An Estimation of Potential Evapotranspiration (PET) Rate fromtheSudan-Sahel Zone of Nigeria: A Case Study of Kano and Katsina

Abstract

This study estimated the potential evapotranspiration (PET) rate of Katsina and Kano situatedinthe Sudano-Sahelian zone of Nigeria. Mean monthly air temperature data for 31 years (1990-2020) was sourced from the Nigerian Meteorological Agency and used to estimate the PETofthe area using the Thornthwaite’s technique. Results showed that the mean PET values for Katsina and Kano during the periods under review were 147.5 mm and 149.2 mm with mean range of 121.6 -177.3 mm and 124.6 - 177.6 mm respectively. The total mean annual range values for the years analysed for the study areas were from 1718.9-1815.8 mmand1748.5-1935.8 mm respectively. The years 1990 and 2012 had the highest and lowest total meanPETrate for Katsina as well as 1990 and 2015 for Kano. The study shows that the rainy months witness the highest PET for both areas indicating the intrusion and availability of rain bearing air mass across the areas while the dryer months had the lowest PET rate. The mean annual total rainfall values for Katsina and Kano which ranged from 259.8-1389.1 mm and 506-1872mm for the same years under review is lower than the mean total PET range. This shows that thereismoisture deficit for the study areas most especially in Katsina than in Kano. There should be alternative means of boosting soil moisture and also via conservative agricultural practices to improve on crop yields in the study areas.