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Griddle method were calculated from the daily maximum and minimum temperature <br />CoAgMet/NCWCD data used with the ASCE Standardized method. Likewise, frost dates were <br />selected from the CoAgMet/NCWCD daily minimum temperature data set. <br />Identify Irrigated Crop Types <br />The SPDSS irrigated acreage assessment shows that common crops in the SPDSS study area can <br />generally be classified into the following categories: <br />• Alfalfa <br />• Corn Grain <br />• Dry Beans <br />• Pasture Grass <br />• Small Grains <br />• Sugar Beets <br />There are also relatively minor percentages of orchard and vegetables grown throughout the <br />SPDSS study area. Because the amount of acreage planted is relatively small, and based on our <br />research, mean crop coefficients that can be used with the ASCE Standardized method are not <br />available for orchard or vegetables, calibrated crop coefficients could not be developed for either <br />of these crops. Therefore, unadjusted TR-21 modified Blaney-Griddle crop coefficients will be <br />used to represent these crops in the historical consumptive use analyses. <br />Compare the ASCE Standardized and Modified Blaney-Griddle PCU Estimates <br />StateCU was run using the ASCE Standardized option with daily climate data and the modified <br />Blaney-Griddle option with monthly climate data and the TR-21 crop coefficients. Table 4 <br />summarizes the average annual PCU results derived from the two methods and the percentage <br />difference as the (ASCE Standardized results -Modified Blaney-Griddle results) /ASCE <br />Standardized results. <br />Task59_l.doc (updated January 11, 2008) 10 of 32 <br />