Hydrologic analysis of storm water drainage system of Bure town under the effect of urban expansion.

Abstract

Bure town is one of the rapidly growing city found in Amhara Region where storm water management is getting in to a great challenge affecting the environment and the community at large. As the result of urbanization expansion and increasing surface impermeability, uncontrolled flooding from the storm water drainage system has resulted in damage of the small drainage channels, blockage of channels, deterioration of roads and land degradation. The aim of this study is hydrologic analysis of storm water drainage system of Bure town under the effect of urban expansion. Landsat imagery of 1986,2010 and 2017 for land use/land cover classification was performed based on the Satellite imageries. Geographical Information System software is used to prepare the classified maps and ground truth observations were also performed to check the accuracy of the classification. As the results of land use land cover three classes in 1986, 2010 and 2017 was performed how much stormwater runoff volume with in study area increase and decrease for different land use land cover from 1986 through to 2010 and 2017 of significant shifts from some classes to others was also observe. The Bure town bare land and built-up region is growing and it has affected the natural resources like water, agricultural and vegetation and impact of on the environment can be seen. In this study, Bentley civil Storm V8i dynamic storm water modeling was used to calculates and analyzes the hydraulic response of the drainage system through dependent systems of conduit, manhole and outlet to visualize flooding problems and identify the flood risk in the Bure town storm water drainage system. The results obtained from hydraulic condition for stormwater is the overcharged-flow street surface flooding from the catchment and manhole that computed peak discharge of drainage system. The findings of this study indicated that the challenge stormwater management in Bure town respondents claimed that the lack of community awareness, shortage of disposing area, existing drains not well planned, flooding occurrences in the street, blockage of drainage system by the solid waste and lack of clearance stormwater drainage lines they have none functional services of the system.