Seasonal evapotranspiration signatures under a changing landscape and ecosystem management in Nigeria: Implications for agriculture and food security

Abstract

An understanding of the evapotranspiration processes and knowledge about the spatial and temporal rates of evapotranspiration is paramount for designing appropriate responses to climate change. But the knowledge about the processes is limited in many African countries. In this paper, we analyzed seasonal and regional trends of evapotranspiration for 36 state capitals of Nigeria and the federal capital, Abuja using data obtained from the International Water Management Institute (IWMI) for the period 1961-1990. Results show that the monthly mean evapotranspiration ranged from 2.68 mm in the month of August at Port-Harcourt (7.00 o E and 4.75 o N) in the coastal part of the country to 9.08 mm for the month of March at Sokoto (5.23 o E and 13.07 o N) in the northern part of the country. The seasonality is consistent with results in literature and the implication of the results for hydrological and allied models has been trumpeted since evapotranspiration in addition to soil moisture are state variables used as initial boundary conditions that influence many hydrological, weather and climate related processes. The study concludes that food shortages arising from climate change and a fast changing landscape due to unsustainable management of the ecosystem could be minimized if the hydrological processes is properly quantified and applied.