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
Follow the links below to access data on water quality of groundwater and surface water.
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
Estimation of time-variable fast flow path chemical concentrations for application in tracer-based hydrograph separation analyses
Application of SPARROW modeling to understanding contaminant fate and transport from uplands to streams
Regional effects of agricultural conservation practices on nutrient transport in the Upper Mississippi River Basin
The importance of base flow in sustaining surface water flow in the Upper Colorado River Basin
Quantifying watershed-scale groundwater loading and in-stream fate of nitrate using high-frequency water quality data
Predicting redox conditions in groundwater at a regional scale
A comparison of high-resolution specific conductance-based end-member mixing analysis and a graphical method for baseflow separation of four streams in hydrologically challenging agricultural watersheds
A new approach for continuous estimation of baseflow using discrete water quality data: Method description and comparison with baseflow estimates from two existing approaches
Effects of suspended sediment concentration and grain size on three optical turbidity sensors
Continuous estimation of baseflow in snowmelt-dominated streams and rivers in the Upper Colorado River Basin: A chemical hydrograph separation approach
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
Follow the links below to access data on water quality of groundwater and surface water.
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
Estimation of time-variable fast flow path chemical concentrations for application in tracer-based hydrograph separation analyses
Application of SPARROW modeling to understanding contaminant fate and transport from uplands to streams
Regional effects of agricultural conservation practices on nutrient transport in the Upper Mississippi River Basin
The importance of base flow in sustaining surface water flow in the Upper Colorado River Basin
Quantifying watershed-scale groundwater loading and in-stream fate of nitrate using high-frequency water quality data
Predicting redox conditions in groundwater at a regional scale
A comparison of high-resolution specific conductance-based end-member mixing analysis and a graphical method for baseflow separation of four streams in hydrologically challenging agricultural watersheds
A new approach for continuous estimation of baseflow using discrete water quality data: Method description and comparison with baseflow estimates from two existing approaches
Effects of suspended sediment concentration and grain size on three optical turbidity sensors
Continuous estimation of baseflow in snowmelt-dominated streams and rivers in the Upper Colorado River Basin: A chemical hydrograph separation approach
Below are news stories associated with this project.