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North Santiam River Basin Turbidity and Suspended-Sediment Study
Definitions
Discharge (Q)
Streamflow, or discharge, is the volume of water flowing past a fixed point in a fixed unit of time. For water flow in streams, the U.S. Geological Survey expresses the value in cubic feet per second (ft3/s)
[excerpt, http://ga.water.usgs.gov/edu/measureflow.html]. |
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Stage (S)
Stream stage (also called stage or gage height) is the height of the water surface, in feet, above an established datum plane where the stage is zero. The zero level is arbitrary, but is often close to the streambed [excerpt, http://ga.water.usgs.gov/edu/measureflow.html]. |
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Water Temperature (WT)
Accurate temperature measurements are required for accurate determinations of important environmental parameters such as pH, specific electrical conductance, and dissolved oxygen, and to the determination of chemical reaction rates and equilibria, biological activity, and physical fluid properties [excerpt, USGS National Field Manual]. |
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pH (pH)
Measurement of pH is critical to the understanding of the viability and vulnerability of environmental waters and is considered a master variable in determining the aqueous geochemistry of an aqueous system. pH is a measure that represents the hydrogen-ion concentration (activity) of a solution [excerpt, USGS National Field Manual]. |
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Specific Conductance (SC)
Electrical conductance is a measure of the capacity of a substance to conduct an electrical current. The specific electrical conductance (conductivity) of water is a function of the types and quantities of dissolved substances it contains, normalized to a unit length and unit cross section at a specified temperature [excerpt, USGS National Field Manual]. |
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Turbidity (TBDY)
Turbidity is one of the indicators used to assess the environmental health of water bodies. Turbidity is caused by the presence of suspended and dissolved matter, such as clay, silt, finely divided organic matter, plankton and other microscopic organisms, organic acids, and dyes [excerpt, USGS National Field Manual]. |
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Dissolved Oxygen/Dissolved Oxygen % (DO/DO%)
Accurate data for the concentration of dissolved oxygen in surface and ground waters are essential for documenting changes in environmental water resources that result from natural phenomena and human activities. Dissolved oxygen is necessary in aquatic systems for the survival and growth of many aquatic organisms and is used as an indicator of the health of surface-water bodies [excerpt, USGS National Field Manual]. |
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Precipitation (Prec)
Precipitation, either as rainfall or snowfall, is measured in inches. Most instruments measure "wet" water; therefore, snowfall measurements are typically converted and reported as rainfall equivalency. |
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Suspended-Sediment Concentrations (SSC)
Part of standard processing of sediment sampling. Suspended-sediment concentrations are reported in milligrams per liter (mg/L), and are highly correlated to turbidity. They are necessary for producing suspended-sediment load values. |
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NWIS-Web
As part of the U.S. Geological Survey's (USGS) program for disseminating water data within USGS, to USGS cooperators, and to the general public, the USGS maintains a distributed network of computers and fileservers for the acquisition, processing, review, and long-term storage of water data. This water data is collected at over 1.5 million sites around the country and at some border and territorial sites. This distributed network of computers is called the National Water Information System (NWIS). Many types of data are stored in NWIS, including comprehensive information for site characteristics, well-construction details, time-series data for gage height, streamflow, ground-water level, precipitation, and physical and chemical properties of water. Additionally, peak flows, chemical analyses for discrete samples of water, sediment, and biological media are accessible within NWIS [excerpt, NWISWeb Help System].
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Custom
As the name implies, the custom option for table and graph input are controlled by the user. |
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U.S. Department of the Interior |
U.S. Geological Survey
