WSP06035

• File Number: 8460.500
• Description: Platte River Recovery Plan - SPDSS Studies ‎(see also 8483)‎
• Basin: South Platte
• Date: 1/1/1998
• Author: Colorado State Univ.
• Title: South Platte Consumptive Use ‎(CU)‎ Model User Manual - Version 1.1
• Water Supply Pro - Doc Type: Publication

I
I
1
I
I
I
I
I
I
I
I

I

II
I
I
I

Consumptive Use Model

2.0

Consumptive Use Model

2.1 Introduction to the Consumptive Use (CU) Model

The CU Model is comprised of a FORTRAN computational program for estimating agricultural
consumptive use and a Graphical User Interface (GUI). This user manual will describe the CU Model
Interface, including creating, editing, running, and viewing output. The interface also contains on-line help
parallel to this document.

2.1.1 About the CU Model Software
The CU Model computational program is written in standard FORTRAN. The CU Model Interface is
written in the C++ programming language and was constructed with Visual C++. The development and user
platform is a PC running Windows 95.

2.1.2 Overview of ConsumDtive Use Calculation
The CU Model estimates water used consumptively by irrigated crops. Consumptive use is primarily
evapotranspiration (ET), which is water evaporated or transpired from plant foliage and adjacent soil during
crop growth. The model assumes that water not consumptively used by crops returns to the surface or
groundwater system in the form of surface runoff or infiltration.
Two techniques have been selected based on the perceive data availability (Blaney-Criddle and
Kimberly-Penman). Both of these methods are monthly calculations based on average temperatures and
crop characteristics. Surface water supplies can be specified to meet crop CU. If there is additional CU
beyond surface supplies, wells tied to the farm are assumed to supply the additional CU.
CU Model input datasets can be developed using SPMAP or by modifying standard input files. The
format of these files is specified in "Section 3.0: Input File Formats" on page 15. Modeling input data
includes crop types, area covered by crops, planting dates, irrigation inputs, temperature maximums and
minimums, etc.

2.2 Input and Output Files Used by the CU Model

I
I
I
I

The file name format for input and output files have a common base name followed by an extension.
When a model run is built in the SPMAP interface a set of input files is created that can be run in the CU
model. The following input files are needed:

*.cmn - general (common) information

*.kbc - crop coefficient information

*. wbc - weather data

Version i.i

3 introduction to the Consumptive Use (CU) Model