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1

The water resource implications of planned development in the Lake Tana catchment, Ethiopia

100%
Alemayehu T., McCartney M., Kebede S.
International Journal of Ecohydrology and Hydrobiology
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2010
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tom 10
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nr 2-4
The water resources of the Lake Tana catchment are largely untapped. Currently, water resource development is being promoted to stimulate economic growth. This study utilized the WEAP model to determine the likely impact of a number of possible development scenarios on lake water levels. For each scenario, the model was used to simulate water demand in three sectors (i.e. irrigation, hydropower and downstream environmental flows) over a 36-year period of varying flow and rainfall. The simulation results revealed that if all the planned development occurs on average 2198 GWhy-1 power could be generated and 677 Mm3 y-1 of water supplied to irrigation schemes. However, the mean annual water level of the lake would be lowered by 0.44 meters. As well as adverse ecological impacts this would have significant implications for shipping and the livelihoods of local people.
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A comparative study on the cleaner production options for fishery wastes around Lake Tana

100%
Getahun E., Wagaw K., Sahu O.
International Letters of Natural Sciences
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2016
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tom 56
Around Lake Tana, there are different types of fish processing cooperatives. These cooperatives simply dump the fish wastes (offal) to the Lake Tana which results environmental pollution for the marine ecosystems. In this study three cleaner production options such as biodiesel, biogas and animal feeding were investigated experimentally for the utilization of fishery wastes around Lake Tana. The study showed that fish species (labeobarbus, tilapia and catfish) wastes have oil yield of 28.65%, 16.35% and 5.63 % and free fatty acid content of 10.5%, 7.5% and 6.03% respectively. In the treatment of the oil, only 3.5% of sulfuric acid was consumed to lower the FFA to the required level (2.5%). In the biodiesel experiment, 6:1 ration of methanol to oil and 1hr of reaction retention time were found to be the optimum operating parameters. The yield of biogas was 0.016ml /gram of fish waste. Nutritional composition of fish wastes were 33.4% protein, 0.007% fiber, 1.26% ash, 44% moisture and 21.367% carbohydrate. The study concluded that biodiesel is the possible cleaner production option among the other for the utilization of fishery wastes around Lake Tana.
3

Ecohydrological status of Lake Tana – a shallow highland lake in the Blue Nile (Abbay) basin in Ethiopia: review

80%
Ligdi E. E., El Kahloun M., Meire P.
International Journal of Ecohydrology and Hydrobiology
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2010
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tom 10
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nr 2-4
This paper is based on a country report for Ethiopia prepared as a part of the ecohydrology component of IHP UNESCO’s FRIEND/Nile-phase II Project. It reviews past and current research in the Lake Tana sub-basin around the lake. The objective of the study was to determine the ecohydrological status of the Lake as a tool for integrated water resource management in improving the sustainability of the quantity and quality of freshwater resources in the Nile basin. The preliminary results show that reduced lake water level with its annual fluctuations and seasonal floods associated with high flows are becoming amplified and frequent, and the total average annual sediment load of the four major tributaries shows an increasing trend. Source pollution from urban waste and rural agriculture, and degradation of biota in the catchment are the two main environmental threats for the lake ecosystem. Knowledge gaps were identified and future research needs were recommended along with suggestion of some potential phytotechnologies to be applied in the study area.
4

Assessment of soil erosion processes and farmer perception of land conservation in Debre Mewi watershed near Lake Tana, Ethiopia

80%
Zegeye A. D., Steenhuis T. S., Blake R. W., Kidnau S., Collick A. S., Dadgari F.
International Journal of Ecohydrology and Hydrobiology
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2010
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tom 10
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nr 2-4
Erosion is of great concern in the Ethiopian highlands. The objective of this study was to determine the soil erosion rates under actual farming conditions by measuring the dimensions and number of rills in 15 agricultural fields in the Debre Mewi watershed near Lake Tana, and to understand farmers’ attitudes towards land conservation through personal interviews with one-third of the watershed households. The annual rill erosion rate was 8 to 32 t ha-1. Greatest rates of erosion occurred at planting early in the season but became negligible in August. Major factors influencing land conservation decisions were the demand of labor and lack of technical support for implementing new conservation measures from experts.
5

A pilot study on anthropogenic faecal pollution impact in Bahir Dar Gulf of Lake Tana, Northern Ethiopia

80%
Goshu G., Byamukama D., Manafi M., Kirschner A. K. T., Farnleitner A. H.
International Journal of Ecohydrology and Hydrobiology
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2010
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tom 10
|
nr 2-4
The anthropogenic effect on faecal and chemical pollution at Bahir Dar Gulf of Lake Tana, Ethiopia was investigated in the period of October 2006 to February 2007. Faecal and physicochemical pollution levels were significantly increased and clearly discernible in the Bahir Dar Gulf locations as compared to presumptively anthropogenic uninfluenced reference locations near the outlet of the Blue Nile River of Lake Tana. One directly sewage influenced lake site at Bahir Dar Gulf was found to be excessively faecally polluted. The total pooled data set from the study for faecal coliforms, Escherichia coli and Clostridium perfringens spores ranged from not detectable (n.d.) to log 6.2 CFU, n.d. to log 6.1 CFU and n.d. to log 1.7 CFU per 100 ml, respectively. A high variation was also observable for the physicochemical parameters including the spectral absorption coefficient at 254 nm, ammonia, nitrite, nitrate, total dissolved solids, total suspended solids and pH values. Although the data have to be considered preliminary, it strongly points to the need for systematic water quality monitoring of Lake Tana and its potential impact sources. This is all the more important as the lake is the largest freshwater body in the country serving a multipurpose role and being identified as a growth corridor of the country.
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Improving management of shoreline and riparian wetland ecosystems: the case of Lake Tana catchment

70%
Wondie A.
International Journal of Ecohydrology and Hydrobiology
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2010
|
tom 10
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nr 2-4
This review paper presents the results of many years’ research and field observations on ecological status of the catchment of Lake Tana in relation to the socioeconomic issues. There are a number of wetlands in Lake Tana region such as shore areas, head springs, permanent and temporary floodplains (riverine and manmade) which serve as crop production, fisheries, sand mining, wetland products harvesting, etc. Population pressure and poverty have led to more intrusive activities, which have damaged the overall natural resources. Poor management practices further restricted the basic ecological services they provide (for example climate control, nutrient retention, drinking water provision, flood protection, etc.). The most outstanding threats of the shoreline and riparian wetlands stability are agriculture, industrial pollution, drainage activities and overharvesting of wetland resources. Management strategies should comprise both biophysical and socioeconomic aspects with emphasis on issues like adoption of watershed/ecosystem approach at policy level, integration of income generation in conservation activities, sharing of responsibility/benefits among local stakeholders, institutional strengthening for environmentally and socioeconomically sustainable development of lakes.
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