A Dissertation Submitted to the Office of Graduate Program of the Ethiopian Institute of Architecture, Building Construction and City Development (EiABC), Addis Ababa University
| dc.contributor.advisor | Ephrem Gebremariam (PhD) | |
| dc.contributor.author | Esubalew Nebebe Mekonnen | |
| dc.date.accessioned | 2024-12-05T11:06:48Z | |
| dc.date.available | 2024-12-05T11:06:48Z | |
| dc.date.issued | 2024-07-01 | |
| dc.description.abstract | Climate variability significantly impacts global environmental conditions, with developing countries like Ethiopia experiencing adverse consequences. This study broadly covered the spatiotemporal urban climate variability and UHI analysis of Addis Ababa, Ethiopia. Grid meteorological datasets consisted of monthly precipitation, maximum, and minimum temperature extending from 1981 to 2018, with a spatial resolution of 4x4 km, obtained from the National Meteorology Agency. Auxiliary data was obtained from the Ethiopian Geospatial Institute. Coefficient of variation (CV) and standardized anomaly index (SAI) were used to examine the rate and amplitude of temperature and rainfall dynamics. A geostatistical model, ordinary kriging, was employed to spatially interpolate both rainfall and temperature datasets. Mann-Kendall (MK), Modified Mann-Kendall test (MMK), Sen's Slope (SS) estimator, Principal Component Analysis (PCA), and T-test were employed to determine the significant level, trends, and dimensions at monthly, annual, seasonal, and decadal levels. To scrutinize the rate of surface temperature anomalies caused by land use dynamics, Landsat 5TM (1985), Landsat 8OLI/TIRS (2020), and Digital Elevation Model (DEM) were employed. An object-oriented supervised classification with maximum likelihood methods was performed. The Mono-window algorithm, spectral radiance, brightness temperature (BT), and land surface emissivity (LSE) were computed to estimate the land surface temperature (LST). Geospatial technologies, “R” programming, JMP, and origin software were utilized. The findings of the study revealed that the monthly, annual, and seasonal temperatures increased significantly except in the months of January and September. The decadal extreme maximum temperature has exorbitantly risen by 2.7 °C. Moreover, the average decadal maximum and minimum temperatures increased by 1.88 °C and 1.72 °C, respectively. The highest temperature occurred during the spring (Belg) season. The PCA analysis results divulge that the first two PCAs account for 90% of the temperature variations. Conversely, the annual, Kiremt (main rainy) and Belg seasons' rainfall displayed low to moderate variability with CV < 20% and CV < 30%, respectively. The Bega season’s variability was extreme, with a CV > 70%. In contrast, the decadal rainfall variability was very low (CV<10%). From October to March there was extreme inter-monthly variability rainfall with a CV>100%. The trends of rainfall decreased in all months and seasons, except Kiremt and the months of May, June, and September. However, none of the changes were statistically significant (P>0.05). Regarding LST, the built-up area proliferated significantly from 195 km2 (37.5%) in 1985 to 326.3km2 (62.8%) in 2020. The average maximum LST increment was detected on built ups, rose by 2.68°C, while bare land grew by 2.64°C. This implied that the land cover dynamics contributed to the increasing trend of the mean LST from 27.2°C in 1985 to 29°C in 2020. Addis Ketema, Arada, Kirkos, and Lideta sub-cities experienced the utmost increase in LST, ranging from 2.79 °C to 4.72 °C. In conclusion, this study offers an indispensable insight into the fluctuation of temperatures, precipitation, and warming tendencies observed in Addis Ababa. The findings underscore the pressing need for the implementation of climate adaptation strategies and policy measures. Keywords: Addis Ababa; climate variability; Geospatial; spatio-temporal; Mann-Kendall, PCA, Ethiopia | |
| dc.identifier.uri | https://etd.aau.edu.et/handle/123456789/3800 | |
| dc.language.iso | en | |
| dc.publisher | Addis Ababa University | |
| dc.title | A Dissertation Submitted to the Office of Graduate Program of the Ethiopian Institute of Architecture, Building Construction and City Development (EiABC), Addis Ababa University | |
| dc.type | Thesis |