Nature-based Design for Stream Rehabilitation Affected by Imperviousness in Addis Ababa: The Case of Kaba River
| dc.contributor.advisor | Assefa, Alazar (PhD) | |
| dc.contributor.author | Abebe, Mengistu | |
| dc.date.accessioned | 2022-04-20T09:26:47Z | |
| dc.date.accessioned | 2023-11-08T11:26:12Z | |
| dc.date.available | 2022-04-20T09:26:47Z | |
| dc.date.available | 2023-11-08T11:26:12Z | |
| dc.date.issued | 2020-10 | |
| dc.description.abstract | Urbanization of watersheds substantially changes the health of a stream by increasing impervious surfaces that deliver pollutants directly to waterways. The major environmental problem that Addis Ababa facing is the increasing impervious surface. Although improving the riparian zone has been attempted to restore urban stream health in Addis Ababa, that does not significantly improve it, since it is not equivalent to the scale of degradation of streams based on recent studies. The main objective of the study is to introduce an appropriate type of watershed-level nature-based design measures for the rehabilitation of urban streams affected by the higher level of imperviousness in Addis Ababa. Stream restoration can be achieved in this case by a cross-sectional study of the specific case watershed to address the issue of urban streams and river system rehabilitation at the watershed level by introducing appropriate nature-based design solutions and by upscaling the solution from the case site into the entire city river system. The study site is selected based on the density by comparing the built-up of upper catchments. The study estimates the existing level of effective impervious area for ‘Kaba’ river watershed and stream health improvement solution. The total impervious cover of the city and effective impervious cover of the study area are 52 and 27.8 percent respectively. The current condition of the stream will not support its intended hydro-ecological functions. Different design scenarios are proposed in the watershed to reduce the effective impervious areas to a level at which measurable improvement in the ecological indicators. Finally, the study concludes that the proportion of the effective impervious areas is a good predictor of the ecological condition of streams and it should be reduced to a level of recommended proportion to maintain stream health. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/31482 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Hydro-ecological function | en_US |
| dc.subject | Runoff volume | en_US |
| dc.subject | Green infrastructure(GI) | en_US |
| dc.subject | Retrofitting measures | en_US |
| dc.title | Nature-based Design for Stream Rehabilitation Affected by Imperviousness in Addis Ababa: The Case of Kaba River | en_US |
| dc.type | Thesis | en_US |