Seasonal Variations in Spectral Reflectance of Microbial Flocculates, Precipitates, and Oil-Like Films Associated with Neutral and Acidic Mine Drainage

A remote sensing technique based on spectral reflectance measurements was recently demonstrated in central Virginia to be effective in distinguishing materials formed in acidic streams from those in circum-neutral streams within iron-bearing provinces. The technique found that yellow and yellow orange precipitates and flocculates in acidic streams had higher near-infrared reflectance values than the red and red orange precipitates and flocculates in circum-neutral streams. In addition, reflectance values were found to vary throughout the year and were highest in the summer months in an acidic creek and its circum-neutral tributary.