Gutkin et al. (2026) Connecting earth observation anomalies to farmer surveys for monitoring impacts of agricultural drought on rainfed rice yields in Nigeria

Identification

• Journal: Earth Observation
• Year: 2026
• Date: 2026-09-07
• Authors: Nick Gutkin, Chiamaka Ibeh Ehiemere, Koen De Vos, Nnamdi David Ehiemere, Jeroen Degerickx, Sarah Gebruers, Uchechukwu Nwafor, Anne Gobin
• DOI: 10.5194/eo-1-77-2026

Research Groups

• Department of Earth and Environmental Sciences, KU Leuven
• VITO (Flemish Institute for Technological Research)
• University of Nigeria Nsukka
• Nigerian Meteorological Agency

Short Summary

This study evaluates the added value of earth observation (EO)-derived vegetation and soil moisture anomalies for monitoring and predicting drought impacts on rainfed rice yields in Nigeria. The results show that EO-based anomaly indicators, especially Soil Water Index (SWIA), provide complementary information and significantly improve yield predictions in years when meteorological indices alone perform poorly.

Objective

• Assess the added value of EO indicator anomalies for predicting the impacts of agricultural droughts on rice yields in Nigeria
• Evaluate the effects of different zonal clustering and anomaly thresholds on anomaly calculation

Study Configuration

• Spatial Scale: National scale, with a focus on major rainfed rice-growing states in Nigeria
• Temporal Scale: 2019-2024, with satellite data covering dates from 1999 until 2020 and from 2020 until 2024

Methodology and Data

• Models used: Multivariate regression models
• Data sources:
  • Satellite-based Normalized Difference Vegetation Index (NDVI) anomalies (NDVIA)
  • Soil Water Index (SWI) anomalies
  • Farmer survey data collected from 146 rainfed rice farmers across four major rice-growing states

Main Results

• The results show that SPI and SPEI explain a substantial share of yield variability in some years, particularly when droughts coincide with sensitive phenological stages.
• EO-based anomaly indicators, especially SWIA (maximum improved R^2 = 0.25), provide complementary information and significantly improve yield predictions in years when meteorological indices alone perform poorly.

Contributions

• This study contributes to a better understanding of how EO indicator-based drought analysis can be tailored to increase relevance for smallholder farmers.
• The results highlight the importance of integrating EO-based vegetation and soil moisture anomaly indicators with existing meteorological indices for monitoring agricultural droughts.

Funding

• This research was funded by the Flemish Institute for Technological Research (VITO) and the University of Nigeria Nsukka.

Citation

@article{Gutkin2026Connecting,
  author = {Gutkin, Nick and Ehiemere, Chiamaka Ibeh and Vos, Koen De and Ehiemere, Nnamdi David and Degerickx, Jeroen and Gebruers, Sarah and Nwafor, Uchechukwu and Gobin, Anne},
  title = {Connecting earth observation anomalies to farmer surveys for monitoring impacts of agricultural drought on rainfed rice yields in Nigeria},
  journal = {Earth Observation},
  year = {2026},
  doi = {10.5194/eo-1-77-2026},
  url = {https://doi.org/10.5194/eo-1-77-2026}
}