Ground-Motion Modeling for Istanbul Using Geographical Information Systems

Abstract

In disaster management, especially where earthquake loss assessment is concerned, one key parameter is the modeling of the ground movement. The model, developed by using ArcToolbox and Model Builder tools of ArcGIS, calculates the PGA and SA values in defined frequencies for the Kalkan and Gulkan [2002] ground-motion model and prepares acceleration distribution maps in raster format within the borders of Istanbul. To obtain the maximum shear velocity (Vs) values of the ground, two data sources were used. The first is the geological map of Istanbul in vector format, digitized from 1:25000 scale geological maps. The second is the drilling data included in the Study on A Disaster Prevention / Mitigation Basic Plan in Istanbul including Seismic Microzonation [JICA & Istanbul Metropolitan Municipality, 2002] from 439 drilling locations in Istanbul. Fault data is prepared using the fault map prepared by the Turkish Petroleum Corporation in 1999 by marking the major segments of the North Anatolian Fault. The mod...