dc.description.abstract |
Reservoir sedimentation is a significant issue that shortens reservoir life and has an
impact on operations like irrigation, hydropower, and drinking water supply since it
significantly diminishes the reservoir's initial capacity. Information on any changes in
storage capacity is required to reduce the reservoir's risk. This study was conducted in the
Amhara region of the Upper Blue Nile basin, Ethiopia. Bathymetric surveys and ArcGIS
10.3 were used in this study to estimate the sedimentation and life of the Angereb
reservoirs. The quantity, distribution, and the sediment yield of the watershed were all
calculated using the Revised Universal Soil Loss Equation (RUSLE) model. Based on the
findings of the bathymetry survey (from 2007 to 2022), a total of 1.74Mm
3
sediment was
deposited. Storage capacity decreased by around 56.83% throughout the fifteen years of
operation (from 3.063 Mm
3
in 2007 to 1.32 Mm
3
in 2022) and an average annual
reduction in storage capacity of 3.79%. Based on bathymetry survey results, the sediment
yield (SY) and specific sediment yield (SSY) of the Angereb watershed were
128,639.51m
3
year
-1
and 2031.34-ton km
-2
year
-1
, respectively. The gross storage capacity
loss was about 70.20% (from 4.43 Mm
3
in 1997 to 1.32 Mm
3
in 2022) and an annual
reduction in storage capacity of 2.81%. To estimate soil erosion from the catchment and
prioritize micro-watersheds for soil and water conservation measures, the soil erosion
model (RUSLE) was utilized. Based on the analysis, the mean annual erosion of the
watershed as about 87-ton ha
-1
year
-1
, total soil loss from the watershed was about
606,283.86-ton year
-1
, the sediment yield was 103,295-ton year
-1
(15-ton ha
-1
year
-1
),
about 39.1% (2758.91 ha) of the watershed was categorized as slight class, and the
remaining 60.9% (4206.85 ha) of land was classified as moderate to very high. In
general, the findings will serve as a foundation for analyzing future sedimentation issues
in the Angereb subbasin, and for developing sediment control and management methods
for the reservoir.
Keywords: Angereb reservoi r s, Reservoir sedimentation, Bathymetry, RUSLE and Blue
Nile basin. |
en_US |