Open-File Report 2015–1027
AbstractWater-quality models allow water resource professionals to examine conditions under an almost unlimited variety of potential future scenarios. The two-dimensional (longitudinal, vertical) water-quality model CE-QUAL-W2, version 3.7, was enhanced and augmented with new features to help dam operators and managers explore and optimize potential solutions for temperature management downstream of thermally stratified reservoirs. Such temperature management often is accomplished by blending releases from multiple dam outlets that access water of different temperatures at different depths. The modified blending algorithm in version 3.7 of CE-QUAL-W2 allows the user to specify a time-series of target release temperatures, designate from 2 to 10 floating or fixed-elevation outlets for blending, impose minimum and maximum head and flow constraints for any blended outlet, and set priority designations for each outlet that allow the model to choose which outlets to use and how to balance releases among them. The modified model was tested with a variety of examples and against a previously calibrated model of Detroit Lake on the North Santiam River in northwestern Oregon, and the results compared well. These updates to the blending algorithms will allow more complicated dam-operation scenarios to be evaluated somewhat automatically with the model, with decreased need for multiple model runs or preprocessing of model inputs to fully characterize the operational constraints. |
First posted February 6, 2015 Supplementary Material For additional information, contact: Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge. More information about viewing, downloading, and printing report files can be found here. |
Rounds, S.A., and Buccola, N.L., 2015, Improved algorithms in the CE–QUAL–W2 water-quality model for blending dam releases to meet downstream water-temperature targets: U.S. Geological Survey Open-File Report 2015-1027, 36 p., https://dx.doi.org/10.3133/ofr20151027.
ISSN 2331-1258 (online)
Abstract
Introduction
Purpose and Scope
Blending Algorithms in CE–QUAL–W2
Modified Blending Algorithms for Version 3.7
Examples to Illustrate New Capabilities
Comparison Test of New Algorithms
Summary and Conclusions
Acknowledgments
Supplementary Material
References Cited
Appendix 1. Example w2_selective.npt Files