Mine rehabilitation: a review of recommended methods for 'garimpo'

Abstract

Mining projects, such as the extraction of agate in Rio Grande do Sul (RS), generate environmental impacts and, for legal obligation, degraded areas must be rehabilitated. The Degraded Areas Rehabilitation Plan (PRAD) is the instrument that aims to qualify the projects, however it is not always sufficiently detailed as to the methodologies to be used. This paper reviews and discusses the most appropriate bioengineering techniques currently employed in the Degraded Area Rehabilitation (RAD) processes globally, with emphasis on the application in stone mining by ‘garimpo’ digging. Effective methods for slope re-shaping and stability, drainage system, soil management and stone tailings’ reuse opportunities are indicated. Plant selection strategies and planting techniques are compared. In all cases, environmental and economically feasible alternatives are prioritized. The best results come from “ecological restoration”, an effective and ever-expanding revegetation practice. The Ecosystem/ Landscape Function Analyses (EFA) is the recommended methodology for a broader process monitoring. The inclusion of PRAD in the initial planning of the mine will revert into its rehabilitating success. This study may contribute towards the minimization of liabilities, for example, by guiding the establishment of terms of reference for PRAD during the licensing of ‘garimpo’ mining.