Search USGS⌕ Search

Geology topics

Research about Savannah River

Source-linked reports with geographic coverage including Savannah River.

14 recordsLinked to original sources
USGS2018

Intraspecific differences in morphology correspond to differential spawning habitat use in two riverine catostomid species

Maintaining intraspecific diversity is an important goal for fisheries conservation and recovery actions. While ecomorphological studies have demonstrated intraspecific diversity related to feeding or flow regime, there has been little assessment of such variation in regard to spawning habitat. We evaluated the relationship between individual morphology of Robust Redhorse and Notchlip Redhorse and variables describing the spawning habitat from which they were captured, such as current velocity, depth, and substrate particle size. Robust Redhorse ( n = 58) and Notchlip Redhorse ( n = 43) were captured from spawning aggregations in the lower Savannah River, South Carolina-Georgia using prepositioned grid electrofishers. They were then measured and photographed before being released. We constructed a truss network using digitized landmarks on each of the photographs. Relationships between the morphological and environmental datasets were assessed using canonical correlation analysis. In both species, these morphological predictors were correlated primarily to depth, though current velocity also contributed to the environmental canonical score for Robust Redhorse. Robust Redhorse captured from the deeper locations with higher current velocities had heads with lower aspect ratio compared to individuals captured from shallower areas. Notchlip Redhorse from shallower areas were deeper-bodied and had shorter trunks than counterparts from deeper areas. These differences suggest that ensuring spawning habitat heterogeneity may be an important component to conserving intraspecific diversity, particularly in systems where such habitat is limiting.

Georgia, South Carolina↗
USGS2014

Salinity of the lower Savannah River in relation to stream‐flow and tidal action

In order to obtain information needed in planning for industrial development along the Savannah River and in the city of Savannah, Georgia, a study of the salinity of the Savannah River was undertaken by the Geological Survey, United States Department of the Interior, in cooperation with the Georgia Division of Mines, Mining, and Geology. The Works Progress Administration of Georgia and the city of Savannah also cooperated in the study. The Savannah River lies on the boundary between the States of Georgia and South Carolina. The River proper from the mouth to the junction of the Tugaloo and Senaca rivers is 314 miles in length. The area of its watershed is about 10,579 square miles, of which 9,850 square miles are above the stream‐flow gaging‐station near Clyo, Georgia. The River is tidal for about 50 miles above its mouth. The average streamflow for the Savannah River near Clyo, Georgia, was 10,410 and 10,820 second‐feet, respectively, for the years ending September 30, 1938 and 1939. The city of Savannah, Georgia, located on the Savannah River 17 miles above its mouth, is an important seaport and industrial center. The lower Savannah River near the city of Savannah is shown in Figure 1.

Georgia, South Carolina↗
USGS2013

Hydrologic monitoring and selected hydrologic and environmental studies by the U.S. Geological Survey in Georgia, 2011–2013

This compendium of papers describes results of hydrologic monitoring and hydrologic and environmental studies completed by the U.S. Geological Survey (USGS) in Georgia during 2011–2013. The USGS addresses a wide variety of water issues in the State of Georgia working with local, State, and Federal partners. As the primary Federal science agency for water resource information, the USGS monitors the quantity and quality of water in the Nation’s rivers and aquifers, assesses the sources and fate of contaminants in aquatic systems, collects and analyzes data on aquatic ecosystems, develops tools to improve the application of hydrologic information, and ensures that its information and tools are available to all potential users. During 2011–2013, the USGS continued a long-term program of monitoring stream and groundwater resources, including flow, water quality, and water use. In addition, a variety of hydrologic and environmental studies were completed to assess water availability, hydrologic hazards, and the impact of development on water resources. Information on USGS activities in Georgia is available online at http://ga.water.usgs.gov/ .

Georgia↗
USGS2012

On the relative roles of hydrology, salinity, temperature, and root productivity in controlling soil respiration from coastal swamps (freshwater)

Background and aims Soil CO 2 emissions can dominate gaseous carbon losses from forested wetlands (swamps), especially those positioned in coastal environments. Understanding the varied roles of hydroperiod, salinity, temperature, and root productivity on soil respiration is important in discerning how carbon balances may shift as freshwater swamps retreat inland with sea-level rise and salinity incursion, and convert to mixed communities with marsh plants. Methods We exposed soil mesocosms to combinations of permanent flooding, tide, and salinity, and tracked soil respiration over 2 1/2 growing seasons. We also related these measurements to rates from field sites along the lower Savannah River, Georgia, USA. Soil temperature and root productivity were assessed simultaneously for both experiments. Results Soil respiration from mesocosms (22.7-1678.2 mg CO 2 m -2 h -1 ) differed significantly among treatments during four of the seven sampling intervals, where permanently flooded treatments contributed to low rates of soil respiration and tidally flooded treatments sometimes contributed to higher rates. Permanent flooding reduced the overall capacity for soil respiration as soils warmed. Salinity did reduce soil respiration at times in tidal treatments, indicating that salinity may affect the amount of CO 2 respired with tide more strongly than under permanent flooding. However, soil respiration related greatest to root biomass (mesocosm) and standing root length (field); any stress reducing root productivity (incl. salinity and permanent flooding) therefore reduces soil respiration. Conclusions Overall, we hypothesized a stronger, direct role for salinity on soil respiration, and found that salinity effects were being masked by varied capacities for increases in respiration with soil warming as dictated by hydrology, and the indirect influence that salinity can have on plant productivity.

Georgia↗
USGS2007

Visualization and Time-Series Analysis of Ground-Water Data for C-Area, Savannah River Site, South Carolina, 1984-2004

In 2004, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, initiated a study of historical ground-water data of C-Area on the Savannah River Site in South Carolina. The soils and ground water at C-Area are contaminated with high concentrations of trichloroethylene and lesser amounts of tetrachloroethylene. The objectives of the investigation were (1) to analyze the historical data to determine if data-mining techniques could be applied to the historical database to ascertain whether natural attenuation of recalcitrant contaminants, such as volatile organic compounds, is occurring and (2) to determine whether inferential (surrogate) analytes could be used for more cost-effective monitoring. Twenty-one years of data (1984-2004) were collected from 396 wells in the study area and converted from record data to time-series data for analysis. A Ground-Water Data Viewer was developed to allow users to spatially and temporally visualize the analyte data. Overall, because the data were temporally and spatially sparse, data analysis was limited to only qualitative descriptions.

South Carolina↗
USGS2006

Simulation and particle-tracking analysis of ground-water flow near the Savannah River site, Georgia and South Carolina, 2002, and for selected ground-water management scenarios, 2002 and 2020

Ground-water flow under 2002 hydrologic conditions was evaluated in an eight-county area in Georgia and South Carolina near the Savannah River Site (SRS), by updating boundary conditions and pumping rates in an existing U.S. Geological Survey (USGS) ground-water model. The original ground-water model, developed to simulate hydrologic conditions during 1987-92, used the quasi-three-dimensional approach by dividing the Floridan, Dublin, and Midville aquifer systems into seven aquifers. The hydrogeologic system was modeled using six active layers (A2-A7) that were separated by confining units with an overlying source-sink layer to simulate the unconfined Upper Three Runs aquifer (layer A1). Potentiometric- surface maps depicting September 2002 for major aquifers were used to update, evaluate, and modify boundary conditions used by the earlier ground-water flow model. The model was updated using the USGS finite-difference code MODFLOW-2000 for mean-annual conditions during 1987-92 and 2002. The specified heads in the source-sink layer A1 were lowered to reflect observed water-level declines during the 1998-2002 drought. These declines resulted in a decrease of 12.1 million gallons per day (Mgal/d) in simulated recharge or vertical inflow to the uppermost confined aquifer (Gordon, layer A2). Although ground-water pumpage in the study area has increased by 32 Mgal/d since 1995, most of this increase (17.5 Mgal/d) was from the unconfined Upper Three Runs aquifer (source-sink layer A1) with the remaining 14.5 Mgal/d assigned to the active layers within the model (A2-A7). The simulated water budget for 2002 shows a decrease from the 1987-92 model from 1,040 Mgal/d to 1,035 Mgal/d. The decreased ground-water inflows and increased ground-water withdrawal rates reduced the simulated ground-water outflow to river cells in the active layers of the model by 43 Mgal/d. The calibration statistics for all layers of the 2002 simulation resulted in a decrease in the root mean square (RMS) of the residuals from 10.6 to 8.0 feet (ft). The residuals indicate 83.3 percent of the values for the 2002 simulation met the calibration error criteria established in the original model, whereas 88.8 percent was within the specified range for the 1987-92 simulation. Simulated ground-water outflow to the Savannah River and its tributaries during water year 2002 was 560 cubic feet per second (ft3/s), or 86 percent of the observed gain in mean-annual streamflow between streamflow gaging stations at the Millhaven, Ga., and Augusta, Ga. At Upper Three Runs Creek, simulated ground-water discharge during 2002 was 110 ft3/s, or 83 percent of the observed streamflow at two streamflow gaging stations near the SRS. These results indicate that the constructed model calibrated to 1987-92 conditions and modified for 2002 dry conditions is still representative of the hydrologic system. The USGS particle-tracking code MODPATH was used to generate advective water-particle pathlines and their associated time-of-travel based on MODFLOW simulations for 1987-92, 2002, and each of four hypothetical ground-water management scenarios. The four hypothetical ground-water management scenarios represent hydrologic conditions for (1) reported pumping for 2002 and boundary conditions for an average year; (2) reported pumping for 2002 with SRS pumping discontinued and boundary conditions for an average year; (3) projected 2020 pumping and boundary conditions for an average year; and (4) projected 2020 pumping and boundary conditions for a dry year. The MODPATH code was used in forward-tracking mode to evaluate flowpaths from areas on the SRS and in backtracking mode to evaluate further areas of previously documented trans-river flow on the Georgia side of the Savannah River. Trans-river flow is a condition in which the local head gradients might allow migration of contaminants from the SRS into the underlying aquifers and beneath the Savannah River into Georgia. More...

Georgia, South Carolina↗
USGS1994

Effects of salinity on striped bass eggs and larvae from the Savannah River, Georgia

Operation of a tide gate installed in the Savannah River by the U.S. Army Corps of Engineers to reduce dredging activities increased salinities upstream in important spawning habitat for striped bass Morone saxatilis . To assess the effects of salinity on survival and growth of striped bass at early life stages, newly fertilized eggs and 48‐h‐posthatch larvae were exposed to serial dilutions of seawater, with salinities ranging from 0 to 33‰ (g/L) in increments of 3‰; in addition, older larvae (5‐d posthatch) were exposed to salinities of 0, 6, 12, 18, and 24‰. Eggs were exposed until 24 h posthatch, 48‐h‐posthatch larvae were exposed for 10 d, and 5‐d‐posthatch larvae were exposed for 6 d. Eggs died within 24 h in salinities greater than 18‰. Both survival and total length of larvae hatched from eggs exposed to salinities of 15‰ or higher were reduced. Percent mortality and mean total lengths of newly hatched larvae followed the same pattern for each of three sets of salinity regimes (i.e., changes in salinities over time) that striped bass eggs might encounter during passage downstream in the Savannah River. Hardening eggs in freshwater did not increase survival or length of hatched larvae over that shown by eggs hardened in saline water. The 5‐d‐posthatch larvae were less sensitive to salinity than the 48‐h‐posthatch larvae. Survival of larvae was negatively correlated with both salinity and exposure time. For 48‐h‐posthatch larvae, the 10‐d LC50 (the salinity lethal to 50% of the test fish within 10 d) was 10‰. Probabilities of survival for larval striped bass exposed to different salinities for different amounts of time can be estimated from curves generated from models of survival analysis. Salinities judged to be critical to Savannah River striped bass eggs and larvae are those greater than 9‰.

Georgia↗
USGS1991

Remote sensing of water quality

Water property data were collected within 3 cooling water reservoirs (active to inactive, large [1,068 ha] to small [68.6 ha]. oligotrophic to eutrophic) at 31 locations. A description of the water characteristics was obtained including algal pigments, total suspended particles, dissolved and particulate organic matter, and total particle absorption spectra. Field data included generated water volume reflectance spectra and secchi depth. Specialized regression techniques were used to derive specific absorption coefficients from measured water property concentrations and total particle absorption spectra. Subsequently, using first order approximations relating water volume reflectance to water intrinsic properties, generated absorption coefficients were combined with an optimization procedure that minimized the difference between the observed and predicted water volume reflectances resulting in specific backscatter coefficient estimates.

South Carolina↗
USGS1990

Flood frequency of the Savannah River at Augusta, Georgia

To fill an increasing need for reliable information on floods of various recurrence intervals on the Savannah River a flood-frequency relation was developed for the long-term gaging station at Augusta, Georgia. The flood-frequency analysis was complicated by the fact that the Savannah River upstream of Augusta has experienced increasing regulation of flow caused by three large dams constructed since 1952. The pre-impoundment period was important to the flood-frequency analysis because it included a number of large floods that, even when adjusted for regulation, exceed all floods since 1952. A reservoir routing model was used to adjust nine such floods for the effects of regulation, and to develop a relation for estimating regulated peak discharges for additional unregulated floods. The 1% chance exceedance flood for regulated conditions on the Savannah River at Augusta was computed as 180,000 cu ft/sec. (USGS)

Georgia↗