| dc.description.abstract | Droughts are one of the most prevalent types of weather-related disasters, characterized as
extended periods of below-average water availability. The immediate consequences of drought
include water-supply shortages especially in valley dams and reservoirs, destruction of ecological
resources, forest fires and losses of agricultural production resulting in famine, human suffering,
death and abandonment of whole geographic regions. These effects are vastly felt in the Kaabong,
Karamoja region, North Eastern Uganda. Valley dams like the Longoromit dam have been
constructed in the recent past in the Karamoja region in North Eastern Uganda, to aid the pastoral
community reserve some water for their animals, and also cater for irrigation needs. However, due
to the high prevalence of droughts, the Longoromit dam, which is the second largest in the
Karamoja region is reportedly drying up. This study therefore sought to evaluate the influence of
drought on water availability in Longoromit dam. The specific objectives for this study were: (a)
To assess the frequency and intensity of drought in Karamoja over 30 years, (b) To determine the
water level fluctuations (storage) in the Longoromit dam, (c) To assess the impact of drought on
the dam’s water availability over the 12 years of its existence and (d) To devise remedial measures
for the effects of drought on water availability in the dam.
The Standardized Precipitation Index (SPI) was used to characterize drought occurrence and
frequency over a period of 30 years (1991-2021). A Water Balance Model (WBM) was then used
to obtain the water level fluctuations in the dam from 2010 to 2021. Hydrological modeling was
carried out using the HEC-HMS Model to generate the inflows into the dam, the results of which
were an input into the Water Balance Model. Comparison between the Standardized Anomaly
Index (SAI) and the dam water levels was then done. Drought mitigation measures (structural and
non-structural) that can be taken up to better manage droughts in the study area were also suggested
in this study. The key findings of this study were: (1) Drought greatly affected the water levels in
the dam with SPI values dropping to as low as a minimum of -1.3860 (in April 2017), a period
when the dam was first reported to dry up. In November and December 2021, the SPI values fell
into the negative zone again, an indication of a drought which led to the drying of the dam in early
2022. Longoromit experienced ten (10) drought periods between 1991 and 2021, four (4) of which
were experienced after 2010. The area initially had a drought return period of 3 years before 2010
which reduced to 2.75 years after 2010. This implied that droughts became more frequent after
2010. (2) There has been high water stress on the dam not only from Loyoro sub-county, but from
the neighboring sub-counties of Sidok and Lodiko as well and this affected the dam water levels
too. In 2021, the change in storage of the dam was calculated at -0.686m, an indication of the dam
drying up before even accounting for water consumption from the neighboring sub-counties. The
dam which was initially designed to cater for 40,000 heads of cattle, was feeding approximately
58,000 heads of cattle by the end of 2021. Since drought was found to significantly affect the water
levels, authorities should put emphasis on drought mitigation measures in the area. | en_US |
