Water has been a big issue in West Texas for decades – and for good reason. Not only is it absolutely vital to sustain both the lives of the people and animals here as well as the agricultural industries for which this area is famous, it’s also a limited resource.

It’s these two factors that make the field of arid-zone hydrology so important.

“Arid-zone hydrology is the study of the water cycle – precipitation, surface runoffs, infiltration to and evaporation from soil, water-usage by plants and recharge of groundwater – in arid regions, including the Southern High Plains of West Texas,” said Juske Horita, a professor of geology and geophysics in the Texas Tech University Department of Geosciences.

Thanks to a National Science Foundation grant, Horita is getting a new tool to help him in this pivotal research: a high-precision water isotope analyzer.

Most people know that a water molecule is composed of two hydrogen atoms bonded to one oxygen atom, hence its chemical formula, H 2 O. Most people also know that each atom is composed of certain numbers of protons, neutrons and electrons. An atom’s number of protons determines what element that atom is, while the sum of its protons and neutrons determines its mass. But sometimes, in nature, an atom will have a few more or a few less neutrons, which changes the atom’s mass. These atoms with different masses are called isotopes – they’re still the same element, but they’re slightly heavier or lighter than the element typically is.

Horita, who specializes in stable isotope geochemistry, intends to use the water isotope analyzer to study how these isotopes behave in the water cycle of dry regions.

“Oxygen and hydrogen have different stable isotopes in nature,” Horita said. “The abundances of stable isotopes of oxygen and hydrogen of water vary slightly in nature, when water goes through the water cycle. Thus, they serve as natural tracers for the study of the water cycle in arid zones.”

Horita says the laser-based technology can help examine questions such as how precipitated water moves through soils and rocks before reaching groundwater, what types of water in soil plants utilize for their growth and how much of the water in soil evaporates and contributes to atmospheric moistures in arid regions.

“Built-in, natural tracers of stable isotopes are an ideal way to study the water cycle in general, and we at Texas Tech are best positioned to utilize this advanced technology for arid-zone hydrology,” he said. “If we understand these issues, we can use the information to better utilize groundwater resources, better manage water resources for agriculture and better predict the water cycle and climate of arid regions.”

CONTACT: Juske Horita, professor, Department of Geosciences, College of Arts & Sciences, Texas Tech University, (806) 834-7027 or juske.horita@ttu.edu