Anthropogenic gravitational mass movements and the fluvial geomorphological changes: The Vale (2019) and Samarco (2015) tailing dam disasters, Brazil

Abstract

Major tailings dam failures have caused death, pain, and disruption to a community’s activities. These dam ruptures mobilize millions of tonnes of tailings, which move with gravity and can therefore be called anthropogenic mass movements. A survey of the typology of the damage caused is a necessity to assess the damage caused, especially to riverside populations. This work describes the mass movements in the 2015 Samarco/Mariana and 2019 Vale/Brumadinho tailing dam disasters. Mass movements have been described as avalanches, high and low-energy debris flows, and mud flows. The regions where the tailings dispersion was active were also verified, where it caused substantial changes in the landscape. On the other hand, it has been verified in areas where this dispersion was passive, carried out only within the fluvial dynamics. The Vale/Brumadinho disaster, which resulted in 270 deaths, was of tremendous energy and destructive power, while the Samarco/Mariana disaster, which resulted in 19 deaths, was catastrophic over thousands of kilometers. A careful evaluation of these modifications is a first step toward mitigating the affected territories and bringing social justice to the affected populations.