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.
|Number of pages||11|
|Journal||Journal of Hydrology|
|State||Published - Mar 30 2010|
Bibliographical noteFunding Information:
The research described herein was funded by the University of Kentucky (UK) College of Agriculture through the Senate Bill 271 program. The investigation reported in this paper (No. 09-05-059) is part of a project of the Kentucky Agricultural Experiment Station and is published with approval of the Director. Supplemental funding was provided by grants from the Geological Society of America Southeastern Section, the UK Graduate School, and the UK Department of Earth and Environmental Sciences Brown-McFarlan Fund to J.T. McFarland. We are indebted to Paul and Jerry Campbell (City of Versailles) and the UK Animal Research Center for access to the springs. Sue Rimmer (UK Earth and Environmental Sciences), John Wiseman and Jack Groppo (UK Center for Applied Energy Research), and Elisa D’Angelo and Martin Vandiviere (UK Plant and Soil Sciences) helped with laboratory analyses. James Ward assisted with field work. Charles Hockensmith, William Andrews, Jr., and Steve Greb shared insights about possible sediment provenance. Associate Editor Barbara Mahler, an anonymous reviewer, Nico Goldscheider, Jim Currens, Frank Ettensohn, and Jonathan Phillips made helpful comments on drafts of the manuscript.
- Inner Bluegrass
- Storm flow
ASJC Scopus subject areas
- Water Science and Technology