Effects of bed material properties on cohesive sediment erosion

A straight benthic in situ flume was used to measure the erosion rate of cohesive sediments in freshwater and saltwater environments in New Zealand. The data show an exponential decay of erosion rate with time, which is indicative of depth-limited erosion. Two approaches for the calibration of an erosion formula are used, both leading to similar results. The data show the dependency of erosion rate on bed material properties, such as dry bulk density, water content, organic content and sand content. Both methodologies also highlight differences between data from freshwater and saltwater environments. Also shown is a requirement for direct measurements of bed density profiles and bed load transport during in situ investigations.