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Sediment discharges during storm flow from proximal urban and rural karst springs, central Kentucky, USA

Journal of Hydrology

By:
, , , , and
DOI: 10.1016/j.jhydrol.2009.12.043

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Abstract

Since the mid-1990s, various studies have addressed the timing of sediment transport to karst springs during storm flow or the composition and provenance of sediment discharged from springs. However, relatively few studies have focused on the flow thresholds at which sediment is mobilized or total sediment yields across various time scales. We examined each of these topics for a mainly urban spring (Blue Hole) and a rural spring (SP-2) in the Inner Bluegrass region of central Kentucky (USA). Suspended sediment consisted mostly of quartz silt and sand, with lesser amounts of calcite and organic matter. Total suspended sediment (TSS) values measured during storm flow were greater at SP-2 than at Blue Hole. By aggregating data from four storms during 2 years, we found that median suspended-sediment size jumped as Q exceeded ???0.5 m3/s for both springs. At Blue Hole, TSS tended to vary with Q and capacity approached 1 g/L, but no systematic relationship between TSS and Q was evident at SP-2. Sediment fluxes from the Blue Hole basin were ???2 orders of magnitude greater for storms in March (2002 and 2004) than September (2002 and 2003). In contrast, sediment fluxes from the SP-2 basin were of similar magnitude in September 2003 and March 2004. The overall range of area-normalized fluxes for both springs, 9.16 ?? 10-3-4.45 ?? 102 kg/(ha h), overlaps values reported for farm plots and a stream in the Inner Bluegrass region and for other spring basins in the eastern USA and western Europe. Sediment compositions, sizes, and responses to storms in the basins may differ because of land use (e.g., the extent of impervious cover in the Blue Hole basin), basin size (larger for Blue Hole), conduit architecture, which appears to be more complex in the Blue Hole basin, and the impoundment of SP-2, which may have promoted decadal-scale storage of sediment upgradient. ?? 2009 Elsevier B.V. All rights reserved.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Sediment discharges during storm flow from proximal urban and rural karst springs, central Kentucky, USA
Series title:
Journal of Hydrology
DOI:
10.1016/j.jhydrol.2009.12.043
Volume
383
Issue:
3-4
Year Published:
2010
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Hydrology
First page:
280
Last page:
290
Number of Pages:
11