The Impact of Fluctuating Rainfall on Water Availability and Management in the Semi-Arid Watershed of North Western Nigeria

Rainfall anomalies create significant challenges for water resources in semi-arid regions, especially in the developing countries of the tropics.Trends and variations, along with their presence and magnitude, represent the degree of rainfall irregularities.This has a significant impact on the management and availability of water resources in these areas.This study primarily aims to evaluate how variability in rainfall affects the availability and supply of water in the semi-arid watersheds of north-western Nigeria.To evaluate the variations between and within the data mean, the study utilized multivariate statistics, including Analysis of Variance (ANOVA) and Cluster Analysis.The study utilized the Mann-Kendall trend test to identify trends.The ANOVA results indicated a significant variation in rainfall between the stations, with [F (3, 140) = 67.012,p < .05].The results of the cluster analysis revealed two classes for the rainfall series, suggesting that it exhibited lower spatial variability.The outcome of the Mann-Kendall trend test indicated an insignificant annual upward trend.In contrast, the monthly rainfall data exhibited varied trends, including both significant and insignificant increases and decreases.To facilitate understanding of the spatial distribution of rainfall series throughout the river catchment, the trend results were spatially interpolated using inverse distance weighting (IDW).Despite the lack of statistical significance for the annual trend results, they are vital for planning and managing rainfall-related activities, particularly in agriculture and water supply, as well as for preparing for extreme weather events like floods and droughts in the region.There are suspicions that additional elements, like alterations in land use and temperature fluctuations, could worsen the effects of irregular rainfall.These factors have been suggested for inclusion in future studies on climate variability in the region.