A method for error analysis of sediment yields derived from estimates of lacustrine sediment accumulation

Abstract

The logistical demands of coring lake sediments tend to preclude the replicate coring necessary to establish error estimates for measured sedimentary parameters. However, if such parameters are to be used to reconstruct sediment yield, and particularly to identify temporal variability of sediment yield, reasonable error estimates are required. In this paper data from a series of alpine lakes in British Columbia are applied to develop a new method for deriving such estimates. Regression surfaces fitted to point values of sediment mass are used to model the physically controlled spatial variability of sedimentation. Deviations from these surfaces are assumed to represent remaining unstructured variance, which constitutes a conservative error estimate. Application of the technique to the alpine lake dataset gives sediment yield estimates with error ranges of ±7–21 per cent. The potential error is minimized where the spatial variability of sedimentation is strongly predictable. The best fits were achieved for elongate lakes of simple basin morphology. The range of the error estimates is sufficiently low to allow detection of variability in Holocene sediment yield to one of the lakes. By using this technique, absolute sediment yields with associated error estimates may be derived. The associated gains in precision justify multicore approaches to lake sediment-based reconstructions of sediment yield. Copyright © 2000 John Wiley & Sons, Ltd.