Web Tools

Long-term groundwater-level data are fundamental to the resolution of problems dealing with groundwater availability and sustainability. Significant periods of time typically are required to collect water-level data needed to assess the effects of climate variability, to monitor the effects of regional aquifer development, or to obtain data sufficient for analysis of water-level trends.

Careful observation and analysis of the movement and condition of surface water is essential for understanding this resource, especially during times of drought. The California Water Science Center uses a network of more than 500 streamgages to collect real-time data on surface water at locations across the state.

The Vegetation Dynamics/Drought viewer provides a dynamic online map interface that can be used to view USGS and other data.

Maximum likelihood logistic regression is used to estimate drought probabilities for selected Virginia rivers and streams 5 to 11 months in advance. Hydrologic drought streamflow probabilities for summer months are provided as functions of streamflows during the previous winter months. This application allows the display and query of these drought streamflow probabilities for Virginia streams.

During the recent droughts of 2007-2010 and 2012-2017, groundwater pumping has increased from the combined effects of the drought and land-use changes, re-initiating land subsidence. In order to document historical subsidence and monitor continued changes, the USGS has gathered and interpreted data from a variety of sources.