A simple formula for estimating evaporation rates in various climates, using temperature data alone

The Penman formula for the evaporation rate from a lake is simplified to the following: E0=700Tm/(100−A)+15(T−Td)(80−T)(mmday−1) where Tm = T + 0.006h, h is the elevation (metres), T is the mean temperature, A is the latitude (degrees) and Td is the mean dew-point. Values given by this formula typically differ from measured values by about 0.3 mm day−1 for annual means, 0.5 mm day−1 for monthly means, 0.9 mm day−1 for a week and 1.7 mm day−1 for a day. The formula applies over a wide range of climates. Monthly mean values of the term (T − Td) can be obtained either from an empirical table or from the following empirical relationship, provided precipitation is at least 5 mm month−1 and (T − Td) is at least 4°C: (T−Td)=0.0023h+0.37T+0.53R+0.35Rann−10.9°C where R is the mean daily range of temperature and Rann is the difference between the mean temperatures of the hottest and coldest months. Thus the evaporation rate can be estimated simply from values for the elevation, latitude and daily maximum and minimum temperatures.

[1]  H. C. Aslyng.  Evaporation, Evapotranspiration and Water Balance Investigations at Copenhagen 1955–64 , 1965 .

[2]  R. G. Smith,et al.  Accuracy of soil water budgets based on a range of relationships for the influence of soil water availability on actual water use , 1975 .

[3]  D. Angus,et al.  Grass, water and soil evaporation at Aspendale , 1964 .

[4]  Edward T. Linacre,et al.  A simpler empirical expression for actual evapotranspiration rates — a discussion , 1973 .

[5]  W. Brutsaert.  Evaluation of some practical methods of estimating evapotranspiration in arid climates at low latitudes , 1965 .

[6]  Edward T. Linacre,et al.  Climate and the Evaporation from Crops , 1967 .

[7]  E. T. Linacre,et al.  Estimating the net-radiation flux , 1968 .

[8]  E. Linacre.  Net Radiation to Various Surfaces , 1969 .

[9]  E. Linacre.  Empirical relationships involving the global radiation intensity and ambient temperature at various latitudes and altitudes , 1969 .

[10]  B. Hicks,et al.  The evaporation from a swamp , 1970 .

[11]  J. Dutton,et al.  HEAT FLUX IN LAKE MENDOTA1 , 1962 .

[12]  J. Taylor,et al.  World Survey of Climatology, Vol. 13. Climates of Australia and New Zealand , 1971 .

[13]  H. L. Penman.  Natural evaporation from open water, bare soil and grass , 1948, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[14]  J. Kutzbach,et al.  Climates of North America. World survey of climatology, vol. 11: H. E. Landsberg (Editor), R. A. Bryson and F. K. Hare (Volume-editors). Elsevier, Amsterdam, 1974, 420 pp., Dfl. 137.00 , 1974 .

[15]  Marvin E. Jensen,et al.  Consumptive use of water and irrigation water requirements : a report , 1973 .

[16]  M. Budyko,et al.  Climate and life , 1975 .