Naturally occurring isotopes provide clues for understanding hydrologic processes in Uzbekistan’s remote snow-covered catchments.
Kristina Masterson (New York WSC), Monica Langhorst and Cassi Crow (both of Oklahoma-Texas WSC) met with UzHydromet Hydrometeorological Research Institute (HMRI) under Uzbekistan’s Ministry of Ecology to launch a joint USGS-HMRI study of the seasonal variability of surface water sources using oxygen and hydrogen stable isotopes.
In September 2025, Kristina Masterson (New York WSC), Monica Langhorst and Cassi Crow (Oklahoma-Texas WSC) traveled to Tashkent, Uzbekistan for the first of several bilateral meetings intended to focus on capacity building and science and technology exchange. September’s meetings, conducted in office and field settings, discussed surface water sampling plan development, sampling site selection, and training on field practices and river sampling procedures.
USGS scientists from New York WSC, Oklahoma-Texas WSC, Colorado WSC, USGS Water Mission Area and the USGS Reston Stable Isotope Laboratory participated in meeting planning and virtual presentations.
USGS scientists from New York WSC, Oklahoma-Texas WSC, Colorado WSC, USGS Water Mission Area and the USGS Reston Stable Isotope Laboratory participated in meeting planning and in-person and virtual presentations.
Study Background
Data describing the temporal variability of glacial water supply and possible controls on major river hydrologic composition in Uzbekistan are limited. Isotope tracers can inform understanding of hydrologic water budget components, helping to differentiate surface water sources and processes such as snowmelt, evaporation, and groundwater baseflow contributions to streamflow.
In this joint effort with Uzbekistan scientists who represent government and academic institutions, USGS and UzHydromet HMRI are investigating sources of water and their seasonal variability in the Qashqadaryo River in the Amu Darya River Basin. Over the course of one year, seasonal river samples (discrete) will be collected at multiple locations. Water samples will be analyzed for isotopic tracers and physicochemical field parameters including major ions, trace elements, nutrients, and stable isotopes of deuterium and oxygen. Selected samples will be analyzed in both UzHydromet HMRI and USGS laboratories for confirmatory analysis.
Data from the study will provide groundwork for assessing potential impacts of changing hydrologic conditions on water resource availability which will inform water resources management in Uzbekistan for domestic, agricultural, industrial, and minerals exploration use. This strategic study is funded by the U.S. State Department.
