Source-to-sink process transitions in fluvial systems

Abstract

ABSTRACT Fluvial networks are characterised by spatial and temporal transitions as geomorphic and ecological processes within these systems are mediated longitudinally by sediment and water fluxes which vary spatially in magnitude and variability. The aim of this special issue was to shed light on the nature of source-to-sink fluvial transitions associated with spatial and temporal variability in geomorphic and hydrological processes. We encouraged contributions that considered fluvial transitions at any spatial or temporal scale, and invited research that addressed the implications of such transitions. The number of submissions was limited, which was potentially indicative of the lack of field-based studies being conducted at a catchment- or source-to-sink scale. Two of the published submissions considered longitudinal transitions in sediment sources using a sediment finger-printing approach, while the remaining two articles combined traditional fluvial sedimentology techniques with optically stimulated luminescence chronology to deduce controls on river reach flood dynamics. As we enter a time of unprecedented human impact on the environment, there is a clear need for future research to focus on the catchment as a holistic unit as the interconnectedness of landscape pattern and process has implications for biodiversity, water quality, ecosystem service provision and thus catchment management.