From the U.S. Geological Survey:
The U.S. Geological Survey (USGS) has released a convenient and informative new method for the analysis of groundwater and surface-water hydrologic data called the Groundwater (GW) Toolbox. The GIS-driven graphical and mapping interface is a significant advancement in USGS software for estimating base flow (the groundwater-discharge component of streamflow), surface runoff, and groundwater recharge from streamflow data.
The GW Toolbox brings together several analysis methods previously developed by the USGS and Bureau of Reclamation.
Each of the methods included with the GW Toolbox use daily streamflow data automatically retrieved from the USGS National Water Information System (NWIS) for more than 26,000 streamgage sites across the United States. In addition to streamflow data, the GW Toolbox facilitates the retrieval of groundwater-level and precipitation time-series data from the NWIS database.
The GW Toolbox will be of use to engineers, academia, and government agencies at all levels for the analysis of many of the water-budget components of a typical watershed. The intensively visual interface will help shed light on water availability and hydrologic trends in response to climate and land-use changes and variability in these watersheds.
The GW Toolbox runs in a Microsoft Windows environment and includes the Base Flow Index (BFI), HYSEP, and PART hydrograph-separation methods to estimate base flow and surface runoff and the RORA and RECESS methods to estimate groundwater recharge.