Estimating the Disparity and Variability of the Seasonal Precipitations of two Regions in Nigeria

Abstract

Climate change and its impact on extreme precipitation is a major concern for the global community, including Nigeria. Despite this, there is limited research on the estimation of the variability of seasonal precipitation specifically in the coastal and Sahel regions of Nigeria including their disparity. To address this gap, the disparity between the variability of June-July-August-September (JJAS) seasonal precipitation was analysed in these two regions using data from six stations in each region spanning 36 years (1979-2014). The seasonal precipitation difference between the two regions was then obtained to estimate their disparity. The Mann-Kendall test was used to determine the variability of precipitation in each region, while the Welch two-sample t-test was used to estimate the differences between them. The results showed that while the Sahel region experienced a significant increasing trend in precipitation over time, the coastal region did not show any significant change. Moreover, there was evidence of a strong decreasing trend in the difference in precipitation between the two regions. The correlation test further confirmed the disparity between the precipitations of the two regions. This finding suggests that climate change is having a significant impact on precipitation patterns in Nigeria, especially the Sahel region. Therefore, there are important regional differences that must be taken into account when planning for future climatic change impact in the country. Overall, this study highlights the need for further research on climate change and its impact on JJAS precipitation patterns particularly the causes of the alteration in Nigeria.