Urban Design

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Browsing Urban Design by Author "Alazar, Assefa"

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    Design and Development of Multipurpose Downpipe system for Rooftop Rainwater Harvesting on Institutional Building: The Case of EiABC Campus
    (EiABC, 2018-10) Jenberea Assefa, Wendesen; Alazar, Assefa
    Water is necessary for human survival, essential to socioeconomic development and environmental wellbeing. Sufficient quantity, safe and affordable potable water is crucial for life and economic development. Urban water scarcity is one of the major problems among the problems induced by the current urbanization and rapid urban population growth. As a result, many urban centers are facing a problem in meeting their water demanded. Rainwater harvesting is becoming alternative solution to fill the gap between demand and supply. Even though, rainwater is naturally the purest form of water on our planets, its quality and quantity degrades due to debris and other pollutants on the potential catchment area. This research aimed to improve the quality and quantity of rooftop rainwater harvesting based on study made on all 34 buildings having corrugated iron sheet roofing in EiABC campus. Data of gutter system and downpipe collected by direct measuring and debris from gutter system collected and analyzed using sieve analysis in the laboratory. Based on these study, integrated nature based debris strainer is developed and tested on urban building of EiABC. Compared to the raw water before the device, the laboratory test result has shown that TSS, TDS, and turbidity has shown remarkable difference by 72.17%, 28.43% and 59.1%, respectively. Simultaneously, the multipurpose integrated rain chain system improve the building façade quality. Since rainwater, resource within the campus is still safe for outdoor use and bridge the gap of water supply. Institutions should have to expand this practice to cover their 70% of water demand and reduce water supply pressure on municipal supply. Key words: , ,,
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    Passive Rainwater Harvesting Structure for Stormwater Management and Green Areas Improvement of Institutional Plots in Urban Areas: The case of EiABC Campus
    (Addis Ababa university, 2018-11) Demu Tura, Dufera; Alazar, Assefa
    Stormwater runoff is the major challenge in urban areas due to the increase in impervious surfaces, higher rate of urbanization and rapid economic growth. EiABC campus is, among institutional plots in Addis Ababa, recently has been transformed into more impervious surfaces characterized by 46% of surfaces developed as buildings, roads, parking lots and pedestrian walkways. The stormwater runoff generated from these impervious surfaces transported into municipal drains and roadway without any interventions that are found to result in chronic impairment of surface water quantity and quality. The objective of this study is to investigate the opportunity of the passive rainwater harvesting system from the impervious ground surfaces of institutional plots in urban areas for its stormwater management and green area improvement. The GIS and remote sensing were used to produce a suitability map for selecting the ideal location for the placement of water harvesting structures in the EiABC campus. The Bio-retention system was selected among the others Best Management Practices and eventually developed at the selected site within the compound. The quantity of stormwater was estimated by a rational method and the quality parameters were collected on site and processed in the laboratory. The study estimated that 620.4m3 of surface runoff was harvested through Bio-retention system from 4122m2 drains area. The Bio-retention average removal rates for pollutants of TSS, TDS and Turbidity were 76.92%, 59.2%, and 45.67% respectively. This indicated that the quantity and quality of stormwater were managed through the development of simple rainwater harvesting structure as a Bio-retention system