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GIS for disasters and emergency management

On April 27, 2011, one of the deadliest storm systems to hit the United States in 80 years swept across the South, spawning 188 tornadoes that killed nearly 300 people in Alabama, Mississippi and Georgia. At least seven twisters touched down in Madison County, where eight died, dozens were hospitalised, and power was lost for five days in many areas.


Tornado Track Map

“The thing that was unique about this event was the surges,” said Chris Tucker, Director of the Huntsville-Madison County 9-1-1 Center. “We’re accustomed to having one storm and then it’s over. With this event, we had one, and then we had another wave, and then another.”

Just two months after the storms, representatives from the public safety agencies that comprise the joint 9-1-1 Center assessed their performance during the incident. They noted the storms helped them identify areas where improvement should be made before the next disaster strikes. They also concluded that investments in updated technologies, outstanding personnel training, and internal emergency planning kept their facility fully functional at a time when citizens needed their services the most.

A unified CAD system
In 1992, Huntsville-Madison 9-1-1 came into existence as a unified center when local officials began looking at a new technology called computer-aided dispatch (CAD). They realised that one CAD system could support the call-taking and dispatch requirements of multiple agencies resulting in faster response times, improved cost effectiveness and enhanced operating efficiencies. The concept of the unified 911 center has delivered on all of those promises with countless lives saved in the process.

Five years later, the 9-1-1 Center found a new home in a Huntsville building especially designed to protect the facility from a direct tornado strike. By then, all seven local public safety agencies were involved: Huntsville Police and Fire, Madison County Sheriff and Volunteer Fire departments, City of Madison Police and Fire, and the not-for-profit ambulance service provider Huntsville Emergency Medical Services (HEMSI). While representatives from each agency are situated in the communications center, call-takers and some dispatchers are cross-trained to handle requests for police, fire and ambulance services.

From its inception, the center was equipped with the I/CAD computer-aided dispatch system from Intergraph Corp., a Huntsville-based company. Selected for its ability to handle call-taking and dispatch needs of multiple public safety agencies involving hundreds of vehicles, this system has been upgraded repeatedly in the last decade to include automatic vehicle location (AVL) capabilities, GIS-based digital maps, and two-way information sharing with mobile terminals in emergency vehicles.

During normal operations, the center is staffed by 26 call-takers and dispatchers referred to as telecommunications specialists. They work in a central operations room handling incoming 911 calls for all of Madison County, which covers 850 square miles with a population of about 360,000 people.


Franklin and Lawrence County tornado tracks for the April 27th northern Alabama EF-5

Adapting to problems
As the storms began rolling across Alabama on April 27, events in the 9-1-1 Center unfolded very quickly, and personnel had to adapt to a rapidly changing situation. Fortunately, their training with the CAD system had prepared them to continue working even when weather conditions went from bad to worse.

Problems with cellular communications became the first, and most pervasive, issues of the day. When power lines went down, people naturally turned to their cell phones for communications with each other and with 911. For reasons that have still not been determined, call centers in surrounding counties began misrouting cellular calls as their systems became saturated. Many of these emergency calls ended up at the Huntsville-Madison center.

“We were dealing with not only the tremendous inflow of 911 calls from Madison County, but we had to handle several calls from Tuscaloosa, Limestone and other surrounding counties,” said Barry Bjork, 9-1-1 Center Systems Manager.

The Huntsville-Madison CAD has a built-in ‘wildcard list’ that enabled call-takers to re-route the errant 911 calls back out to their appropriate agencies in other Alabama counties. Throughout the day, the center handled more than four times its normal volume of calls. In the midst of the crisis, downed power lines shut off electricity in Madison County, including Huntsville. As planned, a back-up generator kept power flowing to the 9-1-1 Center.

“The fact that the CAD system never went down was tremendous,” said Bjork. “Since the center stayed up and operational, we didn’t lose anything – except for some conveniences.”

By late morning, the cellular network in Madison County was getting saturated with too many calls, as had occurred in neighboring areas. The situation was compounded, however, by direct damage to several cellular towers and inadequate back-up power at some wireless transmission facilities. As a result, the center was unable to push event information from the CAD out to the mobile data terminals in some emergency vehicles. Likewise, due to communications bandwidth losses, the AVLs in many police cruisers and fire trucks could not automatically report real-time positions to the CAD.

“The telecommunications specialists did a great job of staying organised,” said Tucker.

While dispatchers were used to the CAD automatically displaying the precise locations of emergency vehicles on the map screen and electronically transmitting event details to the crews via the mobile data terminals, they quickly adapted to the loss of capabilities. The CAD interface had been designed for an easy switch to manual data entry. In this case, the dispatchers began sending verbal instructions to responders over voice radio and asking for location updates. They manually posted vehicle positions to the CAD map display to keep everyone notified of the location and status of each vehicle.

The two main stress points in the 9-1-1 Center on the day of the storms were the reliance on voice radio and its limited bandwidth, and the steadily increasing workload as call volumes spiked with each new wave of storms. Shift supervisors were able to take some pressure off the telecommunications specialists by setting up a spare laptop computer in the operations room. This computer was converted into an extra dispatch terminal by tapping into a CAD module called I/NetViewer, which uses the web to extend CAD functionality to remote public safety facilities.

Despite the problems originating in the cellular network, the veteran emergency response professionals in the room that day were impressed with the performance of the 9-1-1 Center as a whole, especially with the fact the CAD didn’t crash when power was disrupted during the hand-off to back-up electricity.

“It amazes me to think back on how everyone did their jobs as well as they did,” said Tucker. “They worked efficiently and professionally to handle all of the calls and dispatching.”

He cited personnel training as the key factor contributing to their outstanding performance. Included in the CAD training provided by Intergraph with each system upgrade was instruction on how to enter information manually if critical external data feeds failed.

Learning from the storms
Huntsville-Madison County 9-1-1 is fortunate enough to employ several telecommunications specialists who count their public safety experience in decades. Although most agreed the 2011 storms were the worst in their careers, they have still taken the time to discuss lessons learned that could better prepare them for the next major event.

The most important issue that has been addressed was the loss of cellular signals during the storm. Because the cell network is operated and maintained by wireless service providers, the 9-1-1 Center only has limited influence in this arena, and there is nothing anyone can do to prevent damaged relay towers. However, at least some of the signal disruption was due to inadequate battery backup power and available fuel for back-up generators for cellular transmission antennas. The wireless network operators are aware of this problem and are taking steps to remedy it.

In terms of challenges the 9-1-1 Center can influence directly, a major concern was the volume of emergency calls received during the event. Management personnel were on hand to take over some of the load, but they didn’t have enough extra terminals to access the CAD. The center supervisors have already determined that in the future, the back-up 9-1-1 facility located just a few miles from the primary will be activated in a major emergency. That facility will tap into the CAD via the I/NetViewer module to virtually expand the call-taking and dispatch capabilities of the primary center.

Even as additional emergency vehicles are being equipped with mobile data terminals, the 9-1-1 Center is taking steps to ensure that police cruisers, ambulances and fire trucks – as well as the stations where they are housed – keep up-to-date paper maps of their coverage areas on hand. During the tornadoes, some crews had to scramble and find paper maps due to loss of wireless data transmission.

The 9-1-1 Center has also learned that taking care of its personnel is the most important issue that can’t be overlooked in disaster preparation. The supervisors are currently improving procedures for rotating in fresh personnel during a prolonged emergency, setting up sleeping quarters onsite, and having sufficient food on-hand for them to eat if they can’t leave the facility for prolonged periods.

Steps also must be taken to ensure the CAD, communications, and computer equipment continues to function at a high volume for a long period during an emergency. The center is making arrangements with its vendors to provide service and spare parts for critical elements to keep the systems running during emergency situations.

Looking ahead
“We are very pleased with the performance of all the technology within the center during this explosive time,” said Tucker. “Experience and technology were great benefits during these storms and should also be very valuable during future events of this magnitude.”

The tornadoes of 2011 have also compelled The Huntsville-Madison 9-1-1 Center to look forward to the coming i3 standards for NG9-1-1 with great anticipation. The next generation E911 standards require emergency response facilities to monitor and handle requests for help that are posted or sent by popular forms of social media.

Public safety officials don’t know how many wireless 911 calls could not reach the center during the storms, but text messages were unaffected by the oversaturated network. An upgraded phone system capable of receiving text messages, instant messages and video at the center will be obtained.