Responding to the Unthinkable

New York GIS data sharing cooperative proves key to 9-11 disaster recovery.

by / September 26, 2002
Just hours after the Sept. 11 attack on the World Trade Center (WTC), the GIS staff of New York State's Office of Technology (OFT) were supporting the gargantuan recovery efforts at Ground Zero. Although no one was ready for a crisis of such unthinkable magnitude, the important role that GIS played clearly resulted from years of preparation and development.

"For more than four years now, when an emergency occurs in our state and our State Emergency Management Office is activated, we've been providing GIS support to the emergency response effort," explained Bruce Oswald, director GIS services within the State Office of Technology. "Our emergency response office coordinates with county and local government, depending where the event is located."

Indeed, the state's GIS operation had proven itself in a crisis long before 9/11. When a major ice storm crippled the state in 1998, leaving an estimated 320,000 residents without power for an extended period of time, GIS services pinpointed the location of dairy farms where farmers couldn't milk their cows without electricity. "Using our GIS and data available from the state agencies that manage agriculture and real-property data, we were able to locate the farms and then coordinate the deployment of emergency generators to those farms," said Bill Johnson, deputy director of GIS in the OFT.

The situation demonstrated that the state's GIS office could offer significant benefits in a large crisis, and that a new system of cooperative data sharing - which had just been implemented as part of the state's GIS strategy - could turn the GIS operation into a rapid problem solver.

"We needed to use data from our Office of Real Property Services to locate agricultural land, and then we needed to use data from our Department of Agricultural Markets to define which of these was a dairy farm," said Oswald. "And we were able to take census data that had been worked on through our Department of Health, and overlay that with the power outages to see where major populations were being impacted. Because of the cooperative, we knew what data existed [and] where and how to rapidly contact the owners of that data."

The New York State Data Sharing Cooperative, as it is officially called, now comprises more than 400 different entities. New York City had joined the cooperative in the summer of 2001. So when the WTC attack occurred, the state GIS system already contained the best GIS data available for New York City. "New York City's emergency management center had been located in building number 7 of World Trade Center, which came down as a result of the attack," said Oswald. "But also having the information on our system meant that the new imagery we developed through remote sensing was going to meet or exceed the accuracy of the city GIS data that had previously been developed. This provided a huge benefit and solved a lot of problems very quickly."

WTC Response
"Early on, because of the massive damage and huge debris pile that buried everything, the site was essentially unrecognizable even to people who were familiar with the neighborhood," said Johnson. "You kind of lost all sense of direction and the landmarks were gone. So what the folks down at the Pier 92 Command Center were doing was overlaying their GIS data to show where the curb lines were, where the building footprints were. And you could overlay that on a digital ortho image and begin to orient yourself, figuring out what was buried under what. It really created a frame of reference so you could start to make sense of it."

But beyond orientation, GIS also helped to address other significant safety concerns for recovery workers. There were fears, for instance, that some surrounding buildings might become unstable and also collapse. GIS data, accurate down to about 15 centimeters, could show if the buildings were shifting dangerously.

There were hot spots within the rubble that burned long after the collapse, and thermal imaging showed their locations on any given day. This was particularly important as buried under the rubble were 100,000 gallons of fuel oil, huge Freon tanks for the buildings' cooling systems, as well as large gas mains. So GIS thermal data helped to predict whether a new explosion or other problems were imminent.

The second day into the emergency, New York City GIS Director Al Leidner - who had spent two years pulling together city GIS capabilities, creating a base map, and establishing a program for sharing city data - asked the state GIS office to provide imagery to support the rescue and firefighting effort.

The first fly-over of the site was organized by Sept. 13, using an established city contractor. However, Oswald and his associates realized that they needed a technical solution that would allow updated data to be processed and shared within 12 hours or less. By Friday, EarthData International had been hired to collect all the needed information in digital form.

As the crisis moved into Saturday, the state IT Training Academy located a few miles from Albany Airport had been converted into a sophisticated GIS processing center. EarthData had rounded up thermal imaging gear to supplement other systems installed in a small airplane, replacing the passenger seats with racks of electronic equipment. Their first flight over the site occurred Saturday morning, and the data was processed in the next 13 or 14 hours.

From that point on, daily fly-overs provided updated GIS data - a routine that continued for the next six weeks. According to Bill Johnson, the GIS operation was in essence collecting three categories of imagery data. The first was digital ortho imagery, essentially aerial photos with inaccuracies caused by camera perspective and uneven terrain removed. These images also are geo-referenced to align with a ground coordinate system, allowing them to be overlayed with other GIS data. The second category is LIDAR - a technology that creates a three-dimensional image by bouncing a laser pulse off of a surface and measuring the speed of its return. These images showed the changing shapes of the buildings and debris piles. The third category of information was thermal, measuring the relative hot spots at the surface of the pile.

"So what they were actually doing with the data was looking at multiple layers in conjunction with each another," explained Johnson. "For example, you overlay the thermal data on top of the digital ortho image, and you can see which parts of the pile are hot. You could therefore direct the rescue crews to safely avoid those spots."

Officials originally intended to distribute the data through FTP sites on the Internet. But because the disaster had caused so infrastructure damage, they moved to a back up plan - distributing revised GIS data on CD-ROMs that were "pony expressed" daily by the State Police. Later, data also was distributed through the Internet to other state and national entities working on different aspects of the recovery.

Learning From Experience
Despite the operation's success, consultation with users of the GIS data highlighted areas to strengthen for the future, according to Oswald.

"The collaborative effort that we had been making over the last few years really paid great dividends," he said. "That approach, the working with people, really made a difference. But one of the big lessons that came out of this for us was that on-site GIS capabilities were absolutely invaluable. What they did on Pier 92 and with the fire department really showed the need to have a remote GIS capability as close to the site as possible - not only to provide data to the people who are immediately responding to the incident, but also to provide data back to decision-makers in other parts of the state.

"The need for accurate, up-to-date data on critical infrastructure became more and more apparent the further we went into handling the emergency. And one of the things the city learned - because I think they were plotting 320 maps a day at one point - was the need for standard canned products to be efficient."

As well, he said, one lesson painfully learned was the vital need for off-site data back up. "When the event occurred, [New York City GIS Director] Al Leidner could not get to his offices, could not get to his data, could not get to any of his contacts," Oswald said. "That is something we all have to remember - not to put all your eggs in the same basket."

But more than anything in an emergency, things must be kept simple and clear for end-users. When you are dealing with people who are responding to an emergency, who have a high level of adrenaline flowing and a lot of other things going on, you essentially have 15 to 30 seconds to make them understand something in a briefing, Oswald said, adding "If they can't understand it in that timeframe, with everyone racing as quickly as they have to in responding to an emergency, you just won't be effective."
Blake Harris Editor
Platforms & Programs