“…However, the identification and interpretation of geomorphic units is often open to debate and unanticipated units are sometimes evident, requiring additional information to make reliable explanations (Roering et al, 2013; Wheaton, Brasington, Darby, & Sear, 2010; Wheaton et al, 2013, 2015). Regardless, there is significant potential to roll out such analyses across regions and for the full spectrum of river diversity to qualitatively and quantitatively analyse the types and assemblages of geomorphic units that are expected for different river types, and define characteristic or reference states (Fryirs, Brierley, et al, 2019; Fryirs, Wheaton, et al, 2019; Gurnell et al, 2020). The identification of diagnostic, common and ubiquitous geomorphic units and their richness for different river types is possible (Figure 9).…”