Isotope hydrology is a nuclear technique that reveals how water moves through the land, ocean and atmosphere, providing information about the water’s origin, age, quality and movement.
Isotopes are atoms of the same element with the same number of protons but a different number of neutrons. Water (H2O) being composed of two atoms of Hydrogen and one of Oxygen, each drop has a unique isotopic ‘fingerprint’ or ‘signature’, depending on where it comes from. Scientists can track the movement and pollution of water along its path through the water cycle.
For sixty years, the IAEA has been supporting researchers around the world gather and analyse water samples and created the Global Network of Isotopes in Precipitation, the worldwide monitoring network to provide governments and researchers with the long-term, large-scale data they need to gain insights into climate processes at the local, regional and global scale.
Data and information help countries meet Sustainable Development Goal 6 (Clean Water and Sanitation) and deliver on the Water Action Agenda.
Since 1962, water samples have been sent to the IAEA's laboratories in Vienna. The results provide scientists with detailed information on the origin and age, and this information is entered into the largest online isotopic hydrology database.
“This large amount of data allows researchers to better understand the water cycle globally and locally. For example: when, where, and how groundwater is recharged. This is key to decision makers to manage water resources, particularly in the light of climate change,” explains IAEA Isotope Hydrologist Lucia Ortega.
The IAEA datasets and maps are freely available for analysts around the globe to study how changing global rainfall patterns affect local water resources.
These help countries understand how precipitation patterns change and how different rainfall events transfer to the groundwater system and help them also identify the exact source of water pollution when it occurs.