SWAT optimization tool for decision-making agricultural production systems among competing objectives

Authors: Cram, Ana; Moriasi, Daniel; MOGLEN, GLEN - University Of North Carolina; STEINER, JEAN - Kansas State University; AGUIRRE, OSWALDO - Texas A&M University; Verser, Jerry; XIANG, ZAICHEN - Oklahoma State University

Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Identifying agricultural production systems that balance economic viability, conservation of soil and water resources, and a clean environment requires significant time and financial investments. The soil and water assessment tool (SWAT) model is a publicly available tool that provides valuable insights into the potential impacts of different land management scenarios on agricultural production, and soil and water resources under a changing climate. However, SWAT is not equipped with an inherent optimization computation process that can be used to identify optimal production systems that consider multiple competing objectives. Therefore, the SWAT model was linked with a multi-objective evolutionary algorithm (MOEA) to develop SWAT-MOEA, a user-friendly standalone optimization tool to help identify sustainable agricultural production systems under a changing climate. The SWAT-MOEA allows for customized optimization for areas of interest and for creation of combinations of multiple agricultural production systems. A case study in the Fort Cobb Reservoir Experimental watershed located in Oklahoma is provided to demonstrate its use. This tool will assist researchers and stakeholders in understanding the long-term economic and environmental impacts of the prevailing and alternative sustainable agricultural production systems.

Technical Abstract: Identifying agricultural production systems that balance economic viability, conservation of soil and water resources, and a clean environment requires significant time and financial investments. This paper presents the SWAT-MOEA, a user-friendly standalone tool, which couples the Soil and Water Assessment Tool (SWAT) with a Multi-Objective Evolutionary Algorithm (MOEA) to determine Pareto optimal solutions for sustainable watershed management within a reasonable timeframe. This integration enables simultaneous optimization of multiple objectives for existing SWAT projects. The tool identifies placement of management strategies that achieve optimal trade-offs among competing objectives. Key SWAT-MOEA features include the ability to create and execute management practices directly through the SWAT-MOEA interface and to select objectives that reflect regional priorities. SWAT-MOEA streamlines the setup process for simulating conversions of conventional to conservation tillage practices with easy adjustment of initial curve number. SWAT-MOEA allows for customized optimization for areas of interest and for creation of combinations of multiple agricultural production systems at different spatial scales for sensitivity analysis. Results are stored in Excel for efficient display. SWAT-MOEA creates and stores Pareto graphs and geospatial maps of suggested solutions. A case study in the Fort Cobb Reservoir Experimental watershed located in Oklahoma is provided to demonstrate its use. The SWAT-MOEA executable and user’s manual, are available at USDA or upon request.