HAZUS: When the lights go out

When the lights go out

Brick Rule, PE
Florida Power & Light 162 Morgan Lane Pt Charlotte
Fl 33952 (941) 423-4809
brick_rule@fpl.com

Abstract
This paper discussed the use of Geographic Information Systems (GIS) for disaster recovery at Florida Power & Light. Extensive wind loss modeling is used to produce detailed estimates of expected losses. These models have been useful in evaluating the total potential risk and in developing specific response plans for individual storms. GIS is used to quickly re-divide the new workload into manageable portions and to locate suitable sites for temporary work headquarters. Extensive GPS satellite-positioning data is collected after the storm passes to provide re-validation of the estimated damage as well as recalibration of the damage models. GIS systems have great, largely untapped potential to communicate specific recovery information between all agencies involved in a recovery effort.

Background

Florida Power & Light Company is among the largest and fastest growing electric utility utilities in the United States serving nearly 4 million customers in about half the state of Florida. Power is delivered safely and reliably from 86 generating units through more than 70,000 miles of overhead and underground lines. Geographic Information Systems contain precise location data on 1.4 million poles. FPL has added more than 800,000 customer accounts since 1990. In 2001 alone, FPL added nearly 87,000 new accounts. In the past 10 years the reliability of electric service has improved owing in part to the extensive use of systems that analyze customer outage reports and predict the right location to send the appropriate people to effect the necessary repairs.

Perhaps there is no area in the country that is more vulnerable to the destructive power of a hurricane than the crowded coastlines of Florida. Within a few miles one can find very rural and sparsely populated areas as well as dense urban development and everything in between. The impact of any landfalling storm largely depends on the geography of where it hits. The affected areas will require large increases in personnel in a very short time to handle the restoration. Often this means increasing field personnel from 50 to 2500 in 1 day. Existing work locations are never large enough to handle this increase in workers and heavy equipment and so GIS plays an important role in rapidly planning and providing for the deployment. Where geography is an important consideration, Geographic Information Systems are vital. At FPL Geographic Information Systems are critical to maintaining the kind of service reliability that our customers have come to expect.

Anticipating the amount of damage

Forecasted Winds The Tropical Prediction Center, also known as the National Hurricane Center will issue storm position and track forecasts every 6 hours as a storm progresses. These advisories contain latitude and longitude coordinates, maximum winds and the radius of hurricane force, tropical storm force and gale force winds in each quadrant. The expected winds and time of occurrence can be calculated by interpolating the maximum wind speed between position fixes and at radial distances from the center of circulation. Naturally, these expectations must be recalculated as each new forecast is received. Using this data, FPL forecasts the wind at important locations, radio towers, power plants and company buildings. The forecast is also made for each square mile of the service territory. It is this high-resolution wind field data that is used to drive the damage estimates that will define the restoration effort.

Calculating Damage Losses from a hurricane are a function of storm strength, size and the locations involved. A larger storm with lower wind speeds may well cause greater damage than a small more powerful storm. At FPL, loss experience curves developed following Hurricane Andrew and other outage models are then applied to facility counts and wind speed in each square mile of the service territory. The resulting estimate is then summarized into 800 predefined zones, each of which is bounded by natural or political features. When grouped together these predefined zones will form larger areas with common sense boundaries and allow for the re-division of the normal work area assignments.

The Federal Emergency Management Agency (FEMA) has developed a similar free GIS based loss estimation system used for buildings known as HAZUS. Using this system with its many construction specific loss curves and appropriate inventories of the building stock, authorities can evaluate risk, design effective mitigation strategies and quickly estimate the effect of a specific storm.

Expected position, radius of winds and wind speed are all subject to change until the storm actually passes. Damage estimates of course change with each new forecast. But commitments must be made for additional personnel, housing and food prior to landfall when there is still considerable error in the forecasted track. Because of this a suite of scenarios is usually created varying both track and wind speed in order to develop the range of possibilities. The resulting plan is then put into motion well before the storm makes landfall. Hotel rooms are secured, meals are ordered and people are moved from neighboring utilities all over the southeastern United States in preparation for the effort.

Staffing the Response

Divide and Conquer Typically 5000 – 7000 additional workers will need to be brought in to handle the restoration. These new resources and all their heavy equipment will never fit into an existing work center and so new staging sites must be set up. Contracts have been made in advance with over 100 large facilities such as shopping malls or racetracks. These facilities can be used as temporary headquarters for the large number of people and the equipment that will be needed. The estimated workload has previously been divided into 800 common sense bounded zones that can be regrouped into larger common sense areas. Each new area will contain one or more of the possible new work locations and each of these can accommodate a different number of people. There is a limit of the total number of work locations that can be supported and the problem is now to provide a plan that divides the workload that has yet to be discovered and provides for the people that will arrive while minimizing the restoration time for all areas.

Standard Boundaries are tried first. Service center staffing increases with damage and with decreasing restoration days. Staffing is limited to the space available in each service center and the number of Staging Sites possible is limited. The importance of this process can be best illustrated in the example below. Here the normal division of work areas would have required far more people in three locations than could be supported.

In addition, much of the new capacity added would not be utilized and in the end work or workers would shift from one location to another creating more inefficiency.

Here the area is re-divided. Management area boundaries are shifted to best utilize the space available, minimize travel and eliminate one supported location all together. This plan eliminates the overcrowding of existing facilities and minimizes the flux of work and workers between work headquarters. Without geographic information systems developing this plan would be a daunting task.

Validating the Models
Helicopter and ground patrols are initiated as soon as the winds die down. Since all of the planning and deployment so far has been based on hypothetical wind fields and models, it is important to gather and compare real information to decide early on whether the models are correct. At the end of the day, what we really want to know is how long is all of this going to take and unfortunately we will only really know that when it is all over.

GPS satellite positioning is used in the survey to capture the location of damage. This data is transmitted back for processing and posting. By comparing the expected damage from the model to the observed damage from the survey we can determine whether any early adjustment of the plan is warranted. Posting damage information on a map improves its usefulness. Early helicopter patrols relied on video recording or still pictures. It is generally difficult to relate these to locations and easy to loose your bearings. Web-based information is also easier to share with all interested parties.

Aerial Patrol data is automatically compiled in FPL servers to provide reconnaissance information across the network

Sharing Information
The final, and sometimes most difficult step is sharing the plan. Lots of people and lots of agencies are involved in recovery of a major disaster and there is no shortage of data. Having the right information or even current information in the right place less than two weeks late is sometimes a challenge. Certainly this is more of a political challenge than it is a technical challenge. Adequate systems and standards already exist to allow this sharing.

What we all need is:

" A means for all relevant public agencies to share information relevant to any disaster recovery effort.
" A common data platform where information can be uploaded by all subscribing agencies (EOC, Forestry, Fire Rescue, Police, Public Works, FPL, CATV, Telephone)
" A means for all subscribing agencies to view the specific layers and area of interest through an intuitive, easy to use, web-browser.
" Servers and website outside any one agency and the commitment of each agency to maintain good, current data for use by the others.

Conclusion
This has been a brief overview of some of the important uses of Geographic Information at Florida Power & Light, as used in disaster recovery. This is only the beginning. As more and more data becomes available the challenge will be to assimilate and share the pertinent information without overloading the people who may already be stressed to their limits. Crisis occurs in the critical moments following a disaster. We cannot control the path of a hurricane but we can avert a crisis with clear plans, good communication and useful information. GIS and other information systems can help reduce the confusion and get the lights back on.