is hardly any transit between cells under
normal wind and sea conditions, with the only noticeable transit within the cell
against its limits abutment, with no escape beyond the cell downstream boundary.
Between cells, transit occurs when wind and sea conditions change and reverse
abutments. Sediments freed from the cell's attraction, however, by-pass eroded
areas only to accumulate in the next cell.
By creating artificial coastal cells, the eroded area can be integrated with the
intercell and intra-cell transit. Larcher refers to the approach as adjusting the
naturally uneven sand budget. Artificial ripple systems, some made of easily
installed hollow modular careens, aim at ondulating the beach and forebeach to
stabilize it and create stable sand bumps generating natural sandbank responses.
4
Conclusion
The range of credits on debits due to the various lines on the budget ledger are
measured as fractions of the gross longshore transport rate (m3/y/m or cu.yd/y/ft)
of beach front. The relative importance of each is governed by local conditions.
3
The Cell Theory
299
Mention should probably be made of the position that the sand budget being
irregularly distributed, redressing it would provide a viable solution to coastal
erosion. The proponent, following into the steps of work published by Collins in
1988, proposed at Bordomer '95, a "Coastal Cell Method".
According to Larcher's paper at that meeting, sand pockets, a.k.a, coastal cells,
are sites where beach profiles are healthy and keep wave energy away from
bluffs.
Erosion occurs between cells.
The length of coastline within a cell's boundaries determines whether it is a
micro-cell (less than 50 m or 164 ft long), a meso-cell (50 to 1,000 m or 164 to
3,280 fl long, or a macro-cell ( > 1,000 m).
The irregularity of coastal cells impedes parallel spreading of sediments along
coastlines. These cell's morphology determines two kinds of transits : one within
the cell, and one between cells. There is hardly any transit between cells under
normal wind and sea conditions, with the only noticeable transit within the cell
against its limits abutment, with no escape beyond the cell downstream boundary.
Between cells, transit occurs when wind and sea conditions change and reverse
abutments. Sediments freed from the cell's attraction, however, by-pass eroded
areas only to accumulate in the next cell.
By creating artificial coastal cells, the eroded area can be integrated with the
intercell and intra-cell transit. Larcher refers to the approach as adjusting the
naturally uneven sand budget. Artificial ripple systems, some made of easily
installed hollow modular careens, aim at ondulating the beach and forebeach to
stabilize it and create stable sand bumps generating natural sandbank responses.
4
Conclusion
The range of credits on debits due to the various lines on the budget ledger are
measured as fractions of the gross longshore transport rate (m3/y/m or cu.yd/y/ft)
of beach front. The relative importance of each is governed by local conditions.