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GLOSSARY for USGS Lake Gage at ECHO
EVAPOTRANSPIRATION -- The loss of water to the atmosphere from the earth's surface by evaporation and by transpiration. (Transpiration is the process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, such as leaf pores. For more information, see The Water Cycle: Transpiration)
GAGE HEIGHT -- the height of the water surface above the gage's zero point. Gage height is often used interchangeably with the more general term, stage, although gage height is more appropriate when used with a gage reading.
HYDROGRAPHER -- a person who measures and charts characteristics of water bodies, such as depth and flow.
pH -- A measure of the acidity (less than 7) or alkalinity (greater than 7) of a solution; a pH of 7 is considered neutral.
REAL-TIME -- A timeframe so short that it seems immediate. Computers that process information in real-time are reading the information as it comes in, and returning some results to users immediately. The information available on the USGS Web site is said to be real-time because it is available there practically at the same time that the measurements are made in the lake or river. The gages that are set up to transfer the information in real-time are called real-time gages.
SPECIFIC CONDUCTANCE -- A measure of the ability of a liquid to conduct an electrical current. Scientists can use this measurement as an indicator of certain materials being present in the water, for example, salt from nearby roads and other dissolved substances originating from sources such as wastewater facilities and runoff from agricultural lands.
STREAMFLOW -- The amount of water flowing in a river usually expressed in cubic feet per second (ft3/s).
WATER CYCLE -- The circuit of water movement from the oceans to the atmosphere and to the Earth and return to the atmosphere through various stages or processes such as precipitation, interception, runoff, infiltration, percolation, storage, evaporation, and transportation. For more information, see USGS water cycle diagrams.
WATERSHED -- The land area that drains water to a particular stream, river, or lake. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large watersheds, like the Connecticut River watershed, contain thousands of smaller watersheds. Watersheds are important because the streamflow and the water quality of a river are affected by what happens in the land area that drains to it. A watershed is also known as a basin.
