Journal of Soils and Sediments

, Volume 13, Issue 10, pp 1735–1753

Sediment source analysis in the Linganore Creek watershed, Maryland, USA, using the sediment fingerprinting approach: 2008 to 2010

WATERSHED SEDIMENT SOURCE IDENTIFICATION: TOOLS, APPROACHES, AND CASE STUDIES

DOI: 10.1007/s11368-013-0771-6

Cite this article as:
Gellis, A.C. & Noe, G.B. J Soils Sediments (2013) 13: 1735. doi:10.1007/s11368-013-0771-6

Abstract

Purpose

Fine-grained sediment is an important pollutant in streams and estuaries, including the Chesapeake Bay in the USA. The objective of this study was to determine the sources of fine-grained sediment using the sediment fingerprinting approach in the Linganore Creek watershed, a tributary to the Chesapeake Bay.

Materials and methods

The sediment fingerprinting approach was used in the agricultural and forested, 147-km2 Linganore Creek watershed, Maryland from 1 August 2008 to 31 December 2010 to determine the relative percentage contribution from different potential sources of fine-grained sediment. Fine-grained suspended sediment samples (<63 μm) were collected during storm events in Linganore Creek using an automatic sampler and manual isokinetic samplers. Source samples were collected from 40 stream bank sites, 24 agricultural (cropland and pasture) sites, and 19 forested sites. Suspended sediment and source samples were analyzed for elements and stable isotopes.

Results and discussion

Results of sediment fingerprinting for 194 samples collected in 36 separate storm events indicate that stream banks contributed 53% of the annual fine-grained suspended sediment load, agriculture contributed 44%, and forests contributed 3%. Peak flows and sediment loads of the storms correlate to stream bank erosion. The highest peak flows occurred in the winter and, along with freeze–thaw activity, contributed to winter months showing the highest rate of stream bank erosion. Peak flow was negatively correlated to sediment sources from agricultural lands which had the greatest contribution in non-winter months. Caution should be observed when trying to interpret the relation between sediment sources and individual storms using the sediment fingerprinting approach. Because the sediment fingerprinting results from individual storms may not include the temporal aspects of the sourced sediment, sediment that is in storage from previous events, remobilized and sampled during the current event, will reflect previous storm characteristics. Stream bank sediment is delivered directly to the channel during an event, whereas the delivery of upland sediment to the stream is lower due to storage on hillslopes and/or in channels, sediment from stream banks are more likely to be related to the characteristics of the sampled storm event.

Conclusions

Stream banks and agricultural lands are both important sources of fine-grained sediment in the Linganore Creek watershed. Peak flows and sediment loads for the 36 storms show a significant relation to sediment sources from stream bank erosion. Attempting to link upland sediment sources to flow and seasonal characteristics is difficult since much of the upland sediment eroded in an event goes into storage. By averaging sediment sources over several storms, it may be possible to determine not only the sediment sources that are directly contributed during the current event but also sediment from previous events that was in storage and remobilized.

Keywords

Bank erosionChesapeake BaySediment budgetSediment fingerprinting

Supplementary material

11368_2013_771_MOESM1_ESM.xls (218 kb)
ESM 1(XLS 218 KB)

Copyright information

© Springer-Verlag (outside the USA) 2013

Authors and Affiliations

  1. 1.US Geological SurveyBaltimoreUSA
  2. 2.US Geological SurveyRestonUSA