On the 15th January 2022 the underwater Hunga Tonga–Hunga Haʻapai volcano, located in the north of Tongatapu (the main island of Tonga), erupted following several minor eruptions over the previous weeks. It was reported as the largest recorded eruption in the past 30 years. On the 14th January 2022, the Tonga Geological Services issued an alert of the Hunga Tonga Hunga Ha’apai volcanic activity and a tsunami marine warning. The powerful eruption subsequently resulted in a tsunami in Tonga and the surrounding region, with effects reaching countries including Fiji, America Samoa and as far as Chile and Peru. With around 86 percent of Tongans engaged in agriculture, the impacts of the eruption and tsunami may have impacted all agriculture sectors, including fisheries, crops and livestock. The volcanic plume reached 30 km into the atmosphere, releasing volcanic gases and aerosols that were subsequently carried over neighboring countries, potentially impacting public health and the environment. The Government of Tonga declared a state of emergency on January 16, 2022. 

This assessment began a week after the eruption using data from multiple sources and lasted approximately 10 days. Satellite imagery, and spatial and statistical datasets were used as the main datasets considering the time constraints. Four key areas of interest were selected for the analysis (Tongatapu, Eua, Ha’apai and Vava’u divisions). Land cover changes, flooded areas, ash coverage, coastline changes and damage proxy maps were generated. Available baseline datasets for population and land cover for Tongatapu were compared with the results from this assessment. The results from this analysis were combined with each other and/or spatial and statistical data to assess the crop area impacted by flooding and ash cover, the population exposed to ash cover, and damage to agricultural-related built-up areas and infrastructure. Atmospheric and meteorological data was also evaluated in the form of stratospheric SO2 column amounts, UV aerosol index and precipitation.