Introduction

The ET-Demands model develops daily estimates of crop irrigation water requirements using daily weather data (including reference evapotranspiration) along with crop-specific crop growth curves.

Acknowledgements

The basis for the ET Demands model is the dual crop coefficient method presented in FAO-56 (Allen et al., 1998). Original model code was developed by Dr. Rick Alan at the University of Idaho Kimberly Reserarch and Extension Center in Kimberly, ID.

Model History

Original model code was written in Visual Basic for Windows. Reclamation and the Desert Research Institute ported this code to a non-versioned Python release of the model. This non-versioned Python release served as the basis for the et-demands model found in this repository. This methods used in this model were used to evaluate evapotranspiration and consumptive use irrigation water requirements for the state of Idaho (Allen and Robison, 2007) and the state of Nevada (Huntington and Allen, 2010). This approach has been used to quantify historical and future irrigation water requirements for selected irrigation projects operated by the Bureau of Reclamation (Reclamation, 2016). This approach has also been used to quantify historical and future irrigation water requirements in support of Reclamation’s WaterSMART Basin Studies Program.

Model Version History

v1.0.0

Release date: July 15, 2019

This is the first official release of the et-demands model containing workable source code, examples, and documentation. The dual crop coefficient curve approach remains unchanged from previous releases. This version has undergone thorough testing to ensure reliability, with pre-processing and post-processing tools to develop the required input data, and format and visualize model results are much improved. Model workflow has been better refined to rely on ESRI Shapefiles and daily weather timeseries data as the main

v0.1.0

Release date: September 20, 2018

This is a beta release of the et-demands model containing workable source code. The dual crop coefficient curve approach remains unchanged from the original non-versioned Python code, developed from the Visual Basic version of the et-demands model. Structural changes to the code were made to make ESRI Shapefiles and daily weather timeseries the primary source data for running the model. Pre-processing and post-processing tools were written to develop the required input data, and format and visualize model result using the ESRI Shapefile and daily weather timeseries within a standard workflow. Further refinement and testing of this workflow, development of workable examples and source code are required for a v1.0.0 release.

Model License

The software as originally published constitutes a work of the United States Government and is not subject to domestic copyright protection under 17 U.S.C. § 105. Subsequent contributions by members of the public, however, retain their original copyright.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.