GIS Modeling of Earthquake Damage Zones Using ETM Data and Remote Sensing- Bojnoord, Khorasan Province.

Abstract

The devastating earthquake that occurred in Khorasan Shomali Province, Iran, on the 12th May 2008, caused widespread damage and devastation to rural communities and economy. The terrain of the entire region has been weakened and is now highly susceptible to long-term slope instability that will trouble this region for many years to come. Methodology: However, the actual intensity caused by the earthquake ranged between VIII and XI. The seismic intensity map is practical for regional guidance but lacks the detail to provide an adequate representation of the true damage level, in terms of current status and future potential in such a seismically active and populated region, especially when the hazards and risks are likely to be multiple and cascading in high relief areas. Results: This paper presents a GIS-based approach to earthquake damage zone modeling using satellite remote sensing and DEM data. The novelty is to take into account the coseismic ground deformation as an important modulating factor in modeling the susceptibility of earthquake-related geohazards, together with conventional multicriteria factors which draw on geological and topographical variables such as rock competence, slope, proximity to drainage, and fracture density. The modulating effect of the earthquake greatly enhances the susceptibility in the areas where the majority of the ensuing landslides and debris-flows actually took place. Conclusion: When this susceptibility model is further modulated by the mapped surface disruption caused by the earthquake, it is directly linked to seismic intensity and we call it “earthquake damage”. The output earthquake damage map represents both the current damage status as well as the future damage (hazard) potential.