Global River Science: a call for “large-sample” fluvial geomorphology

Fluvial geomorphology has often relied on case studies to deepen our knowledge of landscape processes. Through detailed terrain mapping, historic photo analysis, field measurements, sedimentology and geochronology, we have investigated how rivers respond to the processes that act on them, and how rivers in turn act on the landscape. This site-specific approach is crucial to the foundation and future of our discipline, but recent work across geomorphology and hydrology has highlighted the insights that can be gained from comparing a wide range of sites spanning one or more environmental gradients. In this talk, we advocate for this large-sample approach to fluvial geomorphology, which we term "Global River Science". We present a review of Global River Science research spanning a range of time scales in geomorphology, from landscape evolution through to event scale morphologic change. Finally, we identify challenges to Global River Science and priorities for its future direction.