A. Zinabie; B. Kebede
Abstract
With urbanization impervious surfaces increase, drainage pattern changes, overland flow becomes speedy, flooding and environmental problems such as land degradation increases. The objective of this study is to evaluate the hydraulic performance of storm water drainage system of the study area. The drainage ...
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With urbanization impervious surfaces increase, drainage pattern changes, overland flow becomes speedy, flooding and environmental problems such as land degradation increases. The objective of this study is to evaluate the hydraulic performance of storm water drainage system of the study area. The drainage channels are filled with or blocked by silt and garbage, the blockage of drainage structures is due to flat areas and siltation of drainage system which leads to failures on roadways. Spatial analyses were conducted using Arc GIS, Bentley Flow master, Google Earth pro and Auto CAD software’s as analytical tools. The hydrological analysis was computed by rational method. The existing depth and width of the storm water drainage channel were measured for all sub catchments of the town and used to determine the existing drainage capacity using Bentley Flow master. The existing condition drainage channel depths of sub-catchments 6,7 and 8 increased by 68.40%, 160.20% and 121.07%; and the widths by 55.44%, 116.83% and 100.98%, and the design discharge was also 9.29m3/s, 16.47m3/s and 9.13m3/s, respectively. Therefore, this study recommends improvement in the integration of road and drainage structure; integration of solid waste management system in order to prevent the over flowing of storm water as a result of blockage of drains; the stations of the road requires proper maintenance and suitable measures should be taken in order to make the road and storm water drainage structures serve for the intended purposes sustainably to the stakeholders.
W. Takala Dibaba; M. Kebede Leta
Abstract
Currently the effect of urban discharges on water quantity and quality issues and additional recreational amenities perceived in the urban landscape have gained growing public interest for the provision of sustainable urban development. This is due to the fact that urbanization is converging to challenge ...
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Currently the effect of urban discharges on water quantity and quality issues and additional recreational amenities perceived in the urban landscape have gained growing public interest for the provision of sustainable urban development. This is due to the fact that urbanization is converging to challenge city infrastructure due to their adverse impacts on precipitation extremes and the environment of urban areas at large. This study was aimed at identification of the treats of urban expansion and prediction of the environmental responses to urbanization of Jimma City. This is an important input for the decision of environmentalists, hydrologists, storm and waste water management for the better plan and sustainable development of the city. The study analysis of stream flow indicates, urbanization was found to be one of the responsible factors for changing the surface of the land disturbing the hydrological process of Jimma City by altering the magnitude of surface runoff, aquifer recharge and river flows. The expansion of Jimma city have intensified, surface water discharges from developed areas and uncontrolled waste release which have affected the social, environmental and economic state of the area. Increased flood peaks, water volume and pollutant loads, reduced ground water recharge were found to be the major sources water quantity and quality degradation. Degraded water quantity and quality in turn resulted in water crisis, ecological risk, reduced quality of life and reduced level of ecosystem service.
