Analysis of rainfall and temperature variability in Kebbi State, Northern Nigeria

Abstract

Rainfall and temperature variability can signal climate change and pose challenges to the sustainability of natural water bodies, food security, and ecosystem services. This study aimed to assess trends in rainfall and temperature variability in Kebbi State from 1993 to 2022. The daily rainfall and minimum and maximum temperatures of Kebbi State were obtained at a spatial resolution of 1 km from fifteen (15) meteorological remote sensing stations on the NASA website. One-way ANOVA, the Mann-Kendal (MK) test and Theli-Sen’s slope estimator were employed to assess the magnitude of the trend. In this study, monthly rainfall was significantly (P<0.05) varied, while in two distinct periods (1998-2003 and 2008-2013) a decrease in the total annual rainfall was recorded across the stations but from 2003-2008, a decrease of -26.93 mm was recorded at SW station, while -19.04 mm and -24.44 mm were recorded at the SW and SE stations, respectively. The maximum monthly average temperature was found to be 42.50°C in April 2022, followed by 41.35°C in 1998, 41.25°C in 2018, and the minimum was recorded at 26.54°C in January 2003. Among the stations, the MK and Sen’s slope reveal a rainfall increase at a rate of +12.37 mm/year and 3.88 mm/year in stations C and B, respectively but decreases at rate of -4.12 mm/year in the station A, while temperature shows increasing trends in all the three stations, at rate of 0.028°C, 0.022°C and 0.016°C per year in stations A, B and C for NW, SW and SE respectively. The findings of this study suggest that climate change has influenced the rainfall and temperature patterns in Kebbi State, which can affect the sustainability of climate-dependent ecosystem components, including biodiversity, groundwater level, food security and other ecosystem services.