Estimated Impacts of Environmental Change on Water Quality in the Chesapeake Bay Beyond Midcentury

In order to set nutrient and sediment load targets for the Chesapeake Bay, projections of changing environmental conditions to 2055 have been considered. This article expands the analysis to 2085. Under the CMIP5 RCP 4.5 ensemble scenario, temperature and precipitation trends for the Chesapeake Bay watershed prior to midcentury have a rate of change more than twice that of the post midcentury trend. Prior to midcentury, runoff and nutrient loading to the Bay estuary are projected to increase. In this analysis, model simulations for post midcentury suggest the trend of increasing runoff may be reduced. The combined effect of a reduced trend in temperature and precipitation increases post midcentury with continued sea level rise in the RCP 4.5 scenarios leads to a decreasing trend in Chesapeake hypoxia post midcentury resulting in a leveling off of dissolved oxygen water quality degradation.