|Sauer, Thomas - Tom|
Submitted to: Geological Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/4/2000
Publication Date: N/A
Technical Abstract: Recent studies in Basin 2 of the long-term karst research site, the Savoy Experimental Watershed (SEW), confirm that a major component of ground-water flow may move laterally within the epikarst zone, an area of interflow at the contact of the nonindurated soil and regolith zone and the underlying indurated rock aquifers. Continuous water-level monitoring of wells, springs, and surface-drainage channels, continuous monitoring of precipitation and climatic variables, and recurring sampling at selected sites for key water-quality parameters indicates that for more than 99 percent of the time period of record, recharge at SEW infiltrates rather than runs off. Comparison of lag times and magnitudes of responses by different components of the hydrologic budget within Basin 2 further suggests, at least for this basin after major storms, that the percentage of flow moving in the epikarst significantly exceeds other discharge pathways. A further finding of this study indicates that with ground-water recession after storms, areas of widespread ground-water occurrence in the regolith rapidly diminish to areas of very narrow pathways of flow along connected lowest elevations at the epikarst boundary. This ground-water flood pulse and recession is directly comparable to surface streams which extend to the margins of the flood plains after major storms, and rapidly recede to within channel banks several days later. For periods of low flow and drought, wells tapping the epikarst are dry everywhere except the narrow pathways of flow along connected lowest elevations.