Coastal Ecosystems
Crude Oil and Gas Installations’ Vulnerability to Climate Impacts: A Case Study in the Niger Delta
Paper Presentation in a Themed Session Justin Udie
The coastal Niger Delta is being severely threatened by impacts of climate change exacerbated by floods, corresponding rise in ambient temperature, and Atlantic tidal intrusion, persistent heavy rainfall, and windstorms. These events have continued to disrupt the operations of critical crude oil and gas installations and calls for urgent ranking of the most sensitive system vulnerable to these threats. To adapt effectively, ranking crude oil and gas installations based on stakeholder perception of sensitivity is crucial. We applied analytic review of fifty-two journal articles to synthesise explicit sensitivity assessment indicators for evaluation of selected installations. MCDA tool was implemented in indicator-based pairwise evaluation and ranking of selected installation. We engaged carefully stratified practitioners and experts with a minimum of ten years field experience in the industry in structured focus groups and elite interviews for data collection. The result was analysed using Goepel (2015) multiple-input AHP software and indicates the global sensitivity ranks (eigenvector, EV) for each installation. The result shows the first three most sensitive installation in the following order; terminals (27.3%), flow stations (19.2%) and roads/bridges (15.6%). Ranking of other installations shows transformers/high voltage cable (14.0%) as the mid sensitive installation while the less sensitive installations to climate change are Pipelines (11.1), loading bays (9.3%) and wellheads (5.0%). We recommend that the oil and gas industry could leverage sensitivity analysis outcome from this study to plan effective and efficient adaptation mechanisms to protect most sensitive installations from climate change impact in the coastal Niger Delta.
Shifting Shorelines: Adaptation Strategies for the Fraser River Delta
Paper Presentation in a Themed Session Kees Lokman
Climate change is arguably the greatest challenge facing contemporary societies. The effects of sea level rise, hotter/drier summers, warmer/wetter winters, and increased frequency of extreme weather events will have far-reaching impacts on coastal communities, including people’s livelihoods, critical infrastructures and ecosystems. At the same time, sea level rise provides an opportunity to envision new ways of living with coastal dynamics. In this context, the Fraser River Delta provides a perfect case study. Situated along the Cascadia fault line, and home to a rapidly growing population of nearly 3 million people, the region is in urgent need of comprehensive approaches to coastal resilience. This paper highlights initial outcomes of an ongoing project involving a collaboration between academics, student researchers, design professionals, local experts and decision-makers. Key research questions include: How can visualization assist in raising awareness about climate change risks? Which coastal communities and critical habitats in the Fraser River Delta are vulnerable to sea level rise? And, what are the potential impacts of flooding on critical infrastructures? By applying geospatial analysis, visualization and systems thinking, the research shows the implications of sea level rise on key issues in the region (urban growth, logistics, intertidal habitats, food security). It also reveals opportunities and limitations for coastal adaptation when considering current local, provincial and federal regulations, policies and zoning guidelines. In doing so, this project aims to offer new tools, knowledge and insights to support policymakers, scientists, planners, engineers, and designers in analyzing, visualizing and re-imagining a resilient delta.
Coastal Erosion and Flooding in Saint-Louis, Senegal: Increasing Exposition or Cross-border Coastline Resilience
Paper Presentation in a Themed Session Awa Bousso Drame, Denis Mercier
Publicized during the Bonn COP23, coastal areas have particular ecological potential and are often hubs of natural disasters. Their attractiveness readable in the economy and population coastalisation, especially in the developing world including West Africa. Located on an island in the mouth of the Senegal River, Saint-Louis is an old French colonial settlement, frequently exposed to floods and coastal erosion. After the Sahelian drought, the construction of Diama and Manantali dams hugely impacted on the estuary hydro-sedimentary dynamics. In 2003, a significant flood threatening Saint-Louis, led Senegalese authorities to notch the Langue de Barbarie sandspit to permit water flow and spare it from flooding. Natural barrier protecting the Senegal river estuary, the Langue de Barbarie has become more exposed to coastal erosion and submersion threatening 825 inhabitants/km². Using remote sensing, geographical information system through digital shoreline analysis system, annual erosion rates have been calculated between 2003, 2010 and 2018. Saint-Louis vulnerability to floods have been mapped following the hydrogeomorphological methodology of digital flood areas model. Globally exposed to marine and fluvial erosion, the sandspit shows sectors of distal accretion, erosion that can be linked to an actual dyke construction to protect communities from recurrent floods by marine submersion. The lowest, between 0 and 1.75m (flooding alert in Saint-Louis) are located on Langue de Barbarie, in Saint-Louis peripheral districts. The Saint-Louis case is a grim picture of how anthropogenic footprint amplifies impacts of flooding and erosion in the actual context of sea level rise and climate changes.
Modeling the Coastal Inundation
Paper Presentation in a Themed Session Matteo Postacchini, Francesco Memmola, Francesco Lalli, Debora Bellafiore, Maurizio Brocchini
Coastal inundation is an increasing threat for many nearshore regions worldwide, and has significantly increased in the last years also due to sea-level rise and increased impact of extreme events, like sea storms. Many countries and regions have recently invested to overcome such problems, which commonly lead to structure damages, beach erosion and many other consequences. A series of regulations and legislative approaches has also been proposed and/or applied, with the aim to mitigate such negative effects. Numerical modeling is an important tool for coastal inundation prediction, being a valuable support for management issues to mitigate the inundation risk or suggest resilient solutions. The present work illustrates a novel approach, based on a numerical model chain that exploits a tide-surge-wave operational modeling system (Kassandra), a phase-averaged model (ROMS-SWAN) for the wave propagation towards the shore, and a phase-resolving solver (NSWE) for the prediction of runup and coastal inundation. Such a chain is applied to the bay of Alghero (Sardinia, Italy), where the results of the mentioned chain are compared to those obtained using, in place of the phase-averaged model, an analytical model for the wave propagation. Results confirm that both chain approaches provide comparable inundations, though the use of the analytical, more approximate (e.g., less accurate and reliable description of wave breaking dissipation), model suggests more severe conditions and larger flooded areas. The present contribution provides a methodological approach for an accurate and reliable estimate of coastal flooding.
