Assessing Potential Risks of Impacts of Climate Change on Coastal Landfill Sites: A Case Study of Pennington Landfill Site - Hampshire, United Kingdom

Coastal zones are highly vulnerable to climate change and its variability. Future projections of global climate change suggest that relative sea-level rise and increased storm frequencies could lead to significant increases in coastal flooding and shoreline erosion. Associated with this, it is likely that coastal hazards can have the potential to disrupt landfill sites located in dynamic coastal areas. This could be a determining factor in an accidental release of hazardous contaminants which may cause pollution risks to the local environment. The objectives of this research, thus, were to better understand how coastal landfill sites might interact with coastal hazards and to investigate associated current & future risks, and their implication on future environmental and shoreline management issues under climate change. The first step was to develop a source-consequence flowchart using Source-Pathway-Receptor-Consequence approach to investigate how the different pathways, associated with coastal hazards at a case study area of Pennington, contribute to the risks of contaminant release from waste sites. Then attempt was made to identify and quantify sites at risk of coastal hazards. Linked to this, saltmarsh change and sea defence performance analysis were performed. Finally, possible mitigation measures were investigated to address the issues. It was identified that the risks associated with erosion and flooding happen to be more relevant. Results also reveal that the eroding saltmarshes could only provide a declining natural defence and will completely be lost by 2085, if not sooner. This leads to significant increase in wave action on the seawall which may eventually lead to breaching; as it was designed assuming it is fronted by sufficient width of saltmarshes. It was estimated that, under a 1-in-20year storm event most sections of the seawall will experience significant overflow and wave overtopping and it is more than 75% likely that the highest seawall section will breach before 2055 by which realignment option is proposed. This leads to seawater flooding significant portion of the landfills. This may arise high implication on future environmental & management issues, unless measures are taken. The study suggested that abandoning further waste disposal and relocating existing waste out of vulnerable sites seems reasonably sustainable and cost effective than protecting it. However, it was recommended that further studies on the determination of risks and its future implications based on a wide range of climatic, environmental and socio-economic scenarios would give a broader picture of the issues involved & to be able to address them for a better future environment and shoreline management.CoMEM - Coastal and Marine Engineering and ManagementHydraulic EngineeringCivil Engineering and Geoscience