College of Science and Engineering
8 March 2022
Related Study Areas
Have you ever been on a road trip, driving through lush greenery where huge trees dot the side of the road? While you were there, did you consider what was cleared in order for the road you’re travelling on to be developed?
As the human population continues to explode, so too does infrastructure. Road networks promote important economic and social benefits – they connect workers to their jobs, students to their education, and producers to their markets. But they do not come without costs; roads and their traffic disrupt ecological processes and can lead to deforestation, habitat loss, and light, noise and chemical pollution.
JCU PhD Candidate Jayden Engert is researching methods to mitigate the environmental impacts of road expansion in the Asia-Pacific region.
“Roads are drivers of many threats to nature in the modern world. They give people more access to destroy habitat, hunt and log. The environmental impacts aren’t limited to animals and plants either, but include flow on effects such as deforestation impacting carbon storage and so on,” Jayden says.
“My research primarily focuses on South East Asia and the Pacific region. These are areas that require some level of development because there are remote populations that don’t have adequate access to healthcare or education. It presents a trade-off about how we can promote the development of roads for social and economic gains without causing negative environmental impacts.”
Paving the way to a better future
Around 25 million kilometres of new paved roads are expected by 2050, with approximately 90 per cent of those to be built in developing nations.
These roads will facilitate accessibility and promote indispensable economic and social benefits. But new developments — particularly those that allow access to natural resources — leave delicate ecosystems vulnerable to the proliferation of unplanned or illegal roads.
Road networks are notoriously difficult to keep track of, and there are no mapped records of these unofficial roads. Thus, predictions of future environmental impacts lack accuracy.
“People are trying to predict future effects of infrastructure development using maps of roads that are 30 years old, and they’re assuming that the 30 year-old map is still going to be relevant in another 20 years. So it’s going to be a 50 year-old map of roads,” Jayden says.
“People are trying to predict future deforestation using historical records of infrastructure.”
Jayden says that more than half of the roads that exist across his study region are not mapped.
“There are a number of reasons roads throughout the Asia-Pacific aren’t mapped: they might be illegal or unofficial, or they could be roads that the government doesn’t consider to technically be a road, like logging tracks,” he says.
“It varies between countries. In Malaysia, only about three per cent of roads are actually mapped. So for every one kilometre of roads that we see on the map, there’s about 29 kilometres of roads that aren’t mapped.”
Part of Jayden’s PhD research involves completing the road maps using satellite imagery.
“We download the existing road maps and add them into Google Earth, and with the help of volunteers who are generously giving their time for this project, we go through and we manually trace the roads that aren’t in the maps,” he says.
“For some locations this process can be extremely time consuming. In the future, we hope to develop methods to automatically detect roads from satellite imagery using remote sensing.”
After establishing where the environmental impacts might occur and where they’re likely to spread, Jayden can begin developing methods to reduce these impacts. Although they can be extensive, his research focuses’ specifically on land cover change.
“For me, deforestation and habitat loss are some of the most important costs of road developments because if you don’t have any habitat, you can’t have any animals, regardless of what else is occurring,” he says.
“So, a way to preemptively mitigate the impacts of land cover change is to designate a place as a protected area before the development even goes ahead. Or in cases where that might not be possible, we can suggest changing a section of the highway and moving it a couple of kilometres, where it will have much less environmental impact.”
Removing roadblocks through research
How do we balance the social and economic benefits of road developments with the environmental costs?
In some cases, the answer is simple.
Earlier this year, Jayden and a team of researchers studied a mining road that is planned to cut through the Harapan Rainforest in Indonesia. As it is, the road will give illegal poachers, loggers and miners access to vulnerable species like orangutans, elephants and tigers.
Using a geographic information system (GIS) technique called least-cost path analysis, the researchers were able to identify several alternative routes that were more environmentally friendly than the original road plan.
“Least-cost path analysis allows us to feed in information relating to costs. So, we added in economic variables, like the cost of building the road, and environmental variables, like the cost of destroying elephant habitat. With that information, the system determines the easiest and cheapest route to get from point A to point B while avoiding elephant habitat and so on,” Jayden says.
“This case in particular was relatively easy because the land surrounding the forest is already developed, so it was simple to determine that building the road around the forest instead of through it would decrease construction costs and be less environmentally destructive.”
In most instances, however, striking a balance between social, economic and environmental outcomes can prove challenging. Despite their potential for ecological degradation, road networks make a crucial contribution to the economic and social development of nations.
Even when an alternative route has both environmental and social benefits, if the economic cost to developers is high they are unlikely to change their plans willingly.
“Reducing deforestation and construction costs while ensuring the roads are socially viable can be complex, especially in areas that haven’t really been developed yet,” Jayden says. “In a lot of cases, the developers are not particularly interested in the social or ecological outcomes.”
When planned networks disregard social or environmental impacts, Jayden uses his research outcomes to encourage developers to build roads more responsibly.
“We can use the research to suggest a road route that will increase the cost by a small amount, but dramatically reduce environmental consequences and improve economic outcomes for users. Then, we can share this information and put pressure on developers from non-government organisations, international communities and groups from within the country that will be directly impacted,” he says.
Jayden hopes to use his research to protect essential ecosystems while meeting the needs of the growing Asia-Pacific region.