The Integration of Surface Water and Groundwater—A Critical Linkage
The complex interaction of water above ground and below ground is a key element of the hydrologic cycle
Water and the chemicals it contains are constantly being exchanged between the land surface and the subsurface. Surface water seeps into the ground and recharges the underlying aquifer—groundwater discharges to the surface and supplies the stream with baseflow. USGS Integrated Watershed Studies assess these exchanges and their effect on surface-water and groundwater quality and quantity.
Groundwater and surface water physically overlap at the groundwater/surface water interface through the exchange of water and chemicals. This exchange is a critical part of the hydrologic cycle. Surface water supplies recharge to the underlying aquifer, where the groundwater can remain in storage for days, months, years, centuries, or even millennia. Eventually the groundwater discharges back into the stream. Depending on how much time the water spends underground, and the geochemical conditions within the aquifer, the quality of the original recharge water can undergo profound changes before it discharges at the surface.
USGS Integrated Watershed Studies seek to better understand and quantify the exchanges at the surface water/groundwater interface. This understanding is used to forecast how the chemical quality of water will change in response to changes in climate, land use, or management practices. Integrated Watershed Studies develop methods to quantify the movement of water and chemicals between the watershed, stream, and groundwater to estimate past and forecast future water-quality conditions at regional scales. The USGS also develops new methods to interpret high-frequency water-quality monitoring data to inform and develop watershed models.
Interested in surface-water quality? Find out more here.
Interested in groundwater quality? Find out more here.
Follow the links below to web pages for associated USGS science topics.
Agriculture and the Quality of the Nation's Waters
Groundwater Quality Research
Surface-Water Quality and Ecology
Follow the links below to access data on water quality of groundwater and surface water.
Input and results from a boosted regression tree (BRT) model relating base flow nitrate concentrations in the Chesapeake Bay watershed to catchment characteristics (1970-2013)
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
Datasets and metadata for estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology
Depth to 50 percent probability of oxic conditions, Chesapeake Bay Watershed
Hydrograph-separation results for 225 streams in the Chesapeake Bay watershed derived by using PART, HYSEP (Fixed, Local minimum, Slide), BFI, and a Recursive Digital Filter with streamflow data ranging from 1913 through 2016
Real and synthetic data used to test the Two-tracer Ratio-based Mixing Model (TRaMM)
Data on annual total nitrogen loads and watershed characteristics used to develop a method to estimate the total nitrogen loads in small streams
Water Quality and Hydrologic Data (2011-13) for Freshwater Science Paper titled, "Patterns of Diel Variation in Nitrate Concentrations in the Potomac River"
Follow these links to access USGS and IWS publications on surface-water/groundwater interaction and water quality.
Agriculture — A river runs through it — The connections between agriculture and water quality
Biofilms provide new insight into pesticide occurrence in streams and links to aquatic ecological communities
Monitoring the Riverine Pulse: Applying high-frequency nitrate data to advance integrative understanding of biogeochemical and hydrological processes
Elevated manganese concentrations in United States groundwater, role of land surface–soil–aquifer connections
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
UFINCH: A method for simulating unit and daily flows in networks of channels described by NHDPlus using continuous flow data at U.S. Geological Survey streamgages
Estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology
Regional variability of nitrate fluxes in the unsaturated zone and groundwater, Wisconsin, USA
Estimating discharge and nonpoint source nitrate loading to streams from three end‐member pathways using high‐frequency water quality data
Predicting redox-sensitive contaminant concentrations in groundwater using random forest classification
Optimal hydrograph separation using a recursive digital filter constrained by chemical mass balance, with application to selected Chesapeake Bay watersheds
Statistically extracted fundamental watershed variables for estimating the loads of total nitrogen in small streams
Patterns of diel variation in nitrate concentrations in the Potomac River
Below are news stories associated with this project.
Water and the chemicals it contains are constantly being exchanged between the land surface and the subsurface. Surface water seeps into the ground and recharges the underlying aquifer—groundwater discharges to the surface and supplies the stream with baseflow. USGS Integrated Watershed Studies assess these exchanges and their effect on surface-water and groundwater quality and quantity.
Groundwater and surface water physically overlap at the groundwater/surface water interface through the exchange of water and chemicals. This exchange is a critical part of the hydrologic cycle. Surface water supplies recharge to the underlying aquifer, where the groundwater can remain in storage for days, months, years, centuries, or even millennia. Eventually the groundwater discharges back into the stream. Depending on how much time the water spends underground, and the geochemical conditions within the aquifer, the quality of the original recharge water can undergo profound changes before it discharges at the surface.
USGS Integrated Watershed Studies seek to better understand and quantify the exchanges at the surface water/groundwater interface. This understanding is used to forecast how the chemical quality of water will change in response to changes in climate, land use, or management practices. Integrated Watershed Studies develop methods to quantify the movement of water and chemicals between the watershed, stream, and groundwater to estimate past and forecast future water-quality conditions at regional scales. The USGS also develops new methods to interpret high-frequency water-quality monitoring data to inform and develop watershed models.
Interested in surface-water quality? Find out more here.
Interested in groundwater quality? Find out more here.
Follow the links below to web pages for associated USGS science topics.
Agriculture and the Quality of the Nation's Waters
Groundwater Quality Research
Surface-Water Quality and Ecology
Follow the links below to access data on water quality of groundwater and surface water.
Input and results from a boosted regression tree (BRT) model relating base flow nitrate concentrations in the Chesapeake Bay watershed to catchment characteristics (1970-2013)
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
Datasets and metadata for estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology
Depth to 50 percent probability of oxic conditions, Chesapeake Bay Watershed
Hydrograph-separation results for 225 streams in the Chesapeake Bay watershed derived by using PART, HYSEP (Fixed, Local minimum, Slide), BFI, and a Recursive Digital Filter with streamflow data ranging from 1913 through 2016
Real and synthetic data used to test the Two-tracer Ratio-based Mixing Model (TRaMM)
Data on annual total nitrogen loads and watershed characteristics used to develop a method to estimate the total nitrogen loads in small streams
Water Quality and Hydrologic Data (2011-13) for Freshwater Science Paper titled, "Patterns of Diel Variation in Nitrate Concentrations in the Potomac River"
Follow these links to access USGS and IWS publications on surface-water/groundwater interaction and water quality.
Agriculture — A river runs through it — The connections between agriculture and water quality
Biofilms provide new insight into pesticide occurrence in streams and links to aquatic ecological communities
Monitoring the Riverine Pulse: Applying high-frequency nitrate data to advance integrative understanding of biogeochemical and hydrological processes
Elevated manganese concentrations in United States groundwater, role of land surface–soil–aquifer connections
An exploratory Bayesian network for estimating the magnitudes and uncertainties of selected water-quality parameters at streamgage 03374100 White River at Hazleton, Indiana, from partially observed data
UFINCH: A method for simulating unit and daily flows in networks of channels described by NHDPlus using continuous flow data at U.S. Geological Survey streamgages
Estimates of nitrate loads and yields from groundwater to streams in the Chesapeake Bay watershed based on land use and geology
Regional variability of nitrate fluxes in the unsaturated zone and groundwater, Wisconsin, USA
Estimating discharge and nonpoint source nitrate loading to streams from three end‐member pathways using high‐frequency water quality data
Predicting redox-sensitive contaminant concentrations in groundwater using random forest classification
Optimal hydrograph separation using a recursive digital filter constrained by chemical mass balance, with application to selected Chesapeake Bay watersheds
Statistically extracted fundamental watershed variables for estimating the loads of total nitrogen in small streams
Patterns of diel variation in nitrate concentrations in the Potomac River
Below are news stories associated with this project.