Changing Rainfall Patterns and Agricultural Resilience: Implications for Food Security in Semi-Arid Regions

Semi-arid zones are becoming more susceptible to the impact of the alteration of rainfalls which are other significant challenges to the resilience of agriculture and their food security. The authors compared the experience of three decades (1990-2020) of climatic and agricultural data in the Sahel, East Africa, the Deccan Plateau of India, and Western Australia to describe how changes in rainfall timing, intensity, and variability affect crop productivity and stability in food systems. In a mixed methodology, the timing of rainfall onset, stop early in the season, the frequency of intra-season drought, and intra-seasonal rainfall concentration indices were analyzed along with crop yield of millet, sorghum, maize, and wheat and regional food security indices. It was found that the effects of intra-seasonal dry spells and delayed onset of rain during a season are much stronger negative factors towards crop yields compared to their total annual rainfall and sorghum in India and maize in East Africa were especially susceptible to variability in rainfall distribution. Regression and correlation analysis also supported the fact that dry spell frequency was the most important factor that causes fall in yield and it was the main contributor of variability in the yield of about 60 percent in some regions. The anomalies in rainfall were directly related to the levels of crop failure and increased incidences of food insecurity especially in the Sahel and East Africa which is where the volatility of markets and smaller adaptive capacities worsens exposure. On the other hand, Western Australia exhibited partial resilience as a result of conservation agriculture using machines and policy propagation. Findings highlight the dire necessity of climate-resilient crop adaptation, water-harvesting and soil conservation practices and institutional interventions like climate information services and crop insurance in protecting food system in semi-arid zones characterized by rising climate variability. Keywords: Semi-arid regions; rainfall variability; agricultural resilience; intra-seasonal dry spells; crop yields; food security; rainfall onset; climate change adaptation; drought-tolerant crops; soil and water conservation.