Locating and quantifying exchanges of groundwater and surface water, along with characterizing geologic structure, is essential to water-resource managers and hydrologists for the development of effective water-resource policy, protection, and management. The USGS conducts applied research to evaluate the use of new or emerging hydrogeophysical tools and methods to improve our understanding of groundwater/surface-water exchange.
Overview
Understanding exchanges of groundwater and surface water is essential to water managers and hydrologists for the development of effective water-resources policy, protection, and management. Surface water (including streams, lakes, wetlands, and estuaries) “gains” groundwater discharge via seeps and springs, while surface water also infiltrates into adjacent groundwater under “losing” hydraulic conditions. Groundwater discharge is the main component of stream baseflow, or the channel water flowing in between storm events and snowmelt. Many streams, lakes, and wetlands are primarily sourced by groundwater discharge during dry conditions, while coastal water quality can be strongly influenced by submarine groundwater discharge. Groundwater recharge occurs when surface water is exchanged into aquifers below, impacting groundwater chemistry and water supply. The sediment interface between groundwater and surface water, such as a streambed, is often highly reactive due to diverse chemical and microbial conditions, further modifying water quality over short transport distances (e.g., centimeters).
Physical methods of monitoring groundwater/surface-water exchange are often labor intensive and limited in spatial scale. The effects of groundwater/surface-water exchange can occur on a variety of time scales and distances. The dynamics of groundwater/surface water exchange at the stream reach to regional scale are often characterized based on measurements made at a few individual points, though such extrapolation can be highly uncertain do to inherent spatial and temporal variability. The hydrogeophysics toolkit produces data that span scales and helps put point-based measurements into hydrogeological context, often leading to improved understanding of groundwater/surface water exchange processes and associated management concerns.
Using Geophysics to Study Groundwater/Surface-Water Exchange
The USGS Water Resources Mission Area conducts applied research to evaluate the use of new or emerging hydrogeophysical tools and methods to improve our understanding of groundwater/surface-water exchange. Geophysical methods based on measuring the electrical, thermal, and (or) physical properties of surface water, groundwater, and the shallow subsurface can enable scientists to efficiently locate and quantify groundwater and surface-water related processes. Such spatially comprehensive and spatially distributed information can tie point measurements to larger geologic structures controlling flow and transport at local and regional scales. Similar data types collected over time (i.e., time-lapse data) allow researchers to track highly dynamic processes such as the movement of contaminant plumes, soil moisture, and saltwater intrusion. As a result, we are better able to understand and forecast movement of water between groundwater and surface-water bodies and associated changes in water quality and quantity.
USGS has been a leader in advancing the use of hydrogeophysics to study groundwater/surface-water exchange for decades via methods and software development and pioneering research. Current efforts continue to foster innovation and development of hydrogeophysical technologies and methodologies to answer important questions about our water resources. This work is also part of the USGS Next Generation Water Observing Systems state-of-the-art monitoring technology and methods to increase the spatial and temporal coverage of USGS water data and to make data more affordable and more rapidly available. The USGS Water Resources Mission Area recently released a groundwater/surface water exchange related methods selection tool to aid in the discovery of complimentary tools that may be well suited for specific applications, and to increase the general awareness of the diverse existing toolkit.
USGS Water Resources Mission Area science pages related to Geophysics for Groundwater/Surface Water Exchange Studies
Groundwater/Surface-Water Interaction
Thermal Imaging Cameras for Studying Groundwater/Surface-Water Exchange
What does groundwater have to do with ice in Alaska?
Fiber-Optic Distributed Temperature Sensing Technology for Surface-Water and Groundwater Studies
Thermal Imaging Camera Use: Identifying Groundwater Inputs to a Reef in American Samoa
Fiber-Optic Distributed Temperature Sensing in Waquoit Bay, Massachusetts
- Overview
Locating and quantifying exchanges of groundwater and surface water, along with characterizing geologic structure, is essential to water-resource managers and hydrologists for the development of effective water-resource policy, protection, and management. The USGS conducts applied research to evaluate the use of new or emerging hydrogeophysical tools and methods to improve our understanding of groundwater/surface-water exchange.
Overview
Sources/Usage: Public Domain. Visit Media to see details.USGS Hydrologist Eric White monitors a computer displaying real-time data inversions while towing a novel floating transient electromagnetic (TEM) system (i.e., FloaTEM) on the Columbia River near Richland, Washington, adjacent to the Hanford 300 Area. The FloaTEM is being used by USGS scientists for rapid (up to 15 kilometers per hour) high-resolution electrical resistivity mapping of the subsurface below large water bodies to inform large-scale groundwater/surface water exchange modeling. The FloaTEM images to depths of approximately 50 to 80 meters below the water surface and collects a sounding every 10 to 20 meters along the profile. The FloaTEM system fills a critical gap in our ability to characterize the hydrogeology below surface-water features and supports more accurate prediction of groundwater/surface water exchange dynamics and fresh-saline groundwater interfaces. Understanding exchanges of groundwater and surface water is essential to water managers and hydrologists for the development of effective water-resources policy, protection, and management. Surface water (including streams, lakes, wetlands, and estuaries) “gains” groundwater discharge via seeps and springs, while surface water also infiltrates into adjacent groundwater under “losing” hydraulic conditions. Groundwater discharge is the main component of stream baseflow, or the channel water flowing in between storm events and snowmelt. Many streams, lakes, and wetlands are primarily sourced by groundwater discharge during dry conditions, while coastal water quality can be strongly influenced by submarine groundwater discharge. Groundwater recharge occurs when surface water is exchanged into aquifers below, impacting groundwater chemistry and water supply. The sediment interface between groundwater and surface water, such as a streambed, is often highly reactive due to diverse chemical and microbial conditions, further modifying water quality over short transport distances (e.g., centimeters).
Physical methods of monitoring groundwater/surface-water exchange are often labor intensive and limited in spatial scale. The effects of groundwater/surface-water exchange can occur on a variety of time scales and distances. The dynamics of groundwater/surface water exchange at the stream reach to regional scale are often characterized based on measurements made at a few individual points, though such extrapolation can be highly uncertain do to inherent spatial and temporal variability. The hydrogeophysics toolkit produces data that span scales and helps put point-based measurements into hydrogeological context, often leading to improved understanding of groundwater/surface water exchange processes and associated management concerns.
Using Geophysics to Study Groundwater/Surface-Water Exchange
Sources/Usage: Public Domain.Infrared image indicates water temperature, where warmer temperatures are represented as yellow and cooler temperatures as purple. The image presents an area where a relatively warm groundwater seep is discharging along the edge of a relatively cooler stream, and the water is mixing. The temperature range displayed is approximately 1 to 8 degrees Celsius. The area at the center of the image is about 2 meters across. The USGS Water Resources Mission Area conducts applied research to evaluate the use of new or emerging hydrogeophysical tools and methods to improve our understanding of groundwater/surface-water exchange. Geophysical methods based on measuring the electrical, thermal, and (or) physical properties of surface water, groundwater, and the shallow subsurface can enable scientists to efficiently locate and quantify groundwater and surface-water related processes. Such spatially comprehensive and spatially distributed information can tie point measurements to larger geologic structures controlling flow and transport at local and regional scales. Similar data types collected over time (i.e., time-lapse data) allow researchers to track highly dynamic processes such as the movement of contaminant plumes, soil moisture, and saltwater intrusion. As a result, we are better able to understand and forecast movement of water between groundwater and surface-water bodies and associated changes in water quality and quantity.
USGS has been a leader in advancing the use of hydrogeophysics to study groundwater/surface-water exchange for decades via methods and software development and pioneering research. Current efforts continue to foster innovation and development of hydrogeophysical technologies and methodologies to answer important questions about our water resources. This work is also part of the USGS Next Generation Water Observing Systems state-of-the-art monitoring technology and methods to increase the spatial and temporal coverage of USGS water data and to make data more affordable and more rapidly available. The USGS Water Resources Mission Area recently released a groundwater/surface water exchange related methods selection tool to aid in the discovery of complimentary tools that may be well suited for specific applications, and to increase the general awareness of the diverse existing toolkit.
Sources/Usage: Public Domain.USGS Research Hydrologists Neil Terry and Marty Briggs review fiber-optic distributed temperature sensing (FO-DTS) data with Dale Werkema of the U.S. Environmental Protection Agency as the data are collected along Cement Creek near Silverton, Colorado, in September 2019 to determine the locations of mine drainage inflows to the stream. The data were visualized and analyzed for statistical metrics in real-time using the USGS DTS-GUI software. - Science
USGS Water Resources Mission Area science pages related to Geophysics for Groundwater/Surface Water Exchange Studies
Groundwater/Surface-Water Interaction
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.Thermal Imaging Cameras for Studying Groundwater/Surface-Water Exchange
USGS scientists are using high-resolution handheld and airborne thermal imaging cameras in groundwater/surface-water exchange studies and other investigations where surface temperature contrasts indicate various hydrological processes. These cameras are used to quickly locate and characterize thermal (temperature) anomalies along streams, lakes, wetlands, estuaries, and across the landscape...What does groundwater have to do with ice in Alaska?
USGS scientists are working alongside university researchers in Alaska to understand how groundwater and permafrost conditions change over time due to seasonal variations and climate change. Changes in permafrost can pose a threat to built infrastructure (like roads, homes, and pipelines) and to valued ecological resources that provide important habitats for wildlife.Fiber-Optic Distributed Temperature Sensing Technology for Surface-Water and Groundwater Studies
Fiber-optic distributed temperature sensing (FO-DTS) technology can be used for characterizing estuary-aquifer and stream-aquifer interaction and for identifying transmissive fractures in bedrock boreholes.Thermal Imaging Camera Use: Identifying Groundwater Inputs to a Reef in American Samoa
USGS scientists used a thermal camera in American Samoa to understand the effect of land-based contaminants on an adjacent coral reef lagoon ecosystem. The infrared (IR) camera was used to capture thermal images of the lagoon to look for temperature differences to understand the distribution of freshwater entering the lagoon and the circulation of the lagoon water at various tidal levels.Fiber-Optic Distributed Temperature Sensing in Waquoit Bay, Massachusetts
In 2006 the USGS Office of Groundwater, Branch of Geophysics (OGW BG) conducted a technology demonstration and evaluation project in Waquoit Bay, East Falmouth, Massachusetts, to evaluate the use of fiber-optic distributed temperature sensing (FO-DTS). In this project, the USGS used FO-DTS to investigate aquifer-estuary interaction by monitoring submarine groundwater discharge in Waquoit Bay. OGW... - Data
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