The environmental impact in the Zaamar gold mining zone of Mongolia

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