SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Review and development of ASABE engineering practice 621: "Guidelines for calibrating, validating, and evaluating hydrologic and water quality models" 
Authors:Harmel, R.D., C. Baffaut and K.R. Douglas-Mankin 
Journal:Transactions of the ASABE 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:review/history 
Primary Application Category:calibration, sensitivity, and/or uncertainty analysis 
Secondary Application Category:none 
Watershed Description:none 
Calibration Summary: 
Validation Summary: 
General Comments:This review drew on a special collection of studies published in 2012 in Trans. ASABE, that included specific studies focused on calibration and validation of the EPIC/APEX models (Wang et al., 2012; cited in the text) and SWAT (Arnold et al., 2012; cited in the text and also included in the literature database). The authors provide further insights regarding guidelines for testing hydrologic and water quality models. No specific SWAT results or summaries are presented in this study. 
Abstract:In 2010, the Natural Resources and Environmental Systems Hydrology Committee (NRES-21) of ASABE initiated a long-term process to develop guidelines to improve modeling practice through better understanding of the calibration, validation, and evaluation process across applications and more effective interpretation and communication of model performance. This effort generated a compilation of 23 articles with model-specific descriptions and guidance (2012), a position paper outlining guidance for evaluating, interpreting, and communicating performance of hydrologic and water quality models considering intended use (2014), and a compilation of ten articles addressing key topics related to model calibration and validation (2015). In 2016, the first draft of ASABE Engineering Practice 621 (EP621), “Guidelines for Calibrating, Validating, and Evaluating Hydrologic and Water Quality (H/WQ) Models,” was developed, subsequently revised, and ultimately approved by the ASABE Standards Committee in 2017. EP621 provides guidelines, not prescriptive requirements, and as such recommends “good” modeling practices to enhance calibration, validation, evaluation, and communication of H/WQ models through establishment of consistent terminology; model selection; compilation and processing of input data and calibration, validation, and evaluation data; determination of model performance measures; model parameterization and calibration; re-examination of input and calibration data and/or consideration of model refinement; re-evaluation of model performance; and documentation of modeling process and results. EP621 can be obtained from the ASABE Technical Library at https://elibrary.asabe.org/abstract.asp?aid=47804. The objectives of this technical note are to review the process and rationale used to develop EP621 and to briefly summarize its major components. 
Keywords:Hydrologic processes, Hydrology, Model calibration, Modeling, Model validation, Water quality.