Africa Specific Catchment Area Raster for Hydrology and Erosion Analysis

Africa Soil Information Service provides a 90-meter resolution raster dataset calculating specific catchment area (SCA) for hydrological modeling. The dataset was produced at the World Agroforestry Centre in Nairobi, Kenya, using the AfHydSRTM digital elevation model derived from CGIAR-SRTM 90m Version 4. It models local flow accumulation and direction to assess water runoff and erosion potential.

Use Cases

• Model relative soil saturation and water runoff potential using the specific catchment area (SCA) values across the raster.
• Predict erosion and landslide risk by combining SCA data with other topographic factors from the underlying elevation model.
• Calculate sediment yield for watersheds by analyzing flow accumulation patterns derived from the SCA parameter.

Strengths

• 90-meter spatial resolution provides detailed terrain analysis.
• Derived from the established CGIAR-SRTM 90m Version 4 digital elevation model.

Limitations

• The underlying SRTM data may have accuracy limitations in very flat or densely vegetated areas.
• Temporal coverage is static; it does not represent changes over time.

Provenance

Source

World Agroforestry Centre (ICRAF), distributed by the Africa Soil Information Service (AfSIS).

Collection Method

Calculated from the AfHydSRTM digital elevation model using the formula SCA = A/I (contributing area per unit contour length).

Time Range

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Freshness

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Geography

Africa