Predicting Sediment Physical Properties within a Montane Lake Basin, Southern Coast Mountains, British Columbia, Canada

Abstract

The variability of lacustrine sediment physical properties was examined for a small montane lake in the southern Coast Mountains of British Columbia. A high-density sampling scheme (1 core per 0.01 km2) was utilized for sediment sampling within the 2 km2 lake basin. Vertical patterns in the upper sediment record were controlled by compaction effects with interruptions by major sediment delivery event beds and organic debris deposits. Primary patterns of lateral variability were associated with proximity to the principal lake inflow. A simple sedimentation model based on Stokes Law was shown to reasonably predict down-lake variations of sediment texture. A significant influence of water depth was observed in shallow water settings where highly variable sediment characteristics were observed. Secondary spatial patterns were related to localized rapid deposition effects and past land-use activities. Sedimentary parameters of water content, bulk density, organic content, and particle size were shown to be interrelated to varying degrees. Water content may be used as a key parameter for predicting other physical properties because of its strong negative relation with sediment density, moderate positive relation with organic content, and non-linear association with mean particle size.