Estimates of Baseflow, Runoff, and Groundwater Recharge Based on Streamflow-Hydrograph Methods: Pennsylvania

The U.S. Geological Survey (USGS) in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Geological Survey,�estimated groundwater recharge by automated streamflow-hydrograph methods for watersheds throughout Pennsylvania. These data serve as an update to previous estimates of groundwater recharge described in Risser and others (2005). The current analysis provides estimates of groundwater recharge from the recession-curve displacement method (RORA) and estimates of runoff and baseflow from the hydrograph-separation technique PART. Additional hydrograph separation methods, HySEP-Fixed, HySEP-LocMin, HySEP-Slide, BFI-Standard, BFI-Modified, DF-One Param, and DF-Two Param were included in this analysis. All methods used are available in the USGS Hydrologic Toolbox (Barlow and others, 2022). Recharge, runoff, and baseflow estimates were determined for 197 streamgages using streamflow records collected during 1885-2022.�Estimates of mean-annual recharge in Pennsylvania computed by the use of PART ranged from 1.94 to 44.7 inches; estimates from HySEP-Fixed ranged from 1.93 to 41.7 inches; estimates from HySEP-LocMin ranged from 1.81 to 36.9; estimates from HySEP-Slide ranged from 1.84 to 42.3; estimates from from BFI-Standard ranged from 1.25 to 34.1 inches; estimates from BFI-Modified ranged from 1.25 to 33.8 inches; estimates from DF-One Param ranged from 2.28 to 41.5 inches; estimates from DF-Two Param ranged from 2.28 to 39.9 inches and estimates from RORA ranged from 1.44 to 55.2 inches. � Citations: Barlow, P.M., McHugh, A.R., Kiang, J.E., Zhai, T., Hummel, P., Duda, P., and Hinz, S., 2022, U.S. Geological Survey Hydrologic Toolbox software archive: U.S. Geological Survey software release, https://doi.org/10.5066/P9DBLL43. Risser, D.W., Conger, R.W., Ulrich, J.E., and Asmussen, M.P., 2005, Estimates of ground-water recharge based on streamflow-hydrograph methods?Pennsylvania: U.S. Geological Survey Open-File Report 2005-1333, 30 p. �