Modeling of inland flood vulnerability zones through remote sensing and GIS techniques in the highland region of Papua New Guinea

Abstract

Papua New Guinea (PNG) is saddled with frequent natural disasters like earthquakes, volcanic eruptions, landslides, droughts, floods, etc. Flooding, as a hydrological disaster to humankind’s niche, brings about a powerful and often sudden, pernicious change in the surface distribution of water on land, while the benevolence of flooding manifests in restoring the health of the thalweg from excessive siltation by redistributing the fertile sediments on the riverine floodplains. In respect to social, economic, and environmental perspectives, flooding is one of the most devastating disasters in PNG. This research is conducted to investigate the usefulness of remote sensing (RS), the geographic information system (GIS), and multi-criteria analysis (MCA) for flood susceptibility mapping. MCA methods such as weighted linear combination (WLC) and analytical hierarchy processes (AHP) were used to assess flood vulnerability in the Wahgi catchment area through RS and GIS technology. In the study, attention was focused on different parameters that cause flooding. These parameters include elevation, slope, distance from drainage, soil texture, soil drainage, rainfall, landform, and land use and land cover. The classes within parameters were ranked and suitably weighted depending on their influence to flooding with reference to the PNG Resource Information System (PNGRIS) metadata. The result of the analysis is a flood-susceptibility map showing the most vulnerable areas. This type of map is very useful for better management, planning, and mitigation of future flooding in the Wahgi catchment area. The validation of the flood-susceptibility map was carried out using past flood records in the study area.