Understanding the Trends and Patterns of Rainfall Variability and Its Implications for Climate-Resilient Development in Osogbo, Nigeria

Abstract

The study examined rainfall patterns in Osogbo for 30 years to identify changes in the variability and their implication for sustainable environmental management. The study aimed at understanding rainfall variability trend and pattern.Data for the study is from a secondary source. It was sourced from the Nigeria Meteorological Agency (NiMet). The data was analyzed using statistical technique The study revealed variability in the rainfall pattern across the seasons, with a significant difference between the wet and the dry seasons. The Men –Kendal test revealed that the S value is equal to 83, the Z Value equals 1.46, and the p value is equal to 0.143. The seasonality index shows a fluctuating dry season, which is more intense with a reduction in corresponding reductions in rainfall. The ARIMA analysis showed a stationary value of 0.6171, forecasting an increasing trend with fluctuation around 5.69mm by 2026. The standard precipitation index showed an average standard precipitation index of a wetter than expected condition. The dry years are 2014, 2000, and 2016, while the wet years are 1991, 1997, and 2012. There are alternatives between wet and dry years, but it revealed wet than dry years. It also revealed the increase in frequency and intensity of rainfall extremes like floods, droughts, etc. The study concluded that there is a need for proactive and adaptive strategies to mitigate the effects and risks of extreme rainfall events. Therefore, it recommends strengthening climate monitoring, developing climate-resilient infrastructures.