Author(s): Ian Chandler; Jonathan Pearson; Ian Guymer; Rogerv An-Egmond
Keywords: No Keywords
Abstract: This paper presents experimental results quantifying the vertical variation in diffusion coefficients with depth below the sediment-water interface for one flow and sediment combination. A modified EROSIMESS-System has been used in conjunction with fibre-optic fluorometers to determine the variation. The diffusion coefficient reduces exponentially with depth below the sediment-water interface in two repeat tests with 1. 85mm diameter sediment under a bed shear velocity of 0. 02m/s. There is a discrepancy between the upper most coefficients calculated from the in-bed data and those calculated from the bulk exchange measurement in the water column.