What can we observe in diet using remotely sensed climate data?
# MIRA Madagascar — Vegetation Indices and Household Food Consumption
Data and analysis code accompanying the MIRA study of southern Madagascar,
relating satellite vegetation indices (EVI and NDVI) to household food
consumption at the commune level.
The analysis reduces per-item household consumption records to a single
dominant dimension of dietary variation via mean-centered singular value
decomposition, then tests that component against commune-level vegetation
greenness over time.
> *Recurrent droughts and food shortages in southern Madagascar underscore the need for real-time food security monitoring.
Since 2018, a monthly survey of 602 households has tracked dietary coping strategies in response to food shocks; 547
meeting a 70% response-rate threshold are included in our analysis. Here we assess whether satellite-measured vegetation
greenness can track variation in household-level food consumption. Greenness does not predict the four commonly used food
security indices in the survey. It is instead significantly associated with the leading mode of dietary variability, which captures
substitution between staple or aid-supported foods and lower-preference fallback foods eaten during food stress. Projected
onto commune-level monthly patterns, this mode explains an average of 43% of within-commune dietary variability. Greenness
represents it skillfully, explaining 32–58% of its variability, and 38–70% once seasonality is included. Higher-order dietary
modes show no such relationship, and rotated decompositions, lagged predictors, and alternative vegetation indices do not
improve performance. Satellite-measured greenness therefore captures primary dietary shifts, supporting its integration into
more-detailed food security monitoring systems.
DOI added once available.
## Repository layout
```
data/
commune_food_monthly.csv mean food consumption by commune-month
evi_timeseries/ commune-mean EVI series, c1-c8
commune_vecs/ mont …