Coastal Erosion
The hazard analysis in Barbados, identified regions with increased beach erosion and higher probability of cliff failure. The ensuing vulnerability assessment identified assets that were potentially exposed to coastal erosion. The number of exposed assets was smaller than for many of the other hazards; however, when damages occur, they can be sudden and have significant consequences. It is also important o consider that many or the assets along the coast are more expensive hotels and homes, and that coastal structures are expensive to build and maintain. The ToR two categories for the coastal erosion assessment: beach erosion and cliff recession.
Barbados has highly developed coastline along the south of and west coast, while other versions of coastlines are more rugged and less developed. Loss of land and infrastructure to coastal erosion is not uncommon in Barbados, but it's also isolated enough (especially alog cliffs) that developed sometimes take place in areas that are exposed. An overview of the conditions along the coast in Barbados is provided in table 5.1 from the CRMP shoreline change study (Bears 2016) Note that this Shoreline length definition does not closely follow the shorelines and thus reports a shorter to the length that more details assessments.
Identificación de fuentes sísmicas
Caracterización del potencial de generación de terremotos de cada fuente
Modelación de la distribución de la intensidad sísmica como una función de la magnitud y la distancia
Aplicación de la teoría de la probabilidad
- Damage to coastal structures is based on very limited information (no field studies or inspections were completed).
- The potential physical economic impacts for port hazard scenarios associated with coastal storm damage.
- Classification of the cliff in the hazard mapping has focused more on a planning approach for future development rather than a probability of failure for existing structures.
- Beach erosion is different than other hazards as the beach will accrete and erode in response to varying wave condition including major storms.
Costal erosion risk can be manifested through damage to beaches, damage to coastal structures or erosion of coastal cliffs. Beach erosion is different than other hazard as the beach will accrete and erode in response to varying wave conditions, including major storms. Assigning beach damage immediately after an event may not be appropriate since some natural recovery of the beach occurs.
The other important aspect is the impact on the Barbados economy at the port was compromised. The total value of the imports and exports for Barbados are available through national statistics and provides some indication of the impact that a disruption in operation may have.
Long term trends in beach width were assessed through the beach profile comparison from CZMU’s beach monitor program. The long term reductions and gains need to be considered relative to the value of the beach in each area. For example the condition of a beach along the west coast with expensive hotel will have a greater impact on return visits revenue then an isolated pocket beach on the east coast. Changes in beach width are also more important when the beach is narrower compared to on a very wide beach. For example a 5m increase in beach width is much more important for a beach that grows form 2m to 7m in width, compared to one that increase from 32 to 37 m
Beach erosion and cliff recession are two categories for the coastal erosion assessment. Beach erosion can be a rapid process thah occures during a large sotorm, or it may be a gradual damage over many years. In many instances, these reductions are controlled through the addition of coastal structures such as seawalls or revetments. Thes preventative strucutures can mitigate loss of porperty to beas erosion but often to little to preserve the exestence an value of the beach. Determining damages due to beach erosion is complex due to the regular erosion and accretion processes that take place seasonally and in response to storm events.
The second phase of the project involved assessing the vulnerability of assets to the above hazards vulnerability was classified on both exposure to the hazards, as well as susceptibility to the hazard. For example, a road is not directly susceptible to wind damage, (within reason) and therefore even though a road is exposed to wind, it is not considered to be vulnerable. Conversely, roads are exposed to flood damage then to wind damage or erosion.
Vulnerability mapping was produced for groups of similar assets and similar hazard. Assets and their values were tabulated in the vulnerability phase of the study.
- This analysis utilizes the measured housing stock survey, the modelled housing stock information derived from the measured housing stock survey, Barbados Census data from 2010 and BRA Land Valuation.
- The hazard analysis identified regions with increased beach erosion and higher probability of Cliff failure. The ensuing vulnerability assessment identified assets that were potentially exposed to coastal erosion
- This study is instructive on the potential magnitude of indirect losses, as indicated by the reported multipliers. However disaster adaptation capacity and the economic structure of any area are quite different from Barbados. In addition the specific or the port infrastructure and is vulnerability to storm damage differ greatly between the two locations.
Coastal erosion risk can be manifested through damage to beaches, damage to coastal structures, or erosion of coastal cliffs. Beach erosion is different than other hazards as the beach will accrete and erode in response to varying wave conditions, including major storms. Assigning beach damage immediately after an event may not be appropriate since some natural recovery of the beaches occurs. Therefore, only long term erosion of beaches can be assigned a numerical damage value; however, this is a continuing loss value each year based on long term trends, rather than being associated with a specific event.
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- The assessment of long term erosion damage in Barbados is based on a number of assumptions, which limit how specifically these data should be applied.
- Coastal cliff collapse may be associated with a specific wave event, or a cliff may be seriously weakened in an event and fail in the weeks, months or years that follow. However, cliff damage is generally more cumulative than occurring during a specific event.
