Filters: Tags: Gwinnett County (X) > Date Range: {"choice":"year"} (X)
18 results (87ms)|
Filters
Date Types (for Date Range)
Contacts
Categories Tag Types Tag Schemes |
This dataset contains the daily average base flow, as determined by hydrograph separation, for 14 watersheds in Gwinnett County, Georgia for October 2001 through September 2020. Hydrograph separations were done using the Web-based Hydrograph Analysis Tool (WHAT) using the simple local minimum method on the daily average streamflows, which are also provided in this dataset. Base flow along with the calculated base-flow index (the proportion of base flow to total flow) were used to characterize groundwater recharge and the relative degree of storm runoff in the watersheds. Base flow was also used as predictor variable in models for estimating streamwater constituent loads for 12 water-quality constituents at 13 of...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
datasets,
inlandWaters,
streamflow,
This Geographic Information System dataset contains shapefiles of 200-foot stream buffers for the 15 study watersheds in Gwinnett County, Georgia. The stream buffers are based on flowlines from the high resolution, 1:24,000-scale National Hydrography Dataset.
This dataset contains a list of outlier sample concentrations identified for 17 water quality constituents from streamwater sample collected at 15 study watersheds in Gwinnett County, Georgia for water years 2003 to 2020. The 17 water quality constituents are: biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), suspended sediment concentration (SSC), total nitrogen (TN), total nitrate plus nitrite (NO3NO2), total ammonia plus organic nitrogen (TKN), dissolved ammonia (NH3), total phosphorus (TP), dissolved phosphorus (DP), total organic carbon (TOC), total calcium (Ca), total magnesium (Mg), total copper (TCu), total lead (TPb), total zinc (TZn), and total dissolved solids...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
surface water quality
The dataset contains model coefficients and statistics for the 488 regression models used to estimate streamwater constituent loads for 13 watersheds in Gwinnett County, Georgia for two calibration periods, water years 2003-2010 and 2010-2020. Model terms were selected from an 11-parameter equation, which was a function of discharge, base flow, season, turbidity, and time (trend), using a forward stepwise ordinary least squares regression approach. Model coefficients were fit using U.S. Geological Survey (USGS) LOADEST load estimation software. Models were fit both with and without turbidity explanatory variables for 12 water-quality constituents: total suspended solids, suspended sediment concentration, total nitrogen,...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
mathematical modeling,
streamflow,
This dataset contains the percentage of 14 National Land Cover Database (NLCD) land cover classes within the drainage areas of 15 watersheds in Gwinnett County, Georgia from 2001 to 2019. The dataset includes scenes from eight years, 2001, 2004, 2006, 2008, 2011, 2013, 2016, and 2019, which were analyzed using a consistent approach so that they could be used to assess land cover changes. The NLCD dataset is derived from Landsat imagery and has a grid size of 30 meters. The fourteen land cover classes were categorized into eight land cover groups to simplify the presentation of watershed land cover characteristics (1. developed, low intensity; 2. developed, medium intensity; 3. developed, high intensity; 4. developed,...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
environment,
imageryBaseMapsEarthCover,
inlandWaters,
10: Laboratory standard reference samples for the Gwinnett County, Georgia study for years 2014-2020
This dataset contains laboratory standard reference sample concentrations analyzed by RTI Laboratories, the analytical laboratory used by the Gwinnett County, Georgia study. These water-quality-control samples are part of the U.S. Geological Survey (USGS) Standard Reference Samples (SRS) Project inter-laboratory comparison study. RTI Laboratories sample concentrations along with the included inter-laboratory result statistics (for most probable value and standard error) can be used to assess the laboratory’s analytical precision and bias. Sample concentrations are reported for 12 constituents for 13 round-robin sample rounds, in which prepared samples are sent to participating laboratories twice per year, and were...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
laboratory quality control,
materials standards,
The dataset contains annual and model calibration period streamwater constituent load and yield estimates for 13 watersheds in Gwinnett County, Georgia for the water years 2003 to 2020. Loads and yields were estimated for 12 water-quality constituents: total suspended solids, suspended sediment concentration, total nitrogen, total nitrate plus nitrite, total phosphorus, dissolved phosphorus, total organic carbon, total calcium, total magnesium, total lead, total zinc, and total dissolved solids. The USGS LOADEST load estimation software, which employs a regression-model estimation approach, was used for constituents that had at least a minimal relation with the model explanatory variables, as indicated by concentration...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
mathematical modeling,
streamflow,
This Geographic Information System dataset contains a shapefile of the watershed drainage area boundaries for the 15 watersheds which were used in the study in Gwinnett County, Georgia. The watersheds were delineated with StreamStats.
This dataset contains quality assurance sample concentrations for 19 constituents for the 15 monitored watersheds in Gwinnett County, Georgia, from 2000 to 2020. Samples include 431 replicate pairs and 335 field blanks. Replicate sampling allows for comparison of water quality to assess the combined variability in sample representativeness and laboratory precision and can also be used to identify possible sample contamination. Field blanks, samples of deionized “blank” water collected using the same sampling equipment and similar methodology as routine samples, were used to identify any possible contamination from field collection equipment and methodology.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
surface water quality,
water quality,
The High Resolution National Hydrography Dataset Plus (NHDPlus HR) is an integrated set of geospatial data layers, including the best available National Hydrography Dataset (NHD), the 10-meter 3D Elevation Program Digital Elevation Model (3DEP DEM), and the National Watershed Boundary Dataset (WBD). The NHDPlus HR combines the NHD, 3DEP DEMs, and WBD to create a stream network with linear referencing, feature naming, "value added attributes" (VAAs), elevation-derived catchments, and other features for hydrologic data analysis. The stream network with linear referencing is a system of data relationships applied to hydrographic systems so that one stream reach "flows" into another and "events" can be tied to and traced...
This dataset contains population densities of 15 study watersheds in Gwinnett County, Georgia from 2000 to 2020. Population densities were determined for 2000, 2010, and 2020 from the decadal U.S. Census and for 2012 and 2017 from the American Community Survey 5-year estimates of 2010-14 and 2015¬-19 block group data, respectively. Population density within each watershed was determined by clipping the census block group data by the watershed boundaries and area-weighting the block group population density data within each watershed. Census block group data is the smallest geographic unit for which the census provides data.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
population (human),
society,
watershed
This dataset contains the estimation data that was used in combination with the regression models to estimate streamwater constituent loads for 12 water-quality constituents for 13 watersheds in Gwinnett County, Georgia for the water years 2003 to 2020. Load were estimated using the U.S. Geological Survey (USGS) LOADEST load estimation software. Variables in the estimation dataset include a storm condition indicator variable, streamflow, streamflow during base-flow conditions, base flow, turbidity, and turbidity during stormflow conditions. Variants of the streamflow variable were used depending on whether the regression models were fit with turbidity explanatory variables. The time-step of the estimation datasets...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
mathematical modeling,
streamflow,
The dataset contains the sample constituent concentrations and explanatory variable values used for fitting the load regression models that were then used to estimate streamwater constituent loads for 13 watersheds in Gwinnett County, Georgia for water years 2003 to 2020. Load regression models were fit using U.S. Geological Survey (USGS) LOADEST load estimation software. Models were fit for 12 water-quality constituents: total suspended solids, suspended sediment concentration, total nitrogen, total nitrate plus nitrite, total phosphorus, dissolved phosphorus, total organic carbon, total calcium, total magnesium, total lead, total zinc, and total dissolved solids. Explanatory variables include a storm condition...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
inlandWaters,
mathematical modeling,
streamflow,
This dataset contains the number of buildings and their construction dates within the 15 study watersheds in Gwinnett County, Georgia. Dataset reflects existing buildings as of October 2021 and construction dates range from 1810 to 2021. The dataset was created by matching parcel boundaries obtained from Gwinnett County with building construction dates from the Gwinnett County Cadastral database. Building densities were calculated for each watershed and year to estimate temporal changes in watershed building densities.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
buildings,
imageryBaseMapsEarthCover,
land use and land cover,
This dataset contains the percentages of impervious areas within the drainage areas of 15 watersheds in Gwinnett County, Georgia from 2000 to 2020. The dataset includes data from 16 years, 2000, 2005, 2006, and annually from 2008 to 2020. The dataset was derived from impervious area coverages provided from the Gwinnett County Department of Public Utilities. These coverages were determined from 1:1,200-scale aerial photography with a 1-meter square grid size created by digitizing polygons of impervious surfaces. Watershed imperviousness was determined for various land cover types that were provided with the impervious area coverages. These included transportation and buildings land cover types for all impervious...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
imageryBaseMapsEarthCover,
impervious area,
inlandWaters,
The data herein were collected in support of a larger study in Gwinnett County, Georgia, on the potential impacts of on-site waste water treatment (septic systems) on Lake Lanier water quality. Until recently, a missing component in this assessment was the inclusion of historical sediment and associated nutrient accumulation data from the lake to place results in a broader context. To this end, the USGS collected sediment cores from ten locations that varied in water depth as well as proximity to residential areas with septic systems. Samples were collected using either a gravity corer or box corer depending on site conditions. Cores were sub-sampled and processed for laboratory analyses. Laboratory analyses were...
This data release contains 15 datasets and associated metadata of watershed characteristics and data related to stream water quality and constituent load estimation for 15 study watersheds in Gwinnett County, Georgia. Dataset periods vary but range within 2000 to 2021. The 15 datasets are organized as individual child items. The data release includes three Geographic Information System shapefiles: (1) 01: Watersheds shapefile for the 15 study watersheds in Gwinnett County, Georgia; (2) 02: Stormwater drainage areas shapefile for the 15 study watersheds in Gwinnett County, Georgia, August 2021; and (3) 03: 200-foot stream buffer shapefiles for 15 watersheds in Gwinnett County, Georgia. The data release includes four...
This Geographic Information System dataset contains a shapefile of the stormwater drainage area boundaries for the 15 study watersheds in Gwinnett County, Georgia. Stormwater drainage areas were delineated using a high-resolution digital elevation model (DEM) and the stormwater pipe network within Gwinnett County as of August 2021.
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Gwinnett County,
State of Georgia,
drainage basins,
inlandWaters,
runoff,
|
|
