Hunga Tonga-Hunga Ha’apai Volcano Eruption - Data in Emergencies Hazard Impact Assessment (DIEM-Impact)

This report provides an updated hazard impact assessment of the Hunga Tonga–Hunga Haʻapai undersea volcanic eruption that occurred on 15 January 2022, triggering widespread ashfall and tsunami waves across Tonga. Prepared under FAO’s Data in Emergencies Hazard Impact Assessment (DIEM-Impact) framework, the update builds on initial findings to present a more detailed picture of impacts on agriculture, food systems, and rural livelihoods. The assessment was conducted amid significant data collection challenges due to damaged undersea communication cables and COVID-19 lockdown measures.

Using geospatial analysis, secondary data, and sectoral information from national authorities and partners, the report documents extensive ash coverage and localized flooding across Tongatapu, ʻEua, Haʻapai, and Vavaʻu. It highlights impacts on cropland, grassland, forests, mangroves, built-up areas, and coastal zones, with Tongatapu experiencing the highest levels of ash exposure. Sector-specific sections examine damages and emerging risks for crops, livestock, fisheries and aquaculture, remittances, food security, and market functioning, identifying both immediate losses and uncertainties regarding longer-term productivity and environmental effects.

The report emphasizes the need for continued monitoring and targeted assessments to better understand medium- and long-term impacts on agricultural livelihoods, particularly fisheries, aquaculture, and soil health. It underscores the importance of safeguarding food security, monitoring market access and prices, and supporting vulnerable households whose coping capacity is strained by lockdown measures and income disruptions. Overall, the document supports evidence-based humanitarian response, early recovery planning, and risk-informed decision-making following a complex, multi-hazard disaster.