Floods and Droughts

Land subsidence is a loss of ground elevation, often experienced as the ground slowly sinking over the course of years. In eastern Virginia, high rates of groundwater use is a major factor in the land subsidence affecting the area. The Virginia-West Virginia Water Science Center, with the help of our partners, has been monitoring land subsidence in the Virginia Coastal Plain since 1979 using a...

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...

Many culverts and other drainage structures in rural West Virginia are located in small streams or valleys draining 100 acres or less. Design of these structures in West Virginia is generally done using discharge estimates made with widely used and well accepted methods. However, these methods require information including flow-segment length and channel geometry that are poorly characterized for...

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...

Understanding and anticipating high-flow and peak-flow conditions in Virginia streams is essential to human safety and sound management of our water resources and associated riparian and watershed ecosystems.

Understanding low flows in Virginia streams is essential to sound management of our water resources and associated riparian and watershed ecosystems. Meaningful characterizations of the magnitude, frequency, and duration of low flows provide valuable insights into the dynamics, variability, and flux associated with water movement through these unique stream systems. Improved estimates of low flows...

An important part of the Virginia Department of Transportation's missions is the safe maintenance, design, and constructions of bridges that cross-waterways and wetlands in the State. The data collected by USGS in conjunction with this project is a vital element of the overall task and mission of the Virginia Department of Transportation.

Economic growth and the development, management, and protection of Virginia’s natural resources require anticipating peak stream flows and changes in peak stream flows over time. Extensive hydraulic analysis and smart design are needed to limit the environmental impacts of buildings, pavements, highways, and bridges. Effective design and placement of structures built near streams and on flood...

Objectives of the program are to (1) evaluate the spatial and temporal distribution of chloride concentrations in the aquifers, (2) evaluate the factors that affect the spatial and temporal distributions of chloride, and (3) assess the potential for upcoming or lateral intrusion of saline water in the aquifers.

This project: (1) initiates a continuous water-quality monitoring study for the Roanoke River in the area upstream and downstream of the RRFRP project area; (2) provides a mechanism for detecting short- and long-term changes in Roanoke River suspended sediment water quality during and after the RRFRP implementation; and (3) assesses trends in suspended sediment water quality in this section of the...

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)...