Location: Grassland Soil and Water Research Laboratory
Project Number: 3098-13610-009-101-A
Project Type: Cooperative Agreement
Start Date: Jun 1, 2024
End Date: Apr 30, 2026
Objective:
To develop and parameterize a distributed groundwater phosphorus (P) transport model for selected HUC8 within the conterminous U.S. Groundwater P transport has been shown to be an important yet often overlooked loss pathway in many areas. The SWAT+ model does not currently simulate P losses in groundwater return flows. This work will couple a new P transport model with GWFLOW (integrated into SWAT+) to simulate this process. Elevated groundwater P accumulation may be due to past fertilizer application and may not be immediately responsive to more recent improved nutrient management. By including these Legacy P related components into SWAT+ we should be able to provide better support for the Conservation Effects Assessment Project and related modeling efforts.
Approach:
A new groundwater model, called GWFLOW, was recently integrated into the SWAT+ code. A P transport component will also be developed and added to SWAT+. Multiple HUC8 will be selected in areas with known elevated groundwater P concentrations. These models will be extracted from NAM, augmented with local data provided by the relevant Legacy P group. Scripts will be written to develop required inputs in SWAT+. After the groundwater and P models have been parameterized, they will be validated for watersheds with adequate monitored data. These new modules will enhance SWAT+ prediction capabilities in areas with elevated Legacy P in groundwater and will provide new scenario capabilities.
