Coelho, C., Silva, R., Veloso-Gomes, F., and Taveira-Pinto, F. 2009. Potential effects of climate change on northwest Portuguese coastal zones. – ICES Journal of Marine Science, 66: 1497–1507. Coastal erosion is a common problem in Europe; a result of the dynamic nature of its coastal zones, of anthropogenic influences, such as coastal interventions and littoral occupation, and of the effects of climate change. The increase in the occurrence of extreme events, the weakening of river-sediment supplies, and the general acceleration of sea level rise (SLR) probably tends to aggravate coastal erosion on decadal time-scales. Describing vulnerability and risk patterns for energetic environmental actions is important for coastal planning and management to rationalize the decision-making process. To minimize negative effects, the various processes causing erosion must be understood to assess the possible prediction scenarios for coastal evolution in the medium to long term. This paper describes the application of a coastal (shoreline evolution) numerical model to a stretch of the Portuguese coast to determine the effects of various scenarios of wave action and SLR that might result from climate change over the next 25 years. We conclude that the effects of SLR are less important than changes in wave action. The numerical model was also applied in a generic situation to compare shoreline evolution with and without anthropogenic intervention.

Port cities are on the frontline of emerging coastal risks related to climate change, sea-level rise, and human impacts on coastal zones. This article addresses the need for adaptation in port cities. It reviews key meanings of coastal climate adaptation, and its inherent complexity and uncertainties. It then provides an overview of the current status of coastal climate adaptation, discusses ‘adaptation deficits’ in port cities, and describes barriers to adaptation. Subsequently, it highlights the need for adaptive (coastal) planning and management in the face of changing and uncertain future conditions. Finally, it points out research needs and challenges regarding adaptation in port cities, namely the need for localized risk assessments, the need to reduce adaptation deficits, the need to mainstream adaptation into spatial planning, the need for advanced studies on adaptation measures, the need for integrated efforts, the need for adaptive planning approaches for dealing with changing risks over time, under uncertainty in highly dynamic environments.

The evaluation of beach hydromorphological behaviour and its classification is a complex issue. The main objective of this study was to develop new methodologies to identify coastal features/patterns. Pixel-based and object-oriented classification algorithms were used and a new approach was developed based on Principal Components Analysis and Histogram (PCAH) segmentation, to identify and analyse morphological features and hydrodynamic patterns. The PCAH method consists of three stages: preprocessing, PCA and histogram-based segmentation. Both manual and automatic approaches were addressed regarding the identification of the classes obtained from the segmentation stage. The dataset was composed from two aerial photographs and one IKONOS-2 image. The supervised classification algorithms present good results for both aerial photographs and the IKONOS-2 image. For the two aerial photographs the best results were found for the maximum likelihood classifier and for the IKONOS-2 image the best result was achieved with the parallelepiped classifier. The object-oriented classification performance for the aerial photographs and for the IKONOS-2 image also presented good results. The PCAH method led to promising results, with proportions of correctly classified pixels greater than 90% for the classes ‘Sea’, ‘Sediments+breaking zone’ and ‘Beach’.