Effect of Seasons on Spatial Variability of Rainfall in the Niger Delta, Nigeria

The seasons are the important component of rainfall seasonality that determines the flourishing of agricultural and socio-economic activities in the tropics. This study examined the effect of seasons on the spatial variability of rainfall in the Niger Delta, Nigeria. The mean, percentage of variation and coefficient of variation were used to analyze the data. The result showed that the dry season rainfall ranged from 40 to 100 mm (CV: 49.02 to 151.20%) and the wet season from 2294.8 to 3670.6 mm (CV: 22.28 to 110.05%). The monthly CV varied from 22.28 to 151.20% while the annual CV ranged from 11.59 to 32.07%. A little or no variation in space existed in 3 stations in July with the CV range from 34.02 to 34.80%, 3 stations in September with the CV range from 30.40 to 30.70% and 2 stations in October with the CV range from 32.22 to 32.81%. The CV was highest in January and December with the range of 68.54 to 151.20% and lowest in May and June with a variation of 22.28 to 54.60%. The study concluded that season controls the extent of variation of rainfall in space in the Niger-Delta.

Keywords
Rainfall variation; season; spatial variation; coefficient of variation.