Title: An improved process-based representation of stream solute transport in the soil and water assessment tools
Abstract: Hydrological ProcessesVolume 34, Issue 11 p. 2599-2611 RESEARCH ARTICLE An improved process-based representation of stream solute transport in the soil and water assessment tools Pandara V. Femeena, Corresponding Author Pandara V. Femeena [email protected] orcid.org/0000-0002-9120-8493 Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA Correspondence Pandara V. Femeena, Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907. Email: [email protected] for more papers by this authorIndrajeet Chaubey, Indrajeet Chaubey Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USASearch for more papers by this authorAntoine Aubeneau, Antoine Aubeneau Department of Civil Engineering, Purdue University, West Lafayette, Indiana, USASearch for more papers by this authorSara K. McMillan, Sara K. McMillan orcid.org/0000-0001-7197-7079 Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USASearch for more papers by this authorPaul D. Wagner, Paul D. Wagner Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, Kiel, GermanySearch for more papers by this authorNicola Fohrer, Nicola Fohrer Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, Kiel, GermanySearch for more papers by this author Pandara V. Femeena, Corresponding Author Pandara V. Femeena [email protected] orcid.org/0000-0002-9120-8493 Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA Correspondence Pandara V. Femeena, Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907. Email: [email protected] for more papers by this authorIndrajeet Chaubey, Indrajeet Chaubey Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USASearch for more papers by this authorAntoine Aubeneau, Antoine Aubeneau Department of Civil Engineering, Purdue University, West Lafayette, Indiana, USASearch for more papers by this authorSara K. McMillan, Sara K. McMillan orcid.org/0000-0001-7197-7079 Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USASearch for more papers by this authorPaul D. Wagner, Paul D. Wagner Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, Kiel, GermanySearch for more papers by this authorNicola Fohrer, Nicola Fohrer Department of Hydrology and Water Resources Management, Institute for Natural Resource Conservation, Kiel University, Kiel, GermanySearch for more papers by this author First published: 29 March 2020 https://doi.org/10.1002/hyp.13751Citations: 2 Present address: Indrajeet Chaubey, Department of Natural Resource and the Environment, University of Connecticut, Storrs, CT 06269. Funding information: United States Department of Agriculture – National Institute of Food and Agriculture, Grant/Award Number: Grant S-1063 Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Hydrological models have long been used to study the interactions between land, surface and groundwater systems, and to predict and manage water quantity and quality. The soil and water assessment tool (SWAT), a widely used hydrological model, can simulate various ecohydrological processes on land and subsequently route the water quality constituents through surface and subsurface waters. So far, in-stream solute transport algorithms of the SWAT model have only been minimally revised, even though it has been acknowledged that an improvement of in-stream process representation can contribute to better model performance with respect to water quality. In this study, we aim to incorporate a new and improved solute transport model into the SWAT model framework. The new process-based model was developed using in-stream process equations from two well established models—the One-dimensional Transport with Inflow and Storage model and the Enhanced Stream Water Quality Model. The modified SWAT model (Mir-SWAT) was tested for water quality predictions in a study watershed in Germany. Compared to the standard SWAT model, Mir-SWAT improved dissolved oxygen (DO) predictions by removing extreme low values of DO (<6 mg/L) simulated by SWAT. Phosphate concentration peaks were reduced during high flows and a better match of daily predicted and measured values was attained using the Mir-SWAT model (R2 = 0.17, NSE = −0.65, RSR = 1.29 with SWAT; R2 = 0.28, NSE = −0.04, RSR = 1.02 with Mir-SWAT). In addition, Mir-SWAT performed better than the SWAT model in terms of Chlorophyll-a content particularly during winter months, improving the NSE and RSR for monthly average Chl-a by 74 and 42%, respectively. With the new model improvements, we aim to increase confidence in the stream solute transport component of the model, improve the understanding of nutrient dynamics in the stream, and to extend the applicability of SWAT for reach-scale analysis and management. Citing Literature Supporting Information Filename Description hyp13751-sup-0001-Supinfo.docxWord 2007 document , 57.8 KB Figure S1. Time series plots of NH4-N, NO2-N, NO3-N, Organic N and PO4-P loads during 2015–2016 simulated with uncalibrated SWAT model using default and new values of water quality parameters. Figure S2. Time series plots of NH4-N, NO2-N, NO3-N, Organic N and PO4-P loads during 2015-2016 simulated with calibrated SWAT model using default and new values of water quality parameters. Figure S3. NO3-N loads at the watershed outlet with SWAT and Mir-SWAT model runs. Figure S4. Time series plots of dispersion coefficient (D), storage zone area (As) and storage exchange coefficient (α) in reach 1 of Kielstau SWAT model. Table S1. List of calibrated parameters for Kielstau SWAT model categorized according to streamflow, sediment, nitrate and phosphate calibration. Description of each parameter, type of parameter changes (absolute/percentage) and initial values are also provided. Table S2. Default and new values of water quality parameters used in SWAT and Mir-SWAT respectively. Note: Only basin level parameter values are changed. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume34, Issue1130 May 2020Pages 2599-2611 RelatedInformation