Murodov et al. (2025) Impacts of future climate change on runoff and its components for the Vanj river basin in the western Pamir

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2025
• Date: 2025-11-10
• Authors: Murodkhudzha Murodov, Lanhai Li, Duan Weili, Sheralizoda Nazrialo, Fatima Eshrat, Nasrulloev Farhod, Sonu Khanal, Mustafo Safarov, Amirkhamza Murodov, Lingjie Bu, Kabutov Khusrav, Aminjon Gulakhmadov
• DOI: 10.1016/j.ejrh.2025.102916

Research Groups

• State Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China
• University of Chinese Academy of Sciences, China
• Zhejiang University of Technology, China
• Research Center for Ecology and Environment of Central Asia (Dushanbe), Tajikistan
• State Scientific Institution “Center for the Study of Glaciers of the National Academy of Sciences of Tajikistan”, Tajikistan
• Institute of Environmental Science and Geography, University of Potsdam, Germany
• Hydrominds, Utrecht, the Netherlands
• Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences, China
• Institute of Water Problems, Hydropower and Ecology of the National Academy of Sciences of Tajikistan, Tajikistan
• Department of Hydraulics and Hydro Informatics “Tashkent Institute of Irrigation and Agricultural Mechanization Engineers”, National Research University, Uzbekistan

Short Summary

This study projects the impacts of future climate change on runoff and its components in the glacierized Vanj River Basin, Tajikistan, using the SPHY model under CMIP6 SSPs. Results indicate significant temperature increases, substantial glacier area loss, and a decline in annual runoff, alongside a shift in peak snowmelt runoff, highlighting the urgent need for adaptive water management.

Objective

• To investigate the impacts of climate change on the water resources of the Vanj River Basin and the associated effects on local communities.
• To evaluate the performance of the SPHY model in simulating streamflow dynamics specific to the Vanj River Basin where glacier/snow-melt water dominates the water sources.
• To investigate the effects of climate change on glacio-hydrological processes and the variability of meltwater contributions.
• To evaluate future temperature and precipitation variations in the Vanj River Basin.
• To predict variation in runoff components under future climate conditions.

Study Configuration

• Spatial Scale: Vanj River Basin (VRB), 1920 square kilometers, with elevations ranging from 1524 meters to 6541 meters above sea level. Model resolution is 0.01 degrees × 0.01 degrees (approximately 1 kilometer × 1 kilometer).
• Temporal Scale:
  • Spin-up period: 1998–1999
  • Calibration period: 2000–2010
  • Validation period: 2011–2015
  • Historical/Baseline period: 2000–2023
  • Future projection periods: Near-future (2029–2052), Mid-future (2053–2076), Far-future (2077–2100)

Methodology and Data

• Models used:
  • Spatial Processes in Hydrology (SPHY) cryospheric-hydrological model.
  • Coupled Model Intercomparison Project Phase 6 (CMIP6) Global Climate Models (GCMs) ensemble (EC-Earth3-Veg-LR, NorESM2-LM, FGOALS-g3, MIROC6, MPI-ESM1–2-LR, GFDL-ESM4, CanESM5).
• Data sources:
  • Reanalysis data: ERA5-Land (0.1° × 0.1° grid resolution, downscaled to 0.01° × 0.01°).
  • Satellite data: Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) (90 meters spatial resolution), Randolph Glacier Inventory (RGI7.0) for glacier outlines, MODIS10A2 snow cover data (500 meters resolution), Landsat 7 Enhanced Thematic Mapper Plus (ETM+) imagery (30 meters spatial resolution) for glacier characteristics.
  • Observation/In-situ data: Daily runoff data from Bichkharv station, meteorological station data (Humrogi, N°47 Meghdor, N°57 Khirson, Vanjyakh), geodetic glacier mass balance data (2000–2018).
  • Other data: High-Resolution Soil Maps of Global Hydraulic Properties (HiHydroSoil) (1 kilometer spatial resolution), European Space Agency Climate Change Initiative (ESA CCI) land use data.
  • Climate Scenarios: Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5).
  • Downscaling and Bias Correction: Cubic spline interpolation, delta-change approach, Empirical Quantile Mapping (EQM), linear regression.

Main Results

• Mean annual temperature is projected to rise by +1.0 °C, +2.3 °C, and +5.5 °C under SSP1-2.6, SSP2-4.5, and SSP5-8.5, respectively, by the end of the century.
• Projected far-future precipitation changes are minor: +0.07 % (SSP1-2.6), -0.58 % (SSP2-4.5), and +2.99 % (SSP5-8.5).
• Glaciers are expected to lose -23 % (SSP1-2.6), -27 % (SSP2-4.5), and -77 % (SSP5-8.5) of their area by the end of the century.
• Total annual runoff is projected to decline by -33 % (SSP1-2.6), -32.7 % (SSP2-4.5), and -17.3 % (SSP5-8.5) relative to the historical baseline (2000–2023). The smaller reduction under SSP5-8.5 is due to increased precipitation and accelerated glacier melt partially offsetting warming effects.
• Historically (2000–2015), runoff components contributed: snow-melt (38 %), baseflow (33 %), glacier-melt (24 %), and rainfall runoff (<5 %).
• The peak of snowmelt runoff is projected to shift from July to June, and seasonal flow variability is likely to intensify.
• By the far-future (2077–2100):
  • Glacier-melt runoff decreases by -77.2 % (SSP1-2.6), -67.1 % (SSP2-4.5), and -48.1 % (SSP5-8.5).
  • Snow-melt runoff decreases by -5.1 % (SSP1-2.6) and -6.2 % (SSP2-4.5), but increases by +9.6 % (SSP5-8.5).
  • Rainfall runoff decreases by -15.4 % (SSP1-2.6) but increases by +38.5 % (SSP5-8.5).
  • Baseflow decreases under SSP1-2.6 (-18 %) and SSP2-4.5 (-20.3 %) but increases under SSP5-8.5 (+4.5 %).
• High flows (Q5) decrease across all scenarios, median flows (Q50) decrease under SSP1-2.6/SSP2-4.5 but temporarily increase under SSP5-8.5, and low flows (Q95) decrease in all scenarios.

Contributions

• This is the first study to investigate climate-driven hydrological changes in the glacierized Vanj catchment, providing a comprehensive assessment of future runoff generation and its components.
• It employs a high-resolution cryospheric-hydrological model (SPHY) with improved parameterizations and calibration using diverse observational data (discharge, snow cover, glacier mass balance).
• The study utilizes bias-corrected ERA5-Land reanalysis data and an ensemble of CMIP6 GCMs under three SSPs, offering robust projections for near-, mid-, and far-future periods.
• It quantifies the individual contributions of glacier-melt, snow-melt, rainfall runoff, and baseflow to total streamflow and their projected changes, which is crucial for water resource management.
• The findings highlight the critical need for adaptive water management and sustainable hydropower planning in glacier-fed catchments of Central Asia, informing strategies for downstream water resource management.

Funding

• Research on the Coupled Assessment and Coordinated Development of the "Water-Energy-Food" System in the Aral Sea Basin, Central Asia (Reference: 1117007001)
• Bureau of International Cooperation, Chinese Academy of Sciences (Reference: 072GJHZ2023086MI)
• Third Xinjiang Scientific Expedition Program (References: 2022xjkk0602 and Xinjiang Jiaotou’s unveiling and commanding program in 2021 (ZKXFWCG 2022060004))
• Research Fund for International Scientists of National Natural Science Foundation of China (Grant No. 42150410393)
• Intergovernmental International Science and Technology Innovation Cooperation (Reference: SQ2024YFE0103020)
• University of Chinese Academy of Sciences (UCAS) Scholarship Program (for the first author's doctoral studies)

Citation

@article{Murodov2025Impacts,
  author = {Murodov, Murodkhudzha and Li, Lanhai and Weili, Duan and Nazrialo, Sheralizoda and Eshrat, Fatima and Farhod, Nasrulloev and Khanal, Sonu and Safarov, Mustafo and Murodov, Amirkhamza and Bu, Lingjie and Khusrav, Kabutov and Gulakhmadov, Aminjon},
  title = {Impacts of future climate change on runoff and its components for the Vanj river basin in the western Pamir},
  journal = {Journal of Hydrology Regional Studies},
  year = {2025},
  doi = {10.1016/j.ejrh.2025.102916},
  url = {https://doi.org/10.1016/j.ejrh.2025.102916}
}