Browsing by Autor "Bakhriddin Nishonov"

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Advancing isotope-based understanding of water resources in glacierized catchments to adapt to a changing climate
(2025) Sarah Elise Sapper; Mélanie Vital; Ladislav Roller; Francisco Fernandoy; Marcelo Gorritty; Jeonghoon Lee; Janie Masse-Dufresne; Bakhriddin Nishonov; Aurel Perşoiu; Zarina Saidaliyeva
The livelihoods of millions of people worldwide depend on meltwater from glacierized catchments, which are critical resources for drinking water, agriculture, and power production. However, climate warming profoundly affects the water storage and transfer functions of these catchments, posing significant challenges to water resource management in mountain regions. In alignment with the United Nations&#8217; designation of 2025 as the International Year of Glacier Protection and the pursuit of Sustainable Development Goal 6 (Clean Water and Sanitation), there is an urgent need to understand and address these changes and develop adaptive strategies.The relative contributions of glacier melt, snow melt, precipitation, groundwater, and other sources to streamflow remain poorly understood in many glacierized regions. This knowledge gap complicates efforts to predict and manage water resources amid expected climatic changes. Isotope-based methodologies provide a powerful tool to quantify these contributions, offering valuable insights into the current and future status of water resources in glacierized catchments.As part of the coordinated research project initiative titled &#8220;Understanding Hydrological Processes in Glacierized Catchments under Changing Climate using Isotope-Based Methodologies (F33031)&#8221; by the International Atomic Energy Agency (IAEA), a key objective is to develop a comprehensive database of isotopic signatures for the various endmembers contributing to streamflow. These endmembers, which vary depending on the specific catchment, include for example glacier melt, snowmelt, precipitation, groundwater and outflow from rock-glaciers and ice-cored moraines.This research aims to establish a global reference framework to support the development and application of isotope-based methodologies, enabling a standardized approach to understanding flow paths and their contributions to streamflow. By elucidating these dynamics, the framework will help assess how contributions evolve with seasonal and inter-annual climatic variations. These insights are essential for accurately evaluating changes in total discharge volumes and implementing sustainable water management strategies to address the impact of climate change on mountain hydrology.
Global patterns of stable isotope signatures across cryosphere and hydrological components of glacierized catchments
(2026) Edison Edu Jara Tarazona; Mélanie Vital; Andrew J Wade; Janie Masse-Dufresne; Aurel Perşoiu; Marjan Temovski; Luzmilla Dàvila Roller; Francisco Fernandoy; Jeonghoon. Lee; Bakhriddin Nishonov
Glacierized catchments play an important role in regional and global water resources by storing, releasing, and redistributing freshwater. Stable water isotopes (SWI, δ¹⁸O and δ²H) are widely used to trace these processes, providing information on moisture sources, elevation and temperature effects, subsurface storage, and mixing between cryosphere and non-cryosphere components. They also allow quantifying the contributions of the cryosphere and hydrological component to the streamflow. Integrating SWI analysis into studies of glacierized catchments helps better quantify glacier contributions to regional water resources and assess how these contributions change under different climate conditions. Despite decades of isotope-based studies in glacierized environments, SWI data remain fragmented across regions and hydrological components. In this study, we introduce the first global, harmonized database of SWI signatures from cryosphere and hydrological components in glacierized catchments, enabling a global synthesis of isotope patterns. The database compiles 12,348 isotope records from peer-reviewed literature, institutional repositories, and public data platforms published between 1960 and 2025. It integrates δ¹⁸O, δ²H, and derived d-excess values for a wide range of hydrological endmembers, including precipitation, snow, stream, groundwater, lake, snowpack, snowpack melt, glacier ice, glacier meltwater, supraglacial meltwater, firn, ice-cored moraines, talus slopes, rock glacier and permafrost thaw. Each record is georeferenced and accompanied by standardized metadata describing sampling context, elevation, temporal coverage, analytical method, and uncertainty. This database covers five continents and 20 countries, with the highest data density in the Himalaya–Tibet region. The database focuses on continental glacierized catchments where glaciers interact directly with surface waters and groundwater, excluding Greenland and Antarctic ice sheets due to their specific hydrological conditions. The comparative analysis of isotope distributions reveals systematic contrasts among endmembers and continents. At the global scale, δ¹⁸O values (‰ VSMOW2) clearly distinguish cryosphere and hydrological endmembers. Continental-scale patterns of δ¹⁸O highlight the dominant influence of temperature, elevation, atmospheric circulation, and moisture source on isotope variability. North America shows the widest isotopic range due to strong latitude and elevational contrasts. Snow and glacier waters in the Andes are strongly depleted (−18 to −14‰) reflecting orographic effects. African data are limited but indicate warm conditions and evaporative enrichment, while Asia shows large variability driven by strong climatic and topographic gradients. European waters exhibit moderate depletion typical of mid-latitude precipitation regimes. Distributions of d-excess provide information on moisture sources and post-depositional processes. Most samples show positive d-excess values (8–15‰), indicating that the primary atmospheric signal is preserved. Overall, this dataset aims to support the applications of isotope tracers in water resource studies a provides benchmark constraints for isotope-enabled hydrological models (e.g., iCESM, IsoHydro, JAMS200). The interpretations presented here represent an initial exploration of this unique global compilation. By making these data openly available, we aim to support more detailed investigations into the processes governing the hydrology of glacierized catchments.
Large-scale isotopic fingerprinting of cryosphere and hydrological components in glacierized catchments
(European Organization for Nuclear Research, 2026) Mélanie VITAL; Edison Jara; Andrew Wade; Janie Masse-Dufresne; Aurel Perşoiu; Marjan Temovski; Zarina Saidaliyeva; Maria Shahgedanova; Polona Vreča; Bakhriddin Nishonov
The database compiled in this study represents the first global, harmonized collection of stable water isotope (SWI) measurements across cryosphere and hydrological endmembers in glacierized catchments. It contains 12,348 individual records sourced from 63 peer‑reviewed publications, as well as unpublished datasets contributed directly by the authors. The temporal coverage spans from 1981 to 2025, ensuring both historical and contemporary representation of isotopic conditions in glacier environments. Each entry in the database is described by 44 standardized fields, grouped into four main categories: Bibliographic metadata – data owner, publication year, citation, and publication status. Geographical metadata – continent, country, catchment, glacier name, basin, and coordinates. Sampling details – sample type,sampling period, elevation, and remarks. Isotope data – δ¹⁸O, δ²H, d‑excess, analytical method, measurement error, and uncertainty. The database integrates Cryosphere and hydrological endmembers, covering precipitation (solid and liquid), snowpack melt, glacier meltwater, glacier ice, supraglacial meltwater, talus‑slope water, rock‑glacier outflow, groundwater, lakes, firn, permafrost thaw, and ice‑cored moraine meltwater. The stable water isotopes data was generated primarily using CRDS (7,733 δ¹⁸O measurements), IRMS (2,702), OA-ICOS (418) with mean uncertainties of 0.13‰ for δ¹⁸O and 0.49‰ for δ²H. Outliers are flagged but not removed, preserving the raw data integrity.Geographically, the records span six continents and 20 countries, with strong representation in Europe (5,899 records), Asia (3,132), and North America (3,022), and smaller datasets from South America, Africa, and Oceania. Study locations predominantly include mountain regions where surface waters interact directly with glaciers, excluding most polar systems with limited terrestrial hydrology.Overall, this database provides the most comprehensive global synthesis of isotopic signatures from glacierized catchments. It supports applications such as: endmember mixing and hydrograph separation, calibration of isotope‑enabled hydrological models, assessment of moisture sources and continental climate gradients, reconstruction of past hydroclimatic processes using modern–paleoclimate linkages, development of AI‑driven predictive models of cryosphere–hydrology interactions.
Large-scale isotopic fingerprinting of cryosphere and hydrological components in glacierized catchments
(European Organization for Nuclear Research, 2026) Mélanie VITAL; Edison Jara; Andrew Wade; Janie Masse-Dufresne; Aurel Perşoiu; Marjan Temovski; Zarina Saidaliyeva; Maria Shahgedanova; Polona Vreča; Bakhriddin Nishonov
The database compiled in this study represents the first global, harmonized collection of stable water isotope (SWI) measurements across cryosphere and hydrological endmembers in glacierized catchments. It contains 12,348 individual records sourced from 63 peer‑reviewed publications, as well as unpublished datasets contributed directly by the authors. The temporal coverage spans from 1981 to 2025, ensuring both historical and contemporary representation of isotopic conditions in glacier environments. Each entry in the database is described by 44 standardized fields, grouped into four main categories: Bibliographic metadata – data owner, publication year, citation, and publication status. Geographical metadata – continent, country, catchment, glacier name, basin, and coordinates. Sampling details – sample type,sampling period, elevation, and remarks. Isotope data – δ¹⁸O, δ²H, d‑excess, analytical method, measurement error, and uncertainty. The database integrates Cryosphere and hydrological endmembers, covering precipitation (solid and liquid), snowpack melt, glacier meltwater, glacier ice, supraglacial meltwater, talus‑slope water, rock‑glacier outflow, groundwater, lakes, firn, permafrost thaw, and ice‑cored moraine meltwater. The stable water isotopes data was generated primarily using CRDS (7,733 δ¹⁸O measurements), IRMS (2,702), OA-ICOS (418) with mean uncertainties of 0.13‰ for δ¹⁸O and 0.49‰ for δ²H. Outliers are flagged but not removed, preserving the raw data integrity.Geographically, the records span six continents and 20 countries, with strong representation in Europe (5,899 records), Asia (3,132), and North America (3,022), and smaller datasets from South America, Africa, and Oceania. Study locations predominantly include mountain regions where surface waters interact directly with glaciers, excluding most polar systems with limited terrestrial hydrology.Overall, this database provides the most comprehensive global synthesis of isotopic signatures from glacierized catchments. It supports applications such as: endmember mixing and hydrograph separation, calibration of isotope‑enabled hydrological models, assessment of moisture sources and continental climate gradients, reconstruction of past hydroclimatic processes using modern–paleoclimate linkages, development of AI‑driven predictive models of cryosphere–hydrology interactions.