Transport characteristics of tile drain sediment in clay loam soils.

Increasing use of subsurface tile drains in agricultural watersheds has created concern for sediment delivery to receiving waters and potential undesirable effects on surface and subsurface water quality. In this study, transport characteristics of sediment from tile drains in predominantly clayloam soils of a southern Ontario watershed were tested in a rotating circular flume located at the National Water Research Institute, 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. Empirical relationships are developed to describe erosion and deposition processes of tile drain sediment. The relationships are in a form suitable for use in the fine sediment transport model developed by Krishnappan (1997) and can be used to predict transport characteristics of tile drain sediment in receiving streams.