r = adiabatic lapse rate [(K(m-1] S 9.86 x 10-3 k = von Karman's constant dimensionlesss] = 0.428 U* = shear velocity [mns-1] For neutral conditions the familiar logarithmic velocity profile was used. For unstable or diabetic conditions a variation of the logarithmic profile was used or the KEYPS function (Panofsky, 1963) was used to determine the velocity profile. King stressed that in using profile methods to determine evaporation, one must take extreme care in measuring wind velocity. He suggested that spatial averaging be used for wind speed measurements near ground level and that 30- to 60-minute averages be used considering the steady state assumptions made in developing the equations for the profile equations. Corrections for lower atmospheric instability caused by density gradients in the air near the earth's surface must also be used. Another method requiring only measurements of atmospheric parameters is the eddy flux method (Goddard and Pruitt, 1966). The method is based upon the turbulent transport equations of motion in the atmosphere. The equations of turbulent motion in a fluid include the transient random fluctuations in velocity, temperature, and mass concentration of water vapor of the air. The following equations describe the shear stress (T), sensible heat flux (H) and latent heat flux (LE) due to the turbulent motion of the atmosphere au 7 = PaKm,- awu (2-8) H = cpaPaKh + cpaPaw'' (2-9)