Fig. 5 Brilliant Blue concentration maps determined by image analysis for three profile-sections of the dry sand (DS, top), and wet sand (WS, bottom) at 5 cm (left), 7.5 cm (middle), and 10 cm (right) from the wall. Pixel size is 0.5 by 0.5 mm. The arrows indicate misinterpreted areas that probably had the highest concentrations but were classified as medium concentrations