caa a22 4500 445815515 CHVBK 20180317145227.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s10040-010-0692-z doi (NATIONALLICENCE)springer-10.1007/s10040-010-0692-z Identification of aquifer-recharge zones and sources in an urban development area (Delhi, India), by correlating isotopic tracers with hydrological features [Elektronische Daten] [Manish Kumar, M. Rao, Bhishm Kumar, Algappan Ramanathan] Identification des aires de recharge d'un aquifère et origine de l'eau en zone de développement urbain (Delhi, Inde), par corrélation entre traçages isotopiques et caractéristiques hydrogéologiques Recharge zones and sources in an urban setup (NCT of Delhi, India) were identified using environmental isotopes (2H, 3H, 18O); they were then correlated with hydrogeological conditions. The isotopic results showed that groundwater is being recharged by surface water during the dry season, while recharge associated with local precipitation becomes prominent during the monsoon. The effect of source-water evaporation and altitude on the isotopic characteristics of groundwater was clearly noted. A gradual increase in groundwater age, i.e. decrease in tritium content, while moving away from the river/canals/drains, suggests a degree of mixing of old-aged groundwater with relatively young recharging water. Further, to substantiate the findings of isotopic investigations, surface recharge conditions were differentiated into potential pervious (recharge prone) and impervious (recharge resistant) surfaces through mapping of potential recharge areas based on soil type and water-table depth, to depict a three-dimensional illustration of hydrogeologically mediated recharge zones of the area. The hydrogeological evidence thus obtained about the spatial distribution of permeable zones, slope and boundary conditions, aptly substantiates the isotopic findings. The study seeks its impact by correlation of the isotopic findings with the regional groundwater flow regime which has been altered by the urban development. Springer-Verlag, 2011 Recharge zones nationallicence Groundwater age nationallicence Stable isotopes nationallicence India nationallicence Geographic information systems nationallicence Kumar Manish School of Environmental Sciences, JNU, New Mehrauli Road, 110067, New Delhi, India aut Rao M. National Institute of Hydrology, Jalvigyan Bhawan, 247 667, Roorkee, Uttrakhand, India aut Kumar Bhishm National Institute of Hydrology, Jalvigyan Bhawan, 247 667, Roorkee, Uttrakhand, India aut Ramanathan Algappan School of Environmental Sciences, JNU, New Mehrauli Road, 110067, New Delhi, India aut Hydrogeology Journal Springer-Verlag 19/2(2011-03-01), 463-474 1431-2174 19:2<463 2011 19 10040 https://doi.org/10.1007/s10040-010-0692-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-010-0692-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kumar Manish School of Environmental Sciences, JNU, New Mehrauli Road, 110067, New Delhi, India aut NATIONALLICENCE 700 1- Rao M. National Institute of Hydrology, Jalvigyan Bhawan, 247 667, Roorkee, Uttrakhand, India aut NATIONALLICENCE 700 1- Kumar Bhishm National Institute of Hydrology, Jalvigyan Bhawan, 247 667, Roorkee, Uttrakhand, India aut NATIONALLICENCE 700 1- Ramanathan Algappan School of Environmental Sciences, JNU, New Mehrauli Road, 110067, New Delhi, India aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/2(2011-03-01), 463-474 1431-2174 19:2<463 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer