Africa Topographic Wetness Index 90m Raster Data

A 90-meter resolution raster dataset provides a topographic wetness index for Africa, indicating zones of increased soil moisture. The index was calculated using the AfHydSRTM digital elevation model based on CGIAR-SRTM 90m Version 4 data. It was produced by the World Agroforestry Centre in Nairobi and distributed by the Africa Soil Information Service.

Use Cases

• Model soil moisture distribution using the Topographic Wetness Index (TWI) values across the 90m grid.
• Analyze vegetation pattern correlations with TWI-derived wetness conditions.
• Identify areas prone to water accumulation for agricultural planning by interpreting high TWI zones.
• Integrate TWI raster data with other soil property layers for enhanced landscape modeling.

Strengths

• 90-meter spatial resolution provides detailed continental-scale analysis.
• Based on the established CGIAR-SRTM 90m Version 4 elevation model.

Limitations

• Specific temporal coverage and date of creation for the TWI layer are not provided.
• Data is limited to the African continent, not global.

Provenance

Source

World Agroforestry Centre (ICRAF), Nairobi, Kenya; Africa Soil Information Service (AfSIS).

Collection Method

Calculated by combining local upslope contributing area and slope using the AfHydSRTM digital elevation model.

Time Range

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Freshness

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Geography

Africa