311
In case of variations in the model adjustment, there is an indicator that reflects a
dynamism on the beach, which can be interpreted as dynamic equilibrium. Therefore,
the beach is unstable and can erode quickly at the slightest change in the behaviour
of the coastal system.
The modelling of the plant configuration and application of theoretical parabolic
model was carried out with the MepBay model as shown in Fig. 9.28, developed by
the University Of Santa Catarina Brazil. The importance of using the MepBay lies
in the fact that efficiently determines morphological changes in plant and perform a
physical interpretation of the equilibrium state of the beach (Raabe et al. 2010).
The modelling results (Fig. 9.28) indicate that with the establishment of the
Maritime Terminal “El Superpuerto”, the balance of the beach will be seriously
affected. The coastline undergoes significant changes, especially in the shadow area
generated by the port. However, this condition of the coastline gain should be analysed carefully, because only it will be presented if the current sediments source
remains unchanged of the coastal zone (Fig. 9.28). However, the reality is very different, because for the entry of large ships will be built a navigable channel of 20 m
of deep. This indicates that the little sediment currently crosses by the effect of diffraction of the salient in the groin (Tajamar) will end at the bottom of that navigable
channel.
9.5.9 Identification of Potential Erosion
The erosion rate of the coastline from many countries has dramatically increased in
recent decades. These forces to, the professionals dedicated to the study of coastal
processes, carry out a regular monitoring of changes that are seasonally generated
on a beach. This is not unrelated to the bars that protect coastal wetlands, even if
they have been affected over the years by the establishment of infrastructure for the
development of human activities in coastal environments.
A simple and cost-effective way to elaborate a changes diagnosis and the quantification of potential erosion in a coastal bar, it is based on the analysis of satellite
images. With images of LANDSAT project and the use of the application of
Geographic Information Systems (GIS), it was effected a variability analysis of the
spatial and temporal coastline, from1973 until today. The analysis of the coastline
and its changes over time are a powerful tool to determine processes of erosion and
accretion in a littoral cell, evaluating differences between space increments of each
of the lines drawn.
The methodology consists in drawing for each year and with a seasonal frequently, the polyline representing the coastline for the period measured. In one
image, the different polylines overlap to get a map like the one shown in Fig. 9.29.
Then, to determine the potential for erosion suffered by the wetland littoral bar,
the Digital Shoreline Analysis System (DSAS) developed model by the US
Geological Survey was used (Thieler et al. 2009). Based on selected segments in the
model it described the most representative changes on the coastline. For its applica9 Physical and Morphological Changes to Wetlands Induced by Coastal Structures
In case of variations in the model adjustment, there is an indicator that reflects a
dynamism on the beach, which can be interpreted as dynamic equilibrium. Therefore,
the beach is unstable and can erode quickly at the slightest change in the behaviour
of the coastal system.
The modelling of the plant configuration and application of theoretical parabolic
model was carried out with the MepBay model as shown in Fig. 9.28, developed by
the University Of Santa Catarina Brazil. The importance of using the MepBay lies
in the fact that efficiently determines morphological changes in plant and perform a
physical interpretation of the equilibrium state of the beach (Raabe et al. 2010).
The modelling results (Fig. 9.28) indicate that with the establishment of the
Maritime Terminal “El Superpuerto”, the balance of the beach will be seriously
affected. The coastline undergoes significant changes, especially in the shadow area
generated by the port. However, this condition of the coastline gain should be analysed carefully, because only it will be presented if the current sediments source
remains unchanged of the coastal zone (Fig. 9.28). However, the reality is very different, because for the entry of large ships will be built a navigable channel of 20 m
of deep. This indicates that the little sediment currently crosses by the effect of diffraction of the salient in the groin (Tajamar) will end at the bottom of that navigable
channel.
9.5.9 Identification of Potential Erosion
The erosion rate of the coastline from many countries has dramatically increased in
recent decades. These forces to, the professionals dedicated to the study of coastal
processes, carry out a regular monitoring of changes that are seasonally generated
on a beach. This is not unrelated to the bars that protect coastal wetlands, even if
they have been affected over the years by the establishment of infrastructure for the
development of human activities in coastal environments.
A simple and cost-effective way to elaborate a changes diagnosis and the quantification of potential erosion in a coastal bar, it is based on the analysis of satellite
images. With images of LANDSAT project and the use of the application of
Geographic Information Systems (GIS), it was effected a variability analysis of the
spatial and temporal coastline, from1973 until today. The analysis of the coastline
and its changes over time are a powerful tool to determine processes of erosion and
accretion in a littoral cell, evaluating differences between space increments of each
of the lines drawn.
The methodology consists in drawing for each year and with a seasonal frequently, the polyline representing the coastline for the period measured. In one
image, the different polylines overlap to get a map like the one shown in Fig. 9.29.
Then, to determine the potential for erosion suffered by the wetland littoral bar,
the Digital Shoreline Analysis System (DSAS) developed model by the US
Geological Survey was used (Thieler et al. 2009). Based on selected segments in the
model it described the most representative changes on the coastline. For its applica9 Physical and Morphological Changes to Wetlands Induced by Coastal Structures