Abstract
This chapter includes an assessment of physical vulnerability of the coast, including a coastal vulnerability index composed of 9 physical variables—elevation, distance to shore, tide amplitude, significant wave weight, erosion/accretion rates, geology, geomorphology, ground cover vegetation, and anthropogenic actions—followed by a quantification of coastal recession and the data of special report on emissions scenarios (SRES) developed by the Intergovernmental Panel on Climate Change (IPCC) on the rise in average sea level. It includes an estimate of the economic value of an area of recreation based on the travel cost method. Finally, a bibliographic review is made to assess strategies and responses to the impacts of sea level rise in order to make comparisons and to develop a road map of interventions for shoreline protection. The proposed methodology was applied to a case study on the Portuguese coast corresponding to the beaches of Costa de Caparica, Almada.
TopBackground
It is estimated that 1.2 billion people, approximately 23% of the world's population, live 100 km from a coastline (Nicholls & Small, 2002; Nicholls, 2003). The population density in coastal regions is about three times the world average (Nicholls, 2003). Coastal areas are of great economic value (Schernewski & Loser, 2004) nonetheless, they are susceptible to hazards such as sea level rise.
Key Terms in this Chapter
Wetlands: Land area saturated with water, either permanently or seasonally.
Adaptation: Anticipating the adverse effects of climate change and taking appropriate measures to prevent or minimize the damage they can cause.
Coastal Erosion: Wearing away and breaking up of rock along the coast.
Ecosystems: Community of living organisms in conjunction with the nonliving components of their environment interacting as a system.
CO: Carbon monoxide.
CH4: Methane.
N2O: Nitrous oxide.
CO2: Carbon dioxide.
Vulnerability: Potential for loss.
IPCC: Intergovernmental panel on climate change.
Coastal Morphodynamics: Refers to the study of the interaction and adjustment of the seafloor topography and fluid hydrodynamic processes, seafloor morphologies, and sequences of change dynamics involving the motion of sediment.
Economic Valuation: Assigning monetary value to environmental factors that are normally not considered in financial valuation.
Significant Wave Height: The mean wave height of the highest third of the waves.
Green Cover: Natural or planted vegetation covering a certain area of terrain, functioning as protection against soil erosion, protecting the fauna, and balancing the temperature.
Elevation Related to Datum: Height above or below a fixed reference point.
Sustainable Development: Organizing principle for meeting human development goals while at the same time sustaining the ability of natural systems to provide the natural resources and ecosystem services upon which the economy and society depends.
Biogeochemical: Relation of biological, geological, and chemical factors.
SO2: Sulfur dioxide.
Tide Average: Vertical difference between the high tide and the succeeding low tide.
SRES: Special report on emission scenarios.
Artificial Feeding: Regenerations of beaches by means of the artificial injection of sand.
Accretion: The process through which coastal sediments return to the visible portion of the beach following storm erosion.
NOx: Nitrogen oxides.
Mitigation: Efforts to reduce or prevent emission of greenhouse gases.
Alluvial Balance: Difference between the added and removed sediments from coastal regions.
Bathymetric: Study of underwater depth of lake or ocean floors.
Breakwaters: Structures constructed on coasts as part of coastal defense or to protect an anchorage from the effects of both weather and longshore drift.
Equilibrium Profile: The slope away from shore of a sea floor or lake bottom having a gradient such that waves and currents neither erode it downward nor deposit sediment upon it.