Application of GIS in assessment and analysis of the spatial distribution of seismicity hazards and population density in Iran

The country of Iran is within one of the most seismically active regions of the world. In order to answer this question that how population centers in this country spatially correlate with seismicity hazardous zones, a GIS-based geospatial analysis technique has been employed to assess this correlation. For this purpose, the population density layer map of the country has been prepared based on the national database gathered in 2011. In addition, seismicity hazard maps of the region were prepared by analysis and combining the earthquake data catalog (including historical and instrumental data) and active fault data of the region. By overlying the population density and seismicity hazards maps of the region and employing ArcGIS (version 9.3) package, four zones namely: high population - high seismicity, high population – low seismicity, low population – high seismicity, and low population – low seismicity, are defined in the country. Additionally, the location of major cities of Iran (as the main population centers of the country) in relation to the peak ground acceleration estimated for the neighboring active faults for the cities’ location was assessed. Results obtained indicate that the population density, as a spatial variable, shows a high positively correlation with the seismicity variables, meaning that the most of the high populated centers in Iran are located in areas with high seismicity hazards. It is also concluded that more than 45% of major cities of Iran are located in potentially high earthquake hazard zones, with estimated PGA equal or more than 0.5 g. The results of this study can be very useful for preparing a national long-term plan, necessary for the future development of the country, as well as for reducing and controlling the seismicity risk over the region.n correlation coefficient, Darab County.