Fig. 4: Two examples showing the principle of the hybrid transect classifier.

Upper panels a and b: Madagascar; bottom panels c and d: Suriname. Left-hand panels a and c: 2020 S2 composite TOA images with five transects (1500 m in length) each classified by the multispectral image classifier. Colours indicate the multispectral pixel classification. Right-hand panels b and d: transect profiles of the orange marked transect from the left-hand panel. The horizontal axis is the distance [m] along the transect, where 0 m is the landward end and 1500 m the seaward end. The left y-axis represents the elevation [m] above mean sea level to which the elevation profile and the tidal range are related, the right y-axis represents the water probability [%]. The multispectral image classification is shown at 0 m elevation in the graphs with coloured dots referring to the coastal class of each pixel along the transect. The tidal range is plotted as a horizontal shaded bar, the transition zone is plotted as a vertical shaded bar.