Browsing by Author "Mekonnen, Wondwosen"

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    Conceptualization of Groundwater Flow System and Aquifer Characterization in Awassa Lake Catchment
    (Addis Ababa Universty, 2005-07) Mekonnen, Wondwosen; Ayenew, Tenalem (PhD)
    In this work, hydrogeological study has been carried out in order to characterize the aquifers and conceptualize the groundwater flow in Awassa Lake catchment, located 275km south of Addis Ababa in the central sector of the Main Ethiopian Rift. Hydrometeorological, hydrological, geological, and structural, hydrochemical and isotopic characteristics of the area are assessed through uses of various approaches and methodologies. Fieldwork, observation and measurements of relevant variables along with existing data accompanied by systematic analysis and interpretation helped so as to understand the hydrogeological system. The Awassa Lake catchment is a closed caldera Lake on its one segment overlaps with the Main Ethiopian Rift. The main geological units in the area are lacustrine sediments characterizing the floor; acidic volcanics covering the caldera rims and escarpment and some basalts, hayaloclastites and scoria cones outcrop on the floor. As it is found on the axial zone of the Ethiopian Rift, it is highly affected by rift structures, recent tectonic features are also observed in the area. The aquifers in the area generally occur in unconfined condition where their hydraulic characteristics are spatially highly variable, which is the result of the complex nature of the lacustrine sediments and the degree of fracturing of the volcanic rocks. The most permeable unit is the lacustrine sediment with hydraulic conductivity ranges between 5m/day- 200m/day, where as the least are those acidic volcanics of the rhyolite, obsidian and lapilli tuff having less than 0.1m/day. The others volcanic rocks lie in between depending on the degree of weathering, fracturing or faulting. The hydrochemical and isotopic analysis of 2H and 18O result signifies that groundwater of the floor, caldera rims, and escarpment and highland is found in different flow regime. This is also supported by the large hydraulic gradient between the floor and the highland. Groundwater of the caldera rims, escarpment and highland is characterized by active, shallow flow with low EC less then 300μs/cm and little isotopic fractionation. Intermediate flow characterizes the remaining floor and western caldera rims with relatively higher ionic concentrations (EC ranges between 1000-2400μs/cm) and enriched in isotopic composition. These flows are controlled by the rift faults and structures, which depends on the characteristics of these structures such as depth of penetration. The area gets higher amounts of direct recharge from the eastern and south eastern caldera rims, escarpment and highland where as the other parts are characterized by intermediate and localized recharges. Similar to the groundwater flow, discharge areas are also restricted to rift structures except the swampy areas found on the floor. Not only these structures but also recent tectonics (ground cracks) developed on the area control the groundwater flow. These features facilitate the groundwater flow toward the Lake Awassa by increasing the hydraulic connections of the different rock units, which might be associated with the rise of the Lake level, the main problem of the area. Key words: Aquifer characterization, Awassa Lake catchment,conceptual profile model, ground cracks, hydraulic conductivity.
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    The Effect Of Customs Regulations And Customs Clearance Process On Company Performance: The Case Of Nestle Waters Ethiopia S.Co.
    (Addis Ababa University, 2020-06) Mekonnen, Wondwosen; Temesgen, Busha (PhD)
    The main purpose of the study was to examine the effect of customs regulations and customs clearance process on Nestle Waters Ethiopia s.co. company performance. This paper has tried to discuss the Effect of Customs laws (rules and regulations), Effect of Customs Valuation, Effect of Customs Clearance, Challenging /problematic/ area in conducting clearing process and the cost implication factors to Nestle Waters due to customs regulation and delay in customs clearance process. Purposive sampling technic was used, and total target population are taken as a sample size, data were collected from all operation staff of four customs clearing agents and Nestle waters employees. The questionnaires were distributed to 52 respondents. Out of this only 49 respondents returned the questionnaires and from this 3 of the questionnaires are not returned. These data were tabulated into SPSS software for statistical analysis. The output was analyzed by mean, frequency, correlation and Regression. Descriptive and Inferential statistics were used to analyze the data collected from the respondents. The major finding found out from the survey result was that the existing Proclamation No. 859/2014 and the revised customs proclamations No. 1160/2019 are still unclear, not harmonized and didn’t simplify the customs procedures to meet the international convention of WCO, customs valuation have a huge effect on company performance and according to this study most customs duties and taxes are calculated and paid based on Transaction value of identical or similar merchandise, the risk profiling software is not updated time to time and there is no adequately staffed skilled customs officers to deliver fast and quality services, over all the customs clearance and risk profiling system is not efficient, the customs valuation, risk level given to imported items have effect on company procurement, production, sales and distribution activity and have effect on distributors, customers and employees satisfaction and also have a very huge impact on over all country's economy. Based on these, recommendation was made in such a way that the customs proclamation must be reviewed, discussed with all stakeholders and updated, customs need to support importers specially manufacturing companies, the customs valuation officers must get enough training and also customs must recruit experts in every department, the risk profiling system must be updated to international standards and customs need to focus on trade facilitation than controlling.