INTERNATIONAL SOIL AND WATER ASSESSMENT TOOL CONFERENCE SWAT 2018 19-21 September / Brussels, Belgium Book of Abstracts The Soil and Water Assessment Tool (SWAT) is a public domain model jointly developed by USDA Agricultural Research Service (USDA-ARS) and Texas A&M AgriLife Research, part of The Texas A&M University System. SWAT is a small watershed to river basin-scale model to simulate the quality and quantity of surface and ground water and predict the environmental impact of land use, land management practices, and climate change. SWAT is widely used in assessing soil erosion prevention and control, non-point source pollution control and regional management in watersheds. swat.tamu.edu | facebook.com/swatmodel | twitter.com/swat_model Contents Wednesday 11:00 – 12:30 A1 SWAT+ A2 Sensitivity Calibration and Uncertainty A3 Environmental Applications 14:00 – 15:30 B1 SWAT Applications for Ecosystem Services B2 Model Development B3 Hydrology B4 Large Scale Applications 16:00 – 17:30 C1 Climate Change Applications C2 BMPs C3 Hydrology C4 Pesticides, Bacteria, Metals, and Pharmaceuticals Thursday 9:00 – 10:30 D1 SWAT Applications for Ecosystem Services D2 Sensitivity Calibration and Uncertainty D3 Model Development D4 Climate Change Applications 11:00 – 12:30 E1 SWAT+ E2 Sediment, Nutrients, and Carbon E3 Environmental Applications E4 Hydrology 15:00 – 17:00 G1 Poster Friday 9:00 – 10:30 H1 Sediment, Nutrients, and Carbon H2 Hydrology H3 Climate Change Applications 11:00 – 12:30 I1 Environmental Applications I2 Climate Change Applications I3 Hydrology 13:30 – 15:00 J1 Model Development J2 Climate Change Applications J3 Hydrology 2018 SWAT Conference 1 Brussels, Belgium Foreword The organizers of the 2018 International SWAT Conference want to express their thanks to the organizations and individuals involved and their preparation and dedication to coordinate a successful conference. We would also like to thank the Scientific Committee for their support in preparing the conference agenda and allowing for scientists and researchers around the globe to participate and exchange their scientific knowledge at this conference. A special thank you to the Vrije Universiteit Brussel (VUB) along with Ann van Griensven, Veronica Minaya, and the rest of the local organizing committee in Brussels for their countless hours and efforts to host the SWAT Community. On behalf of the SWAT Community, we extend our sincere gratitude to you and your university for the kind invitation and welcoming hospitality. The following Book of Abstracts contains abstracts for presentations covering a variety of topics including but not limited to large scale applications; climate change applications; model development; database and GIS application and development; environmental applications; hydrology; best management practices (BMPs); sensitivity, calibration and uncertainty; and more. The Conference Organizers hope you enjoy the conference and continue to view these SWAT gatherings as a positive opportunity for our international research community to share the latest innovations developed for the Soil and Water Assessment Tool. Local Organizing Committee • Prof. Ann van Griensven — VUB/IHE-Delft • Dr. Veronica Minaya — VUB • Dr. Zainab Zomlot — VUB • Dr. Solomon Seyoum — VUB • Imeshi Weerasinghe — VUB • James Celray Chawanda — VUB • Douglas Nyolei — VUB • Hilde De Coninck — VUB • Prof. Elga Salvadore — IHE-Delft/VUB • Prof. Jiri Nossent — Flanders Hydraulics/VUB International Organizing Committee • Raghavan Srinivasan — Texas A&M University, USA • Jeff Arnold — USDA-ARS, USA • Jaclyn Tech — Texas A&M University, USA 2018 SWAT Conference 2 Brussels, Belgium Scientific Committee Karim Abbaspour — EAWAG, Switzerland — Warsaw University of Life Sciences, Poland Jeff Arnold — USDA-ARS, USA Mikołaj Piniewski Hendrik Rathjens — Stone Environmental, USA Claire Baffaut — USDA-ARS, USA Elga Salvadore — IHE-Delft, Belgium Katrin Bieger — Texas A&M AgriLife Research, USA José Miguel Sánchez-Pérez — CNRS-ECOLAB, France José María Bodoque Del Pozo — UCLM, Toledo, Spain Sabine Sauvage — CNRS-ECOLAB, France Pierluigi Cau — CRS4, Italy Solomon Seyoum — Vrije Universiteit Brussel, Belgium Pedro Chambel Leitão — IST-MARETEC, Portugal Raghavan Srinivasan — Texas A&M University, USA Indrajeet Chaubey — Purdue University, USA Ann van Griensven — Vrije Universiteit Brussel, — Warsaw University of Life Belgium Sciences, Poland Jarosław Chormański Martin Volk — Helmholtz Centre for Environmental Gerald Corzo Perez — IHE-Delft, Netherlands Research - UFZ, Germany Prasad Daggupati — Univeristy of Guelph, Canada Mike White — USDA-ARS, USA Yihun Dile — Texas A&M University, USA Patrick Willems — KU Leuven, Belgium Nicola Fohrer — Christian-Albrechts-University Kiel, Seleshi Yalew — Wageningen Univerisity, Germany Netherlands Philip Gassman — Iowa State University, USA Xuesong Zhang — Pacific Northwest National A.K. Gosain — Indian Institute of Technology, India Laboratory, USA Fred Hattermann — PIK, Germany Zainab Zomlot — Vrije Universiteit Brussel, Belgium Jaehak Jeong — Texas A&M AgriLife Research, USA C. Allan Jones — Texas A&M AgriLife Research, USA Valentina Krysanova — PIK, Germany Anthony Lehmann — University of Geneva, Switzerland Antonio Lo Porto — IRSA-CNR, Italy Ilyas Masih — IHE-Delft, Netherlands Shreedhar Maskey — IHE-Delft, Netherlands Venkatesh Merwade — Purdue University, USA Veronica Minaya — VUB, Belgium Clyde Munster — Texas A&M University, USA Balaji Narasimhan — Indian Institute of Technology- Madras, India Yiannis Panagopoulos — Iowa State University, USA 2018 SWAT Conference 3 Brussels, Belgium Session A1: SWAT+ Utilizing the New SWAT+ Structure to Improve U.S. National Conservation and Environmental Assessments Jeff Arnold*1, Katrin Bieger2, Mike White3, Raghavan Srinivasan4, Peter Allen5 1. USDA-ARS, Grassland, Soil and Water Research Laboratory. Email: [email protected] (corresponding author) 2. Texas A&M AgriLife, Blackland Research & Extension Center. 3. USDA-ARS, Grassland, Soil and Water Research Laboratory. 4. Texas A&M University, Spatial Sciences Laboratory. 5. Baylor University, Department of Geology. Abstract SWAT+ is a completely restructured version of SWAT, written in a more modular format, with input files structured in a relational format. The new structure will facilitate code development and maintenance; support data availability, analysis, and visualization; and enhance the model’s capabilities in terms of the spatial representation of elements and processes within watersheds. SWAT+ also offers more flexibility than SWAT in defining management schedules, routing constituents, and connecting managed flow systems to the natural stream network. These improvements have allowed us to downscale the CEAP (Conservation Effects Assessment Project) national assessment and improve modeling of the sediment and nutrient budgets based on more a detailed framework of process based watershed connectivity, taking into account sources (fields and first order streams) and sinks (valley accommodation and reservoirs). The CEAP project was developed to guide the design and implementation of conservation programs across the U.S. In the downscaled version of CEAP, representative fields are modeled with a gully, ditch or swale connecting the field to the first order channel. The first order channels are connected to the main channel of each 12-digit hydrologic unit (there are 86,000 12-digit watersheds in the U.S. with an average area of 90 km2). Each 8-digit watershed will comprise a SWAT+ simulation with flow, sediment, and nutrients passed in a daily recall file to downstream 8-digits. There are 2,100 8-digits with an average size of 3,500 km2. In past national assessments, small scale processes were lumped explicitly with a delivery ratio or implicitly with the MUSLE equation. Simulating transport processes down to first order streams allows realistic simulation of the entire sediment/nutrient budget including simulation of riparian buffering, structural controls, bank stabilization, and incorporation of wetlands on lower order streams. Other improvements will be discussed including soft calibration of the water balance and the use of decision tables in SWAT+ to simulate management. Keywords modular SWAT code, national assessments, small-scale processes 2018 SWAT Conference 4 Brussels, Belgium Session A1: SWAT+ Using Soft Data to Calibrate SWAT+ Models Celray James Chawanda*1, Jeffrey G. Arnold2, Ann van Griensven3 1. Vrije Universiteit Brussel (VUB). Email: [email protected] (corresponding author) 2. Grassland Soil and Water Research Laboratory (USDA-ARS). 3. Vrije Universiteit Brussel (VUB). Abstract During calibration for hydrological models such as the Soil and Water Assessment Tool (SWAT), model performance statistics such as Nash-Sutcliffe efficiency and P-Bias are used to assess how accurate a model is. However, models that pass as ‘good’ do not always well represent the water balance of the area under study. Thus, a positive evaluation of calibration does not guarantee that the processes in the landscape are properly represented. When such models are used for scenario investigation, the results can be unrealistic. This can be avoided using a soft calibration technique that quickly calibrates the model against user specified water balance proportions derived from soft data such as literature and remotely sensed products. In this study, a soft calibration method was developed that uses linear regression to set parameters that minimise the