Earthquake Hazard Micro Zonation in Fiji Islands: A Research of Viti Levu Island

Abstract

Depending on magnitude the earthquake hazards can have collateral retort of devastations in collusion with the site-soil geology. Fiji – Tonga region accounts for about 70 percent of the world’s earthquakes with depths greater than 400 kilometres. Risk management through spatial planning is paramount for tectonism linked disasters in order to reduce the extent of fatality and economic cost. Humanity is at the ‘tipping point’ of self-destruction unless knowledge on disaster risk reduction is disseminated on time in the form of implementable solutions such as using ArcGIS as a tool to provide worthwhile segmentation of disaster prone zones to administrators. The present study aims at assessing the site-soil geology and earthquake hazard potentiality of VitiLevu Island using the GIS and remote sensing techniques. Site-soil geology, geomorphology, seismology and SRTM DEM data were the main sources of layers used to carry out analysis using the Saaty’s Analytical Hierarchical Process (AHP) and ArcGIS Multi-Criteria Analysis (MCA).The technology involves preparing and assessing several contributing factors (thematic layers) those are assigned with weightage and rankings, and finally normalizing the assigned weights and ranking. In the ArcGIS 10.5 spatial analyst tool, the raster calculator, reclassify and weightage overlay tools were mainly employed in the study. The final output of EHZ indicates the ‘low’, ‘moderate’ and ‘high’ zones of potential earthquake disasters. The result provides a substantial readable guide for urban and regional spatial planners as well policy makers to formulate disaster reduction policies. Thus, informing civil societies, private societies and community to become well - versed with adaptive strategies suitable to withstand and encounter earthquake hazards.