Climate variability impact on crop evapotranspiration in the upper East region of Ghana

Abstract

Ghana's agriculture is primarily rain-fed, making it vulnerable to the impact of climate variability and climate change. This study examined the trends and impact of climatic variability and evapotranspiration on the crop evapotranspiration of selected staple crops across three districts in the Upper East region of Ghana over a 19-year period. Data on agro-climatic conditions (rainfall, temperature, relative humidity, and sunlight) in the Upper East region were obtained from the Ghana Meteorological Agency (GMet) from 2000 to 2018. Given the non-conformity of the response variables to the normality assumption, the Quantile Regression (QR) was employed to examine the impact of climatic variability on different crop evapotranspiration scenarios (low = 10 %, typical = 50 %, and high = 90 %) of the selected crops. The analyzes disclosed a significant difference in crop evapotranspiration between the districts, except for maize, which remained consistent. There was an increase in crop evapotranspiration trend for all, but the maize crop informs the potential improvement of crop evapotranspiration notwithstanding the climatic variability. The study offers a vital insight into the complex dynamics of crop evapotranspiration in response to climatic variability and evapotranspiration. It is recommended, therefore, to consider advances in crop varieties through continuous investment in crop breeding research programmes to improve drought tolerance crops and develop regional water balance techniques.