Let’s talk hazard trees: Mitigation is about more than just tree health
Trees within and outside utility ROWs are under pressure from all sides: Climate-driven droughts, fires, storms, and floods are on the rise, as are invasive pests and fungal pathogens.
With all these stressors, tree loss is inevitable. These dead, dying, and otherwise unhealthy hazard trees are unpredictable (and dangerous) disruptors. When branches or whole trees fall in, customer interruptions (CIs) are largely unavoidable. Plus, fall-ins can ignite fires, which can quickly spread to devastate acres and communities.
Amid the push for utilities to gain an edge over hazard trees by determining tree health, there is one important caveat to keep in mind: Hazard tree mitigation is not only about tree health. Successful mitigation will consider a variety of factors, including terrain, soil, and likelihood of striking lines.
Tree health is just one factor
Remote sensing is a key technology for locating hazard trees at scale. Using the highest quality satellite imagery, it detects unhealthy tree canopies and pinpoints where utilities should inspect for hazard trees.
But there is an important next step: identifying which trees are likelier to strike power lines and heavily impact reliability.
This determination is essential for creating the most efficient and effective approach to managing hazard tree risk. But regrettably, budgetary restrictions can make mitigation difficult.
Keeping these limitations in mind, utilities can take steps to work smarter to address hazard trees. How? Consider additional factors to determine where mitigation will be most effective — that is, where you can heighten reliability and enhance SAIDI and SAIFI.
Those factors include asset proximity (height, clearance, and overhang), surrounding environment (terrain, wind breaks, and tree lean), and failure risk (tree type and tree health).
AiDash Intelligent Vegetation Management System™ (IVMS) surveys these factors via satellite-first remote sensing and uses AI to analyze them across more than 3 million T&D line miles.
Create a hazard tree management plan
It takes more than anecdotal reports of unhealthy trees or specific fall-in risks from work crews or customers to mitigate hazard tree risk. A plan for consistent and continual risk identification, monitoring, and removal is in order. You need to see not just where there are unhealthy trees, but also where those trees will likely cause reliability issues (see Figure 1).
Frequent monitoring by remote sensing, and assessment of related factors, allows you to:
- Optimize field inspections: Efficiently examine areas with detected unhealthy and striking trees to confirm risks.
- Build a backlog: Create a holistic digital inventory of hazard trees to understand risk and the budget you’ll need to achieve your risk reduction targets.
- Prioritize backlog: Plan hazard tree mitigation based on risk, rather than time-based cycles, to maximize impact per dollar spent.
- Execute plans: Mitigate hazard trees and track progress toward your year-over-year risk reduction goals.
AiDash IVMS identifies unhealthy tree canopies from space, and it also evaluates other factors to determine whether the unhealthy trees are strike risks. ISA-certified arborists have validated these results in the field, finding that 9 times out of 10, IVMS is correct when it predicts that a tree is unhealthy.
However, because remote sensing could miss some high-risk trees, AiDash offers a mobile application you can use to log hazard trees you discover in the field (eg, while inspecting areas with unhealthy tree canopies detected by IVMS, or while completing routine cycle trim work).
Optimize your approach to hazard tree risk mitigation
Once you’ve used IVMS to maximize your visibility into fall-in risks and build a hazard tree inventory, it’s time to ensure you’re taking the steps to optimize your approach.
- Identify all trees — hazard or danger trees — that have the greatest probability of falling into your powerlines.
- Determine which of these fall-in risks would have the greatest impact to your system reliability, resiliency, and safety. IVMS applies an algorithm to assign a criticality score to match your specific risk tolerance and business rules (see Figure 2 below).
- Prioritize according to risk severity as identified by AiDash IVMS to reduce outages.
- Operationalize and streamline the process so you can do more mitigation work with fewer resources: Follow the priorities you set in step 3 to direct inspection and mitigation crews to the highest-risk areas, and logically group work plans to reduce truck rolls and remove more trees per dollar spent. Further improve the process by feeding your existing models with IVMS hazard tree analysis.
- Close the loop by measuring results — tracking mitigation work in real time, collecting data from these efforts, and feeding data back into the software to gain insights and improve operations.
Mitigate current and future hazard tree risk
Remote sensing with IVMS identifies tree health risk zones inside and outside of your ROWs, helping utilities become far more efficient with their trim priorities. This approach also considers asset proximity, surrounding environment, failure risk, and wildfire risk to provide the most accurate hazard tree risk assessment.
Conducting comprehensive annual remote sensing scans, rather than monitoring via manual time-based cycles and costly line patrols, keeps tree health insights fresh and hazard tree risk mitigation on point.
Catch the demo for more information on mitigating hazard tree risk with AiDash.