Lightning Behavior and Its Relationship with Topography, Precipitation, and Land Use in the São Francisco River Basin

Abstract This study quantifies how topographic features influence lightning activity in the São Francisco River Basin, Brazil, filling a critical gap by establishing previously unavailable thresholds. A 16-year climatology (1998–2013) was developed using LIS/TRMM lightning data, ASTER GDEM topography, CHIRPS precipitation, and MapBiomas land use, all standardized to a 0.1° grid. The analysis integrates elevation, slope, aspect, and land use with lightning flash rate density (FRD) and precipitation. Results show a non-linear response of lightning to topography, with a 261.7% increase in FRD above 517.14 m during the dry season, and additional thresholds of 45.4% above 601.96 m (spring) and 24.9% above 583.14 m (summer). Lightning hotspots range from 29.2 to 39.9 flashes km –2 yr –1 , with the maximum value recorded in São Desidério (BA), concentrated in the Western Bahia Plateau (Cluster 04). A seasonal shift is identified, with large-scale thermodynamics dominating in the wet season and topographic forcing controlling lightning activity in the dry season. Ultimately, this study establishes a robust quantitative framework for the terrain–lightning relationship, highlighting zones of elevated risk for expanding agricultural activities in the basin.