Advancing water security in Africa with new high-resolution discharge data

Area of Science:

• Hydrology and Earth System Science
• Environmental Modeling
• Remote Sensing Applications

Background:

• Accurate river discharge data is crucial for water resource management in Africa.
• Existing datasets may lack the spatial resolution or temporal coverage needed for detailed analysis.
• Coupled modeling approaches offer a promising avenue for generating high-fidelity hydrological datasets.

Purpose of the Study:

• To introduce VegDischarge v1, a comprehensive natural river discharge dataset for Africa.
• To provide a reliable, high-resolution (1-km) dataset covering the period 2001-2021.
• To quantify continental and oceanic basin-specific discharge contributions.

Main Methods:

• Employed a coupled modeling system integrating the agro-hydrologic VegET model and the mizuRoute routing model.
• Utilized remote sensing data and hydrological modeling to simulate and route runoff.
• Validated model performance using established metrics such as R², NSE, and KGE.

Main Results:

• VegDischarge v1 covers over 64,000 river segments across Africa.
• Model performance demonstrated strong reliability with continental-scale R² (0.5-0.9), NSE (0.6-0.9), and KGE (0.5-0.8).
• Total average annual discharge for Africa was quantified at 3271.4 km³·year⁻¹, with detailed contributions to major oceanic basins.

Conclusions:

• The VegDischarge v1 dataset offers valuable insights into African water availability and its variations.
• This dataset supports informed decision-making for water infrastructure planning and resource allocation.
• Findings contribute to developing effective climate resilience strategies across the continent.