|
Résumé :
|
In this study, transport characteristics of sediment from tile drains in an agricultural watershed of the Thames River, near Kintore, Ontario, Canada were tested in a 5 m diameter, rotating circular flume located at the National Water Research Institute in Burlington, Ontario. Tile drain sediments were collected and mixed with river water at different speeds in the flume to study transport processes such as deposition, erosion and flocculation as a function of bed shear stress. During deposition and erosion experiments, water samples were collected to determine changes in the concentrations of cations, anions and dissolved organic carbon. The results show that tile drain sediments have a tendency to flocculate when subjected to a range of shear stresses. The median diameter (D-50) of the floc size distribution reached a maximum value at a shear stress of 0.169 Nm(-2) which can be considered an optimum shear stress for flocculation for this sediment
|
