You dont often associate the words heroism and cartography. Yet just hours after the collapse of the World Trade Center buildings last September 11, mapping experts across New York City were working fast to put the dimensions of the disaster down on paper, helping rescue and recovery workers stay safe at the site. They too surely saved lives.
No one could have imagined the magnitude of this effort, says Chris Schielein of Environmental Systems Research Institute (ESRI), a company that specializes in geographic information systems (GIS) software, which allows layers of data to be displayed as maps. By September 14, banks of computers running GIS plotters were already humming at Pier 92, an empty terminal on the Hudson River set up as an emergency mapping center.
From there, and from other sites around the city, specialists from city agencies, private firms such as ESRI, and the federal government worked as a team to meld maps of Manhattan with incoming data on the damage. Under high security, their around-the-clock efforts were producing hundreds of maps a day by the end of Pier 92s first week in operation.
The maps they made provided information on everything from the structural integrity of the World Trade Centers seawall to places where rescue workers could get cold drinks. They charted the density of the acrid smoke plume and used computer models to track its likely path across the city. Maps of street closings, gas and electric outages, and loss of water and telephone service were updated dailysometimes every few hoursand distributed to anyone who needed them.
Other mapping technologies also played a vital role. Since air traffic was limited after the disaster, satellite photographs offered immediate aerial views of the devastation in lower Manhattan. Several days later, airplane-mounted light-detection-and-ranging (LIDAR) devicesthink speed gunsused their lasers to pierce clouds of smoke and dust and thus locate hidden support structures in wrecked buildings. Additional LIDAR views showed color-coded heights of the damaged structures and the constantly shifting rubble piles. This information helped officials know how tall debris-removal cranes needed to be. A third technology, thermal scans, helped firefighters pinpoint underground fires burning near fuel and Freon tanks.
Even before September 11, New York City had in place an extensive digital base map so detailed it shows home plate at Yankee Stadium. Known as NYCMAP (pronounced NICE-map), it was compiled from some 5,000 aerial photographs. In the disasters aftermath, NYCMAP served as a geographic foundation for information critical to Manhattan residents, including damaged-building assessments and access to transportation and other public services.
Other citiesPhiladelphia, Seattle, and San Diego, to name a fewhave similar mapping projects. And those that dont, should, says Alan Leidner, the director of GIS for New York Citys Department of Information Technology. Because we were working with an accurate geography of the city, we were able to get up and running very quickly.
Dave Kehrlein, a California state government GIS expert, was one of many geographers from across the country who traveled to New York last September to help the mapping effort. He hopes that GIS technology gets more national attentionand more government funding.
Preparation for a terrorist attack is no different than preparation for an earthquake or a flood, he says. We have natural disasters often enough in California that we take GIS very seriously. If another attack happens, we know were going to be asked to perform.