Research Implications and Knowledge Gaps

The Role of Sediment

Preliminary results indicate that sediments may act as a conveyor of nutrients through the South Tobacco Creek (STC) watershed and may therefore have a significant impact on the fate of nutrient s in the Red - Assiniboine - Lake Winnipeg basin. There is a need to determine the major sources of sediment in STC and to understand the processes involved in their release and movement.

The components of a sediment load include the wash load and suspended bed material. The wash load is finer material and generally originates from the slopes feeding into the stream. The suspended bed material is coarser and typically originates from stream channel erosion. Thus particle size analysis, particularly on major runoff events, may help sort out the relative contributions of soil from cultivated fields, and channel erosion.

Atmospheric Inputs

An analysis of winter and summer precipitation would help determine the importance of atmospheric inputs of nutrient and ions.

Field Monitoring and Sampling Alterations

A more intense sampling procedure during rainfall events at the Twin Watersheds may provide better detail on discharge of high intensity storms, which contribute significantly to all water quality parameters.

The Role of Climate

Climate is believed to be a key factor in controlling the release of nutrients and sediments in the South Tobacco Creek. There is a need to collect detailed data on the frequency, duration, and the intensity of rainfall events, and link this information to the results of nutrient and sediment investigations.

Nutrient Sources and Fate

Ongoing work will help identify the major sources of nutrients and sediments in the South Tobacco Creek. Future intensive spring snowmelt and rainfall runoff data collection will be required to formulate and develop accurate cycling models for nitrogen, phosphorus, carbon and sediment predictions.