Investigation of human thermal perception and local adaptation to climate change in hot-humid climates – the case of Dar es Salaam, Tanzania

The coastal urban areas in the tropics are well known for their hot and humid climates. The impacts of climate change are likely to exacerbate the already sultry conditions to the level of limiting the local human thermal comfort. In this study, micro-meteorological measurements accompanied by human thermal sensation interview surveys at two outdoor public spaces (i.e. a park and a beach) were performed in Dar es Salaam Tanzania, one of the current rapidly urbanizing metropolis in Africa. The study aimed at determining the acceptable range of human thermal comfort and the local adaptive capacity to climate change in urban areas, typical to African cities. The human thermal perception was interpreted using the thermal indices of Physiologically Equivalent Temperature (PET) and Universal Temperature Climate Index (UTCI) as analyzed in the RayMan model. Additionally, the measurements done in various local climate zones (LCZ) were used to model the thermal effects of several adaptation measures and varying meteorological parameters in the ENVI-met model. The neutral thermal comfort range for PET in Dar es Salaam was found to be a bit higher to that experienced in mid-latitude cities. The lightweight low-rise local climate zone predominate the urban settlements especially in the unplanned areas. However, the existence of multicultural backgrounds in many fast growing cities like Dar es Salaam limit the local adaptation to the climate hence calling for various adaptation measures to ensure thermal comfort and quality of life in hot-humid urban areas. This includes parks with sufficient shade-providing trees and water bodies as contribution to urban planning.