SPDSS_Task59-1_Develop Locally Calibrated Blaney-Criddle Crop Coefficients

• Title: SPDSS Task 59.1 - Develop Locally Calibrated Blaney-Criddle Crop Coefficients
• Description: This memorandum presents the recommended regional Blaney-Criddle crop coefficients for use in the SPDSS CU analysis. Revised January 11, 2008
• Decision Support - Doc Type: Task Memorandum
• Date: 1/11/2008
• DSS Category: Consumptive Use
• DSS: South Platte
• Basin: South Platte
• Contract/PO #: C153954
• Grant Type: Non-Reimbursable
• Bill Number: SB01-157, HB02-1152, SB03-110, HB04-1221, SB05-084, HB06-1313, SB07-122
• Prepared By: Leonard Rice Engineering

Comparison of Average Monthly (1993-2003) PCU Estimates Using the ASCE
Standardized Method and the Modified Blaney-Criddle Method with TR-21 Crop
Coefficients:
PCU for Alfalfa at the Fort Collins Climate Station
0.8
0.7
N 0.6
7
~ 0.5
Q
~ 0.4
U 0.3
~ 0.2
a 0.1
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-ASCE Standardized - -Modified Blaney-Criddle,TR-21 Coeff.
Figure 6 - Avg PCU for Alfalfa at Fort Collins
PCU for Alfalfa at the Greeley Climate Station
0.8
0.7
N 0.6
~ 0.5
Q
E 0.4
0 0.3
U
`-° 0.2
0 0.1
a
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-ASCE Standardized - -Modified Blaney-Criddle, TR-21 Coeff.
PCU for Alfalfa at the Fort Lupton Climate Station
0.8
0.7
N 0.6
~ 0.5
~ 0.4
U 0.3
~ 0.2
a 0.1
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-ASCE Standardized - -Modified Blaney-Criddle, TR-21 Coeff.
Figure 6 - Avg PCU for Alfalfa at Fort Lunton
PCU for Alfalfa at the Sterling Climate Station
0.80
., 0.70
0.60
~ 0.50
Q
E 0.40
~ j 0.30
m
0.20
0
o_ 0.10
0.00
-ASCE Standardized PM - -Modified Blaney-Criddle, TR-21 Coeff.
Figure 7 - Avg PCU for Alfalfa at Greeley Figure 8 - Avg PCU for Alfalfa at Sterling
PCU for Corn Grain at the Fort Collins Climate Station
0.7
m 0.6
~ 0.5
n 0.4
E
~ 0.3
U
m 0.2
0 0.1
a
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-ASCE Standardized - -Modified Blaney-Criddle, TR-21 Coeff.
PCU for Corn Grain at the Fort Lupton Climate Station
0.7
~ 0.6
0.5
n 0.4
E
~ 0.3
U
m 0.2
a 0.1
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
-ASCE Standardized - -Modified Blaney-Criddle, TR-21 Coeff.
Figure 9 - Avg PCU for Corn Grain at Fort Collins Figure 10 - Avg PCU for Corn Grain at Fort Lupton
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Task59_l.doc (updated January 11, 2008) 23 of 32