Sediment delivery and bedform variability of the lower Fraser River and Delta

Large lowland river and delta management requires an understanding of the sediment dynamics governing the system. The lower Fraser River sediment budget, an integral tool to sustainably manage the Fraser Delta, has not been updated in decades. I explore bedform distributions in the lower Fraser River which reveals dunes characterized by low sand supply to the bed in the main channel which supplies the delta. Repeat measurements of topography indicate that bed elevation has declined over the past 70 years, explaining why low sand supply dunes developed. To better understand the ongoing changes to the lower Fraser River and Delta, I examined changes in sediment delivery to the delta channels from changes in upstream sediment supply and bed topography, updating the contemporary sediment budget. The results indicate sediment delivery to the Fraser Delta has declined through time leading to a deficiency in bed material sediment needed to replenish the delta channels.