@proceedings {302,
	title = {Implications of diurnal river fluctuations on mass transport in a valley-fill aquifer},
	volume = {38},
	year = {2006},
	note = {Accession Number: 2010-061334; Conference Name: Geological Society of America, 2006 annual meeting; Philadelphia, PA, United States; Conference Date: 20061022; Language: English; Coden: GAAPBC; Collation: 1; Collation: 468; Publication Types: Abstract Only; Serial; Conference document; Updated Code: 201034; Monograph Title: Geological Society of America, 2006 annual meeting; Monograph Author(s): Anonymous; Reviewed Item: Analytic},
	month = {2006/10/01/},
	pages = {468 - 468},
	publisher = {Geological Society of America (GSA) : Boulder, CO, United States},
	address = {United States},
	abstract = {Aquifers located in isolated stratified drift deposits in the northeastern portion of the US are extremely fragile and important groundwater resources. These aquifers, when restricted to bedrock valleys, are often strongly coupled to significant surface water drainage systems. In northwestern Massachusetts, surface water associated with the Deerfield River watershed is highly regulated by dams to protect against flooding and to generate hydroelectric power. Regular releases of water from these dams cause diurnal fluctuations in river stage. In a previous study performed by the USGS, measurements from two clusters of wells show a significant response to river stage fluctuations in the aquifer. Fluctuations in river stage and resulting changes in head levels in the aquifer cause a switch from a losing to a gaining stream. The flow reversals have implications for mass transport and nutrient cycling within the hyporheic zone. In this paper we investigate the physical hydrologic controls on mass transport in the shallow aquifer. Using a coupled groundwater flow and transport code, we built a quasi three dimensional transient numerical model to approximate the head changes in the aquifer caused by the stage fluctuations in the river. Flow velocities and residence times were estimated in the aquifer for a variety of flow conditions. The mixing process driven by the aquifer head changes were quantified in the proximity of the hyporheic zone and shown to significantly influence both vertical and horizontal flow velocities in a region close to the stream-aquifer boundary. The diurnal river stage changes also appear to influence farfield hydrologic conditions and potentially hydrologically isolate the river and hyporheic zone. To further investigate these mixing processes we applied a mass transport code with conservative tracers to the aquifer. Fluctuation of the river stage combined with the heterogeneous nature of the aquifer creates a pumping mechanism that creates excess mixing within shallow portions of the aquifer. Aquifer dispersivity and molecular diffusion both contribute to the anomalous mixing modeled in the shallow aquifer. Mixing driven by stream stage changes has important implications for nutrient cycling as well as contaminant transport in the shallow aquifer.},
	keywords = {$\#$StaffPubs, aquifers, BEDROCK, clastic sediments, controls, diffusion, diurnal variations, drainage, drift, Eastern U.S., Environmental geology 22, floods, fluctuations, geochemical cycle, geologic hazards, ground water, measurement, mixing, models, Northeastern U.S., numerical models, nutrients, pollution, processes, pumping, quantitative analysis, residence time, sediments, shallow aquifers, surface water, three-dimensional models, tracers, transport, United States, valleys, water pollution, water resources, water wells},
	isbn = {00167592},
	url = {https://gsa.confex.com/gsa/2006AM/finalprogram/abstract_115285.htm},
	author = {Brandon J Fleming and David F Boutt and Stephen B Mabee}
}
@article {265,
	title = {A method of collecting and analyzing lineaments for regional-scale fractured-bedrock aquifer studies},
	journal = {Ground Water},
	volume = {32},
	year = {1994},
	note = {Accession Number: 1996-036299; Language: English; Coordinates: N435500N435500W0691000W0691000; Coden: GRWAAP; Collation: 11; Publication Types: Serial; Updated Code: 199612; Illustration(s): illus.; Number of References: 20; Reviewed Item: Analytic},
	month = {1994/12/01/},
	pages = {884 - 894},
	publisher = {National Water Well Association, Ground-Water Technology Division : Urbana, IL, United States},
	address = {United States},
	abstract = {A new method is proposed for collecting and reducing large collections of lineament data. The method consists of three steps: (1) collection of lineament data using multiple observers, multiple observation trials, and several types of imagery; (2) reproducibility tests; and (3) domain overlap analysis. Collection of lineament data and reproducibility tests are performed by overlaying lineament maps drawn by several observers or by superimposing multiple maps prepared by a single observer and identifying lineaments which are coincident (coincident lineaments = lineaments that have azimuths within 5 {\textpm} and separation distances are within 1{\textendash}2 mm at the scale of drawing). Domain overlap analysis is accomplished by measuring the trends of near-vertical fractures at outcrops distributed over the study region and comparing the spatial distribution of these trends with similar-trending coincident lineaments. Lineaments that are not reproducible and are not geographically correlative with fractures are considered unimportant and removed from the data base. The method was applied to a 44 km2 study area in Maine and resulted in a reduction in the lineament data base from 6500 to 217. Transmissivities determined for bedrock wells located within 30 meters of lineaments that are both reproducible and geographically correlative with outcrop-scale fractures are generally higher than the transmissivities of wells located near lineaments that are not separated on the basis of these criteria. Application of the method serves as an important filter by providing a more manageable lineament data base from which to begin detailed field checking and/or geophysical surveys directed toward specific lineaments.},
	keywords = {$\#$StaffPubs, aquifers, BEDROCK, coastal environment, fractured materials, Georgetown Island, ground water, Hydrogeology 21, Knox County Maine, lineaments, Maine, mapping, mathematical methods, processes, tectonics, United States},
	isbn = {0017467X},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1745-6584.1994.tb00928.x/abstract},
	author = {Stephen B Mabee and Hardcastle, Kenneth C. and Donald U Wise}
}
