In August, the Chesapeake Bay Program requested a rapid response STAC peer-review of the land-use and land cover dataset and methodology used in the Phase 5 Bay-wide Watershed Model. STAC assembled a team of experts to investigate the following questions:
1. How important are low-density residential development and rural and suburban roads to estimating nutrient and sediment loads to the Bay?
2. Are the assumptions and methodology used to estimate the extent of developed lands scientifically sound?
3. Are the assumptions and methodology used to forecast changes in developed lands, agriculture, and populations on sewer and septic systems scientifically sound?
4. Are the assumptions and methodology used to estimate and spatially represent extractive lands scientifically sound?
5. What improvements to the methodologies are needed?
Overall, the experts who reviewed the land-use and land cover dataset and methodology were impressed with the technical quality of work. Reviewers recognized that the Chesapeake Bay Program applied state-of-the-art approaches where confronted with challenging conceptual and technical issues. However, reviewers suggested the CBP consider conducting systematic sensitivity analysis, develop multiple plausible land use and land cover scenarios, and communicate uncertainties associated with land-use and land cover future scenarios.
These suggestions echo previous recommendations made by STAC and previous review teams. The committee believes the CBP must work closer with STAC in the future, allowing members to participate in the development of models and methodology rather than requesting quick response reviews that offer very little time for thorough recommendations. These recommendations, and others, were recently forwarded to the CBP.