BRIDGING MORPHOLOGICAL SCALES IN SEDIMENT TRANSPORT: PATH LENGTH ESTIMATION FROM FLUME EXPERIMENTS TO NETWORK-SCALE SEDIMENT TRANSPORT MODEL VALIDATION

The movement of sediment through river networks is crucial for the health and functionality of river ecosystems, flood control, and water availability. However, the difficulty in measuring sediment transport limits our ability to accurately model network scale sediment transfer and predict changes in river morphology essential for water managers to manage flood protection, water storage, and habitat preservation. This project exploits advances in remote sensing to model sediment transport and connectivity at the network scale through flume, field, and network scale simulations and to explore the feasibility of using morphological indicators to infer path length information which allows for the estimation of sediment transport. We develop a method to extract the characteristic path length from repeat topographic surveys to estimate sediment transport in flume experiments (Chapter 2). In Chapter 3 we apply the method to the Tagliamento River, a large braided river in northeastern Italy, and compare these estimates to flow metrics and published values in literature. Finally, in Chapter 4 we then use these investigations to initialize and validate the D-CASCADE (Dynamic CAtchment Sediment Connectivity And Delivery) model to generate estimates of network scale sediment connectivity using remotely sensed and field data from the Tagliamento River in northeastern Italy. This project aims to bridge the gap between qualitative understandings of channel morphology and quantitative estimates of sediment transport and network scale sediment connectivity.