Drought spatiotemporal characterization using self-calibrating Palmer Drought Severity Index in the northern region of Nigeria

Abstract

Hazards from drought events has made it of utmost importance for scientist to concentrate on the establishment of a dependable early warning systems that will enable stakeholders to effectively cope with the probable effect of this climatic phenomenon. Drought assessment in the northern region of Nigeria (NRN) was conducted majorly using a self-calibrated Palmer's Drought Severity Index (sc-PDSI). Between 1981 and 2015, the number of drought episodes identified ranged from 5 to 18. The most severe drought episodes took place from 1998 to 2001, next to it was between 2006 and 2008. The power spectral analysis of sc-PDSI timeseries identified periodicities ranging between 3 and 18 years. The spatial extent of extreme drought episodes shows that, the peak coverage area (10%) occurred at multiple times (August 1987, 2001, 2002 and 2009), most of which is in the 21st century. sc-PDSI reveals the long-term hydrological drought of River Niger indicated at Baro gauging station about 12 months before the low flow occurred. There is a need for policymakers to make adequate preparation by drawing out appropriate mitigation plans using established drought indices before future drought events occur. Keywords: Drought, sc-PDSI, Relative frequency, Agroecological zones, Spatial extent, Nigeria