Transport infrastructure is usually the first to bear the brunt of weather events and because crucial services like power lines, telecommunications, water, wastewater, and sewage system are usually built alongside transport infrastructure, it is the lifeline to any society. Damage to it to due extreme natural events will not only hinder transportation but can block access to critical services in case of an emergency.
The study, “Climate Change and Transport Infrastructures: State of the Art,” that Laura Moretti and Guiseppe Loprencipe authored, reviewed and analysed several research papers on climate change and its influence on transport infrastructure. It looked at the impacts of climate change to infrastructure, methods and technology used to mitigate impacts on infrastructure, and best practices adopted by agency bodies around the world and its pros and cons.
The study identified three climate change challenges to transport infrastructure: extreme heat, precipitation, and sea-level rise. Then it looks at how engineering and architectural solutions can make infrastructure resilient and adaptable to climate change.
According to the Intergovernmental Panel on Climate Change (IPCC) 5th assessment report, human activities influence global climate change by releasing carbon and greenhouse gas emissions in the atmosphere. In the same report, they’ve shown climate predictions under various carbon emissions scenarios. The predictions show that within the 21st-century temperature will increase by at least 0.61 degrees celsius and there will be increased heat wave occurrences that will raise sea-levels between 0.45 to 0.82 meters due to thermal expansion and melting of glaciers and ice caps.
Climate change impacts will only increase in frequency and intensity and to protect these infrastructures requires a deep understanding of future weather patterns and climate conditions during its service life.
Not only will these events negatively impact society, economy, environment, health and migration but will also increase the frequency and intensity of rainfalls, droughts, and wind patterns creating strong cyclones and hurricanes which will be devastating. These anticipations have led some countries to begin formulating and implementing on adaption and mitigation strategies to which the European Union have adopted this in 2013 and plans to do more in terms of climate-proofing infrastructure to make it more resilient to the changing weather patterns.
Temperature is predicted to increase in the next decades due to climate change. Urban areas with lots of lots of grey infrastructures such as tall buildings and impermeable structures like pavements constructed using asphalt concrete can trap a lot of heat, hinder wind circulations, creating a micro-climate. For instance, asphalt concrete absorbs 95% of solar energy which contributes to urban heating.
The study examined various pavement materials and designs to counter heating. Solutions include use of paving materials that absorbs less solar energy and reflects the light back, reflective coating layer in pavements, and use of porous materials that allow water or fluid to move in its surface and assist in evaporation, and use of modular pavements which allows for vegetation inside its gaps can produce a cooling effect.
Heat can adversely affect people’s health. In very hot and humid countries they have designed some cooling mechanisms to help their citizens cope with the heat and preserve their health. For example, in crowded bus stations in Delhi India, they built fresh air chambers to refresh passengers while waiting for their bus rides. In China, they have hydraulic systems that spray cool water to bus passengers on hot days, and in some cities wading pools can offer opportunities to refresh people.
Aside from temperature rise, there are also other climatic extremes happening. For example, in the last few years in several US states, an increase in snow activity is observed.
This has caused damaged to their traffic systems, and to avoid these some measures were taken such as the use of anti-freezing agents, application of antifreeze sprays to reduce freezing of roads, and combining deicing agent to asphalt mixes to speed up the melting of ice.
With the frequency and increased rainfall predicted, excess amounts of water should be managed well. Permeability of the ground or surface will determine how much water will be absorbed, evaporate, and retained in the surface or runoff. To counter the anticipation of excess water, some cities have built water squares, large underground storage facilities, designated areas for trees and vegetation, and substituting waterproof surface for permeable or penetrable ones.
Example of water squares is found in Rotterdam, Netherlands. They have built two water squares that can hold 750 cubic meters, and 1800 cubic meter of water respectively. In addition to that, they have constructed a large underground parking and water storage with a capacity of 10,000 cubic meters.
Singapore, a country identified as one with a high risk of flooding, is also doing the same mitigation measures to protect their citizens and their city against flooding.
In New York, they have constructed the Big U, 10-mile long protection around in Manhattan a few years after Hurricane Sandy.
Barcelona Spain has built 15 water retention chambers to store massive amounts of water.
Sea Level Rise
Sea-level rise is also predicted to happen due to warming oceans and melting glaciers. Counties and cities located along the coasts are the most at risk of sea-level rise. The OECD listed 20 port cities with the highest number of people at risk, the top 10 cities have 400 million population and all of them are in Asia.
To counter the gradual encroachment of water and sudden flooding during typhoons and high tides, construction of dikes and seawalls, beach and coastal rehabilitation, structure elevations are the usual defence and adaptation strategies implemented, with relocation and abandonment of hazardous areas as the last recourse.
In Italy, they have constructed a MOSE mobile gates to protect their harbour and Lagoon of Venice against flooding. These retractable mobile gates are placed at the port’s mouth, where the lagoon connects to the Arctic sea to protect the lagoon from high tides and flooding.
The article presents some examples of adaptation and mitigation measures that the paper discussed. Read the full research document by clicking on the button below: