Investigating Drought–Seismicity Linkages Across Botswana and surrounding areas: Evidence from SPEI and Earthquake Catalogues

This dataset integrates climate and seismic records to investigate potential linkages between drought variability and earthquake occurrence across Botswana and its surrounding areas, with particular emphasis on the Okavango Rift Zone. The central hypothesis is that prolonged drought conditions, as captured by the Standardized Precipitation Evapotranspiration Index (SPEI), may influence seismic activity through hydrological loading and stress redistribution in the crust. SPEI values were derived from reanalysis and observational climate datasets, calculated at multiple timescales, and aggregated into five‑year bins spanning 1900–2024 to capture long‑term drought variability. In parallel, a harmonized earthquake catalog—compiled from International Seismological Centre was grouped into five‑year bins to enable direct temporal comparison with drought indices.
The dataset highlights Botswana and its neighboring regions as a critical area for studying climate–tectonic interactions in southern Africa. Preliminary analysis shows that periods of severe and prolonged drought often coincide with elevated seismic activity in the Okavango Rift Zone and adjacent areas, suggesting a coupling between hydrological stress and tectonic processes. Notable findings include clustering of moderate‑magnitude earthquakes (Mw ≥ 2.5) during multi‑year drought episodes, and a tendency for seismicity rates to decline during wetter intervals. These patterns underscore the importance of considering climate variability in regional hazard assessments.
Earthquake records include event identifiers, date, time, latitude, longitude, depth, magnitude, and source catalog, while SPEI files present standardized drought indices across multiple timescales. Preprocessing steps involved magnitude homogenization, duplicate removal, and spatial filtering of seismic events, alongside standardized SPEI computation using R-based scripts. The dataset is structured into tabular files (CSV/Excel) with accompanying metadata and scripts to ensure transparency and reproducibility. Potential applications include multi-hazard risk assessment, investigations of climate–tectonic interactions, and educational use in geophysics and climate science. Limitations include variations in seismic catalog completeness and uncertainties in SPEI values, particularly in arid regions.