Assessment of a time‐integrated fluvial suspended sediment sampler in a high arctic setting

Abstract.

Two versions of a fluvial sediment trap designed to collect integrated samples of ambient suspended sediment load were deployed in a small river at Cape Bounty, Melville Island, Nunavut in the Canadian High Arctic. Daily and bi‐daily sediment capture in the traps was broadly proportionate with suspended loads estimated directly from daily sediment flux measurements but showed highly variable trap capture rates. Grain size analysis showed that the median grain size (D₅₀) of the captured material was significantly coarser than the ambient material, although the D₅₀ of the two trap versions deployed was not significantly different. These results suggest that the traps did not consistently collect a representative mass or particle size sample in a river environment with highly variable conditions. This is explained by consideration of the hydraulic design of the traps and a highly dynamic stream environment. Hence, deployment of fluvial traps in small ephemeral Arctic rivers will require further testing and refinement of the hydraulic design.

Key words:

• sediment transport
• particle size
• trap
• sediment flux