Abstract:
: It is important to understand variations in hydro-meteorological variables to provide
crucial information for water resource management and agricultural operation. This study aims to
provide comprehensive investigations of hydroclimatic variability in the Bilate watershed for the
period 1986 to 2015. Coefficient of variation (CV) and the standardized anomaly index (SAI) were
used to assess the variability of rainfall, temperature, and streamflow. Changing point detection,
the Mann–Kendell test, and the Sen’s slope estimator were employed to detect shifting points and
trends, respectively. Rainfall and streamflow exhibited higher variability in the Bega (dry) and Belg
(minor rainy) seasons than in the Kiremt (main rainy) season. Temperature showed an upward shift
of 0.91 C in the early 1990s. Reduction in rainfall ( 11%) and streamflow ( 42%) were found after
changing points around late 1990s and 2000s, respectively. The changing points detected were likely
related to the ENSO episodes. The trend test indicated a significant rise in temperature with a faster
increase in the minimum temperature (0.06 C/year) than the maximum temperature (0.02 C/year).
Both annual mean rainfall and streamflow showed significant decreasing trends of 8.32 mm/year
Citation: Orke, Y.A.; Li, M.-H.
Hydroclimatic Variability in the Bilate
Watershed, Ethiopia. Climate 2021, 9,
98. https://doi.org/10.3390/
cli9060098
Academic Editor: Nektarios
Kourgialas
Received: 22 May 2021
Accepted: 16 June 2021
Published: 17 June 2021
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4.0/).
and 3.64 mm/year, respectively. With significant increase in temperature and reduction in rainfall,
the watershed has been experiencing a decline in streamflow and a shortage of available water.
Adaptation measures should be developed by taking the increasing temperature and the declining
and erratic nature of rainfall into consideration for water management and agricultural activities