ArcNews Online

Spring 2002
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Using GIS to Track Terrorism

The Commonwealth of Pennsylvania's Incident Response System Grows Out of Virus Surveillance System

Esri Services logoThe Winter 2000-2001 ArcNews presented an article that showed how the Commonwealth of Pennsylvania was developing and implementing a system designed to combat the spread of West Nile Virus. The surveillance system was designed to permit the storage and collection of the various field and lab data and to make the data immediately available to Commonwealth staff, key decision makers, and the public so the spread of the virus could be tracked and appropriate decisions made. Three Commonwealth departments collaborated with each other and the Esri Professional Services Division to build the system with ArcPad and ArcIMS. The article below explains how the system has evolved due to new concerns born of recent events.

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Incident data can be viewed or queried in a number of ways with the PAIRS map viewer. This ArcIMS viewer is launched from the main menu or from any agency reports.

Many state and local agencies across the country lack strategies for responding to terrorism, or their activities are generally not well integrated with those of other state agencies responsible for responding to emergencies. The Commonwealth of Pennsylvania has found a solution to this problem. Over the last two years, the Pennsylvania Departments of Environmental Protection (DEP), Health (DOH), and Agriculture (PDA) have implemented the GIS-based Pennsylvania West Nile Virus (WNV) Surveillance System. Given the success of this system in combating the spread of the West Nile Virus in the Commonwealth, and the events of September 11, 2001, the WNV system model has been modified by the Commonwealth for the development of the Pennsylvania Incident Response System, better known as PAIRS.

PAIRS is a data system that provides a secure Internet-based application for reporting and tracking potential terrorism events associated with anthrax exposure, smallpox, nuclear incidents, chemical attacks, foot and mouth disease, or contamination of water treatment systems. In addition, the system supports routine emergency events such as hazardous materials on highways, atmospheric release of toxic chemicals, toxic spills, or natural disasters. This is the first system that incorporates both health and environmental data in everyday decision making, and is the first of many health and environment related projects on which the Commonwealth is working.


At the highest level, PAIRS is intended to fill a unique position within participating agencies by providing timely, spatially defined information through data acquisition (surveillance), laboratory analysis, decision making and response, and communications. It is intended to be an integral part of any overall system that the Commonwealth developed for incident response with access to the system and data being provided to any Commonwealth system or agency that requires health, agricultural, and environmental data during an incident using preestablished protocols. PAIRS is the best GIS-based solution to provide a system for terrorism actions response because it builds upon the existing experience, infrastructure, and database that was successfully developed to respond to the West Nile Virus by DEP, DOH, and PDA.

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PAIRS users initially enter incident and location data into a Web form and click the locate button to launch the point locator that geocodes the incident and stores its location in ArcSDE.

In PAIRS, users can facilitate password protected Internet-based data entry, issue immediate alerts to agencies involved in an emergency event, and generate maps and reports that immediately document the location and nature of the event. "If multiple agencies are involved in the response, we will be able to quickly alert other agencies or states," says Eric Conrad, DEP's acting deputy for field operations and Pennsylvania's PAIRS and WNV system creator. "For example, in the case of the use of weapons of mass destruction, the Pennsylvania Emergency Management Agency (PEMA) could immediately notify the Health Department which in turn can alert hospitals of the need to treat patients due to exposure to weapons of mass destruction and simultaneously notify other response agencies as well."

The PAIRS system allows decision makers to communicate effectively with the large numbers of people responding to the same incident. In any emergency event, time is of the essence, and this system meets the Commonwealth's need by providing decision makers with tools to view and analyze data from various sources. Eventually these sources will include 9-1-1 and hospital admissions data along with environmental and veterinary data.

PAIRS Development

Initial development of PAIRS included the same agencies that were involved with the West Nile Virus system--Pennsylvania's DEP, DOH, and PDA--but also includes PEMA. Since each agency has its own Business process for tracking and responding to incidents, Esri Professional Services initially met with the agencies with the objective of eliciting their specific requirements for the system. Esri then developed mock-ups of Web forms representing the fields of data that each agency would require in order to capture the same information that in most cases was being captured manually on paper. Upon completion of the database design, the system was developed using an application service provider (ASP) and an Oracle database with ArcIMS to provide the mapping functionality of the system.

Current Status and Future Plans

Pennsylvania is using a phased approach in the development of PAIRS. To date, a basic PAIRS system has been built and deployed that links PEMA, PDA, DOH, and DEP to emergency response outfits. Many other State and federal agencies will be added over time. Subsequent phases will enable linking to data systems in other agencies including laboratories and existing databases, modeling with real-time data, and eventually the ability to share summary data with the public.

For more information, please contact Craig Devine, Esri project manager (e-mail:; tel.: 909-793-2853, ext. 1-2117).

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