Virginia Water Science Center
1730 East Parham Road
Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in major rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay Nontidal Network (NTN) stations for the period 1985 through 2018. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). The load results represent the total mass of nitrogen, phosphorus, and suspended sediment that was exported from each of the NTN watersheds. To determine the trend in loads, the annual load results are flow normalized to integrate out the year-to-year variability in river discharge....
Groundwater residence times were simulated for the major regional aquifers of the Northern Atlantic Coastal Plain aquifer system from New York to North Carolina using particle tracking in a regional groundwater flow model. Millions of particles were distributed throughout the aquifers of the North Atlantic Coastal Plain in a MODFLOW model with a volume-weighted algorithm, then tracked backwards using MODPATH6 (Pollock, 2012) until termination of their paths at their sources of origin, usually the simulated water table. Particles were tracked under simulated transient hydrologic conditions from the reference time of January 1, 2018 backwards to 1900, then under simulated steady-state conditions prior to 1900 until...
A revision to the hydrogeologic framework of the Virginia coastal plain southwest of the James River was developed by USGS during 2019-2021. This revision includes modifications to existing understanding of the groundwater system in Prince George, Surry, Sussex, Isle of Wight, and Southampton counties and the cities of Franklin and Suffolk in southeast Virginia. This USGS data release contains a csv file of interpreted borehole hydrogeologic-unit top-surface altitudes, a shapefile of the study area extent, a shapefile of faults within the study area, shapefiles of altitude contours for 12 hydrogeologic-unit top surfaces, shapefiles of hydrogeologic-unit margins for 10 hydrogeologic-units in the coastal plain of...
Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay Nontidal Network (NTN) stations for the period 1985 through 2018 Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted Regression on Time, Discharge, and Season). A recently published extension of WRTDS allows users to separate these estimates into high- and low-flow conditions. This data release contains (1) a table of daily high- and low-flow concentration and load estimates for NTN stations between 1985 - 2018 and (2) an R file that contains...
This data release documents spatiotemporal water-quality, landscape, and climatic conditions in Fairfax County, Virginia from 2007 through 2018. These data were used to evaluate the water-quality and ecological condition of 20 Fairfax County watersheds monitored since 2007. Data include measures of water-quality, precipitation, air temperature, land use, land cover, wastewater and stormwater infrastructure, soil properties, geologic setting, and stream networks. Annual values from 2007 through 2018 are reported for data expected to change over time. Watershed-specific values are reported for data that differ across the landscape. Annual values for the 20 study watersheds and Fairfax County are reported in the file...