Spatio-temporal analysis of urban thermal trends in the selected urban areas of Ethiopia

Abstract

A high rate of urbanization is a common manifestation of developing countries, including Ethiopia. This high rate of urbanization in Ethiopia is significantly altering the country’s energy balance. The study employed the long-term spatio-temporal thermal trends across three areas of the Amhara region (Bahir Dar, Debre Markos and Enjibara). By utilizing a 43-year time series data (1982–2024) from NASA POWER database, the study employed the Mann–Kendall trend test and Sen’s Slope estimator to quantify the thermal change over time. The study results confirmed a statistically significant warming trend at P < 0.05 across all three areas, indicating a regional climate change signal. Nevertheless, there was a distinct thermal divergence among the areas; Bahir Dar experienced the steepest warming rate at 0.02 °C/year, outpacing Debre Markos (0.012 °C/year) and Enjibara (0.01 °C/year). The findings also showed that Bahir Dar is warming twice as fast as Enjibara, suggesting that rapid horizontal expansion and land cover modification together amplify the local temperature. Furthermore, the analysis of extremes reveals a more severe warming trend in Bahir Dar compared to the highland cities. While the highland areas remain buffered against peak daytime heat with stable TXx trends, Bahir Dar is experiencing a significant intensification of heatwaves, with TXx rising at 0.031 °C/year. Conversely, nighttime warming was found to be a pervasive regional phenomenon, with a significant loss of cool nights observed across all altitudes. By providing empirical evidence of urban warming, this study contributes to Sustainable Development Goal (SDG) 11 (Sustainable Cities and Communities) and SDG 13 (Climate Action), providing a baseline for climate-resilient urban planning in Ethiopia. Finally, the study recommended that urbanization acts as a potent driver of local microclimate necessitating the integration of green infrastructure and climate-responsive urban planning to mitigate heat stress.