A GIS Based Approach into Delineating Liquefaction Susceptible Zones Through Assessment of Site-Soil-Geology-A Case Study of Madang and Morobe Province in Papua New Guinea (PNG)
Tectonism induced liquefaction can be a major disaster that warrants appropriate emphasis in any infrastructure development planning. Various procedures and methods are applied throughout the world to identify potential zones of liquefaction. The output results are used as tools for site selection and finding viability of funding in infrastructure development. Thus such measure is slated to preclude future loss of life and property owing to infrastructure collapse by earthquake induced liquefaction. Liquefaction is likely to occur due to saturated soils or unconsolidated sediments under the infrastructure basement that are subjected to give way due to ground shaking. Liquefaction is one of the main geohazards related to tremor. The present study aims at assessing different soil properties and geological structures of Morobe and Madang Province culminating in delineation of Liquefaction potential zones using multi-criteria evaluation and Analytical Hierarchy Process (AHP) appraisal using GIS and Remote sensing technologies. The main data layers that are chosen for carrying out the assessment consist in available geological, soil and SRTM DEM data. Several thematic layers are prepared from the data base as mentioned, followed by assigning weightage to each thematic layer generated. Weightages were further normalized using Saaty’s analytical hierarchy process. The final Liquefaction potential zone was prepared using the raster calculated from ArcGIS. The output liquefaction potential zone map was delineated and reclassified into five categories such as ‘very high', ‘high', ‘moderate', ‘low’ and ‘very low’ potential zones.