Assessment of rehabilitation projects results of a gold mine area using landscape function analysis.

Abstract

Mining activity is indispensable for the current stage of progress of our civilization. Although it is a temporary activity, its impacts are remarkable, especially with respect to landscape modifications. To mitigate such impacts, the implementation of monitored environmental recovery projects is of fundamental importance. Landscape Function Analysis (LFA) is a multicriteria analysis using remote sensing data and field information, suitable for monitoring the performance of recovery projects in areas degraded by the mining activity. In this work, LFA was used to evaluate the results of 20 years of environmental recovery projects in a gold mine. Ten base maps were developed: Declivity, Vegetation/Physiognomy Stratification, Fractures and faults, Compaction degree/soil structure, Erosion features, Geotechnical stability, Local hydrogeology, Degree of fragment isolation, Soils and Drainage. These were combined in order to give rise to three intermediate maps: Erosion and soil stability, Vegetation and Water. With the union of these three maps, it was possible to create the map with the final analysis of the environmental recovery performance. The technique used allowed the separation of native areas (which obtained the highest scores), recovered and self-sustaining areas (old mine dumps and waste piles) and areas still deficient in environmental recovery, with stability and erosion problems (mining sites and active mine dumps). In addition to allowing the analysis of large areas, the presentation of LFA results on maps facilitates decision-making and the dissemination and understanding of results by the different stakeholders involved.