f Detection of ph values in sediments in abandoned open cast lignite mine sites using hyperspectral remote sensing data

Mining activities pose some ofthe greatest environmental challenges worldwide. Increasingly, the environmental impacts of mining activities become an economical and social concern. The existing mine sites vary in age, geomorphological forms and processes, geochemistry, and hydrochemical properties. The technology of overburden conveyor bridges has led to extreme, profound changes in the environment. The new landscape systems are very complex, complicated and above all highly dynamic. The distribution of the cover sediments are very heterogeneous ,and varying in all geochemical properties and the hydrological regime. The cover materials showing not in any case the typical distribution of the upper layer in the dumped sediments, as we know it from natural soils or geological sites. As a result of this wide spread varying properties we can observe a very distributedvdevelopment of pioneer vegetation. The species plant type and the spatial distribution of these vegetation shows indirectly the geochemistry, and hydrological regime in this systems. They can be used as indicator for different geochemical properties, such as ph value. In relation to the sparse vegetation cover and also the pixel size of the used airborne imagine spectrometer data of the casi and HyMap sensor we developed a complex method for the pH value mapping. Based on spectral field measurements, field mapping and geochemical analyses, the algorithm include the semi-automatic endmember extraction, and the combination of linear as well as signal unmixing procedures. The methods would used successfully in different test sites in Germany and Czechia with large variety in the pH values (3.0 - 7.0). The signal unmixing of sediments and vegetation improves quality of the results of the sediment classification as well as the vegetation classification. The results can be used also for the reclamation activities in the area.