Assessment of damage areas near open pit mines by means of time series data analysis

The anthropogenic impact of the mining industry on the environment is seen all over the world. In the last decades several mining areas and corresponding waste disposal sites in Bulgaria are being monitored for ongoing reclamation processes. In this research we were focused on the one of the most important copper producing fields for our country - Medet deposit. The objectives of the study were to analyze multispectral satellite images for years 1972 - 2011 in order to assess the environmental pollution from the mining activity in the Medet open pit mine in temporal perspective. After ceasing its exploitation a rehabilitation program for the soil cover and hydrographic network was established and launched. A continuous task is the monitoring of these activities from the beginning for at least 20 years period. We think that the informative potential of satellite multispectral and multitemporal imagery will provide valuable information on the impact of this long-term mining activity on the environment. One of the first tasks was to prepare thematic maps for several years of the affected areas at regional scale. On the next step change detection methods were used to assess the short-term reclamation activities by examination of vegetation cover status in the areas surrounding the mine. To complete this tasks data from Landsat TM/ETM+ instruments combined with in-situ measured data was used. In-situ multispectral data from the region under study was collected by the authors using the Thematically Oriented Multichannel Spectrometer (TOMS). For data processing several techniques such as basic and advanced statistics, image enhancement and data fusion were used. The results obtained show that used data and the implemented approach are useful in environmental monitoring and economically attractive for the company responsible for the ecological state of the region.