Rainfall and Temperature trends in Samaru and Minjibir, Northern Guinea and Sudan Savannas of Nigeria

Abstract

The changing trend of rainfall and temperature has been shown to vary in magnitudes in different regions of the globe and this has raised a lot of concerns with regards to the changing climate. This study investigated the rainfall and temperature trends from data collected from two research centers located in Samaru, Zaria (11º 11’N; 7º38’E and Minjibir, Kano (11º59’N; 8º 34’E), both in the northern Guinea and Sudan Savannas of Nigeria respectively. Mean annual rainfall from 1968 to 2017 was 1015.9 mm in Samaru and shows a trend of later onset and early cessation. In Minjibir, mean annual 744.5mm of rainfall (1975 -2017) whose onset was almost the same for the years studied, show a trend of early cessation. Standardized rainfall anomaly was experienced in 43% of years between late 1960’s to early 1990’s with varying degrees of drought from moderate to severe, while conditions of no drought to extreme wetness was observed from 2000’s till date with exception of few years. Similar trend was observed in Kano, with 39% of the years in the 1970’s to 1990’s with moderate to severe droughts, with no drought in the years from 2000’s till date. An increasing trend at the rate of 0.61^oC and 0.34^oC at Samaru and 0.67^oC and 0.76^oC at Kano for the maximum and minimum temperatures respectively was experienced, with mean minimum temperatures of 17.2 ºC in 1995 (the lowest recorded from 1968) and 20.9 ºC in 2013 in Samaru. Mean maximum temperatures were 29.5 ºC in 1970 and increased to 34.5 ºC in 2017 in Samaru, while the highest mean maximum temperature was 35.4 ºC recorded in 2011 for Minjibir. These results show the climatic cycles for rainfall and drought events and the increasing global temperatures, confirming a changing climate. Mitigation and adaptation strategies in these agroecological zones and the globe in general remain a crucial option to the consequences of climate change.