Spatiotemporal Variations in Rainfall and Temperature in Ghana Over the Twentieth Century, 1900–2014

Abstract

Climate-dependent subsistence agriculture remains the main livelihood for most populations in Ghana. The spatiotemporal variations in rainfall and temperature have influence particularly in poorly-developed agrarian regions with limited or no irrigation infrastructure. Therefore, a systematic understanding of climate patterns across space and time is important for mitigating against food insecurity and household poverty. Using over a century of high-spatial resolution data, this study examines the spatiotemporal variations in rainfall and temperature across Ghana to identify climate-stressed locations with potential effect on the production of major staple crops. The data for the analysis were drawn from the University of Delaware's Gridded Precipitation and Temperature Monthly Climatology version 4.01. The analysis was restricted to the main crop-growing periods (March to December). The Mann-Kendall nonparametric regression test was used to examine significant changes in rainfall variability and temperature at the district level. The results show that Ghana's climate has become progressively drier over the last century and prone to drought conditions. The most climate-stressed districts are clustered within the three northern regions (Upper West, Upper East, and Northern) and the Western region. The most recent census in Ghana shows that the three northern regions also have the highest prevalence of subsistence agriculture. The findings from this study have implications for targeted interventions such as the Ghanaian government's recent policy initiative aimed at alleviating rural poverty by encouraging youth participation in agriculture along with efforts to intensifying crop production using modern farming techniques.