Towards integrated modelling of Watershed-Coast System morphodynamics in a changing climate: A critical review and the path forward.

The term "Watershed-Coast System" refers to the entities consisting of watersheds and the areas adjacent to their outlets, where sediment delivery from rivers and natural streams plays a key role in the evolution of coastal morphology. Climate change implications in these complex systems are projected to extend from morphological to ecological and socio-economic ones, threatening ecosystems, cultural heritage, settlements, infrastructure and human life itself. Accordingly, the design of protection and adaptation measures that will enhance resilience against relevant hazards has emerged as an imperative need in both research and policy. Understanding how watershed and coastal processes are intertwined into a web of dependencies that shape morphology evolution, how climate change would affect watershed/coastal dynamics and how scientists can design effective protection/adaptation measures, can only be achieved on the basis of integrated modelling systems that simulate the morphodynamics of the watershed-coast continuum. Within this context, the present work provides a critical review of the theoretical background and state-of-the-art of research on the modelling of Watershed-Coast System morphodynamics, and through this: (a) presents a scheme for the integrated modelling of Watershed-Coast System morphodynamics in a changing climate and analyses its core aspects, (b) proposes a methodological framework for adapting integrated modelling approaches for management and engineering purposes, (c) identifies and evaluates the major scientific and modelling challenges ahead, and (d) systematises the path towards informed decision-making for building resilient Watershed-Coast Systems by bridging the gaps between science, society and governance. The overall approach is applied as proof-of-concept to a hypothetical case study of a Watershed-Coast System located in the Mediterranean.

Towards a common oil spill risk assessment framework ­ Adapting ISO 31000 and addressing uncertainties.

Oil spills are a transnational problem, and establishing a common standard methodology for Oil Spill Risk Assessments (OSRAs) is thus paramount in order to protect marine environments and coastal communities. In this study we firstly identified the strengths and weaknesses of the OSRAs carried out in various parts of the globe. We then searched for a generic and recognized standard, i.e. ISO 31000, in order to design a method to perform OSRAs in a scientific and standard way. The new framework was tested for the Lebanon oil spill that occurred in 2006 employing ensemble oil spill modeling to quantify the risks and uncertainties due to unknown spill characteristics. The application of the framework generated valuable visual instruments for the transparent communication of the risks, replacing the use of risk tolerance levels, and thus highlighting the priority areas to protect in case of an oil spill.

Towards improving the representation of beaching in oil spill models: a case study.

Oil-shoreline interaction (or "beaching" as commonly referred to in literature) is an issue of major concern in oil spill modeling, due to the significant environmental, social and economic importance of coastal areas. The present work studies the improvement of the representation of beaching brought by the introduction of the Oil Holding Capacity approach to estimate oil concentration on coast, along with new approaches for coast type assignment to shoreline segments and the calculation of permanent oil attachment to the coast. The above were tested for the Lebanon oil spill of 2006, using a modified version of the open-source oil spill model MEDSLIK-II. The modified model results were found to be in good agreement with field observations for the specific case study, and their comparison with the original model results denote the significant improvement in the fate of beached oil brought by the proposed changes.