title: Nature-based solutions as climate change adaptation measures for rail infrastructure
Creators: name: Blackwood, Lorraine
Publisher: name: University of Glasgow
Year: 2024

description: Globally, railways provide vital social and economic functions by enabling the movement of people and cargo across cities, countries and continents. Rail infrastructure is therefore critical to the ongoing delivery of safe and efficient passenger and freight train services. However, railway assets are extremely vulnerable to extreme weather events such as temperature extremes, droughts, floods and storm surges. The projected escalation in the intensity and frequency of extreme weather conditions due to climate change is likely to increase the damage to and inoperability of rail infrastructure. This presents a significant challenge to the rail industry worldwide, as the failure to proactively adapt its infrastructure to withstand the impacts of a changing climate will significantly increase service disruption and potentially compromise the safe operation of rail networks. To date, climate change adaptation (CCA) options for rail infrastructure have generally involved grey (engineered) interventions. This research proposes and investigates the potential suitability of applying Nature-based Solutions (NbS) as alternatives or complements to grey adaptation techniques for use in the rail context. NbS can provide ecologically sustainable means to adapt infrastructure to withstand and/or accommodate the impacts of current weather extremes and those anticipated under future climate change, whilst also delivering a range of valuable co-benefits. Very few examples of the application of NbS have been observed in the rail environment thus far.

This research used systematic literature reviews to identify instances of NbS use for CCA in rail, and in non-rail scenarios which may be applicable to the rail sector, and to investigate the potential barriers and aids to NbS deployment by the industry. An online questionnaire was then utilised to explore the knowledge, experience, and perspectives of 55 rail industry professionals with regards their perceived and/or in practice obstacles and aids to the use of NbS for CCA on rail infrastructure. This was followed by case study research performed on the application of NbS on two rail case studies in Adelaide, Australia, and Yorkshire, UK. Findings from the barriers encountered and the aids to NbS implementation on these live rail examples, combined with rail stakeholder engagement, have been used to develop a framework tool for use by the industry to operationalise NbS for CCA.

Whilst this study confirms multiple examples of NbS being used in rail which are not included in the literature, results from the mixed methods applied in this research corroborate that a lack of awareness of the NbS concept is the principal barrier to its dissemination in the industry. The provision of education on NbS to the rail sector will therefore be essential to its widespread operationalisation; the outputs of this study, including rail audience specific case studies and diagrammatic tools, contribute to rail industry knowledge to support this. Legislation, policy and standards were also highlighted as key tools to support NbS uptake by the rail industry. The use of rail demonstration sites is therefore recommended to gather robust evidence of NbS performance in the rail context to inform legal instruments, specifications and guidance, as well as providing real-life NbS awareness to rail stakeholders and neighbouring communities. These endeavours, along with the testing of the framework proposed in this study, will support the further research on and trialling of NbS concepts in the rail sector which are urged to enable the industry to implement NbS as credible CCA measures, supporting the ongoing provision of reliable, resilient rail infrastructure.