isotope hydrology
英[ˈaɪsəˌtəʊp haiˈdrɔlədʒi]美[ˈaɪsəˌtop haɪˈdrɑlədʒi]
Isotope hydrology is a field of hydrology that uses isotopic dating to estimate the age and origins of water and of movement within the hydrologic cycle. The techniques are used for water-use policy, mapping aquifers, conserving water supplies, and controlling pollution.