Skip to main content
ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Research Project #441174

Research Project: FY2021 Contribution of Legacy Phosphorus to Watershed Outcomes, Phase 2 (Temple, TX)

Location: Grassland Soil and Water Research Laboratory

Project Number: 3098-13610-009-090-I
Project Type: Interagency Reimbursable Agreement

Start Date: Sep 1, 2021
End Date: Jul 30, 2026

Objective:
Apply new knowledge learned from our Phase 1 efforts to identify current gaps in knowledge and limitations within SWAT. Lead a national workshop to understand how legacy phosphorus is simulated in SWAT and other models (e.g., AnnAgNPS, AGES, SPARROW). With input from individual sites in this project, determine where it is appropriate to implement these solutions in SWAT, and test the updates using site-specific data from the teams. Then pending funding, carry out simulation of baseline and legacy phosphorus mitigation strategies with the major basins that contain the various study sites.

Approach:
1) Lead project workshop of model developers and applicators to determine how legacy P is handled within different models (SWAT, APEX, AnnAGNPS, SPARROW, AGES). 2) Work with the legacy phosphorus modeling community in general to ensure that any improvements to the representation of legacy phophorus processes that are gained from individual site teams are considered and may be used in the final assessment. 3) Pending additional funding - Conduct basin-scale assessment of legacy phosphorus contributions to watershed outcomes under baseline and mitigation strategy scenarios for Lake Champlain, Upper Chesapeake, Lower Chesapeake, Western Lake Erie, Upper Mississippi, Lower Mississippi, Upper Snake River watersheds. If possible a national assessment will also be conducted.