HazMapper: a global open-source natural hazard mapping application in Google Earth Engine

Abstract. Modern satellite networks with rapid image acquisition cycles allow for near-real-time imaging of areas impacted by natural hazards such as mass wasting, flooding, and volcanic eruptions. Publicly accessible multi-spectral datasets (e.g., Landsat, Sentinel-2) are particularly helpful in analyzing the spatial extent disturbances, however, large require intensive processing on high-powered computers trained analysts. HazMapper is an open-access hazard mapping application developed Google Earth Engine that allows users to derive map GIS-based products from Sentinel or Landsat without time- cost-intensive resources required traditional analysis. The first iteration relies a vegetation-based metric, relative difference normalized vegetation index (rdNDVI), identify landscape where was removed following disaster. Because tool typically not suitable use desert polar regions. semi-automated routine but makes repeatable analysis visualization feasible both recent historical disasters. Case studies included identification landslides debris flows, wildfires, pyroclastic lava flow inundation. intended scientists non-scientists, emergency managers public safety decision-makers.