By Lily Paniagua Alfaro
Abstract
The Sotiel Migollas mine complex is part of the Iberian Pyrite Belt region in Southern Spain. This area has been used for mining since Roman times. More recently, the Sotiel mine was exploited for silver and copper extraction in 1984. It was abandoned in 2002 and some rehabilitation activities have taken place since 2006. Several flight campaigns organized by DLR have flown the mine site and HyMap images were taken during the period it was active, abandoned and rehabilitated. This thesis project aims to evaluate the opportunities to monitor rehabilitation development between 2004 and 2008 in the Sotiel Migollas mine according to methods derived from imaging spectroscopy such as mineral characterization and boundaries delimitation by describing the main changes through this period of time and analyzing advantages and limitations from each method. Two main areas within the study region were analyzed and described: the mining area where rehabilitation measures had started and tailing area that is in an abandon state. For the mining area, completed rehabilitation measurements have been monitored and reflected almost no coverage of tailings related minerals. Areas where there is still presence of tailing related minerals in 2008, are in a further stage of oxidation than in 2004. Abandoned tailing areas do not preset drastic changes but transition of oxidation states are located where water runs off into the Rio Odiel. A new method is proposed by defining tailing boundaries based on image scene statistics of each year and not on static percentages. Imaging spectroscopy is a useful tool for characterizing mining environments. The results from this study offer validation of rehabilitation efforts, and guidance of areas that still need attention. Results could be useful in describing what may be occurring in other mines from the region, that have similar characteristics as those studied in these project. Information retrieved presents a valuable contribution to mine managers who usually do not have access to an spatial assessment of the mine environment.