caa a22 4500 445815094 CHVBK 20180317145224.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10040-011-0722-5 doi (NATIONALLICENCE)springer-10.1007/s10040-011-0722-5 A comparison of recharge rates in aquifers of the United States based on groundwater-age data [Elektronische Daten] [P. McMahon, L. Plummer, J. Böhlke, S. Shapiro, S. Hinkle] Comparaison des taux de recharge d'aquifères basée sur des données d'âge de nappe, Etats Unis An overview is presented of existing groundwater-age data and their implications for assessing rates and timescales of recharge in selected unconfined aquifer systems of the United States. Apparent age distributions in aquifers determined from chlorofluorocarbon, sulfur hexafluoride, tritium/helium-3, and radiocarbon measurements from 565 wells in 45 networks were used to calculate groundwater recharge rates. Timescales of recharge were defined by 1,873 distributed tritium measurements and 102 radiocarbon measurements from 27 well networks. Recharge rates ranged from < 10 to 1,200mm/yr in selected aquifers on the basis of measured vertical age distributions and assuming exponential age gradients. On a regional basis, recharge rates based on tracers of young groundwater exhibited a significant inverse correlation with mean annual air temperature and a significant positive correlation with mean annual precipitation. Comparison of recharge derived from groundwater ages with recharge derived from stream base-flow evaluation showed similar overall patterns but substantial local differences. Results from this compilation demonstrate that age-based recharge estimates can provide useful insights into spatial and temporal variability in recharge at a national scale and factors controlling that variability. Local age-based recharge estimates provide empirical data and process information that are needed for testing and improving more spatially complete model-based methods. Springer-Verlag (outside the USA), 2011 Groundwater age nationallicence Groundwater recharge/water budget nationallicence USA nationallicence McMahon P. US Geological Survey, Mail Stop 415, 80225, Denver, CO, USA aut Plummer L. US Geological Survey, 12201 Sunrise Valley Dr., 20192, Reston, VA, USA aut Böhlke J. US Geological Survey, 12201 Sunrise Valley Dr., 20192, Reston, VA, USA aut Shapiro S. US Geological Survey, 12201 Sunrise Valley Dr., 20192, Reston, VA, USA aut Hinkle S. US Geological Survey, 2130 SW 5th Ave., 97201, Portland, OR, USA aut Hydrogeology Journal Springer-Verlag 19/4(2011-06-01), 779-800 1431-2174 19:4<779 2011 19 10040 https://doi.org/10.1007/s10040-011-0722-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-011-0722-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- McMahon P. US Geological Survey, Mail Stop 415, 80225, Denver, CO, USA aut NATIONALLICENCE 700 1- Plummer L. US Geological Survey, 12201 Sunrise Valley Dr., 20192, Reston, VA, USA aut NATIONALLICENCE 700 1- Böhlke J. US Geological Survey, 12201 Sunrise Valley Dr., 20192, Reston, VA, USA aut NATIONALLICENCE 700 1- Shapiro S. US Geological Survey, 12201 Sunrise Valley Dr., 20192, Reston, VA, USA aut NATIONALLICENCE 700 1- Hinkle S. US Geological Survey, 2130 SW 5th Ave., 97201, Portland, OR, USA aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/4(2011-06-01), 779-800 1431-2174 19:4<779 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer