Bed-Load Validation for ISSDOTv2

AbstractBed-load transport is an important process impacting riverine morphology, but until recently it has proven difficult to measure in large sand-bed rivers. Integrated Section, Surface Difference Over Time, version 2 (ISSDOTv2) method provides a means of quantifying the bed load in large sand-bed rivers. A series of flume experiments, which included frequent measurements of bed topography and an independent measurement of bed load across a range of flows, was used to provide validation for the ISSDOTv2 method. The mean difference between the ISSDOTv2 calculations and the estimated bed load was 5.6% (high flow), 12.9% (medium flow), and 56% (low flow), indicating improved accuracy for higher flow and transport conditions. It was also found that the ISSDOTv2 method responded appropriately to rapid step-downs in flow, as indicated by agreement between ISSDOTv2 load results and accompanying independent measurements of bed load.