Spectral modeling based on ground measurements for mine tailing mapping with Landsat ETM+ imagery

In the north of Tunisia, mine tailings cause multiple environmental consequences in the Mejerda watershed. In this paper, we are interested in mine tailing mapping around the Jebel (Hill) Hallouf Bouaouane mine. Several ways to estimate the spectral reflectance for end-members in a mixture problem have been proposed in the literature such as pure pixels, spectral library, and field measurements. One of the most common approaches consists in the use of spectral library. This approach presents the advantage of using pure end-members and replacing field measurements. However, it is generally not possible in the case of low spectral resolution image data, due to the large spectral range covered by mineral reflectances. In this paper, a methodology aiming to overcome this limitation is proposed. The proposed approach makes use of the spectral linear mixing model. In the proposed methodology, the spectral component of tailing end-member is estimated using a fusion of available mineral spectra. This spectral modeling approach is based on laboratory analysis as well as on the use of spectral library data. The performance of this method is tested through the comparison of resulting tailing maps using both modeled and Landsat ETM+-derived end-members. The best results were obtained with the JPL spectral library data.