Assessing rainfall and extreme weather variability for climate resilient agricultural production systems in Nigeria

Abstract

Nigeria's food production heavily relies on smallholder rainfed agriculture. Unfortunately, this sector is highly vulnerable to the negative impacts of climate change, such as floods and droughts. It is crucial to examine the frequency, intensity, and magnitude of these events and develop effective mitigation and adaptation strategies to ensure the resilience of Nigeria's agricultural system. This study analyses rainfall variability in Nigeria's agroecological zones (AEZs) over the past sixty years. The research evaluates annual, quarterly, and seasonal rainfall patterns and uses the Standardised Precipitation-Evapotranspiration Index (SPEI) to examine drought and flood frequency and intensity. The study's findings reveal that the period from 1981 to 1990 experienced the weakest rainfall patterns across all AEZs, while the best occurred from 1961 to 1970. The humid forest zone consistently received the highest rainfall, although with a declining trend over the decades. Conversely, the Arid/Sahel and Semi-arid zones exhibited the lowest with a slight upward trend in precipitation, while others experienced a reduction. Spatial analysis of drought patterns also reveals that most of the AEZs face high drought risks, with over 65% of the country experiencing a considerable increase in drought in the last three decades. The rainfall pattern was less erratic in zones of lower latitudes than in the higher altitudes. Heavy rainfall events exceeding 10 mm and 20 mm revealed a decreasing trend from the Arid to the Humid Forest zone. Extreme weather events have significant economic consequences. Policymakers and stakeholders must take action to ensure climate resilient and sustainable agricultural production systems.