Small rivers in a post-glacial landscape: Complex meandering and river evolution in the Humber River Basin, Ontario

River channels within the Humber Basin exhibit complex meandering patterns. As urban development continues to modify basin hydrology, there is interest in understanding existing fluvial processes and channel geomorphology. In this study, river behavior and evolution are investigated within the context of this changing hydrology. Recent changes in river form are assessed using a bi-temporal comparison of channel planform using orthorectified airphotography and statistical analysis of curvature series. Holocene valley evolution is assessed using digital elevation models, topographic surveys, and radiocarbon dated floodplain stratigraphy.; Complexity of river form is somewhat controlled by heterogeneous sediment distribution and valley geometry; however, lateral channel migration and meander development are also common. Further, the contemporary discharge array (i.e. range and pattern) is capable of controlling the scale of waveform development. The maximum cutbank recession observed over a 39 year period is 35 metres. Contemporary incision rates are spatially heterogeneous due to variations in slope, confinement, and riffle-pool formation.; Radiocarbon dating and digital elevation models suggest that the majority of valley incision occurred during or soon after regional deglaciation. Looping valley features (i.e. meander forms preserved in valley walls) and terrace patterns indicate that most valley morphology can be attributed to larger ancestral rivers. This history can contribute to understanding the complexity of contemporary river form and behaviour.