Why tree species detection is key in wildfire prevention
As climate change drives rising global temperatures, weather patterns change and ecosystems continue to transform. These changes, coupled with human activity, mean that wildfires are increasing in frequency and intensity. With utility services reaching deep into the heart of these changing ecosystems, power supply companies are under increased pressure to address these challenges.
Utilities are fighting to prevent wildfire ignition and spread while being considerate of delicate and balanced biomes. Vegetation management is currently focused on mapping tree height and proximity but as living, changing ecosystems, the reality of the forest frontier is much more complex. New insight into flora and fauna identification is changing the way we view the right-of-way and its interaction with forest species. Could species identification and vitality measurement shed new light on wildfire prevention?
From tree dimensions to forest conditions
Historically, tree trimming was centred on basic rotation, with each area cut back on a time-based schedule. As satellite imagery, LiDAR and drone-based data provided more insight about the condition of the right-of-way, energy companies combined tree height and proximity data to move towards cutting schedules that are risk-informed. However with increasing depth, breadth and quantity of data, new insights are being revealed:
Species — by identifying the predominant plant species in a forest area, growth can be more effectively predicted for both the height and the crown size.
Vitality — particular diseases, such as bark beetle infestations can be identified, and their spread throughout the forest can be monitored and intervened.
Condition — by combining forest density, species and vitality information, the condition of the forest can be tracked. Even areas some distance from the right-of-way can be monitored for disease migration or the prevalence of invasive species.
Understanding the condition of the forest is one element of a preventative approach to managing the right-of-way and decreasing the risk of a wildfire. Species and vitality data can help build a picture of both the grow-in and fall-in risk.
Limiting the grow-in risk through species identification
Identification of fast-growing species is relevant to predict future encroachment. Monitoring tree species and growth rate data are a relevant building block for optimizing trimming cycles.
“Species identification isn’t just important for wildfire mitigation,” explains Indra den Bakker, CEO, Overstory. “This insight helps prevent power outage in Southern Europe, where invasive species can grow several meters in height in a year. In Finland, we identify species with wide crowns that are susceptible to snow-loading. This information allows us to focus the operational spend on the high-risk areas. Fall-in rates are reduced and reliability improved. We know that increased biodiversity can reduce wildfire spread. By understanding the risk at each point of the right-of-way, utility companies can target their trimming, which helps to protect both the right-of-way as well as biodiversity.”
Left: invasive Spanish trees (Spanish Moss); Right: snow-loaded Finland species.
Monitoring disease to reduce fall-in
Forest vitality is an important factor in preventing the ignition and spread of wildfire. Dead or dying trees can fall on the power line, causing an outage or a spark. In a dry forest area, perhaps with increased leaf litter, this spark is enough to start a wildfire. As drying or diseased trees lose their water content, making them even more susceptible to fire and further infestation. There is now compelling evidence to suggest that bark beetle infestations in Birch trees have directly impacted the ferocity and scale of the wildfires that have once again been racing through the state of California. In fact, in a report by CBS News in 2018, Information Officer Scott McLean of California’s leading fire department CAL FIRE stated that “California has 129 million dead trees from drought and bark beetle infestation.”
Climate change is thought to be adding fuel to infestation, reducing the time that it takes for bark beetles to reach maturity and providing more of the dry conditions that make trees susceptible to infection.
“Once a tree is diseased it is at more risk to the right-of-way,” continues den Bakker. “Identifying infested trees bordering power cables can allow immediate intervention but widening the scope to nearby forest areas can show threats as they emerge. Increasingly, we are seeing a more collaborative approach to forest management with multiple stakeholders coming together to deliver multi-pronged approaches to wildfire prevention and control.”
Left: Bark beetle; Right: A tree after bark beetle infestations.
A four-pronged approach to preventative maintenance
Species and vitality identification is part of a four-pronged approach to risk-based vegetation management and wildfire mitigation:
Current encroachment — immediate threats can be identified through height and proximity data. Maintenance is targeted to those areas most at risk, delivering cost savings by preventing unnecessary trimming and less reactive and ad hoc trimming.
Grow-in risk — identified through analysis of species data. Risk areas can be predicted 12–24 months in advance.
Fall-in risk — drought areas and infestations can be tracked, even at distance from the right-of-way, enabling collaboration with landowners and helping to maximum resource value.
Verification — imagery can be captured to provide evidence of trimming — demonstrating due diligence.
Left: Satellite image of bark beetle outbreak
“Before now, species and vitality data haven’t formed part of most wildfire mitigation plans because it couldn’t be captured or updated accurately enough,” concludes den Bakker. “The technology is here now and offers tremendous benefit as part of a preventative maintenance plan.”
Utilities are already taking responsibility for their part in wildfire reduction through preventative approaches. New insights and continuing advances in satellite technology will continue to provide tools to protect the right-of-way, ensure the continuation of supply and help stop the ignition and spread of wildfire.