Madagascar Subnational Rainfall: Dekadal Indicators and Forecasts

Madagascar subnational rainfall indicators provided by the World Food Programme (WFP) utilize CHIRPS satellite imagery and CHIRPS-GEFS forecasts. The data tracks dekadal (10-day) precipitation, long-term averages, and anomalies across administrative units identified by Pcodes. Updates occur multiple times per month to transition from short-term forecasts to final validated observations.

Use Cases

• Drought monitoring using the 3-month rainfall anomaly (r3q) to detect prolonged dry spells
• Agricultural yield forecasting by comparing current 10-day rainfall (rfh) against long-term averages (rfh_avg)
• Hydrological trend analysis using 1-month rolling aggregations (r1h) to assess regional water availability

Strengths

• 9 distinct rainfall indicators including rolling averages and anomalies
• Standardized WFP Pcode references for subnational administrative units
• Data status transparency via the type column distinguishing forecasts from observations

Limitations

• Satellite-derived CHIRPS estimates may vary from ground-truth rain gauge measurements
• Data is subject to revision as forecasts are replaced by preliminary and then final observations

Provenance

Source

World Food Programme (WFP) using CHIRPS v2 and CHIRPS-GEFS

Collection Method

Satellite imagery combined with in-situ station data and short-term rainfall forecasts

Freshness

Updated frequently following a cycle on the 1st, 6th, 11th, 16th, 21st, and 26th of each month.

Geography

Madagascar