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Wildfires pose an on-going hazard to people, homes, critical infrastructure and the environment across the Nation. With climate change and trending drought conditions, the occurrence and intensity of wildfires is increasing annually. Fire seasons are getting longer, fires are becoming more intense, and the subsequent impacts are more devastating.
While this change in wildfire frequency and intensity is putting people living in the Wildland Urban Interface at more risk, it is also affecting industries that service society through communication, power and other related facilities. In particular, electric and communication companies have substantial risk and liability from wildfires. This includes the risk of potential damage to critical infrastructure assets, such as utility poles, structures and transmission/distribution conductors.
In addition, power lines are often a cause of fire ignitions, especially when lines are blown down due to high winds and extreme weather conditions. This issue is not restricted to certain areas of the U.S., although the Santa Ana winds that occur in Southern California are frequently reported in the press. Some of the wildfires that occurred in the 2007 Firestorm in San Diego County were caused by downed power lines. This can result in significant liability for electric utility companies.
With recent advancements in GIS technology, LiDAR data collection, and fire science, solutions are now readily available to proactively analyze wildfire risk and potential exposure. This information can be used to support mitigation of vegetation and fuels to reduce the potential for ignition and extensive fire spread when fires do occur. Electric companies are actively engaging in risk analysis to support vegetation management activities to reduce potential damage and liability. LiDAR data provides a detailed source of vegetation data for power line rightof-ways as well as surrounding areas.
In addition to incorporating wildfire risk analysis as a standard element of asset management practices, companies are also interested in real-time monitoring of fire incidents, including simulating fire spread, and evaluating potential impacts for individual fires in real time. This information can be obtained in minutes of a fire notification, providing capabilities to alert key managers on potential consequences. This information is key for decision making in support of response, suppression, and infrastructure logistics and activities. By providing real time analysis, more accurate information is available to support response for company field crews, as well as coordination with fire management agency partners and the public.
Methods for Mapping Vegetation, Fuels, Landscape Characteristics and Infrastructure
Vegetation encroachment is an on-going issue for electric utility companies. Practices and programs are in place to support on-going inspection and trimming of vegetation to minimize potential damages to lines. LiDAR data is a critical data source for providing detailed, accurate data to support ROW vegetation management. LiDAR data is collected along a corridor and processed to identify "points-of-interest" (POI). These POIs are then used to develop projects that are designed to raise structures and their associated conductors or to trim the surrounding vegetation, decreasing the likelihood of "grow-in" or "fall-in" occurrences.
Figure 1 presents an example of using LiDAR data to identify areas where vegetation is encroaching on power line ROWs and could potentially damage lines during certain weather conditions.
Traditionally vegetation and fuels data has been derived using remote sensing processing methods to determine vegetation species, type and fuels load. Satellite or aerial imagery is a common source providing data at resolutions varying from 1m to 30m on the ground. Medium resolution data, such as 10m to 30m, is ideal for wildfire risk analysis across large landscapes, such as counties or states. This data can be used for fire behavior analysis providing adequate scale outputs when combined with asset data.
For local areas and specific sites or ROWs, more detailed data is often required. LiDAR provides the most robust and cost-effective approach for acquiring high resolution data, for vegetation, canopy mapping, and infrastructure mapping (poles, towers and conductors). Recent methods have been developed to analyze LiDAR data to provide very detailed representations of vegetation canopy. This is important for localized canopy fire potential mapping. While not commonly applied in fire management agencies or private industry today, LiDAR holds promise for providing the most accurate mapping of site-specific fire hazards in the future. It is anticipated that LiDAR will become the norm for data acquisition for certain industries, especially when conditions of man-made features combined with natural vegetated landscapes are important.
While LiDAR mapping specifically addresses vegetation encroachment concerns, it does not immediately address risk from wildfire due to infrastructure-caused ignitions. The potential damage from wildfires is an issue for power companies in two ways: 1) potential damage to infrastructure assets from wildfires that start elsewhere and burn into infrastructure, and 2) potential damage to homes, people and commercial buildings from wildfires caused by power lines. The second issue can have substantial financial liability associated with it as seen in recent legal decisions across the Nation.
Analyzing Wildfire Risk for Infrastructure Assets
Wildfire risk assessment and fire behavior analysis methods are well defined in the fire management arena. The fire science, while being sophisticated, is available through custom programs and vendors, to define potential fire conditions and quantify areas of greatest risk. In particular, the development of GIS datasets that define surface fuels, canopy fire potential, rate of spread and flame length (fire intensity) provide excellent information to aid companies in determining the risk surrounding infrastructure assets.
Surface fuels are a definition of the expected fire behavior based on fuel loads for specific vegetation types, given density, and topographic conditions (elevation, slope, aspect). Of special concern is the potential for a canopy fire to occur, as compared to a surface fire. Canopy fires occur in specific situations when weather conditions and vegetation characteristics conspire to produce extreme fire situations where spread and intensity can cause extreme conditions and significant damage. Other fire behavior outputs, such as rate of spread define how quickly a fire will move across the landscape given active weather, fuels and topography; flame length is a measure of fire intensity, describing the conditions of a fire front. Higher flames generally mean worse conditions and greater potential for damage when a fire reaches an asset, infrastructure or building.
Determining Risk to Prioritize Mitigation Projects
Companies must be concerned about risk conditions not only at the location of assets, but also adjacent to assets, and surrounding proximity. Consideration of surrounding fire behavior conditions is a critical element in determining those areas of most concern, and prioritizing mitigation activities to reduce fuel loads and vegetation density. Identifying these areas helps companies proactively work with private landowners and local government agencies in planning activities to reduce and mitigate risk. This typically involves fuel treatments to minimize fire intensity and spread should a fire occur.
Figure 2 presents examples of wildfire risk analysis outputs that are used to assess conditions around infrastructure assets, and lead to identification of priority areas for mitigation and partner collaboration. The map on the left portrays fire behavior Rate of Spread (measured in chains per hour) for an area in San Diego. Orange and red areas represent extreme spread conditions where a wildfire will move quickly across the landscape. Note the conditions not only within the Right of Ways (ROW) but also in areas adjacent to those areas. The map on the right presents a zoomed in example of the same data showing only the ROS within the ROW. These orange and red areas should be considered as priorities for vegetation management and fuels mitigation.
Enhancing Asset Management Risk Evaluation
The mapping of wildfire risk can also be combined directly with infrastructure data to aid in the calculation of risk scores for assets. Traditionally risk scores are derived using asset management software by considering inspection data and asset characteristics, such as age of the asset, voltage/capacity, recovery complexity, number of identified defects (based on inspection), and other Failure Modes. However, recently some companies are expanding this risk evaluation to include wildfire risk, at or near, the particular asset. Wildfire risk data provides additional information that can useful in determining priorities for conducting asset inspections, or establishing priorities for work orders to correct asset deficiencies identified by field inspections. Figure 3 presents an example of where wildfire intensity data has been assigned to poles and integrated into the VUEWorks asset management software for consideration during failure mode analysis and subsequent work order prioritization.
Monitoring Active Wildfires and Quantifying Potential Impacts
Electric utility infrastructure can also be a source of wildfire ignitions, resulting in substantial liability to companies. Typical situations occur when high winds and extreme weather can cause power lines to fall and spark underlying vegetation. Many companies actually have their own firefighter crews for initial attack and suppression of wildfires to respond to these situations. In addition, companies actively collaborate with local fire management agencies to provide supplemental resources during any fire scenario.
While risk analysis methods help to proactively mitigate risk, they do not address real-time incident requirements. Having current information about when ignitions occur, where they are, and their potential for damage is important information used to direct company resources for suppression efforts. Timely, accurate information about an incident is critical for reducing damages and potential liability.
With recent advancements in fire modeling and GIS technologies, tools are now available to provide services to monitor active fire incidents, simulate the spread of fires, and calculate potential impacts and damage in real time. DTSwildfire (Orlando, FL) offers a suite of advanced capabilities to meet these needs using a web and mobile subscription service. By integrating with local, state and federal dispatch systems, DTSwildfire is able to track verified active incidents, and then simulate fire spread on-the-fly, providing the basis for quantifying potential impacts to infrastructure, people and homes. Analysis is done automatically in less than 2 minutes providing incident impact reports via email quickly to key company decision makers. This approach monitors fire status and informs when thresholds for potential damage are met. An interactive web mapping application provides more advanced tools for qualified users to conduct more detailed analysis should the incident warrant, particularly for large fires that extend beyond a day.
The impact analysis uses a range of data sources to produce the summary report. Often this may include census data, local parcel and assessor data used to identify home locations and values, detailed building locations, and proprietary company data on ratepayers, customers and infrastructure assets.
Figure 4 presents examples of the real-time incident monitoring outputs generated by the DTSwildfire subscription service. The map on the left shows the expected spread of a wildfire for 12 hours during typical Santa Ana event conditions in San Diego County. The simulation mimics an ignition caused by a downed power line. The map on the right presents a more detailed view of the ignition location and local spread conditions near adjacent homes and infrastructure.
Figure 5 presents an example of the DTSwildfire interactive web mapping application with typical impact analysis reports that are generated in seconds for any fire simulation.
Conclusion & Next Steps
Field activities for vegetation management, asset inspections, and hardening of power lines can be costly. Knowing the most at-risk areas is critical information to help prioritize where field activities should be focused, and where investments should be made. Understanding wildfire risk and the potential impacts is also key to reducing corporate liability and justifying insurance coverage determination. This approach will provide an immediate Return-on-Investment to any utility looking to quantify their potential fire risk as well as implementing a program to mitigate these risks in their highest consequence areas.
The integration of wildfire risk analysis, asset management and advanced modes of data acquisition, such as LiDAR, offer many benefits to electric utilities and service providers. These include:
Proactively mitigate risk through the ability to target and prioritize vegetation management activities and homeowner prevention programs
More accurately estimate costs for mitigation activities by identifying risk near company assets.
$ Where should you focus vegetation management, mitigation and prevention efforts?
$ Where should you prioritize more frequent inspections of network infrastructure and assets?
$ Prioritize expenditures for line maintenance by including surrounding wildfire risk conditions.
$ Where are jurisdictional collaboration, agreements and partnerships required?
Know where to locate new assets to minimize potential risk and damage in the future.
Identify those home and business owners who are located in high risk areas around your assets to support outreach and prevention programs.
$ Identify and potentially justify additional costs to rate payers in high risk areas to support company mitigation efforts.
Real-time forecasting of where a wildfire is going and what is actually happening.
$ Immediately determine potential impacts to support operations and response efforts.
$ Prioritize service restoration and mobilization of resources.
$ Minimize employee risk for field teams.
Through technology and scientific advancements, opportunities now exist to enhance the ability of electric utility and communication companies to better address and respond to infrastructure maintenance requirements by integrating consideration of wildfire risk and impacts. In the future, the integration of wildfire modeling will become the norm and ultimately help to reduce the damage and liability caused by wildfires for this industry. The need for more detailed data, from technologies like LiDAR, will be critical to providing the most accurate, and up-to-date information possible.
Jason Amadori is the CMO of DTS and VueWorks. He specializes in building custom Asset Management solutions utilizing LiDAR, GIS and custom software solutions.
David Buckley is an expert in the application of remotely sensed fire data to support GIS and database applications.
A 1.211Mb PDF of this article as it appeared in the magazine complete with images is available by clicking HERE