277
hydrophilic, marshy, saturated or flooded lands; and (c) it has hydrophilic vegetation that are plants that live in flooded zones.
The most important physical processes that involve in coastal wetlands are the
currents tidal and the sediment transport (Brunn 1994). Furthermore, there the variations of phreatic level associated with the contributions of river and maritime
waters, the residues discharges and even, the wind action.
In relation to landforms, the bars of coastal wetlands can be continuous or discontinuous given the oscillation of the astronomical tide. In some situations by the
action of the meteorological tide and processes of short scale that modify the
hydraulic behaviour of the body of water such as the salinity intrusion.
Analysing these water bodies, in terms of the mass balance equation, it is possible to identify contributions that influence in the hydraulic of wetlands, such the
flow deviations by hydraulic works and the precipitation. The marine border not
only provides a transitory flow of seawater due to the tide; so it has a saline layer
that notably affects in the wetland hydrodynamics. The outputs are system losses as
product of the evaporation; the tide ebb current; and in lesser extent, the opening of
artificial mouths in bars and edges that surround the body of water.
Coastal processes have a major role in the dynamics of a coastal wetland, influencing not only in the variation of the water level or in the hydrodynamics behaviour
as mentioned in the previous paragraph, it also can change the physic-chemical features of a wetland. Changes in salinity levels are giving by the tidal rise flow through
a lagoon mouth that generates discontinuity in the coastline. Dimensions of this
natural channel regulate the amount of flow entering, determining the flow velocity
that dominates the mouth behaviour and the stability. According to studies made by
Brunn and Gerritsen (1961), flows can reach in this tide channels up to 1 m/s.
Despite its importance from the physical and environmental perspective, these
systems are under strong anthropogenic impacts. The most common degradation
activities are: (a) deforestation; (b) urbanization; (c) water contamination; and (d)
restriction of water flows.
In virtue of the aforementioned, this work is focused on the definition of a methodological approach that allows assessing the affections that negatively impact in
the coastal bars stability of wetlands. Particularly, the works of coastal infrastructure can generate an imbalance that entails to the wetland disappearance in longterm. The effects of the defence and shelter works such as breakwaters or jetties
perpendicularly arranged to the coastline are characterized by the methodology of
proposed analysis.
Synthetically, the document seeks to address basic concepts but relevant for the
coastal geomorphology which allows defining the study zone through the establishment of a littoral cell. Subsequently, it assesses sediments features in order to understand how the material is transported by currents from the source to the end of
calculus domain. No diagnostic study that seeks to understand the integral behaviour, can omit the wave climate weather of a littoral zone so the waves, the tidal and
the currents, not only model the shape of the bar; but also, they have a fundamental
role in the wetland equilibrium. Alongside, the study of maritime weather is carried
out a hydro-morphological model that allows observing how currents interact with
9 Physical and Morphological Changes to Wetlands Induced by Coastal Structures
hydrophilic, marshy, saturated or flooded lands; and (c) it has hydrophilic vegetation that are plants that live in flooded zones.
The most important physical processes that involve in coastal wetlands are the
currents tidal and the sediment transport (Brunn 1994). Furthermore, there the variations of phreatic level associated with the contributions of river and maritime
waters, the residues discharges and even, the wind action.
In relation to landforms, the bars of coastal wetlands can be continuous or discontinuous given the oscillation of the astronomical tide. In some situations by the
action of the meteorological tide and processes of short scale that modify the
hydraulic behaviour of the body of water such as the salinity intrusion.
Analysing these water bodies, in terms of the mass balance equation, it is possible to identify contributions that influence in the hydraulic of wetlands, such the
flow deviations by hydraulic works and the precipitation. The marine border not
only provides a transitory flow of seawater due to the tide; so it has a saline layer
that notably affects in the wetland hydrodynamics. The outputs are system losses as
product of the evaporation; the tide ebb current; and in lesser extent, the opening of
artificial mouths in bars and edges that surround the body of water.
Coastal processes have a major role in the dynamics of a coastal wetland, influencing not only in the variation of the water level or in the hydrodynamics behaviour
as mentioned in the previous paragraph, it also can change the physic-chemical features of a wetland. Changes in salinity levels are giving by the tidal rise flow through
a lagoon mouth that generates discontinuity in the coastline. Dimensions of this
natural channel regulate the amount of flow entering, determining the flow velocity
that dominates the mouth behaviour and the stability. According to studies made by
Brunn and Gerritsen (1961), flows can reach in this tide channels up to 1 m/s.
Despite its importance from the physical and environmental perspective, these
systems are under strong anthropogenic impacts. The most common degradation
activities are: (a) deforestation; (b) urbanization; (c) water contamination; and (d)
restriction of water flows.
In virtue of the aforementioned, this work is focused on the definition of a methodological approach that allows assessing the affections that negatively impact in
the coastal bars stability of wetlands. Particularly, the works of coastal infrastructure can generate an imbalance that entails to the wetland disappearance in longterm. The effects of the defence and shelter works such as breakwaters or jetties
perpendicularly arranged to the coastline are characterized by the methodology of
proposed analysis.
Synthetically, the document seeks to address basic concepts but relevant for the
coastal geomorphology which allows defining the study zone through the establishment of a littoral cell. Subsequently, it assesses sediments features in order to understand how the material is transported by currents from the source to the end of
calculus domain. No diagnostic study that seeks to understand the integral behaviour, can omit the wave climate weather of a littoral zone so the waves, the tidal and
the currents, not only model the shape of the bar; but also, they have a fundamental
role in the wetland equilibrium. Alongside, the study of maritime weather is carried
out a hydro-morphological model that allows observing how currents interact with
9 Physical and Morphological Changes to Wetlands Induced by Coastal Structures