Climate Change

Chesapeake Bay region has the highest rate of relative sea-level rise on the Atlantic Coast of the United States, and data indicate that vertical land motion in the form of subsidence has been responsible for more than half the relative sea-level rise measured in the Chesapeake Bay region. The Chesapeake Bay Vertical Land Motion Project is a cooperative effort between the USGS and our many...

Informed management of groundwater resources for the Eastern Shore of Virginia depends on the availability of detailed and up-to-date scientific information. The USGS and the Virginia Department of Environmental Quality are conducting a long-term cooperative study to enhance the understanding of groundwater resources in the sole-source aquifer system beneath Accomack and Northampton counties...

Climate change raises concern that risks of hydrological drought may be increasing. We estimate hydrological drought probabilities for rivers and streams in the United States using maximum likelihood logistic regression (MLLR). Streamflow data from winter months are used to estimate the chance of hydrological drought during summer months. Daily streamflow data collected from 9,144 stream gages...

The southern Chesapeake Bay region is experiencing land subsidence along with rising sea levels, both of which can contribute to coastal flooding. The rates at which these two processes are occurring are not exactly known. Mapping of land elevation change requires ground-truth survey data at multiple locations that are accurate and precise. With the exception of a few CORS sites that have...

The 64,000-square mile watershed that drains to the Chesapeake Bay is highly populated and has diverse land use, including forested, agricultural, and urbanized areas. Increased precipitation in the eastern United States over the last 100 years has affected stream flow and thus the loading of pollutants delivered to the bay. Such pollutants as suspended sediment and dissolved phosphorus and...

The objectives of this study are to identify 1) the relations between water levels in the ditches and groundwater levels near the ditches and in the interior of the Blocks, 2) possible relations between groundwater levels and tree growth rates, and 3) current nutrient chemistry and possible nutrient transport pathways in these wetlands.

Planning for drought conditions in Virginia streams is essential to the sound management of water resources and associated riparian and watershed ecosystems. Reliable estimations of the likelihood that stream flows during drought-prone months will exceed specific low-flow thresholds can provide advance warning of drought conditions, allowing extended lead times for improved drought awareness and...

Groundwater is a heavily used source of water in the Virginia Coastal Plain. Long term and widespread groundwater withdrawals have resulted in regional water-level declines, and created the potential for saltwater intrusion. Sound management of this vital resource relies on continual improvement of the scientific understanding of the aquifer system.

The USGS, with cooperation from the Virginia Department of Environmental Quality and the Hampton Roads Planning District Commission, is involved in several related and on-going regional projects directed at better characterization of this important resource. The large amount of information needed for these projects requires the development and integration of a Geographic Information System (GIS)...

The objective of this study is to provide concentrations and estimates of loads and trends of suspended solids, nitrogen, phosphorus, and other selected constituents at the James, Rappahannock, Appomattox, Pamunkey, and Mattaponi Rivers.