Location: Grassland Soil and Water Research Laboratory
Project Number: 3098-13610-009-108-I
Project Type: Interagency Reimbursable Agreement
Start Date: Aug 15, 2025
End Date: Sep 30, 2029
Objective:
The project will integrate recent advances in legacy nitrogen, sediment, and phosphorus processes into the SWAT+ hydrologic and water quality model, leveraging prior NRCS-funded research. Specific objectives include incorporating improved groundwater nutrient transport routines, enhancing nutrient-carbon interactions in soils, and improving the representation of legacy sediment and nutrient storage in streambeds, banks, and reservoirs. All enhancements will be integrated into SWAT+ to ensure broad accessibility. The enhancements provide planners, agencies, and stakeholders with robust tools to address water resource concerns. Ultimately, the project will feed previously fund research back into the overall Conservation Effects Assessment Project effort leading to more efficient conservation policy development, better environmental outcomes, and increased resilience of agricultural and watershed systems.
Approach:
The research approach will involve systematically integrating recently developed legacy nutrient and sediment transport and storage algorithms into the existing SWAT+ model. Initially, relevant data collected from ongoing NRCS-funded legacy studies will be identified and evaluated for compatibility. Selected routines, including groundwater transport of nitrogen and phosphorus, will be fully integrated and validated through testing against observed datasets. Soil nutrient-carbon interaction routines adapted from existing models will be incorporated to enhance upland process simulations. Generalized algorithms representing legacy sediment and nutrient dynamics within stream channels and reservoirs will be developed, integrated, and tested. All model enhancements will be packaged within SWAT+ for public release, ensuring broad usability for conservation practitioners, planners, and policymakers.