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Groundwater Drift as a Tracer for Identifying Sources of Spring Discharge
Author(s) -
Mori Nataša,
Kanduč Tjaša,
Opalički Slabe Maja,
Brancelj Anton
Publication year - 2015
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/gwat.12314
Subject(s) - phreatic , vadose zone , aquifer , spring (device) , groundwater , δ18o , karst , stable isotope ratio , geology , hydrology (agriculture) , dissolved organic carbon , tracer , δ13c , radionuclide , groundwater recharge , environmental chemistry , geochemistry , chemistry , oceanography , paleontology , mechanical engineering , physics , geotechnical engineering , engineering , quantum mechanics , nuclear physics
Groundwater invertebrate drift, collected from the spring outlets at the interface of vadose and phreatic zones, has been examined for its potential for identifying sources of discharge from a karst aquifer. Concurrently, major ion geochemistry, dissolved inorganic carbon ( δ 13 C DIC ), particulate organic carbon ( δ 13 C POC ), and naturally occurring stable isotopes of oxygen and tritium ( δ 18 O , 3 H ) were investigated over a period of 1 year in two outlets, a temporary ( TS ) and a perennial ( PS ) spring. A few differences in major ion geochemistry and stable isotope composition were found between the two springs together with moderate seasonal variability. In contrast, invertebrate drift showed clear differences between TS and PS springs in density and composition. Canonical correspondence analysis showed the presence of two distinct groups of samples from TS and PS , with Ca 2+ as the only significant explanatory variable for differences in drift composition. Finally, certain species from the drift were found to be useful tracers for distinguishing between the phreatic and the epikarst and vadose zones as the origin of spring water.