Spatial distribution of the benthic diatom community along the Sangker River catchment (Tonle Sap Basin). Hierarchical clustering (cluster dendrogram) according to the similarity of diatom genera composition (top left). Polygonal dots represent the diatom monitoring sites associated with the identified cluster (Ia & Ib, II). Different colors indicated benthic diatom community assemblages: red (Ia), yellow (Ib), and blue (II), while the black dot represented the dams.