| dc.description.abstract |
Studying rainfall's spatial variations and temporal trends is crucial for assessing climaterelated
changes
and
designing
future
water
resource
management
strategies
and
agricultural
planning.
This study investigated the spatiotemporal variability and comparative trend
analysis of rainfall and its implication on development sectors using time-series rainfall data
from Enhancing National Climate Services (ENACTS) over western Amhara for the period
1991–2020. None of the past researchers has addressed the analysis of the spatiotemporal
trend of seasonal and annual rainfall using ITA over western Amhara. Rainfall variability
was assessed using the coefficient of variation, precipitation concentration index (PCI), and
standardized anomaly index (SAI). Mann-Kendall and Sen's slope estimator tests were also
used to assess spatiotemporal trends, and the low, medium, and high rainfall clusters were
analyzed using the most recent innovative trend analysis (ITA) approach. The spatial
distribution of annual rainfall was varied from 600 mm to 2300 mm. In most of the rainfall
grid points, a high amount of annual rainfall happened in the Kiremt (JJAS) season, and high
rainfall variability occurred during the Bega (October - January) season. SAI also witnessed
the presence of inter-annual variability of rainfall with negative and positive anomalies in
46.7% and 53.3% of the reference years, respectively. The PCI result indicated that the
distribution of rainfall in the area was strongly irregular. The result indicated that in most
grid points, the MK test and SSE showed a statistically non-significant trend in annual
rainfall. Most rainfall grid points displayed high clusters and increasing trends during the
Kiremt and annual periods, but low rainfall was observed during the Bega season, indicating
declining trends. The comparison results showed that the ITA approach is more reliable and
superior to the MK test because it can identify both monotonic and non-monotonic trends that
the MK method is unable to identify. The rainfall trend during the Kiremt and Bega seasons
shows that it is increasing and decreasing, respectively. Therefore, I recommend planting
drought-tolerant and early-maturing crops to cope with the risks associated with rainfall
variability. |
en_US |