WSPC04421

• File Number: 8064.100
• Description: Ute Tribes
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 9/1/1986
• Author: Boyle Engineering
• Title: Agricultural Engineering Study - Southern Ute and Ute Mountain - Ute Indian Reservations - Task A Report - On-Farm Water Requirements
• Water Supply Pro - Doc Type: Report/Study

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

2476

met by winter precipitation and irrigation water applied in excess of
field capacity.

1.3.2 Review of Evapotranspiration Methods

Methods for predicting evapotranspiration can be broadly classified

by the climatic variables used in their calculation. These are

temperature, radiation, and combination methods.

Radiation methods

use temperature and solar radiation while combination methods add an

advective energy transfer term to the radiation term. Temperature

methods considered in this review are the SCS modified Blaney-

Criddle method 2/ and FAO modified Blaney-Criddle method 2/.

Radiation methods considered in this review are the FAG modified

radiation method 2/,and four versions of the Jensen-Haise method.

These include the standard Jensen-Haise with and without elevation

correction ~/,and two modified Jensen-Raise equations calibrated

for conditions in northeast Utah, and the NIIP. The only combination

method considered is the FAO modified Penman equation ~/.

1.3.3 Temperature Methods
Temperature methods are the simplest and easiest to use of the
various ET prediction methods. The Blaney-Criddle formula is the
most popular of the temperature methods. The original form of the
equation as developed and later modified by H. F. Blaney and W. D.
Criddle in 1950 is not commonly used today. The Soil Conservation
Service version and the Food and Agriculture Organization of the

United Nations version are the most popular.

1- 13