Hyper-resolution naturalized streamflow data for Geum River in South Korea (1951-2020)

Area of Science:

• Hydrology
• Environmental Science
• Climate Science

Background:

• High-resolution, long-term streamflow data is critical for assessing hydroclimatic extremes and ecological health, especially in river basins experiencing rapid socioeconomic development.
• Existing streamflow data often lacks the necessary resolution or temporal coverage for comprehensive basin-wide analysis.
• The Geum River basin in South Korea, a major river system, faces challenges due to socioeconomic growth impacting water resources.

Purpose of the Study:

• To reconstruct naturalized daily streamflow at a 90-meter resolution for the Geum River basin from 1951 to 2020.
• To provide a high-fidelity dataset for evaluating hydroclimatic changes and ecological impacts.
• To establish a reference dataset for understanding human disturbance effects on river systems.

Main Methods:

• Utilized the Variable Infiltration Capacity-River Routing Model (VIC-RRM) for streamflow reconstruction.
• Simulated daily streamflow at a 90-meter spatial resolution.
• Validated model performance against observed streamflow seasonality and used statistical metrics like correlation coefficient and modified Kling-Gupta Efficiency.

Main Results:

• The VIC-RRM demonstrated high temporal consistency with observed streamflow seasonality (correlation coefficient > 0.6) at over 60% of gauge stations.
• Model performance showed limitations (low modified Kling-Gupta Efficiency) at 36% of stations, attributed to runoff data uncertainties and human impacts (irrigation, reservoirs).
• Reconstructed data revealed decadal streamflow variability in the 1990s and increased day-to-day variability in the 2010s compared to the 1970s.

Conclusions:

• The generated 90-meter resolution naturalized streamflow dataset for the Geum River is physically consistent and valuable for research.
• This dataset serves as a crucial reference for evaluating climate change impacts on streamflow dynamics.
• Understanding human disturbance impacts is essential for accurate streamflow modeling and water resource management in developed river basins.