Erina et al. (2026) Projected changes in streamflow seasonality and flood characteristics in the Moskva R. Basin

Identification

• Journal: Theoretical and Applied Climatology
• Year: 2026
• Date: 2026-04-10
• Authors: O. N. Erina, Xiaohua Lin, Natalia Ogneva, N. K. Semenova, D. I. Sokolov, Georgy Ayzel, Xiyan Xu
• DOI: 10.1007/s00704-026-06212-z

Research Groups

• Faculty of Geography, Shenzhen MSU-BIT University, China
• Department of Hydrology, Faculty of Geography, Lomonosov Moscow State University, Russia
• School of Chemistry and Chemical Engineering, Beijing Institute of Technology, China
• Center for Regional Water Management, Moscow, Russia
• Hydrometeorological Research Center of the Russian Federation, Moscow, Russia
• Yandex Weather, Moscow, Russia

Short Summary

This study quantifies projected changes in streamflow seasonality and flood characteristics in the Moskva River Basin under future climate scenarios, revealing a significant shift from snowmelt-dominated to rainfall-influenced runoff with increased winter flow and decreased spring freshet, leading to a reorganization of the flood regime and an overall annual streamflow deficit.

Objective

• To project long-term trends in key hydroclimatic variables (precipitation, air temperature, runoff, potential evapotranspiration) under multiple climate scenarios.
• To quantify changes in the seasonal water cycle and river flow regime.
• To evaluate future changes in flood characteristics, including their frequency and magnitude, to provide a basis for reassessing reservoir operation under a nonstationary hydroclimate.

Study Configuration

• Spatial Scale: Moskva River Basin upstream of the Barsuki gauging station, European Russia, with a drainage area of 755 square kilometers. Elevation ranges from 122 to 334 meters.
• Temporal Scale:
  • Historical baseline: 1979–2014.
  • Model calibration: 2000–2009.
  • Model validation: 1979–1990, 1991–1999, and 2010–2016.
  • Future projections: 2015–2100 for climate forcing, and 2020–2100 for analysis of hydroclimatic and hydrological changes.

Methodology and Data

• Models used:
  • Hydrological model: HBV-96 (Hydrologiska Byråns Vattenbalansavdelning) conceptual lumped model.
  • Climate models: Multi-model ensemble of five CMIP6 Global Climate Models (GFDL-ESM4, IPSL-CM6A-LR, MPI-ESM1-2-HR, MRI-ESM2-0, and UKESM1-0-LL) under three Shared Socioeconomic Pathways (SSP1-2.6, SSP3-7.0, and SSP5-8.5).
• Data sources:
  • Baseline meteorological forcing: EWEMBI reanalysis dataset (0.5° × 0.5° spatial resolution, 1979–2016) from ISIMIP2a.
  • Future meteorological forcing: ISIMIP3b bias-adjusted atmospheric climate input archive (0.5° × 0.5° spatial resolution, 2015–2100).
  • Observed daily discharge: Barsuki gauging station.
  • Snowpack characteristics: Northern Hemisphere Snow Water Equivalent (NH-SWE) dataset (1949–2021).
  • Land cover data: Zanaga et al. (2022).

Main Results

• Hydroclimatic Trends (SSP5-8.5, 2020-2100): Annual precipitation increases by approximately 1.0% per decade, mean temperature rises by 0.15 °C per decade, runoff depth increases by 2.2% per decade, and potential evapotranspiration increases by 4.4% per decade. The long-term drought index shows a pronounced decline (up to -26.0% under SSP5-8.5), while the runoff coefficient remains largely stable at approximately 0.30.
• Streamflow Seasonality Shift: Winter runoff is projected to increase by up to 73% (SSP5-8.5) due to warmer temperatures and a transition from snow to rain. The historically dominant spring freshet is expected to decrease by up to 42% (SSP5-8.5) due to reduced snow accumulation and earlier melt. Autumn flow decreases by 4% to 12%, while summer flow experiences a significant increase of 18% to 37%. Despite increased winter flow, an overall annual streamflow deficit relative to the historical baseline is projected due to reduced spring flow and enhanced warm-season evaporative losses.
• Flood Regime Reorganization: Winter flood frequency more than doubles (e.g., from 0.939 to 2.032 events per year under SSP5-8.5), with increased duration, peak flow (from 16.9 to 17.8–18.9 cubic meters per second), and volume (from 6.7 to 7.7–10.3 × 10⁶ cubic meters). Spring floods exhibit a moderate decline in frequency and peak flow, but still retain the largest absolute peak flows and volumes. Summer floods transition towards fewer but slightly longer and more voluminous events.
• Extreme Precipitation (R95p) and Flood Characteristics: Extreme precipitation (R95p) is strongly and positively correlated with flood frequency, peak flow, and volume in summer and autumn. However, these correlations are weaker in spring, indicating the continued modulating effect of snow accumulation and melt processes. The strength of these correlations does not systematically increase under higher emission scenarios, suggesting a non-linear basin-scale response likely modulated by shifts in the spatial organization of heavy rainfall.

Contributions

• Provides a quantitative assessment of future hydroclimatic and hydrological changes in the Moskva River Basin, a critical headwater catchment for Moscow's water supply, under CMIP6 SSP scenarios to 2100.
• Highlights a significant shift in streamflow seasonality from snowmelt-dominated to rainfall-influenced runoff, with substantial increases in winter flow and decreases in spring flow, consistent with broader regional trends in European Russia.
• Demonstrates a structural reorganization of the flood regime, with winter floods intensifying and the historical dominance of spring floods weakening, while spring still retains the largest events.
• Reveals a non-linear basin-scale response to extreme precipitation, where the correlation between extreme precipitation and flood characteristics does not systematically strengthen under higher emission scenarios, suggesting the importance of the spatial organization of rainfall.
• Offers crucial insights for reassessing static reservoir operating rules (unchanged since 1968) in the Mozhaysk Reservoir, emphasizing the need for adaptation to altered intra-annual flow distribution, evolving flood risks, and an overall annual streamflow deficit under nonstationary climate conditions.
• The study's focus on a minimally anthropogenically disturbed headwater basin allows for clearer attribution of hydrological responses primarily to climate variability and change, enhancing its broader relevance for snow-affected basins in European Russia.

Funding

• Russian Science Foundation (Project 25-17-00073) for work on flood shift projections.
• State research assignment of the Department of Hydrology, Faculty of Geography, Lomonosov Moscow State University for HBV modeling and the interpretation of calibration and validation results.

Citation

@article{Erina2026Projected,
  author = {Erina, O. N. and Lin, Xiaohua and Ogneva, Natalia and Semenova, N. K. and Sokolov, D. I. and Ayzel, Georgy and Xu, Xiyan},
  title = {Projected changes in streamflow seasonality and flood characteristics in the Moskva R. Basin},
  journal = {Theoretical and Applied Climatology},
  year = {2026},
  doi = {10.1007/s00704-026-06212-z},
  url = {https://doi.org/10.1007/s00704-026-06212-z}
}