The effect of pulp mill effluent on fine-grained sediment morphology and storage in the Fraser River at Prince George, B. C.

Abstract

The data show that the natural size of floes in the Fraser River, as represented by differences in the effective and absolute particle size distribution, is small when compared to results from measurements in other rivers. Floc sizes are larger under low-flow conditions, especially under winter ice. The annual range of floc sizes of the natural t ~ 10 pm) was much larger than the increase measured due to the presence of pulp mill t ~ 1 pm). No statistically significant increase in the rate of fine sediment accumulation in the sediment traps was noted due to the influence of the pulp mill effluent,indicating that, at least in the near-field plume (300m), it has no effect on deposition.

Seasonal variability of fine-grained sediment morphology in a salmon-bearing stream.

“…Potential limits to this method are the difficulty in aligning the camera parallel to the flow, especially in turbulent systems, and the fact that there is a minimum resolution of 32-43 pm/pixel due to the Aim, digitization, and lens aperture . Thus, this technique is not useful in systems where the measured floe size is less then the techniques' resolution (Biickert, 1999). …”

“…The Fraunhofer diffracAon theory is used to convert the resulAng diffracAon pattern to particle sizes (Kiishnappen et al, 1994;Biickert, 1999). The backscatter instrument (e.g., Par-Tec 200/300) used by requires an oscillating lens that sweeps the focus point of a laser across a deGned water column.…”

“…The implications of this are that the larger the particle, the more energy it requires to become entrained or to remain entrained. Thus, if the mode is large, it is likely characteristic of a high-energy environment with higher bottom shear stress (Biickert, 1999).…”

“…Another method was as per Biickert (1999), who circumvented this problem by using a non-parametiic measure of goodness of fit, the Kolmogorov-Smimov test. Kurashige and Pusejima (1997) Biickert (1999) used the two-sample version of this test to identify differences between a base case (i.e., control) and experimental cases.…”

“…Kurashige and Pusejima (1997) Biickert (1999) used the two-sample version of this test to identify differences between a base case (i.e., control) and experimental cases. In this study, SYSTAT® 9.0 (Systat Software Inc., Richmond, CA) was used to execute the Kolmogorov-Smimov twosample test on data from spectra selected based on the objectives stated above.…”