Expanding on current efforts to evaluate the role of groundwater dynamics in managing and restoring Chesapeake Bay (USA), the integrated hydrologic model ParFlow-CLM was applied to a 374,976-km2 area encompassing the Chesapeake Bay watershed. The model included a representation of surface water, groundwater and land-surface energy fluxes with spatially variable atmospheric forcing at an hourly time step. The study tackled issues of data availability, access, assembly, and synthesis for estimating hydrogeologic properties in the context of the development of a large-scale model. Hydrogeologic properties from literature and other sources were assembled, processed, and synthesized to derive a conceptual hydrogeologic model consisting of 29 hydrofacies and a three-dimensional hydraulic conductivity field. Evaluation of the ParFlow-CLM model output showed that the constructed model captured seasonal and spatial variability in subsurface storage, surface storage and surface runoff, and produced water-table depths consistent with the topography, meteorological forcing, and hydrogeology. Comparison with well data from the US Geological Survey showed good agreement of model output with observed hydraulic heads for most of the data. Modeled terrestrial water storage changes compared well with GRACE satellite data with a root mean square error of 2.3 cm. Model results showed the dominant contribution of subsurface storage changes (90%) to terrestrial water storage changes in the region.
Quantifying groundwater storage dynamics in the Chesapeake Bay watershed (USA) using a large-scale integrated hydrologic model with detailed three-dimensional subsurface representation Archives
This report describes activities conducted during the 2020 drought exercise. The exercise was virtual, and took place on Monday, Tuesday, and Wednesday, November 16-18, from 7:30 AM to 4:00 PM.
Communications during the exercise were via telephone, email, and Microsoft Teams Meeting, and all
operations were “simulated.” Twice daily email reports were sent out to stakeholders reporting on current flow and demand conditions and on simulated operations. The exercise included two special events:
- An actual test release from Little Seneca Reservoir, which was conducted over an approximately
12-hour period, beginning at 10:00 AM on Tuesday, November 17.
- A webinar by Hazen & Sawyer on the use of the Potomac OASIS model to provide probabilistic
information on future streamflows and reservoir storage levels. A PDF of the webinar on forecast informed reservoir operations is available.
Learn more about previous drought exercises and the ICPRB’s Section for Cooperative Water Supply Operations on the Potomac on the Drought Monitoring and Operations page.
Every five years since 1990, ICPRB’s Section for Cooperative Water Supply Operations on the Potomac (CO-OP) has conducted a water demand and resource availability forecast for the Washington, D.C., metropolitan area. These studies assess whether or not the current water supply system will be able to meet the needs of the region 20 or more years in the future.
Learn more about these reports on the CO-OP Long-Term Planning page.
The 4-page Executive Summary is available HERE.