Pedestrian level wind assessment of historic urban forms: A study of Massawa, Eritrea

Pedestrian-level wind comfort and safety are essential considerations in promoting urban comfort for shaping the quality of the urban environment. Assessment of pedestrian wind environments is, however, typically associated with modern urban development areas, with limited application in historic contexts despite their embedded wisdom in climate responsive building design and city planning. Moreover, there is a limitation in accounting for the effects of comprehensive planning and the combined influence of different morphological factors, with emphasis commonly limited to building scales in most studies. This research examines the impact of urban form and building design on the pedestrian wind environment in the historic port city of Massawa, Eritrea. Computational Fluid Dynamics (CFD) simulations were conducted on six models representing the evolution of urban forms over nearly 150 years to understand their effect on the pedestrian wind environment. Simulations were conducted for each model in two prevailing wind directions, with a particular focus on velocity amplification analysis to understand the design-related contributions comparatively. Results mainly show that organic urban forms created less wind activity in the core of the city, with high wind acceleration mostly related to buildings in the windward direction. In contrast, gridded urban forms with broad and straight street corridors create a channeling effect, creating more areas of potential wind discomfort in the core of the city. Thus, highlighting the need for future microclimate studies to understand microclimate differences in different urban forms informed by varying underlying factors. • Pedestrian-level wind environment study was conducted in a historic heritage site. • Six models representing urban form change over nearly 150 years were studied. • Organic urban forms created less wind activity in the core of the city. • Gridded urban forms with broad and straight street corridors increase wind activity. • Destruction of heritage causes loss of heritage and alters the wind flow patterns.