Super Gages and Water Quality Sampling

Science Center Objects

Super gages provide real-time data specifically designed to improve understanding of watershed processes and to address specific water-resource issues such as climate and land-use effects or hazardous substance spills.

Return to Water >> USGS Transboundary River Monitoring in Southeast Alaska 

Super gages provide real-time data specifically designed to improve understanding of watershed processes and to address specific water-resource issues such as climate and land-use effects or hazardous substance spills. The ability to model estimates of water quality constituents based on a record of continuous data helps improve estimates of loads to downstream areas that are critical for salmon spawning and rearing habitats.

What types of equipment are used in a super gage?

Water-quality monitors for measuring water temperature, pH, dissolved oxygen, specific conductance, and turbidity.

How are data from the super gages are verified?

Representative stream-width and depth-integrated sampling verifies the super gage data and is used to develop surrogate models.

What's a surrogate model?

Measured in-stream values of a parameter and measured concentrations of a constituent are used to develop a regression model to estimate concentrations during non-sampled periods. Computed or estimated concentrations of a constituent of greater interest can be calculated from the surrogate model.

 

Additional Graphs

  • Temperature, water, degrees Celsius  [Graph]
  • Specific conductance, water, unfiltered, microsiemens per centimeter at 25 degrees Celsius  [Graph]
  • Dissolved oxygen, water, unfiltered, milligrams per liter  [Graph]
  • pH, water, unfiltered, field, standard units  [Graph]
  • Turbidity, water, unfiltered, formazin nephelometric units (FNU)  [Graph]
  • Temperature, air, degrees Celsius  [Graph]

Water Quality Measurements

Water quality samples are collected on each river every 6-8 weeks depending on weather and aircraft availability. Samples are collected following USGS sampling methods for surface water. The measured constituents are included in the following table and results are posted to the USGS National Water Information System.

 
Constituent Group Analytes
Physical Specific conductance, dissolved oxygen, turbidity, water temperature, pH
Solids Total dissolved solids, total suspended solids
Nutrients Dissolved ammonia, dissolved nitrite+nitrate, total ammonia+organic nitrogen, total phosphorus, dissolved orthophosphorus
Major Ions Calcium, iron, magnesium, sodium, potassium, chloride, suflate
Alkalinity Alkalinity as CaCO3
Trace Metals Total recoverable and dissolved aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, iron, lead, lithium, manganese, mercury, molybdenum, nickel, selenium, silver, strontium, thallium, uranium, vanadium, and zinc
Organic Compounds Total organic carbon, inorganic carbon, total particulate carbon, total particulate nitrogen