A compositional approach to stable isotope data analysis
Full Text
Share
Isotopic data are currently becoming an important source of information regarding
sources, evolution and mixing processes of water in hydrogeologic systems. However, it
is not clear how to treat with statistics the geochemical data and the isotopic data
together. We propose to introduce the isotopic information as new parts, and apply
compositional data analysis with the resulting increased composition. Results are
equivalent to downscale the classical isotopic delta variables, because they are already
relative (as needed in the compositional framework) and isotopic variations are almost
always very small. This methodology is illustrated and tested with the study of the
Llobregat River Basin (Barcelona, NE Spain), where it is shown that, though very
small, isotopic variations comp lement geochemical principal components, and help in
the better identification of pollution sources
Tots els drets reservats