The saltation-abrasion model captures bedrock incision due stones striking bedrock. We present the Macro-Roughness-based Saltation-Abrasion-Alluviation (MRSAA) model, which tracks spatiotemporal variation of both bedload and alluvial thickness. It captures migrating waves of incision upstream and alluviation downstream. We apply it to incision problems not captured by saltation-abrasion, including the response to alluviation and stripping, and a simplified graben with uplift and subsidence.