Remote Sensing Technologies Applied to Rehabilitation and Monitoring of Large Contaminated Mining Sites

Rehabilitation of lands contaminated from mining activities is a complex process and requires an high level of domain knowledge. The areas in which minerals occur often have other resources that also present an exploitation potential. In this perspective is fundamental to set up proper strategies to define choice, or order of land use keeping, taking into account the development, as well as the needs to protect the environment. Mining activity, in fact, often leads to environmental problems like land degradation, particularly in opencast mining, land subsidence in underground mining, deforestation, atmospheric pollution, pollution of rivers and streams, disposal of solid wastes, etc.. Prevention and mitigation of adverse environmental effects due to mining activities, as exploited area morphological surface re-modeling and revegetation, constitute an integral part of mine development strategy. A correct preliminary assessment of the environmental impact of a mining site over the interested areas thus represent the first step to set up proper impact models in order to design, develop and apply correct rehabilitation action. In this context, the possibility offered by multispectral satellite images represent one of the key issues to utilize as data source (contextual-territory-based-relatedinformation) to develop dynamic land models addressed to fully understand and quantify the environmental impact of mining activities, not only at the end of the exploitation phase, but also during the activity. On these bases an evaluation of the proposed approach, in terms of recognition-classification logics investigated and results obtained, was carried with reference to three different coal basins in three different areas: India, Thailand and China.