RGDSS_Historic_CUreport_20040601

• Title: RGDSS - Rio Grande Historic Crop Consumptive Use Analysis
• Description: The documentation is for the Rio Grande Basin Historic Crop Consumptive Use Analysis, developed during the RGDSS implementation for the period 1950 through 2002. It includes 100 percent of the crop consumptive use in the basin for the period. Documentation consists of the final Historic Crop Consumptive Use Analysis Report and supporting appendices.
• Decision Support - Doc Type: Modeling Dataset Documentation
• Date: 6/1/2004
• DSS Category: Consumptive Use
• DSS: Rio Grande
• Basin: Rio Grande
• Contract/PO #: C153863
• Grant Type: Non-Reimbursable
• Bill Number: HB98-1189, SB99-173
• Prepared By: Leonard Rice Engineering

4.11 Blaney-Criddle Crop Coefficient File (rgdss.kbc)
The Blaney-Criddle crop coefficient file contains locally calibrated crop coefficient data
used in the RGDSS historic consumptive use analysis. Standard TR-21 Blaney-Criddle
crop coefficients, as well as crop characteristics described in Section 4.13 below, were
revised to yield average evapotranspiration results more consistent with results obtained
using the Modified Hargreaves method over a thirteen year period. The Modified
Hargreaves method for estimating crop ET was developed by Agro Engineering, Inc. to
better represent lysimeter data from the San Luis Valley. Unlike the monthly-modified
Blaney-Criddle method, the Modified Hargreaves method operates on a daily time step
and uses wind and solar radiation data not readily available before 1980. The procedure
and results of this analysis are provided in the Rio Grande Historic Crop Consumptive
Use -Calibration ofBlaney-Criddle Coefficients memorandum, included in Appendix ~
Table 12 shows original TR-21 and locally calibrated crop coefficients for selected days
developed for pasture and alfalfa, perennial crops.
Table 12
TR-21 and Calibrated Crop Coefficients for Pasture and Alfalfa
Pasture Irrigated Meadow Alfalfa
Day of the Year TR-21 Calibrated TR-21 Calibrated
1 0.480 0.480 0.600 0.600
15 0.470 0.470 0.630 0.630
32 0.525 0.525 0.680 0.680
46 0.575 0.575 0.730 0.730
60 0.640 0.640 0.790 0.790
74 0.740 0.740 0.850 0.850
91 0.815 1.880 0.920 0.420
105 0.855 1.970 0.990 0.450
121 0.880 1.210 1.045 1.950
135 0.900 1.230 1.090 2.020
152 0.915 1.600 1.120 1.870
166 0.920 1.610 1.135 1.890
182 0.925 1.350 1.130 1.430
196 0.925 1.350 1.115 1.410
213 0.915 1.310 1.090 1.570
227 0.905 1.290 1.065 1.540
244 0.890 1.540 1.030 1.400
258 0.870 1.500 0.990 1.360
274 0.840 2.210 0.950 1.430
288 0.795 2.090 0.905 1.360
305 0.735 0.735 0.850 0.850
319 0.670 0.670 0.790 0.790
335 0.605 0.605 0.720 0.720
349 0.550 0.550 0.640 0.640
366 0.480 0.480 0.600 0.600
cureport_6-2004.doc 31 of 48 June, 2004