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0 <br />47 <br />• . from Table 9, and Kc is a crop cover coefficient which, according to <br />4 Wymore, has a value of 0.5 for bare soil. The constant C is a conver- <br />sion factor which converts Langley/day to inches. Taking an average month <br />to be 30.4 days, C is equal to 0.02053. It was assumed that all snowfall, <br />less evaporation losses in the months Nov.-Mar., accumulates and begins <br />melting in April. All snowpack was assumed to melt in the months of April <br />1 and May at a rate of 50 `o per month. These calculations were carried out <br />~ for a normal year and for a year in which above normal amounts of preci- <br />pitation occurred. These calculations are summarized in Table 10. <br />Evaporation during the growing season was estimated using the Jensen- <br />~ Raise equation as modified by Wymore (1974): <br />Et = Kc [0.014T - (0.57 - 0.04E1)] RSC <br />~ in which Et is the monthly evaporation, El is the elevation in thousands <br />of feet, and other symbols are as previously defined. Values of Kc vary <br />• throughout the growing season and are presented in Table 11 along with a <br />1 summary of the calculations. <br />TABLE 11 Calculation Of Evaporation With <br />Water Not Limiting <br />Month K (in.) <br />E <br /> c t <br />~ Apr .6 2.20 <br />i May .65 3.49 <br />Jun .65 4.65 <br />'~ Jul .65 4.98 <br />Aug .6 3.98 <br />' Sep .5 2.44 <br />` Oct .5 1.42 <br /> 23.16 <br />• The values of Et in Table 11 represent the evaporation that would occur <br />if adequate water were available at all times. Actual evaporation, Eta, <br />• ` depends on water availability and will be computed as a part of the sub- <br />surface water budget. Clearly, the actual evaporation over the .season will <br />be less than the seasonal value of Et sho~.vn in Table ll since the available <br />precipitation is 13.15 inches (Table 10). <br />