Methods for Postdisaster Impact Assessment: A Case Study of the Impacts of the Fundão Dam Failure on Terrestrial Species Threatened with Extinction

Abstract

The Fundão tailings dam held back approximately 50 million cubic meters of tailings from an Fe ore mine in the state of Minas Gerais, Brazil. The dam failed on 5 November 2015, releasing tailings into the Rio Doce watershed and causing an environmental disaster in a biodiversity hotspot. To guide conservation action following the event, Brazilian authorities demanded an impact assessment focused on terrestrial species threatened by extinction. Postdisaster impact assessment is substantially more challenging than predevelopment impact assessment. Predisaster baseline data were sparse, and much was unknown about how the Fundão dam failure impacted terrestrial species threatened with extinction. Baseline reconstruction and impact pathway validation and characterization was critical. Ecosystem reconstruction revealed that 1580 ha of terrestrial ecosystems were destroyed, including approximately 480 ha of Atlantic rainforest. Collaboration with local experts identified 346 species of vertebrates, invertebrates, and vascular plants threatened with extinction that were impacted or potentially impacted. Species composition and impacts varied within 4 distinct segments of the Rio Doce watershed. Nine potential impact pathways were identified using data and literature review combined with information provided by regulators, experts, and media. Not all were valid. Validating and characterizing each pathway within each watershed segment involved data evaluation, an ecological risk screening, and field assessments. Impact pathway evaluation proved critical to dispelling misconception, accurately understanding postdisaster impacts, and directing conservation action; the importance of this step cannot be overemphasized. Integr Environ Assess Manag 2020;16:676–680. © 2020 SETAC

Strong relationships between soil and vegetation in reference ecosystems of a riparian Atlantic rainforest in the upper Doce River watershed, southeastern Brazil

“…Therefore, more studies need to be developed along the Doce River watershed, to better understand its plant diversity and community changes along the river. In the area affected by the collapse of the Fundão dam, 166 threatened species were described (Knopff et al 2020), which is not a surprising number, since this catastrophe affected one of the world's biodiversity hotspots that is extremely endangered. The possibility of high turnover rates of plant species composition along the Doce River from its origin to its end at the Atlantic Ocean represents information of major relevance to the ecological restoration of biodiversity and ecosystem services in the region.…”

Determination of Environmental Factors for the Implementation of the Exploitability Index in Industrial Aggregate Mining Using Multi-Criteria Analysis

“…Protected natural areas depend, to a large extent, on the sensitivity of national, autonomous and local governments, and can be of very varied typology, such as national parks, natural parks, areas of special interest, special conservation areas, etc. [42]. For the determination of the map with the impact of special ecosystems (Figure 3b), a classification of the entire territory into three different groups is proposed: the protection areas themselves, the buffer zone at 500 m and the rest of the territory.…”

A laboratory-based test procedure for the investigation of slaking-induced changes in geotechnical properties of tailing dam embankment materials

“…A review of historical tailings dam failures has revealed two distinct mechanisms in which the strain softening behaviour of the material plays a pivotal role. The first mechanism pertains to the progressive development of failure in a weak soil layer within the dam foundation [ 20 , 21 ]. The second mechanism is associated with the static or dynamic liquefaction of loose tailings material at a critical state [ 22 ].…”