GIS Based Evaluation in Earthquake Hazard Micro-Zonation - A Case Study of Madang and Morobe Province, Papua New Guinea

Abstract

Tectonism induced liquefaction, landslide, Tsunami, fire, etc. are the common earthquake hazards that cause immense destruction of infrastructure, life, properties of people. Areas vulnerable to tectonism related hazard warrant appropriate emphasis in any infrastructure development planning. Various procedures and methods are applied throughout the world to identify levels of earthquake risk within a site of interest. The output results are used as tools for site selection and finding viability of funding in infrastructure development, the former could also be an instrument for the insurance companies for fixing premium of the insured infrastructure. The output aids in devising appropriate building codes for civil construction, judicious selection of sites to preclude future loss of life and property owing to infrastructure collapse by earthquake induced hazard. Earthquake hazard micro-zonation has been a recently adopted technique throughout the world for site selection and investment in infrastructure developments. It is the way forward in analyzing and integrating several linked factors in a GIS environment to delineate specific areas of hazard zones. For any earthquake disaster the fatalities mostly happen depending on the ferocity, depth of the epicenter / focus and distance of the infrastructure from the epicenter, along with its shaking intensity conditioned by geomorphology and geological factors of the terrain. The present study aims at assessing the historical seismicity databases with liquefaction potential zones that house the geological and geomorphological factors into demarcation of levels of earthquake hazard zones within the study region with the knowledge of multi-criteria evaluation and Analytical Hierarchy Process (AHP) appraisal in GIS and Remote sensing technologies. The main data layers that are chosen for carrying out the assessment consist in available seismicity data layers and geomorphological and geological databases. Several thematic layers were prepared and the weightage and ranking was assigned followed by normalization using Saaty's analytical hierarchy process. The final seismic hazard zones map was prepared using the raster calculated tool from ArcGIS 10. The output hazard zones were then reclassified into five categories such as 'very high', 'high', 'moderate', 'low' and 'very low' levels of hazard.