Techniques and Methods

Harmful algal blooms (HABs) are caused by a complex set of physical, chemical, biological, hydrological, and meteorological conditions. Many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duration, and toxicity of HABs.

The U.S. Geological Survey recognizes the need to provide sediment acoustic training and to develop standardized techniques and practices.

The USGS collects fluvial sediment and geomorphic data and conducts related research at numerous sites across the Nation. This information is essential to informed solutions to sediment-related and overall water resource management issues.

The USGS Quality Systems Branch (QSB) represents the Water Resource Mission Area’s commitment to generating environmental data of known quality. QSB produces water and sediment performance-assessment samples and data to provide the USGS laboratory users, USGS laboratories, and field personnel with quantitative performance information to assess data quality.

The National Field Manual for the Collection of Water-Quality Data (NFM) provides documented methods and protocols for USGS field personnel who collect water-quality data. The NFM provides detailed, comprehensive, and citable procedures for sampling water resources, processing samples for analysis of water quality, measuring field parameters, and specialized procedures.

USGS National Water Quality Assessment (NAWQA) studies require analyses of stream and bed-sediment samples for major ions, nutrients, sediments, and organic contaminants that are consistent across time and space. Procedures have been designed specifically to produce information that is comparable among studies in different parts of the Nation.

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...

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 (FO-DTS) technology can be used for characterizing estuary-aquifer and stream-aquifer interaction and for identifying transmissive fractures in bedrock boreholes.

Borehole nuclear magnetic resonance (NMR) is an emerging geophysical method being applied to hydrogeology investigations.

Spectral gamma borehole geophysical methods measure natural-gamma energy spectra, which are caused by the decay of uranium, thorium, potassium-40, and anthropogenic radioactive isotopes. Spectral gamma data can be used to identify and quantify the amount of uranium, thorium, and potassium-40 isotopes detected in boreholes.

Patent for a pore-water profiler and method for sampling pore water. The pore-water profiler includes a sample intake probe that receives the fluid to be sampled. (Full details provided by the U.S. Patent and Trademark Office website.)