https://video.osgeo.org/videos/watch/91a4090c-0f6e-45ea-bc93-3314bf56bea1 "Flooding caused by rainfall poses a significant hazard to Pacific Island nations that are at risk of cyclones and large rainfall events. Particularly, island nations such as Samoa, which are characterised by high mountains and steep river gullies, are highly susceptible to flash flooding events. Despite this recognised threat, a notable absence of reliable, high-quality data hinders the application of traditional hydrodynamic models that typically rely on precise river flow values and often disregard rainfall factors. Furthermore, there is an absence of flood hazard inundation maps that can provide a basic indication and outline the potential consequences of rainfall-induced flooding on both the populace and the environment within these regions. To address these challenges, the Pacific Risk Tools for Resilience Phase-2 (PARTneR-2) project, co-led by the New Zealand National Institute of Water and Atmospheric Research (NIWA) and the Pacific Community (SPC), has introduced a novel approach to rapid rain-on-grid modelling. This methodology uses a combination of open-source geo-spatial software, including QGIS, RAS Mapper, and 2D hydrodynamics software BG-Flood, on limited geo-spatial data to rapidly produce indicative flood depth inundation maps. Our study has concentrated on two Pacific Island nations: Samoa and Vanuatu. For these two countries, we have developed a series of flood depth inundation maps at national coverage for 10-, 50-, and 100-year Annual Recurrence Intervals (ARI). The model used to produce the maps requires limited input data, is reasonably easy to set up, and can be run in under 12 hours. The maps produced are useful in providing a basic indication of areas that are at the most risk of flooding in a specified rainfall event. The method is cost-effective and can be implemented using entirely open-source software. Furthermore, by integrating the flood maps produced by this study with geo-spatial asset data sets, particularly focusing on buildings, our study shows how we can quantify the exposure and potential losses to flooding events, employing the Riskscape multi-hazard risk modelling software. The outcomes generated by this innovative method offer valuable insights that can inform resource allocation decisions during the critical hours following a significant rainfall event, particularly in the context of a Post Disaster Needs Assessment (PDNA) study. James Battersby Use cases & applications" Wed, 27 May 2026 17:23:43 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://video.osgeo.org https://video.osgeo.org/lazy-static/avatars/de841c88-3a57-45ac-9eff-a00237356bfc.png https://video.osgeo.org/videos/watch/91a4090c-0f6e-45ea-bc93-3314bf56bea1 All rights reserved, unless otherwise specified in the terms specified at https://video.osgeo.org/about and potential licenses granted by each content's rightholder.