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http://hdl.handle.net/123456789/2165
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| Title: | WATER RESOURCE UTILIZATION AND ITS RELATED EFFECTS : LAKE ABIYATA AND THE SURROUNDING |
| Authors: | TIGIST, TADESSE |
| Advisors: | Dr. Seifu Kebede |
| Keywords: | Central Rift Valley Lakes,
WEAP model,
Lake Abiyata
lake level change. |
| Copyright: | Jun-2009 |
| Date Added: | 3-May-2012 |
| Abstract: | ABSTRACT
The Study was conducted in Ziway-Abiyata Catchment in the Central Rift Valley of Ethiopia,
to assess the effects of current and future water use practices on the hydrology mainly lake
level change of the Lake Abiyata and its surroundings using a WEAP model. Records of
hydrology, meteorology, irrigation, domestic water supply and industrial water supply for
the study area have been statistically tested and arranged as an input data source to fit the
model. Hydrologic and climatic data were correlated with lake levels. The demand and the
supply of water resource, base line data and the future development activities of the area
were compared using mainly three different scenarios SN1, SN2 and SN3. While by altering
the priority settled for the Bulbula River s flow to a least priority level, additional three
scenarios SN11, SN22 and SN33 were generated. The results revealed that unless the
minimum historical flow requirements are maintained, all scenarios indicated the future
effects on Lake Abiyata. For the SN1, the lake level declined by 0.79 m and 0.34 m for Ziway
and Abiyata lakes respectively. While compared with the baseline scenario, in the SN11 the
lake level drops were 2.61 m and 0.59 m for Abiyata and Ziway lakes respectively. The SN2
scenario revealed a decline by 0.89 m and 0.42 m for the Lake Ziway and Lake Abiyata
compared with the baseline scenario respectively. But in the SN22 scenario, a maximum
level drop over the simulation period of 3.5 m and 0.7 m below the mean value of the
existing condition for Lake Abiyata and Lake Ziway respectively was predicted. The SN3
option had less level drop effect compared with the SN2 scenario for both lakes despite the
additional level drop by this development. The lake level drop below the natural sill in Lake
Ziway may result in the total dry up of the Bulbula River, which consequently threatens Lake
Abiyata s existence as a permanent lake. Similarly, compared with the lake baseline mean
lake level, the Abiyata Soda Ash Enterprise expansion will drop the Abiyata Lake level by
about 0.09 m, which was less than the effect due to upstream irrigation development
proposition in a general sense. It is necessary that more detailed resource assessment of
water should be done, including sustainable abstractions (safe yields) and the spatial
variability of water quantity. In addition to this, the new projects on the study area demand
Integrated Water Resources Management and Environmental Impact Assessment before the
realization of the projects. |
| URI: | http://hdl.handle.net/123456789/2165 |
| Appears in: | Thesis - Environmental Sciences
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