Documenting catchment suspended sediment sources: problems, approaches and prospects
Date
2004
Authors
Walling, Des,E.
Journal Title
Journal ISSN
Volume Title
Publisher
Progress in Physical Geography
Abstract
Establishing catchment suspended sediment sources is fraught with difficulty. Data
collection comprises indirect and direct approaches and an overview is provided. The indirect
approach uses a range of techniques to measure or evaluate sediment mobilization. Yet,
although recent technological advances in surveying, remote sensing and photogrammetry
provide improved resolution of temporal and spatial patterns of catchment erosion, these
procedures take no account of source–river connectivity and the uncertainties associated with
sediment routing. It is therefore only possible to infer the provenance of suspended sediment
loads on the exclusive basis of on-site erosion data for different portions of the upstream
catchment unless supportive information on sediment delivery is readily available. In contrast,
the direct approach attempts to link sediment sources and flux using alternative means and
therefore avoids the need for complementary information. Sediment fingerprinting best
represents the direct approach to sediment sourcing and there remains substantial scope for
exploiting the potential of this technique. The spatial complexity of sediment mobilization and
transfer at the catchment scale necessitates a distributed approach to modelling. Recent
developments in computer power and programming techniques are proving useful in this
respect, but assembling the input and validation data required by distributed models
continues to pose problems and it is frequently difficult to apportion the relative contributions
from individual sediment sources. General prospects for future developments are discussed.
Key words: catchment suspended sediment sources, direct approach, indirect approach,
modelling, sediment fingerprinting.
Description
Journal Article
Keywords
Catchment suspended sediment sources , Sediment fingerprinting.