Estimates of ground-water recharge based on streamflow-hydrograph methods: Pennsylvania
Open-File Report 2005-1333
- Dennis W. Risser , Randall W. Conger , James E. Ulrich , and Michael P. Asmussen
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.
Additional publication details
- Publication type:
- Publication Subtype:
- USGS Numbered Series
- Estimates of ground-water recharge based on streamflow-hydrograph methods: Pennsylvania
- Series title:
- Open-File Report
- Series number:
- Year Published:
- U.S. Geological Survey
- Contributing office(s):
- Pennsylvania Water Science Center
- 34 p.
- United States