dc.contributor.author	Schwartz, Benjamin Farley	en
dc.contributor.committeechair	Schreiber, Madeline E.	en
dc.contributor.committeemember	Burbey, Thomas J.	en
dc.contributor.committeemember	Daniels, W. Lee	en
dc.contributor.committeemember	Rimstidt, J. Donald	en
dc.contributor.committeemember	White, William B.	en
dc.contributor.department	Geosciences	en
dc.date.accessioned	2014-03-14T20:19:14Z	en
dc.date.adate	2007-11-28	en
dc.date.available	2014-03-14T20:19:14Z	en
dc.date.issued	2007-11-16	en
dc.date.rdate	2007-11-28	en
dc.date.sdate	2007-11-26	en
dc.description.abstract	This dissertation presents the results of a detailed physical and hydrogeophysical study of two soil-filled sinkholes mantled by ancient New River fluvial terrace deposits. Research was performed at the Virginia Tech Kentland Experimental Farms in Whitethorne, Virginia, USA between fall 2003 and spring 2007, and focused on characterizing infiltration, deep drainage, and recharge through soil-filled sinkholes. Using hydrogeophysical methods, the spatial and temporal distribution of soil moisture was modeled and potential recharge was quantified in two soil-filled sinkholes. Access-tube time domain reflectometry (TDR) was used to derive one-dimensional (1-D) soil moisture profiles. During access-tube installation, 470 soil samples were obtained from depths between 0.3 and to 9.0 m and characterized both physically and chemically. Using these data, a TDR calibration method was developed. Physio-chemical, TDR moisture, and 1-D electrical resistivity tomography (ERT) data were used to derive a numerically optimized form of Archie's Law which was used to convert ERT measurements into volumetric soil moisture. These results led to development of 2-D ERT-derived distributions of soil moisture in three transects across the two sinkholes in two terraces. Potential recharge was quantified using time-series ERT data with comparison to modeled cumulative potential evapotranspiration (PET) and cumulative precipitation between May 17 and October 9, 2006. The patterns of ERT-derived potential recharge values compared well with those expected from PET and precipitation data. Over the monitoring period from late spring to early fall during this study, results showed that a period of intense rain followed by a 31-day period of consistent rain, in which the rate of precipitation was equal to or exceeded PET, were the only periods in which significant amounts of potential recharge occurred (from 19 to 31% of cumulative precipitation during the study). Spatial distributions of ERT-derived moisture clearly revealed that significant amounts of infiltration occurred on sinkhole flanks and bottoms. Runoff during periods of intense rain flowed to the topographically lowest point in the sinkholes where it infiltrated and resulted in localized zones of enhanced infiltration and potential recharge to the water table.	en
dc.description.degree	Ph. D.	en
dc.identifier.other	etd-11262007-142211	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-11262007-142211/	en
dc.identifier.uri	http://hdl.handle.net/10919/29748	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	Part_2_not_ok_to_distribute.pdf	en
dc.relation.haspart	Part_3_ok_to_distribute.pdf	en
dc.relation.haspart	Dissertation_Final.pdf	en
dc.relation.haspart	Part_1_ok_to_distribute.pdf	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	mantled karst	en
dc.subject	deep drainage	en
dc.subject	potential recharge	en
dc.subject	karst hydrology	en
dc.subject	concentrated recharge	en
dc.subject	diffuse recharge	en
dc.title	Hydrogeophysical quantification of infiltration and recharge through soil-filled sinkholes using Time Domain Reflectometry and Electrical Resistivity Tomography	en
dc.type	Dissertation	en
thesis.degree.discipline	Geosciences	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Ph. D.	en

Hydrogeophysical quantification of infiltration and recharge through soil-filled sinkholes using Time Domain Reflectometry and Electrical Resistivity Tomography

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