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Deprecated[72866] Lower Mississippi-Gulf Water Science Center

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Seventeen streamflow-gaging stations, operated by the U.S. Geological Survey and distributed across the Ouachita Mountains of Arkansas and Oklahoma were selected for analysis. Bed material sampling was conducted to obtain information on the particle-size distributions of the streambed materials and to determine the shapes of the individual particles comprising the streambeds. Information on stream-bed particle-size distribution was used to compute the potential rate of bed-load transport and is a parameter used in the Rosgen (Rosgen, 1996) stream reach classification system. Streambed-material particle sizes were measured using two methods. The first method was Wolman pebble counts conducted across the riffles...
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This data set includes WRTDS nutrient flux trend results and the values of daily streamflow trend results displayed in the Quantile-Kendall plots. For 1995-2015 nutrient trends, the method of generalized flow normalization (FNG) was used which explicitly addresses non-stationary streamflow conditions. For 2005-2015 nutrient trends, the WRTDS trend analyses used the method of stationary flow normalization (FNS) because streamflow nonstationarity is difficult to assess over this shorter duration time frame. The 1995-2015 annual nutrient trends were determined for all five nutrient parameters (TP, SRP, TN, NO23, TKN), and monthly trends were evaluated only for SRP. The 2005-2015 annual nutrient trends were determined...
DC Resitivity Methodology Direct current (DC) resistivity transects were surveyed using an IRIS Syscal Pro Switch 96 instrument (IRIS Instruments, Inc., Orléans, France). Steel electrodes were hammered into the ground at a fixed distance along the profile. These were connected to the instrument using copper wires and junction boxes. The number of electrodes on each profile and their spacing is shown below: Line 1: 180 electrodes, 5 meter spacing Line 2: 48 electrodes, 2 meter spacing Line 3: 48 electrodes, 2 meter spacing Line 4: 24 electrodes, 2 meter spacing Line 5: 36 electrodes, 2 meter spacing On Line 1, the roll-along method was used to extend the line to its full extent. In this method, 48 electrodes...
Categories: Data
FDEM Methodology For this project frequency domain electromagnetic (FDEM) data were collected with a GEM-2, a broadband, multifrequency, fixed-coil electromagnetic induction unit (Geophex, 2015). Both in-phase and quadrature data were collected on 15 channels from a frequency of 810 Hz to 66,090 Hz. This system was carried along profiles that followed the axis of the dam and along tie lines that were perpendicular to the axis of the dam. Each data point was located using a backpack mounted GPS. To correct the drift of the instrument, a base station was established on the east side of the dam. Each survey started and ended with an occupation of the base station. These occupations occur as even line numbers...
Categories: Data
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Reelfoot Lake, in northwestern Tennessee and southwestern Kentucky, is home to a Federal wildlife refuge, a State wildlife-management area, and to a tourism industry that is based on hunting, fishing, birding, and the area’s unique cultural history. In 2012, the U.S. Geological Survey, in cooperation with the Tennessee Wildlife Resources Agency, began a series of hydrologic investigations to support the U.S. Fish and Wildlife Service in managing lake level. The objective was to develop operational models that preserved the historic patterns of variability that had characterized the lake for the past 60 years while meeting seasonal water-level targets (Heal and others, 2022). Preliminary models for gate operations...
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