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Using sediment travel distance to estimate medium‐term erosion rates: a 16‐year record
Author(s) -
Parsons Anthony John,
Wainwright John,
Fukuwara Tomomi,
Onda Yuichi
Publication year - 2010
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.2011
Subject(s) - erosion , sediment , surface runoff , hydrology (agriculture) , environmental science , arid , flux (metallurgy) , grassland , soil science , geology , geomorphology , geotechnical engineering , materials science , ecology , paleontology , agronomy , metallurgy , biology
Fine grained (80 µm) magnetite was introduced onto a semi‐arid grassland hillslope in 1992, as part of a set of rainfall‐simulation experiments. Using measurements of magnetic susceptibility, the median distance travelled by these magnetite grains during subsequent natural runoff events in the 16‐year period up to 2008 was estimated. Coupling this estimate to direct measurements of sediment flux obtained during the rainfall‐simulation experiments has enabled estimation of the erosion rate over this period. The estimated average erosion rate of between 2·61 × 10 −2 and 4·36 × 10 −2 kg m −1 year −1 , is equivalent to a rate of ground lowering between 0·020 and 0·033 mm year −1 . This estimate is consistent with (in the sense of being less than) an estimate of total sediment detachment over the same period. The rate of erosion measured using this travel‐distance approach is an order of magnitude less that obtained from a study based on 137 Cs in a nearby catchment, and compatible with the longevity of continents. Copyright © 2010 John Wiley & Sons, Ltd.