A paradigm for landslide rapid response: use of satellite data for decision support during Hurricane Eta

Abstract:

In early November 2020, extreme rainfall from Hurricane Eta triggered flooding and landslides across Central America, with particularly intense landsliding observed in Guatemala, Honduras, Nicaragua and El Salvador. During this natural disaster and immediately afterwards, disaster response professionals indicated a need for information about the potential landslide hazard and exposure of people and infrastructure, as well as detailed maps of where landslides occurred. Consistent information about landslide hazard and exposure is often challenging to obtain in rapid-response scenarios, but is crucial to understanding where impacts may be most severe. Here, we report on the activities of the NASA GSFC Landslides Team (landslides.nasa.gov) to support disaster response activities across the region. We provided experimental landslide hazard and exposure products to a variety of stakeholders, to highlight areas where people and infrastructure may have been most severely damaged by landslides. We also leveraged low-latency, high-resolution optical imagery to rapidly map landslides in several areas where media reports indicated landslides caused fatalities. However, by combining landslide hazard estimates from our experimental model outputs, we also searched areas without media reports to find extensive landslides in unpopulated parts of Honduras. By combining hazard and exposure models with observational data on landslides we provided stakeholders with a more complete picture of the landslide impacts across the region. While these results remain provisional given the experimental nature of the models, we suggest that this combined approach represents an effective strategy to inform stakeholders of the impacts of landslides in areas affected by extreme rainfall.