The environmental impact in the Zaamar gold mining zone of Mongolia

Abstract

The mining sector is a major contributor to the Mongolian economy. Many ongoing operations are managed in a sub-optimal way leading to significant environmental damage and production losses. Changes in hydrological regimes remain a significant problem, particularly for placer gold. On balance, current mining practices are inefficient and use excessive process water, thus overtaxing surface waters and underground supplies, and also generate excessive effluent, which is difficult to manage and poses a threat of uncontrolled discharges of slurry. In addition, where rivers are illegally dredged and where tailings are discharged into surface waters, turbidity of surface waters is a major concern. The water pumped from mines of all types and discharged into open surface water bodies may also cause flooding, leading to the formation of new, transient wetlands, which generally fall dry once the mine ceases to operate. This paper describes a general overview and some methodologies to use remote sensing techniques for change detection in Zaamar gold mining district of Mongolia. Keywords: change detection, environment, multi-temporal satellite data, mining activity