Danger and hazard trees: How climate change and invasive species impact tree health


Electric utilities can look to climate technology for help

2021 was California’s second driest year, ever. And this isn’t an isolated stat. The impact of climate change is felt globally.

Increasing temperatures and diminishing rainfalls are causing drought conditions not experienced in modern times. Storms wreak havoc on vegetation, within and outside rights of way (ROWs).

Invasive pests like the emerald ash borer (EAB) and fungal pathogens affect entire forests. Consider the bark beetle — it’s already decimated 45 million forest acres in California.

With all these stressors, the loss of many trees is inevitable. These dead and dying hazard trees are unpredictable (and dangerous) disruptors.  When branches or whole trees fall in, fires can start. In fact, since 2000, more than 7 million acres of land have burned in wildfires annually — twice the average reported in the 1990s.

And utilities bear the brunt of public outrage when hazard trees spark fires, or their branches fall on utility lines.

Hazard trees multiply customer electric service interruptions, driving reliability down. Not to mention how hazard trees hit utilities with rising expenses for removal: workforce as well as machinery, such as bucket trucks and all-terrain trimmers.

Beyond hazard tree removal costs, there are heightened worker safety concerns. Vegetation management is one of the most dangerous industries in the United States. Regrettable statistics reported by the U.S. Bureau of Labor Statistics reveal that tree workers have at least 15 times the fatality and rate 3 times the nonfatal rate of all other industries.

This means increased pressures for an industry that is already balancing O&M with strict regulations and tight budgets.

Which only increases the need for new cost-effective strategies and new efficiencies.

Step up hazard tree identification efforts

Dying trees are hazards, but dead trees are even more dangerous. Removal of both requires focused attention and care to keep clear of drop zones.

But dead trees multiply risk as they become brittle — easily dropping a branch that propels a trimmer from the bucket, or striking workers in the fall/drop zone.

The bottom line: Early hazard tree identification is a must for safety.


However, whether created by pests, a structural problem, climate change, or just general poor health, these hazard trees are outliers that don’t always get inspected. And, a lot of the time, with human eyes, you don’t notice that the tree’s dying until it’s dead.

Weakened root conditions, infestations, or stem damage from heart-rot diseases, aren’t easily spotted during manual ROW inspections. And sending inspectors out by truck to assess every line mile drives up costs.

LiDAR, now in use by many utilities as part of aerial inspections, can easily identify split trunks and weak tops. But LiDAR cannot measure the inner aspects of tree health.

Proceeding with calendar-based trim cycles and inspections can easily miss hazard trees, even if those cycles fall within new ANSI requirements: Minimum vegetation inspection frequency of once per calendar year but with no more than 18 months between inspections on the same ROW. The trouble is: Trees are dying in less than 6 months.

Stepping up ID efforts is about collecting the data on wire zones and border zones to assess tree health and determine where to act. There’s a lot of room for utilities to better understand where in the future these dead or dying trees are going to be.

I think, as a program manager, the more information that I had, the better I was able to make a full and complete assessment of what needs to be done. A calendar-based approach? Probably not the best way of doing it.

Hazard tree identification at the press of a button

With many decline periods for trees occurring in six months or less, cycle trims/inspections are unlikely to catch many hazard trees across line miles of overhead assets. But what if a utility program manager could work with a full risk matrix?

Climate technology — satellites and artificial intelligence (AI) — can provide this much-needed 360-degree view.

There’s not enough money to inspect and trim and work on every single tree. And so, you have to build that risk profile in. By using satellites to gather information, to gather data, to use and predict, and look at past tree mortality and future tree mortality, we can identify these stresses and unhealthy trees before the human eyes can.

Satellite climate technology, including multispectral imagery analysis, can reveal telltale signs of weakness, like fire-damaged limbs or thick sloughing bark and clearance issues. Importantly, it can dig deeper for data on chlorophyl content, moisture content, inner infestations, how healthy soil is, and erosion.

And if the whole 360 picture opened up and I could tell you where my greatest 10% risk areas were, I can guarantee you that I would have tree crews working in those areas.

In a satellite and AI solution, all this important data can be analyzed and presented in a single dashboard — identifying hazard trees, as well as tree health risk factors, in terms of high fire threat areas or hazards near hospitals or schools, for example.

The solution can identify trees before they die and help the utility to understand that they can get crews out there to take the tree down in a quicker and more cost-effective manner. It eliminates the need for manual inspections.

Satellites as climate tech may be the new kid on the block, but they also may be what’s going to change the system.

Want to see how a 360-degree satellite view can help your utility identify and manage hazard tree issues? Talk with a specialist today.