Comparative Analysis of Climatic Indices for Basis Risk Reduction in Senegal’s Crop Index Insurance

This study investigates agricultural risk mapping and the performance of climate index insurance in Senegal, with emphasis on basis risk—the gap between actual farmer losses and compensation determined by indices. Data were collected through surveys with 203 insured producers in 17 villages across Kaolack and Tambacounda, combined with meteorological records from ANACIM and IRD and compensation data from CNAAS. Results highlight drought, locust invasions, and parasitism as major risks, with drought perceived as the most critical hazard. Farmers expressed reservations about index reliability: in Kaolack, 65% reported discrepancies between manual rainfall gauges and satellite estimates, while in Tambacounda, 47% considered satellite rainfall estimates (RFE) less reliable than ground measures. Concerns included excessive spatial coverage of automatic gauges (83% in Kaolack) and irregular rainfall distribution (76% in Tambacounda). Quantitative analysis revealed varying levels of basis risk across indices: ARS (3.75% for producers; 0% for CNAAS), RFE (6.7% for both producers and CNAAS), and EARS/ETr (3.125% for producers; 12.5% for CNAAS). Findings suggest that ARS and EARS indices are better adapted to local realities, while RFE requires methodological adjustments to improve accuracy and farmer confidence. The study concludes that reducing basis risk is crucial for the wider adoption of index insurance in Senegal. Enhanced calibration of indices, integration of composite indicators, and participatory design involving farmers are recommended to strengthen trust, ensure fair compensation, and improve the sustainability of climate insurance as a resilience strategy for smallholder agriculture.