280
There is another behaviour related to seasonal variations during a time interval in
the spit. The coastline of the bar changes its morphological aspect until reaching the
equilibrium (static or dynamic), but this is a regular state which is infinite, given the
incidence and effect of meteo-marine conditions. According to Woodroffe (2003), a
spit that has these features can be classified as metastable.
According to Ruiz (2006), the geometric configuration of coastline is a physical
representation which shows the sediments response to process that act on it. In consequence, the spatial domain of a coastline can be analyzed from two approaches;
for one hand, assessing the variation in plant and for the other one, with the transversal section of a beach.
The development of plant analysis must be performed by dividing the spit bar or
the beach that separates the wetland in differential spatial increments within a
coastal cell (Fig. 9.1) that by physical factors presents some morphological features
of that particular environment. The idea of carrying out this analysis is to find any
erosion sign or sediments accumulation throughout time.
Analyzing the wave climate, it can be observed that the main modeller of marine
environment in terms of erosion is the waves generated by the wind. There are other
secondary variables with a bold influence in erosion phenomena as: (a) weathering
of rocky environments; (b) the tidal range; and (c) the configuration of beach.
By virtue of described processes, the most significant morphological features or
frequently more observed in coasts and that are associated with the topic of coast
erosion are cliffs, coastal terraces, natural archs, caves, bays or coves and the abrasion platform (Thornbury 1954).
In relation to the material deposition on the coast, this process owes its existence
to the sustained action and medium intensity of waves that carry the material towards
the beach. Most of coasts in the world are composed by sand and in some cases, by
gravel; but sediment sources are originated from the material transported by rivers
that can generate deltas that sustain extensive beaches. Another scenario consists in
beaches defined by cliffs that are affected by erosion and also support the coastal
zone. Based on these sediments, there are different coastal shapes such as beaches,
bar, spit, tombolo and submerged bars.
Currently, the coastal bar of Mallorquín Lagoon has 3.5 km of length and an
average width of 96.7 m of variable section. The recent lagoon mouth that connects
the sea has a length of 88.41 m and is located at the east of the groin, at a distance
of 1.4 km. The littoral coast is confined between Madalena River discharge (close to
the coastal groin) and León stream (to the west), which intermittently flows into the
sea and commonly finalizes its flow in the Mallorquín wetland (Fig. 9.1).
In the littoral bar of the coastal lagoon can be found three types of sedimentary
environments: (a) beach environment; (b) narrow and open lagoon environmental
ambient; and (c) restricted and protected lagoon environment. With regard to the
first feature, it can observe that the beach environment is affected by a swell perpendicularly arriving at the coast and waves diffracted by the coastal structure. Besides,
it can observe a coastal spit 2 km away from the coastline which is adhered to the
G.D. Rivillas-Ospina et al.
There is another behaviour related to seasonal variations during a time interval in
the spit. The coastline of the bar changes its morphological aspect until reaching the
equilibrium (static or dynamic), but this is a regular state which is infinite, given the
incidence and effect of meteo-marine conditions. According to Woodroffe (2003), a
spit that has these features can be classified as metastable.
According to Ruiz (2006), the geometric configuration of coastline is a physical
representation which shows the sediments response to process that act on it. In consequence, the spatial domain of a coastline can be analyzed from two approaches;
for one hand, assessing the variation in plant and for the other one, with the transversal section of a beach.
The development of plant analysis must be performed by dividing the spit bar or
the beach that separates the wetland in differential spatial increments within a
coastal cell (Fig. 9.1) that by physical factors presents some morphological features
of that particular environment. The idea of carrying out this analysis is to find any
erosion sign or sediments accumulation throughout time.
Analyzing the wave climate, it can be observed that the main modeller of marine
environment in terms of erosion is the waves generated by the wind. There are other
secondary variables with a bold influence in erosion phenomena as: (a) weathering
of rocky environments; (b) the tidal range; and (c) the configuration of beach.
By virtue of described processes, the most significant morphological features or
frequently more observed in coasts and that are associated with the topic of coast
erosion are cliffs, coastal terraces, natural archs, caves, bays or coves and the abrasion platform (Thornbury 1954).
In relation to the material deposition on the coast, this process owes its existence
to the sustained action and medium intensity of waves that carry the material towards
the beach. Most of coasts in the world are composed by sand and in some cases, by
gravel; but sediment sources are originated from the material transported by rivers
that can generate deltas that sustain extensive beaches. Another scenario consists in
beaches defined by cliffs that are affected by erosion and also support the coastal
zone. Based on these sediments, there are different coastal shapes such as beaches,
bar, spit, tombolo and submerged bars.
Currently, the coastal bar of Mallorquín Lagoon has 3.5 km of length and an
average width of 96.7 m of variable section. The recent lagoon mouth that connects
the sea has a length of 88.41 m and is located at the east of the groin, at a distance
of 1.4 km. The littoral coast is confined between Madalena River discharge (close to
the coastal groin) and León stream (to the west), which intermittently flows into the
sea and commonly finalizes its flow in the Mallorquín wetland (Fig. 9.1).
In the littoral bar of the coastal lagoon can be found three types of sedimentary
environments: (a) beach environment; (b) narrow and open lagoon environmental
ambient; and (c) restricted and protected lagoon environment. With regard to the
first feature, it can observe that the beach environment is affected by a swell perpendicularly arriving at the coast and waves diffracted by the coastal structure. Besides,
it can observe a coastal spit 2 km away from the coastline which is adhered to the
G.D. Rivillas-Ospina et al.