Autor(es):
Sampath, Dissanayake Mudiyanselage Ruwan 
Data: 2008
Identificador Persistente: http://hdl.handle.net/10400.1/698
Origem: Sapientia - Universidade do Algarve
Assunto(s): Teses; Zonas costeiras; Marés; Gestão costeira; Algarve
Descrição
Tese dout., Gestão da Água e da Costa, Universidade do Algarve, 2008 The integrated impact assessment of shoreline retreat and inundation due to sea level
rise over the coastal zone of the Guadiana estuary, Portugal/Spain border was carried
out to identify and map hazard zones. Geographical Information System tools were used
to visualize and analyse impacts on built-up area, transportation network and habitats.
The shoreline retreat with the present shoreline evolution rate and the accelerated sea
level rise given by three SRES scenarios, namely, B1, A1B and A1FI (upper-bound
values: 38, 48 and 59 cm rise in sea level, respectively) exhibit high spatial variability.
The adjacent coastline of Monte Gordo tourist beach (Portugal) and the entire shoreline
of Ayamonte municipality (Spain) are susceptible to severe erosion. The erosion extent
increases gradually with the sea level rise. However, the main forcing of the shoreline
retreat is not the climatic change but anthropogenic interventions including construction
of coastal defense structures.
The first order assessment of shoreline retreat for a hypothetical storm surge with
elevated flood contours due to sea level rise shows that the damage to the built-up area
and urban habitat can be long lasting while the sandy dune and salt marsh habitats may
have resilience depending on sediment supply.
The vulnerability of Portuguese side of the Guadiana estuary coastal zone for
inundation due to storm surges of 3.0 and 4.9 m from mean sea level (1 and 2 m from
the maximum spring high tide level, respectively) shows approximately two-fold and
four-fold increase, respectively, relative to the hazard zone marked by the maximum
spring high tide (1.9 m from MSL). Two- and three-fold respective increase can be seen
in Spain side of the estuary. However, in terms of total area of inundation, Spanish side
would severely affect.
The main response should be focused on Integrated Coastal Zone Management
programme with strategically planned soft engineering interventions to mitigate the
negative impacts of shoreline retreat due to sea level rise hazards.
