Water Accounting and Productivity Analysis to Improve Water Savings of Nile River Basin, East Africa: From Accountability to Sustainability
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Date
2022-03-28
Journal Title
Journal ISSN
Volume Title
Publisher
agronomy
Abstract
Complete water accounting (WA) and crop water productivity (CWP) analysis is crucial
for evaluating water use efficiency (WUE). This study aims to evaluate the contributions of hydro meteorological factors to the changes of WA and CWP and subsequent WUE based on the data from
2009–2020 in the Nile River Basin (NRB), East Africa (EA). The Mann-Kendall (MK) statistical test
and Sen’s slope estimator were applied to detect the trends of climatic factors, and the AquaCrop
model was used to simulate the crop yields in response to water balance and consumption based
on crop physiological, soil water, and salt budget concepts. For the years 2012 and 2019, the mean
of climatic water deficit P − ETa was 71.03 km3 and 37.03 km3
, respectively, which was expected to
rise to ~494.57 km3 by 2050. The results indicated that the basin water budget was unbalanced due
to the coupled impact of year-to-year hot and dry conditions and increase in water abstraction, an
indication of water deficit or stress. CWP and WUE increased during the study period with different
changing patterns. CWP was also found to correlate to the yield of major crops (p-value > 0.05). It
was concluded that climatic factors influenced the crop yield, CWP, and WUE in the study area. Thus,
the improvement of CWP and WUE should rely on advanced water-saving innovations. The findings
of this study could help water managers to improve water productivity by focusing on water account
potentials and creating regional advantages by deploying water in combination with surplus flow
from upstream to downstream consumption.