Evapotranspiration and its Components in the Nile River Basin Based on Long-Term Satellite Assimilation Product

• Main Authors: Isaac Kwesi Nooni, Guojie Wang, Daniel Fiifi T. Hagan, Jiao Lu, Waheed Ullah, Shijie Li
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: Water
• Subjects: Nile River Basin; actual evapotranspiration (ET); evapotranspiration components; GLEAM; water resource management
• Online Access: https://www.mdpi.com/2073-4441/11/7/1400

Actual evapotranspiration (ET) and its individual components’ contributions to the water−energy nexus provide insights into our hydrological cycle in a changing climate. Based on long-term satellite ET data assimilated by the Global Land Evaporation Amsterdam Model (GLEAM), we analyzed changes in ET and its components over the Nile River Basin from 1980 to 2014. The results show a multi-year mean ET of 518 mm·year^−1. The long-term ET trend showed a decline at a rate of 18.8 mm·year^−10. ET and its components showed strong seasonality and the ET components’ contribution to total ET varied in space and time. ET and its components decreased in humid regions, which was related to precipitation deficits. ET increases in arid-semiarid regions were due to water availability from crop irrigation fields in the Nile Plain. Precipitation was the dominant limiting driver of ET in the region. Vegetation transpiration (an average of 78.1% of total ET) dominated the basin’s water fluxes, suggesting biological fluxes play a role in the regional water cycle’s response to climate change. This analysis furthers our understanding of the water dynamics in the region and may significantly improve our knowledge of future hydrological modelling.