Geography and Environmental Studies

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Browsing Geography and Environmental Studies by Author "Abegaz (PhD), Assefa"

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    Environmental and Socioeconomic Effects of Wind Energy production The Case of Adama II Wind Farm. A
    (Addis Ababa University, 2019-06) Tafesse, Getachew; Abegaz (PhD), Assefa
    Purpose of the study is to assess environmental and socio economic effects of wind energy production of Adama II wind farm. The data used for the study were collected from 77 sample respondents who were randomly selected from 1576 households by simple random sampling technique by lottery method and feedback of key respondents like the wind farm managers and some farmers were used. In addition to this, production data from the beginning of the power plant (March 23, 2014) up to July 31st, 2018 and topographic map and remote sensing image of the study area which was obtained from Ethiopian Geospatial information institute and climatic data from National Meteorology Agency was used for data analysis. The main findings of the study are. As 2000-2016 Land use land cover change shows the wind farm plant contribution in altering the land use pattern particularly in shrub and forest clearing and sharing farm land is negligible except in aggravating soil erosion in some farm lands, The standard distance between two consecutive wind turbine is kept by 76%, .During dry season when there is shortage of power due to erratic water problem, wind energy is used to compensate energy supply, with the introduction of wind farm the local community have got the following economic benefit like accesses to public transport, employing as daily laborers and guard during the construction and operation phase, growing red onion as cash crop, they have got compensation for the farm land that used for wind farm even if they have complaint about the amount of compensation, wind farm contribute its own part in reducing the amount of carbon that will penetrate in to the atmosphere, the area ( foot print ) that is used for wind turbine is very small which does not affect the farming activity including grazing unlike hydro power which requires a huge area. The major social problem seen in relation to establishment of wind farm in the local community is noise created by wind turbine and flicker effect seen as minor problem, about 94% of the local community do not benefited with electric light. Wood and animal dung and charcoal is used as fuel for cooking food. About 50 (65%) used solar panel as source of light and 23 (30%) uses others like kerosene lumps as a source of light, consultative meeting was not carried with the local community before the introduction of wind farm .Therefore ,it is suggested that, among other soil conservation measure, reduction of noise of wind turbine near to residential area and social institution like churches, schools ,health station, resolving the grievance of the local community in relation to compensation payment , looking the way for supplying electric power to the local community must get police attention for sustainability of the wind farm in the study area. Keywords: wind, wind energy, wind farm, wind turbine
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    Household Energy And Soil Nutrient; Implications for Crop Production, Household Finances and Greenhouse Gas Emissions in the Central Highlands of Ethiopia
    (Addis Ababa University, 2019-09) Negash, Dugassa; Abegaz (PhD), Assefa
    This study tries to assess household energy and soil nutrients with particular emphasis on implications for crop production, household finances and greenhouse gas emissions in the Central Highlands of Ethiopia. Household survey, focus group discussions, key informant interviews, observations and measurements were used for data collection. Kitchen Performance Test and Controlled Cooking Test were applied for assessing stove efficiency. On-farm trials were established to evaluate effects of fertilizers on soil and yield. Descriptive statistics, a paired sample t-test, one way ANOVA, correlation coefficients and linear regression were employed for statistical analysis. Microsoft excels and SPSS version20 were used for data presentation and analysis. Crop residues and dung cakes accounted for 80(±3) % by energy content and 85(±4) % by dry mass weight of total biomass fuel consumption. Mean per household nutrient losses were 109(±8) kg yr-1nitrogen, 26(±2) kg yr-1 phosphorus, (150(±11) kg yr-1 potassium and 3000(±300) kg yr-1 organic carbon. Rich farmers lost significantly more carbon and nutrients in fuel than farmers in other wealth groups. However, these losses were spread over a larger area, so losses per land area were significantly higher for medium and poor than for rich farmers. This means that the land of poorer farmers is likely to become degraded more rapidly due to fuel limitations than that of rich farmers, so increasing the poverty gap. The estimated financial loss per household due to not using dung and crop residues as organic fertilizer was 162(±8) US$ yr-1. However, this is less than their value as fuels, which was 490(±20) US$ yr-1. Therefore, farmers will only be persuaded to use these valuable assets as soil improvers if an alternative, cheaper fuel source can be found. Substitution of a three-stone open fires with improved stoves resulted in significant improvement of fuel use efficiency (p<0.01) with the highest saving in biomass fuel achieved by the mirt stove together with biogas (53.6%) and lowest by the mud-stove without biogas(32.1%) and respective reduction in greenhouse gases emissions were 4534 (±32) kg CO2e yr-1 and 7661 (±43) kg CO2e yr-1; and financial savings from fuel were 471(±2.6) US$ yr-1 & 279(±4) US$ yr-1 per household. Soil texture of the trial fields were suitable for cereals (clay to clay loam) but high to very high in bulk density implying the existence of soil compaction problem. The trial fields were characterized by very low to low total nitrogen, available phosphorus, organic carbon while the C: N ratios, cation exchange capacity and base saturation were within the optimum ranges. The soil pH at Doliyo was strongly acidic (5.10) whereas that of Kumbursa was nearly neutral (6.89). The post-treatment soil test data revealed that application of bioslurry and bioslurry compost individually as well as in combination with inorganic fertilizer tended improve the soil bulk densities and chemical properties with relatively better performance in nutrient uptake. Both total above ground biomass and grain yields linearly increased with increased application rates of nitrogen & phosphorus for all of the treatments with the highest and lowest responses respectively obtained from bioslurry compost combined with inorganic fertilizer and bioslurry only. Wide scale dissemination of improved cookstoves combined with biogas technology is recommended for enhancing availability of organic fertilizer. Integrated application of organic and inorganic fertilizer should be encouraged for maintaining soil fertility and improving crop yield. Finally, further experimentation is required on application rates of different fertilizer types on different soil types in different agroecologies. Key words: Ethiopian Highlands, biomass fuel, household energy, crop residues, dung cakes, cookstove, soil nutrients, agronomic response, nutrient use efficiency, apparent nutrient recovery