August 17, 1999, will forever remain etched in the minds of the Turkish people. That day, a 7.4 earthquake struck western Turkey, leaving more than 17,000 dead, 44,000 injured, and 320,000 homes and businesses lost. More than 300,000 people became instantly homeless from a disaster that caused more than $3 billion in damage.

Geological map of Yalova Province prepared from the Geological Data Base of General Directorate of Mineral Research and Exploration.

This catastrophic event was surpassed only once in the 100 years that Turkey has been recording earthquake data. On December 27, 1939, a 7.9 quake struck, killing nearly 33,000 people and damaging 117,000 buildings.

These are not, however, isolated incidents. According to Turkish seismic records, 66 major earthquakes (5.5 or greater on the Richter scale) have struck Turkey during the past 100 years, almost half of which were 6.5 or greater. Scientists who study the causes of earthquakes say that there are so many deadly temblors in this region because it is located at a point, known as the Anatolia fault, where several of the earth's tectonic plates meet.

In addition to the ever-present danger of living in a high-risk earthquake zone, Turks are also vulnerable to other common natural and man-made disasters such as fire, flood, and terrorism.

To develop an integrated response to potential national disasters, the Republic of Turkey tasked its Ministry of Environment, a longtime user of GIS technology, with developing a national emergency response center, designated as the Emergency Center Project (ECP).

The ministry turned to Islem Geographic Information System & Engineering Ltd. (Islem GIS), Esri's software distributor and GIS integrator in Turkey, for technical help with the project. It was decided to initially implement a pilot project in the Kocaeli and Yalova Provinces.

According to Yalcin Akkas, head of the Section of Industrial Accidents Control, Ministry of Environment and Forestry, ECP was developed to "analyze the effects of accidents and natural disasters on Turkey's strategic commercial and industrial installations."

After extensive study, GIS-based environmental predictive models were integrated into the ECP system to provide the necessary analytic capabilities.

The data for the database was processed using the ArcView Image Analysis extension (a collaborative effort between ERDAS and Esri), and ArcInfo, ArcView, ArcView 3D Analyst, ArcView Spatial Analyst, and ERDAS IMAGINE.

The team chose two models to incorporate into ECP. One is the Areal Locations of Hazardous Atmospheres (ALOHA) that was developed by Environmental Software and Services of Gumpoldskirchen, Austria. ALOHA is an environmental model used to simulate the dispersion of specific chemicals in the atmosphere. The other model, Risk Management Plan (RMP–HazMat) from the U.S. Environmental Protection Agency, creates dispersion models for land- and water-based spills. These models, which require atmospheric and geographic data input, can predict with great accuracy the affected areas in the event of a large industrial accident.

To test and refine the models, environmental studies were conducted on two factories that were severely damaged in the August 1999 earthquake. The team prepared accident reports, environmental pollution assessments, and mitigation studies on AKSA, a synthetic fiber and textile factory, and Tupras, a petroleum refinery, and analyzed them in detail to generate model parameters.

In addition, a wide variety of data was processed to generate the geospatial database necessary for ECP. The data includes soil and land capability maps (1:100,000 scale), topographic maps (1:25,000 scale), Landsat TM images, SPOT PAN images, aerial photography, and a digital elevation model. Also included was information from Turkey's Industrial Site Establishment Information Questionnaire, which details production and consumption amounts, the location of hazardous materials on-site, NACE Codes (a pan-European classification system), CASNOs (lists in descending order of concentration) of chemical agents, and an industrial site location map at a scale of 1:25,000.

Concludes Akkas, "Phase one of the Emergency Center Project is now complete. In the next phase, we will set up an ArcSDE server to manage the data with ArcIMS to allow the distribution of our National Environmentally Hazardous Industries database via the Web, which will allow our emergency response agencies to react more quickly in times of disaster."

For more information, contact Mehmet Tankut, Islem GIS (e-mail: mtankut@islem.com.tr).