3. Sédiment Transport
67
SC-II, with medium to low energy conditions, the Southern and northern
boundaries are the Thangassery headland and Munambam inlet in Cochin,
respectively. The third and fourth Sédiment Cells — SC-III and SC-IV,
which again, represent a combination of medium to low wave energy conditions hâve the Nandhi headland in Calicut and the Manjeswar inlet in
Kasargod as their respective northern boundaries, whereas, the Southern
boundary of these cells are same as the northern boundary of the préviens cell.
Table 3.2. Shoreline orientation, wave condition, nearshore bed slope and grain
size of each sédiment cell.
Sédiment
cell
Average shoreline
orientation
(° w.r.t N)
Nearshore wave
climate
Average
nearshore
slope
Average
grain size
(mm)
I
228
High
0.005-0.05
0.34-0.37
II
255
Medium to low
0.005-0.003
0.24-0.31
III
250
Low, medium to low
0.003-0.004
0.20-0.30
IV
248
Low to medium
0.002-0.004
0.24-0.3
3.10 Sédiment Transport During Extrême Events
3.10.1 General
A hazard is a situation that possesses a level of threat to life, health,
property, or environment and hence a Coastal hazard refers to incidents
which possess the same effect in the coast which is an interface between
the land and shoreline. The hazards in the Coastal environment can either
be manmade or natural. The risk evoked by a natural hazard is measured
by the impact it leaves behind on the people, facilities, services and structures in a Coastal community. There are many Coastal hazards including
storm surge resulting in immédiate érosion hazard and Coastal inundation,
Coastal recession (long term érosion hazard), dune instability and sand
movement, geotechnical hazards (for example, rock fall and landslides),
sea level rise due to climatic change, harmful algal bloom, oil spills and
tsunami.
Of ail the Coastal hazards, three major disasters such as storm surge,
oil spills and tsunami, are discussed in detail in this chapter.
An abnormal rise in the sea level witnessed during a storm event, that
is much higher than the predicted astronomical tide at a particular location
is known as a storm surge. It is a Coastal phenomenon, the surge is caused
67
SC-II, with medium to low energy conditions, the Southern and northern
boundaries are the Thangassery headland and Munambam inlet in Cochin,
respectively. The third and fourth Sédiment Cells — SC-III and SC-IV,
which again, represent a combination of medium to low wave energy conditions hâve the Nandhi headland in Calicut and the Manjeswar inlet in
Kasargod as their respective northern boundaries, whereas, the Southern
boundary of these cells are same as the northern boundary of the préviens cell.
Table 3.2. Shoreline orientation, wave condition, nearshore bed slope and grain
size of each sédiment cell.
Sédiment
cell
Average shoreline
orientation
(° w.r.t N)
Nearshore wave
climate
Average
nearshore
slope
Average
grain size
(mm)
I
228
High
0.005-0.05
0.34-0.37
II
255
Medium to low
0.005-0.003
0.24-0.31
III
250
Low, medium to low
0.003-0.004
0.20-0.30
IV
248
Low to medium
0.002-0.004
0.24-0.3
3.10 Sédiment Transport During Extrême Events
3.10.1 General
A hazard is a situation that possesses a level of threat to life, health,
property, or environment and hence a Coastal hazard refers to incidents
which possess the same effect in the coast which is an interface between
the land and shoreline. The hazards in the Coastal environment can either
be manmade or natural. The risk evoked by a natural hazard is measured
by the impact it leaves behind on the people, facilities, services and structures in a Coastal community. There are many Coastal hazards including
storm surge resulting in immédiate érosion hazard and Coastal inundation,
Coastal recession (long term érosion hazard), dune instability and sand
movement, geotechnical hazards (for example, rock fall and landslides),
sea level rise due to climatic change, harmful algal bloom, oil spills and
tsunami.
Of ail the Coastal hazards, three major disasters such as storm surge,
oil spills and tsunami, are discussed in detail in this chapter.
An abnormal rise in the sea level witnessed during a storm event, that
is much higher than the predicted astronomical tide at a particular location
is known as a storm surge. It is a Coastal phenomenon, the surge is caused