Linking Flow Hydraulics with the Transport of Suspended Soils

 

Principal Investigator: Dr. Daniel Wren

Problem:

Eroded sediments and associated chemicals derived from agricultural areas due to farming practices are continually being introduced to streams and rivers. The transport of these solids and their sites of deposition can have detrimental effects on water quality, ecology and river flow processes such as conveyance and the severity of floods. The transport of suspended solids is strongly affected by the presence of river bed topography such as bedforms and bars.

Objective:

The aim of this research is to link the amount of suspended solids being transported by the stream to the physical characteristics of the flow, and how this information can provide more accurate predictions of total suspended load.

Description of Work:

Using a laboratory channel with rigid dune bedforms fixed in place to the bottom of the flume, investigations are underway to characterize how suspended sediment concentration varies with respect to position along the bedform and with respect to time. Measurements of the turbulent fluctuations in velocity are also being obtained in order to correlate the characteristics of the stream flow with the observed variations in suspended sediment concentration.

Benefit:

The goals of this research are to provide better interpretations of suspended load measurements and to improve predictive technologies for total sediment load in streams and rivers. This information is important to both the USDA and other federal agencies who assess sedimentation problems such as increased flood potential and loss of ecological habitat.