Abstract

The issue of climate change appears to be on the fore burner and it cannot be ascertained to occur without evidence. Rainfall is one of the climatic factors that can indicate climate change. In this work, the non-parametric Mann-Kendall test is used to test for significant trend in rainfall in Nigeria through randomly selected locations in the six geopolitical zones within a 30 years period (1978-2007). The selected locations are; Maiduguri (13°10',11°50') in the North East, Kaduna (7°27',10°31') in the North West, Lokoja (6°45',7°43') in the North Central, Ibadan (3°53',7°22') in the South West, Enugu (7°30',6°27') in the South East and Calabar (8°28',4°57') in the South South. During the 30 years period, the yearly average rainfalls (mm) were 580.5, 1187.5, 1228.7, 1317.2, 1753.8 and 2925.6, respectively. While the rest of the locations had no significant trend yet Maiduguri showed an increasing trend at a rate of 9.88 mm/year, where formally the trend there from the period 1961-1990 was decreasing. This change could either be a problem or blessing to dwellers in that location and there is need for continuous monitoring.

Key words: Mann-Kendall test, rainfall, significant trend, six geopolitical zones in Nigeria.