EXPLORING THE MULTIFACETED IMPACTS OF INCREASED SEDIMENT SUPPLY ON FLUVIAL SYSTEM FORM AND FUNCTION (Invited Presentation)

Though it is well-established that sediment supply exerts a primary control on the general nature and behavior of the river corridor, the manner, degree, and extent to which alterations to the sediment regime may manifest in the river landscape remains a comparatively open question. With increasingly favorable attitudes towards management of rivers as dynamic systems and projected future alterations to climate and land-use that imply heightened sediment supply to many global watercourses, it is essential that our understanding of the spatial and temporal expression of alterations to sediment supply be robust. Here, we describe recent work focused on unpacking and discretizing the complex signature of river evolution following sediment supply alteration. We present and discuss a general framework for anticipating river channel response to increased sediment supply, emphasizing the multi-scalar and progressive nature of potential fluvial adjustments and the drivers therein, and apply this framework to several case study scenarios. We also consider how alterations to sediment supply may drive change in the ecological dynamics of floodplain forests, underlining that variations in sediment supply manifest beyond the physical character of the river channel and may extend across considerable space and time. Taken as a whole, we highlight the complex and tiered nature of river channel change as driven by sediment supply and discuss the need for future river management to be holistic and adaptable.