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The recent destruction of thousands of homes by lava flows from Cumbre Vieja, La Palma, Spain and Nyiragongo volcano, Democratic Republic of Congo, serves as a reminder of the devastating impact that lava flows can have on communities living in volcanically active regions. Damage to buildings and infrastructure in particular can have widespread and long-lasting effects on rehabilitation and livelihoods. Our understanding of how lava flows interact with buildings is limited and based upon sparse empirical data. Often a binary impact is assumed (lava flows destroy buildings), although previous events have shown this to be an oversimplification. Empirical damage data collected after past events can provide an evidence base from which to better understand lava flow impacts across a range of building types, environments and eruption styles, as well as temporal and spatial trends. However, information on lava flow impacts is scattered across literature, reports and maps; no comprehensive dataset of lava flow impacts exists. In this study, we review, compile and standardise lava flow impact information in published literature to create the first comprehensive global dataset of lava flow events with impacts on the built environment. We found that since the first recorded event between 5494 year B.P. and 5387 year B.P., lava flows from at least 127 eruptions impacted buildings or infrastructure, with the most (34%; n = 43) located in Europe. There are almost six lava flow impact events per decade, with 57 events occurring in the past 100 years (or 39 events without infrastructure-only impacts). This greatly expands on the past estimate of lava flow impact frequency of two events per decade. Impacts from lava flows are documented in less than 10% of recorded lava flows globally, with this remaining constant since ∼1800 CE; prior to 1800 CE, impacts were recorded much more variably representing between 0 and 35% of lava flows in any 10 year time bin. The most destructive recorded events were the 1669 CE lava flows at Etna volcano, Italy, which destroyed up to 12 villages and part of the city of Catania, and the 2002 CE lava flows at Nyiragongo volcano, Democratic Republic of Congo which destroyed at least 4,500 buildings. We found that few studies in the dataset report building typology, damage severity, hazard intensity, or damage at the structure-level scale, limiting our ability to assess past building-lava interactions. Future collection of structure-level hazard and impact data can be used to inform models to forecast future impacts, support lava flow risk assessments and develop potential mitigation measures.

Cataloguing damage and its correlation with hazard intensity is one of the key components needed to robustly assess future risk and plan for mitigation as it provides important empirical data. Damage assessments following volcanic eruptions have been conducted for buildings and other structures following hazards such as tephra fall, pyroclastic density currents, and lahars. However, there are relatively limited quantitative descriptions of the damage caused by lava flows, despite the number of communities that have been devastated by lava flows in recent decades (e.g., Cumbre Vieja, La Palma, 2021; Nyiragongo, Democratic Republic of Congo, 2002 and 2021; Fogo, Cape Verde, 2014–2015). The 2018 lower East Rift Zone (LERZ) lava flows of Kīlauea volcano, Hawaiʻi, inundated 32.4 km2 of land in the Puna District, including residential properties, infrastructure, and farmland. During and after the eruption, US Geological Survey scientists and collaborators took over 8000 aerial and ground photographs and videos of the eruption processes, deposits, and impacts. This reconnaissance created one of the largest available impact datasets documenting an effusive eruption and provided a unique opportunity to conduct a comprehensive damage assessment. Drawing on this georeferenced dataset, satellite imagery, and 2019 ground-based damage surveys, we assessed the pre-event typology and post-event condition of structures within and adjacent to the area inundated by lava flows during the 2018 LERZ eruption. We created a database of damage: each structure was assigned a newly developed damage state and data quality category value. We assessed 3165 structures within the Puna District and classified 1839 structures (58%) as destroyed, 90 structures (3%) as damaged, and 1236 (39%) as unaffected. We observed a range of damage states, affected by the structural typology and hazard characteristics. Our study reveals that structures may be damaged or destroyed beyond the lava flow margin, due to thermal effects from the lava flow, fire spread, or from exposure to a range of hazards associated with fissure eruptions, such as steam, volcanic gases, or tephra fall. This study provides a major contribution to the currently limited evidence base required to forecast future lava flow impacts and assess risk.

Over the past 20 years, our understanding of volcanic eruption impacts on the built environment has transformed from being primarily observational with small datasets to one grounded in field investigations, laboratory experiments, and quantitative modeling, with an emphasis on stakeholder collaboration and co-creation. Here, we summarize key advances and knowledge gaps of impacts across volcanic hazards and built environment types from the past 20 + years. Studies have concentrated on impacts from tephra fall (ash) and to buildings, with less examination of other hazards' impacts to critical infrastructure. As we look to the next decade, we speculate on likely research directions, including the increasing role of new technologies, higher resolution modeling, transdisciplinary collaborations, and evidence-based mitigative solutions.