USGS Groundwater Information
Groundwater Resources Program
New & Noteworthy
Press Release: High Plains Aquifer Groundwater Levels Continue to Decline
USGS Groundwater Watch
USGS maintains a network of active wells to provide basic statistics about groundwater levels.
Other Water Topics
USGS in Your State
USGS Water Science Centers are located in each state.
Recession-Curve Displacement Method for Estimating Groundwater Recharge In Humid Regions
Execution of RORA Program
For details regarding the theory and application of the recession-curve displacement method by the use of RORA, the reader is referred to Rutledge (1998, 2000). Parameters that can be varied by the user in the RORA program are the recession index (K) and the requirement of antecedent recession. Changing the value of K causes minor changes in the magnitude of the estimated recharge. Increasing the requirement of antecedent recession can substantially decrease the estimated recharge.
New S-PLUS® Version of RORA
The RORA program is being incorporated into S-PLUS® statistical/graphical package by the USGS Minnesota Water Science Center to allow easier analysis because of enhanced ability to graphically analyze hydrograph data. S-PLUS® provides a consistent user interface and the possibility of developing a graphical user interface. Functions are also being developed to plot the analyses, print a concise listing of the analysis, and extract summary information. These functions produce output that replaces the output files from the original programs and eliminate the need to use a separate program to plot the data.