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STREAM TEMPERATURE ESTIMATION FROM AIR TEMPERATURE 1
Author(s) -
Stefan Heinz G.,
Preud'homme Eric B.
Publication year - 1993
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.1993.tb01502.x
Subject(s) - streams , environmental science , hydrology (agriculture) , lag , range (aeronautics) , drainage basin , standard deviation , air temperature , atmospheric sciences , geology , mathematics , materials science , geography , statistics , computer network , geotechnical engineering , cartography , computer science , composite material
Air temperatures are sometimes used as substitutes for stream temperatures. To examine the errors associated with this procedure, linear relationships between stream temperatures, T, and air temperatures, T a , recorded for 11 streams in the central U.S. (Mississippi River basin) were analyzed. Weather stations were an average 42 miles (range 0 to 144 miles) from the rivers. The general equations, T w = 5.0 + 0.75 T a and T w = 2.9 + 0.86 T a with temperatures in °C, were derived for daily and weekly water temperatures, respectively, for the 11 streams studied. The simulations had a standard deviation between measurements and predictions of 2.7°C (daily) and 2.1°C (weekly). Equations derived for each specific stream individually gave lower standard deviations, i.e., 2.1°C and 1.4°C, respectively. Small, shallow streams had smaller deviations than large, deep rivers. The measured water temperatures follow the air temperatures closely with some time lag. time lags ranged from hours to days, increasing with stream depth. Taking into account these time lags improved the daily temperature predictions slightly. Periods of ice cover were excluded from the analysis.