The shape of a river influences flow and therefore how much sediment is transported. Directly measuring sediment transport is challenging at the catchment-scale but numerical modelling can enable the prediction of sediment erosion and transport. We use flow model to map patterns of bedload transport rates to reveal patterns associated with different river patterns (i.e. meandering, wandering, braided and deltaic). We show spatial variability in bedload transport is a function of channel pattern.

Decades of delta avulsion (i.e. channel abrupt jump) studies have not resolved what the main controls of delta avulsion are. Using a computer model, integrated with field observation, analytical, and laboratory-made deltas, we found that the sediment load, which itself is controlled by the steepness of the river upstream of a delta, controls the timing of avulsion. We can now better understand the main cause of abrupt channel changes in deltas, a finding that aids flood risk management in river deltas.

Estimating the sizes of flood events is critical for flood-risk management and other activities. We used data from several sources in a statistical analysis of flood size for rivers in the Philippines. Flood size is mainly controlled by the size of the river catchment, along with the volume of rainfall. Other factors, such as land-use, appear to play only minor roles in flood size. The results can be used to estimate flood size for any river in the country alongside other local information.