Testing of a passive sediment trap for river environments
This study examines the hydraulic characteristics of a horizontal flux sediment trap that can be used to sample suspended sediment in a river environment. Through a review of the literature, dimensional analysis was shown to be a proven method for studying passive sediment traps. Using this method, values related to sediment trap dimensions were identified and used as a basis for experimental design. The amount of sediment trapped using various trap configurations was then studied in a controlled laboratory environment. Suspended sediment was simulated using uniform glass beads to maintain uniform settling characteristics. Sediment concentrations and size distributions were found using a Spectrex Laser particle counter. Data collected from the North Saskatchewan River assisted in the analysis of trap performance. Sediment capture was found to scale with the cross sectional area of the sediment trap and the integration time. Results from the controlled laboratory studies showed that reduced concentrations within the trap are a function of the port diameter. This, however, could not be substantiated through field testing. Increased trapping rates were found with increased aspect ratio and suspension angle. The use of baffling (restriction placed above inlet ports) was not found to increase trapping.