Resuspension of particulate organic matter in sand-bed lowland streams

A method has been developed to calculate the resuspension of small organic particulate matter in various small lowland streams by means of deposition experiments using a mixture of ultra fine and very fine particular organic matter. Hydrodynamic characteristics were modelled from chloride tracer experiments to examine the influence of hydrodynamic stream characteristics on particle resuspension. The rates of resuspension, relative to the seston concentration in the water column, ranged from 0 to 0.05 m -1 and were significantly correlated to the water exchange rate between main channel and transient storage zone. Resuspension rates were higher than deposition rates in most stream reaches, governing the load of suspended small organic particles. The results suggest that the resuspension and deposition of particles alternate within relative short time scales.