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<br />References
<br />1. Allen, R. G. and C. E. Brockway. 1983. Estimating
<br />consumptive use on a statewide basis. Proo:edings of the Irrigation and
<br />Drainage Speciality Conference of the American Society of Civil
<br />Engineers. Jackson Hole, WY, July 20-22.
<br />2. Blaney, H. F. and W. D. Criddle. 1962. Determining
<br />consumptive use and irrigation water requirements. USDA Technical
<br />Bulletin 1275, 59 p.
<br />3. Borrelli, J. 1981. Future of irrigated agriculture in the Oreal
<br />Plains. The Great Plains. Perspectives !lnd Prospects, University of
<br />Nebraska, Lincoln. pp. 181.191. .
<br />4. Borrelli, J. et a!. 1981. Blaney-Criddle coefficients for western
<br />turf grass. J. Irrig. and Drain. Div., ASCE. 107:333.341.
<br />5. Cuenca. R. H., J. Erpenbeck, and W. O. Pruitl. 1981. Advances
<br />in computation of regional evapotranspiration. Proc. of the Specially
<br />Conference WAter Forum 'SI, San Francisco, ASCE, 1:73-80.
<br />6. Davidson,_S. C. 1981. Evapotra.ospiratiQn of mountain meadows
<br />near Laramie, WY. M. S. Thesis, University of Wyoming, Laramie.
<br />70 p. .
<br />.7. Doorenbos, J. and W. O. Pruitt. 1977. Crop Wa.\tt
<br />requirements. FAO Irrigation and Drainage Pap.er 24, Rome, 144 p.
<br />8. Jensen, M. E. 1966. Discussion of irrigation water requirements
<br />of lawns. J. Irrig. and Drain. Div., ASCE, 92:95-100.
<br />9. Jensen, M. E., D. C. N. Robb, and C. E. Franzoy. 1970.
<br />Scheduling irrigations using climate-crop-soil data. J.lrrig. and Drain.
<br />Div., AXCE, 96:25..
<br />10. Soil Conservation Service. 1967. Irrigation water requirements.
<br />Tech. Rt:lease No. 21, USDA, revised 1970, 88 p.
<br />11. Wyoming Conservation Commission. 1981. Wyoming Resources
<br />and Comervation Plans 1981-85 and Beyond, Cheyen~e, 48 p.
<br />12. Wyoming State Engineer's Oftice. 1973. The Wyoming
<br />framework water plan. Water Planning Program, Cheyenne, 23 p.
<br />13. Youngner, V. B. 1979. Turfgrass water use........ University of
<br />earlier in this paper, this pheno~a has been observed California studies. Proc. Arizona Turfgrass ConferenCe, Tucson, Ariz..
<br />by others. Our results also confirm the-statem~thin pp.8.17. . .
<br />
<br />TABLE 7. COMPARISONS OF ESTIMATED (U) V~EASURED (ET) CONSUMPTIVE USE. 14M, FOR ALFALFA
<br />
<br />TABLE 5. SITES AND REFERENCE SOURCES FOR
<br />ALFALFA DATA
<br />
<br />002824 ElevlltJon,
<br />Loclltion L4I.titudt: m Reference
<br /> Larllmie. WY 41.00 2195 Davidson, 1981
<br /> LOSlln, UT 42.00 1375 BlaneY-Criddle, 1962
<br /> Men.,AZ 33.50 1350
<br /> Scottsbluff, NE 42.00 1205
<br /> St. GeorW;l:, UT 37.00 82.
<br /> Dt:ep Rivt:r. NO 47.0" 500
<br /> .Redfield, NO 45.00 '50
<br /> Ollvis, CA 38.50 15
<br /> Stockton, CA 38.00 7
<br />
<br />kt'" 0.0254t + 0.376. . . . . . . . . . . . . . . . . . . . . " [5J
<br />
<br />I
<br />
<br />Crop growth stage coefficients (k.) were then calculated
<br />(Table 6). The k. values were close to those give by the
<br />SCS (1967) for alfalfa. Estimated (u) consumptive use
<br />was then compared to measured (ET) consumptive use
<br />(Table 7). Overall results suggest a 6.4'r. adjustment for
<br />calculated potential ET per 1000 m elevation for the
<br />season (April through October) and a 9.1 'r. adjustment
<br />for the summer months (June through August).
<br />
<br />SUMMARY
<br />
<br />ET data from lysimeters are only measured at a few
<br />locations. Estimates of ET, however, are required at
<br />most locations for various types of water studies. This
<br />study indicated that a correction factor for elevation can
<br />be used that will improve estimates of ET when using the
<br />Blaney Criddle method. Six to 10% adjustment per
<br />1000 m altitude were found to be required for calculated
<br />evapotranspiration when using the SCS Blaney Criddle
<br />formula for Kentucky bluegrass and alfalfa. The
<br />adjustment should increase the ET estimates for sites
<br />with elevations greater than the location at which the
<br />formula is calibrated and decrease estimates for sites
<br />with lower elevations.
<br />The apparent cause for the adjustment is that the
<br />mean temperatures do not accurately reflect the plant's
<br />reaction to the warm daytime temperatures and cool
<br />nights. Further, mean temperatufe tends to dt:crease
<br />while solar radiation intensity increases with elevation
<br />providing increased energy for the ET process. As stated
<br />
<br />TABLE 6. CALIBRATED CROP GROW'!'H
<br />STAGE COEFFICIENTS FOR ALFALFA
<br />AVERAGED FOR THE NINE SITES
<br />OF TABLE 6.
<br />
<br />Month
<br />
<br />Coefficient
<br />
<br />April
<br />M.y
<br />June
<br />July
<br />AUlust
<br />Septl:mber
<br />October
<br />
<br />0.92
<br />1.08
<br />1.16
<br />1.11
<br />1.01
<br />0.92
<br />0.86
<br />
<br />F AO-24 that an approximate 10'r. ?pward adjustment in
<br />temperature based reference crop ET per 1000 m
<br />increase in elevation is generally necessary for accurate
<br />estimates of ET.
<br />
<br /> Laramil: Logan Mesa Scottsbluff St. George Deep Riv'er Redfield DaviS Stockton
<br />Month u ET u ET u ET u ET u ET u ET u ET u ET u ET
<br />Ap, 55 58 121 135 62 .. ., 116 .6 86 57 .7 " '2 101 83
<br />M.y 96 108 188 191 12. 113 163 17. 128 150 131 126 135 125 163 133
<br />Jun 120 167 151 15. 253 232 187 172 244 21. 175 178 188 '" ,.7 163 216 I"
<br />Jul 152 159 187 18. 2'3 258 225 206 271 231 195 183 224 235 203 "0 233 2011
<br />Aug 139 16' 256 23. 161 165 217 18. 151 "5 165 2,03 175 178 "7 198
<br />S.p 8. 10. 8. 99 176 176 9. 98 141 123 8. 68 91 128 120 117 13. 151
<br />0" .. 4. 47 38 106 118 .. 38 .5 58 .. .. . .. " '101 107
<br />Season .,2 .7. 75. 7.5 1393 1344 908 836 1222 1115 7" gOO .00 '77 1015 956 1134 1060
<br /> 13.3% Under- 6.2% Under- 3.6% Over- 8.6% Over- 9.6% Over- 0.8% Over- 7.9% Under- 6.2% OVt:r- 1.0%Ovtl'
<br /> t:stimtt.tt: t:stirnate estimate estimatt: t:stimate estimate estimllte estlmtltt! estimate
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<br />1984- TRANSACTIONS of th. ASAE
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