Evaporation from Lake Michie, North Carolina 1961-71
Water-Resources Investigations Report 73-38
- W.L. Yonts , G.L. Giese , and E.F. Hubbard
The Geological Survey, in cooperation with the city of Durham, N. C., collected evaporation data at Lake Michie, Durham's 480-acre water-supply reservoir, for 10 consecutive years from September 1961 to September 1971. Wind speed, air temperature, and water temperature-collected continuously-were used in conjunction with water-budget data to calibrate the semi-empirical mass-transfer equation, E Nu(eo - ea), where E is evaporation; N is the mass-transfer coefficient, which is a constant for a given lake; u is wind speed; eo is the vapor pressure of the saturated air at the water surface; and ea is the vapor pressure of the surrounding air. For evaporation expressed in inches, the mass-transfer coefficient for Lake Michie is 0.0036.
During the study period the average annual evaporation from Lake Michie was 37.9 inches. Within-year variation of evaporation from the lake is sinusoidal, with a high during July averaging 4.71 inches and a low during January averaging 1.45 inches.
Evaporation from Lake Michie was 0.72 (or about three-quarters) of the evaporation from the National Weather Service evaporation pan at Chapel Hill. This ratio, called a pan coefficient, was not constant throughout the year, ranging from an average of 0.57 for April to 1.09 for December.
Additional publication details
- Publication type:
- Publication Subtype:
- USGS Numbered Series
- Evaporation from Lake Michie, North Carolina 1961-71
- Series title:
- Water-Resources Investigations Report
- Series number:
- Year Published:
- U.S. Geological Survey
- Contributing office(s):
- South Atlantic Water Science Center
- iv, 27 p.
- United States
- North Carolina
- Other Geospatial:
- Lake Michie