Abstract:
Coastal zones are socially and economically very important, leading to a high pressure for its permanent
development. Simultaneously, these zones are subject to several maritime hazards, able to cause
coastal erosion. Therefore, a thoughtful management of these zones is required in order to protect
society, economy and natural environments. This work presents a GIS-based tool that aims to provide a
quick assessment to coastal erosion risk, called CERA: Coastal Erosion Risk Assessment. The simple
processes and small amount of data required by the tool provides a viable alternative to other methods,
which are often more complex and difficult to apply. The assessment method used in CERA is divided in
two parts. The first part is a vulnerability assessment, which combines several parameters that influence
coastal erosion, each being classified in a scale of 1e5. The second part, a consequence assessment,
follows the same procedure, but considering socio-economic aspects. Then, a risk matrix is applied to
determine a risk classification, also divided in 5 classes, from I to V. Aveiro, in Portugal, and Macaneta
spit, in Mozambique, were selected to test the application. Data was gathered for both locations. While
in Aveiro it was used a considerable amount of available georeferenced data, for the Macaneta spit the
data was mainly prevenient from previous publications and local expert knowledge. The results show
that both study areas have similar vulnerabilities to coastal erosion, with classes IV and V dominating
along the areas closer to the shoreline. On the other hand, the consequence classification in Aveiro is
higher than in Macaneta, resulting in a higher risk level in several regions in Aveiro district. The higher
level of detail in Aveiro data also resulted in a more even distribution across all class levels in the
results.
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