Spatial Configuration and Extent Explains the Urban Heat Mitigation Potential due to Green Spaces: Analysis over Addis Ababa, Ethiopia

Abstract

Urban green space (UGS) is considered a mitigative intervention for urban heat. While increasing the UGS coverage is expected to reduce the urban heat, studies on the effects of UGS configuration have produced inconsistent results. To investigate this inconsistency further, this study conducted a multi-spatial and multi-temporal resolution analysis in the Addis Ababa city metropolitan area for assessing the relationship between UGS patterns and land surface temperature (LST). Landsat images were used to generate land cover and LST maps. Regression models were developed to investigate whether controlling for the proportion of the green area (PGS), fragmentation, shape, complexity, and proximity distance can affect surface temperature. Results indicated that the UGS patches with aggregated, regular and simple shapes and connectivity throughout the urban landscape were more effective in decreasing the LST as compared to the fragmented and complicated spatial patterns. This finding highlighted that in addition to increasing the amount of UGS, optimizing the spatial structure of UGS, could be an effective and useful action to mitigate the urban heat island (UHI) impacts. Changing the spatial size had a significant influence on the interconnection between LST and UGS patterns as well. It also noted that the spatial arrangement of UGS was more sensitive to spatial scales than that of its composition. The relationship between the spatial configuration of UGS and LST could be changed when applying different statistical methods. This result underlined the importance of controlling the effects of the share of green spaces when calculating the impacts of the spatial configuration of UGS on LST. Furthermore, the study highlighted that applying different statistical approaches, spatial scale, and coverage of UGS can help determine the effectiveness of the association between LST and UGS patterns. These outcomes provided new insights regarding the inconsistent findings from earlier studies, which might be a result of the different approaches considered. Indeed, these findings are expected to be of help more broadly for city planning and urban heat mitigation.

Impact of landscape dynamics and intensities on the ecological land of major cities in Ethiopia

“…1). These cities are among the largest and the fastest-growing urban centers of Ethiopia (Gashu and Gebre-Egziabher 2018;Terfa et al 2020;Wubie et al 2020). The cities are found in the central, northern, southern, and eastern parts of Ethiopia.…”

“…The cities are found in the central, northern, southern, and eastern parts of Ethiopia. Moreover, the cities were selected as study areas based on the following criteria (i) being the largest, a capital city or metropolitan (ii) being the main political, economic, and commercial center of their country (iii) being an active zone of industrialization and a rapid rate of the urban growth, (iv) experiencing rapid urbanization with the highest population in their respective cities of the country and (v) has relatively bettered availability of ecological land as compared to other cities in the order to maximize the probability of detecting changes in ecological land due to the urban sprawl (Gashu and Gebre-Egziabher 2018;Terfa et al 2020;Wubie et al 2020;Li et al 2021).…”

Evaluating urban greening scenarios for urban heat mitigation: a spatially explicit approach

“…Overall, the effect of the spatial configuration of trees on its urban heat mitigation depends on how it affects the shading and evapotranspiration processes. Such a relationship is known to be strongly mediated by the tree species, background climatic and environmental conditions as well as the spatial scale [36,54,55,62,[64][65][66][67].…”

Study on Spatial-Temporal Change of Urban Green Space in Yangtze River Economic Belt and Its Driving Mechanism

“…There has been a consensus of scholars at home and abroad to carry out the quantitative and qualitative and multidisciplinary research on urban green space, and it is also a hot spot in the fields of ecology, geography, landscape ecology, environmental science, forestry, and landscape architecture [ 15 ]. The research on urban green space carried out by scholars currently focuses on how urban green space improves the urban thermal environment [ 16 , 17 , 18 ], the efficiency of urban green space use [ 19 , 20 ], association between urban greenery and travel propensity [ 21 , 22 ], and the connection with urban morphology [ 23 , 24 ]. The frontier of urban green space morphology includes studies on urban green space planning, studies on urban green space patterns and urban landscape patterns, and studies on strategies, planning management, and solutions for the sustainable development of urban green space [ 25 ].…”