Enhancing Climate Resilience of Small Island States’ Bridges

Climate change is increasing rainfall intensity and frequency, which can cause severe scouring on bridge pier foundations and abutments due to increased river flow.

In the US, scouring is one of the top three causes of bridge failure, collision, and overloading. Although bridge design considers historical flooding levels, climate change is increasing the magnitude and frequency of flooding. Therefore, bridges may not be able to maintain their serviceability and safety, resulting in significant risk to users and economic losses.

Other climate change threats to bridges include temperature swings, which subject materials to more significant thermal expansion and contraction. Thermal stress can lead to cracking, buckling, and fatigue, especially in metal components and expansion joints (Olmos, 2020).

A rising sea level can cause scouring and reduce the bridge’s clearance. Increased wind speed due to increased storm intensity can become a threat, especially for tall bridges (Olmos, 2020).

Small Island Developing States (SIDS) face significant risks from climate change. Essential infrastructure, such as bridges, can sustain damage from extreme weather events like intense cyclones and flooding, which may render them unusable.

Bridges play a vital role in connecting communities, allowing for the transport of goods and services, and facilitating transport. When these structures are compromised, they can isolate communities, halt economic activities, and hinder the provision of crucial emergency support and services during disasters.

A 2022 study published in the Journal of Springer Nature examined the vulnerabilities of bridges in small island developing states (SIDS) and what resilience means for the design and management of SIDS bridge infrastructure by applying a post-disaster forensics and systems approach that is not reliant on complex methods or large amounts of data.

The paper focuses on climate resilience in Small Island Developing States (SIDS) in four main geographical regions: the Caribbean, the Pacific, coastal West Africa, and the Indian Ocean. SIDS’s vulnerability to natural hazards due to their location and geography – surrounded by water, isolated, small and within areas in the paths of tropical storms- is well known but still poorly studied due to a lack of data and local bridge standards.

The study collected and assessed data from three sources to overcome data constraints: First, local data where possible and supplement this with novel low-cost rapid collection methods that could be used locally; second, apply modelling and engineering standards that are applied when designing and modelling bridges in these contexts; and lastly, take advantage of recent innovations in open data such as satellite remote sensing, and image and video sharing through social media by residents.

To successfully implement resilience in bridge structures within SIDS, it is crucial to consider the structure’s technical characteristics, the environmental conditions surrounding it, and the socio-economic factors that affect its design, construction, and long-term maintenance.

In SIDS, bridges are often constructed at the base of steep terrain along the coastline, making them susceptible to flooding and landslides. Dominica, where this study is conducted, is a prime example of these conditions. The country frequently experiences tropical storms and hurricanes.

The paper also examines how to manage bridge structures in SIDS that face limitations in capacity and resources. Based on the study’s vulnerability assessment and analysis, it provides recommendations for strengthening bridge resilience.

Read the study’s recommendations for bridge resilience in Dominica.

Read more by clicking links in the “Sources” section below.