Drought characterisation across Agro-climatic zones in Ghana

Résumé fourni par la source

The analysis uses the CHIRPS precipitation dataset at 5 km spatial resolution to compute the Standardized Precipitation Index (SPI) across agro-climatic zones in Ghana for the period 1981–2023. CHIRPS combines satellite-based rainfall estimates with in-situ station data, providing a long-term, high-resolution gridded precipitation product well suited for drought monitoring in data-sparse regions. SPI was derived by standardizing monthly accumulated precipitation against a long-term climatological baseline. SPI was computed at multiple time scales (SPI-1, SPI-3, SPI-6, and SPI-12) to capture short-, medium-, and long-term moisture conditions relevant to agricultural systems. SPI-1 reflects immediate meteorological conditions affecting crop emergence and early growth, SPI-3 captures seasonal rainfall anomalies influencing crop development and yield formation, SPI-6 represents medium-term moisture deficits relevant to soil water availability and cropping season performance, while SPI-12 characterizes long-term hydrological drought conditions affecting groundwater, reservoir storage, and overall agricultural water security. The resulting time series captures interannual to multi-decadal rainfall variability and supports the classification of hydroclimatic conditions into seven categories, ranging from extreme dryness to extreme wetness.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.