A conceptual framework for predicting the occurrence of sediment focusing and sediment redistribution in small lakes

Abstract

Four processes are important in causing either sediment focusing or overestimation of sediment accumulation rates by traps, or both. A simple model to predict the occurrence of these events was constructed from published data for monomictic and polymictic lakes which contained sufficient detail to identify the major redistribution process. Boundaries between the regions where different mechanisms dominate were calculated from the expected mode of operation of the processes. The model was tested using sediment trap and accumulation rate vs. water depth data from the literature. Other published work is in general agreement with the predictions of the model.

The spatial distribution and sedimentary processes of organic matter in surface sediments of Nam Co, Central Tibetan Plateau

“…Lake sediments have experienced transportation, deposition or re-deposition since originating from their source areas, and then been permanently deposited in the lake bottom, where the proxies might imply different environmental conditions. In some small lakes, the proxies may have very simple explanations, because they consist of simple sedimentary processes [4], but these environmental conditions might only have local representations. Proxies from large lakes are indicators of the regional environment, but development of proper understanding and explanation of these factors is always difficult because large lakes have complicated sedimentary processes [5].…”

Three‐dimensional hydrodynamic and sediment transport modeling to test the sediment focusing hypothesis in upland lakes

“…In Esthwaite Water, Hilton et al (1986a) found that 6% of the total variance of the accumulation rate estimated by sediment traps was due to wave action, manifest as a negative correlation between sedimentation rate and fetch. Similar studies of lakes in the Muskoba-Haliburton region of Canada (Hilton 1985) also implicate peripheral wave action, in conjunction with intermittent complete mixing, as the main mechanisms of sediment focusing.…”

“…The work of Hilton (1985) and Hilton et al (1986a) has been especially valuable in providing a conceptual framework for understanding sedimentation in small lakes. Hilton et al (1986a) identified 10 distinct mechanisms for sediment dispersal.…”

Microphytobenthos in Shallow Arctic Lakes: Fine-Scale Depth Distribution of Chlorophylla, Radiocarbon Assimilation, Irradiance, and Dissolved O2

“…However, resuspended materials from extensive, shallower zones can be deposited at the sampling sites, and shear stresses from circulatory currents (Hamilton and Mitchell, 1997) can effect sediment flux. Turnover events (Hilton, 1985) and ice scour (Que-292 / ARCTIC, ANTARCTIC, AND ALPINE RESEARCH sada et al, 2008) present additional possible avenues of vertical and horizontal sediment redistribution and homogenization in these lakes. The photosynthetically capable biomass was dominated by inactive cells, as only 26-44% of the chl a in vertical profiles was sited in the euphotic zone, and therefore was photosynthetically active.…”

“…Resuspension has been inferred from sediment trap studies in shallow lakes in the Arctic Foothills region, including E-4 (Fortino et al, 2009). Sediment resuspension and redistribution processes are rarely studied directly with respect to the microphytobenthos (Cyr, 1998), but are a function of fetch, wind speed and duration, and sediment properties such as grain size, and water and organic content (Hilton, 1985;Bloesch, 1995). Following Bachmann et al (2000), we calculate that wind-driven waves are not likely to directly influence the sediment surface at the site of sampling in any of these relatively small lakes (maximum fetch Ͻ1400 m) at maximum sustained wind speeds (Յ6 m s ‫1מ‬ ; http://toolik.alaska.edu/edc/abiotic_monitoring/data_query .php).…”