TY - JOUR T1 - Implications of anthropogenic river stage fluctuations on mass transport in a valley fill aquifer JF - Water Resources Research Y1 - 2009 A1 - David F Boutt A1 - Brandon J Fleming KW - #Hydro KW - #WaterResources KW - aquifers KW - boundary conditions KW - Charlemont KW - Deerfield River basin KW - fluctuations KW - fluvial features KW - Franklin County Massachusetts KW - ground water KW - human activity KW - Hydrogeology 21 KW - hydrology KW - massachusetts KW - numerical models KW - preferential flow KW - rivers KW - shallow aquifers KW - streams KW - surface water KW - transport KW - two-dimensional models KW - United States KW - valleys AB - In humid regions a strong coupling between surface water features and groundwater systems may exist. In these environments the exchange of water and solute depends primarily on the hydraulic gradient between the reservoirs. We hypothesize that daily changes in river stage associated with anthropogenic water releases (such as those from a hydroelectric dam) cause anomalous mixing in the near-stream environment by creating large hydraulic head gradients between the stream and adjacent aquifer. We present field observations of hydraulic gradient reversals in a shallow aquifer. Important physical processes observed in the field are explicitly reproduced in a physically based two-dimensional numerical model of groundwater flow coupled to a simplistic surface water boundary condition. Mass transport simulations of a conservative solute introduced into the surface water are performed and examined relative to a stream condition without stage fluctuations. Simulations of 20 d for both fluctuating river stage and fixed high river stage show that more mass is introduced into the aquifer from the stream in the oscillating case even though the net water flux is zero. Enhanced transport by mechanical dispersion leads to mass being driven away from the hydraulic zone of influence of the river. The modification of local hydraulic gradients is likely to be important for understanding dissolved mass transport in near-stream aquifer environments and can influence exchange zone processes under conditions of high-frequency stream stage changes. PB - American Geophysical Union : Washington, DC, United States VL - 45 SN - 0043139719447973 UR - http://onlinelibrary.wiley.com/doi/10.1029/2007WR006526/full IS - 44 JO - Water Resources Research ER - TY - Generic T1 - USGS Groundwater Watch Y1 - KW - #EducationalResources KW - #Hydro KW - #MapsDataPublications KW - #NaturalHazards KW - #Water KW - active KW - aquifer KW - drought KW - flood KW - flow KW - groundwater KW - historic KW - level KW - rivers KW - static water level KW - stream gauges KW - streamflow KW - streams KW - surface water KW - water KW - water quality AB - The USGS has a distributed water database that is locally managed. Surface water, groundwater, and water quality data are compiled from these local, distributed databases into a national information system. The groundwater database contains records from about 850,000 wells that have been compiled during the course of groundwater hydrology studies over the past 100 years. Information from these wells is served via the Internet through NWISWeb, the National Water Information System Web Interface. NWISWeb provides all USGS groundwater data that are approved for public release. This large number of sites is excellent for some uses, but complicates retrievals when the user is interested in specific networks, or wells in an active water- level measurement program. These "groundwater watch" web pages group related wells and data from these active well networks, and provide basic statistics about the water-level data collected by USGS water science centers for Cooperative Programs, for Federal Programs, and from data supplied to us by our customers through cooperative agreements. PB - USGS UR - http://groundwaterwatch.usgs.gov/ ER - TY - Generic T1 - USGS Water Resources of Massachusetts and Rhode Island Y1 - KW - #EducationalResources KW - #Hydro KW - #MapsDataPublications KW - #NaturalHazards KW - #Water KW - aquifer KW - drought KW - flood KW - flooding KW - flow KW - groundwater KW - historic KW - level KW - rivers KW - static water level KW - stream gauges KW - streamflow KW - streams KW - surface water KW - water KW - water quality AB - This is your direct link to water-resource information on Massachusetts's rivers and streams, ground water, water quality, and biology. Provides links to real time and historic streamflow, groundwater, drought, water quality, and precipitation data. PB - USGS UR - http://ma.water.usgs.gov/ ER -