Estimates of ground-water recharge based on streamflow-hydrograph methods: Pennsylvania

Open-File Report 2005-1333
By: , and 



This study, completed by the U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey (T&GS), provides estimates of ground-water recharge for watersheds throughout Pennsylvania computed by use of two automated streamflow-hydrograph-analysis methods--PART and RORA. The PART computer program uses a hydrograph-separation technique to divide the streamflow hydrograph into components of direct runoff and base flow. Base flow can be a useful approximation of recharge if losses and interbasin transfers of ground water are minimal. The RORA computer program uses a recession-curve displacement technique to estimate ground-water recharge from each storm period indicated on the streamflow hydrograph.

Recharge estimates were made using streamflow records collected during 1885-2001 from 197 active and inactive streamflow-gaging stations in Pennsylvania where streamflow is relatively unaffected by regulation. Estimates of mean-annual recharge in Pennsylvania computed by the use of PART ranged from 5.8 to 26.6 inches; estimates from RORA ranged from 7.7 to 29.3 inches. Estimates from the RORA program were about 2 inches greater than those derived from the PART program.

Mean-monthly recharge was computed from the RORA program and was reported as a percentage of mean-annual recharge. On the basis of this analysis, the major ground-water recharge period in Pennsylvania typically is November through May; the greatest monthly recharge typically occurs in March.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Estimates of ground-water recharge based on streamflow-hydrograph methods: Pennsylvania
Series title Open-File Report
Series number 2005-1333
DOI 10.3133/ofr20051333
Year Published 2005
Language English
Publisher U.S. Geological Survey
Contributing office(s) Pennsylvania Water Science Center
Description 34 p.
Country United States
State Pennsylvania
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