Predicting the outcome of flow and sediment transport events quantitatively has been difficult due to the complex nature of stream systems and the effects of woody vegetation on flow and sediment transport. Interactions between channel and floodplain flow, sediment transport, and woody vegetation have important implications for the health of riparian vegetation and as well as for contaminant transport and deposition. The goal of my research is to develop methods for the application and testing of predictive, process-based models (no empirically adjusted coefficients) that compute the flow and sediment transport from fluid mechanical theory for (1) known channel and floodplain topography and (2) measured tree and shrub characteristics. [...]