The metals and metal compounds that have been exposed by mining or have been discarded in mine wastes tend to become chemically more available, generating acid mine drainage as well as releasing toxic metals into soils, surface waters and groundwater in the affected catchment area. Here we present a case study of the spatial assessment of contamination in a catchment area impacted by mining. A detailed statistical analysis was performed in order to identify geochemically homogeneous areas, including those contaminated by mining. A distributed model is also presented. This assesses the mean annual export of heavy metals from a catchment area, taking into account the spatial pattern of metal concentration and the topological relationships between sediment sources and sinks. Results show that the spatial pattern of background geology, mineralization and mines is important for understanding and assessing the geochemistry of contamination in the affected catchment. Moreover, certain spatial configurations of land use can minimize the total amount of sediment exported and the volume of polluted waste and sediments that is exported.

Land Contamination & Reclamation, 17 (3-4), 413-421 (2009)

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