Geohazard Mapping of Panaon Island As Inputs For Disaster Management and Land Use Planning

Claro Jose Manipon, Salvio Laserna, Alvin Fernando, Digna Evangelista and Gilbert Bascos

Mines and Geosciences Bureau

Abstract

Unusually heavy moonsonal rains last December 2003 triggered several landslides and flash floods in Panaon, Southern Leyte. Shallow landslides were ubiquitous but deep landslides were confined in clastic sedimentary formations with daylighting beds and in andesite formations with numerous fractures.

Geohazard mapping on a scale of 1:50,000 using an expert’s system approach on a GIS platform indicated large areas with high potential for landslides with a strong structural signature. Field mapping at 1:10,000 of selected areas delineated in more detail the landslide and flood-prone areas. These geohazard themes were overlain with digital terrain model to look for relocation sites and permanent housing areas.