Mitigating Urban Heat Island effects in Beirut

Abstract: Urbanisation in Beirut has led to a situation where the city suffers from a severe lack of green public space—Lebanon’s capital have ended up with some of the least amount of public green space per capita in the world. The lack of green surfaces and vegetation in Beirut contributes to the city’s Urban Heat Island (UHI)—a phenomenon where an urban or metropolitan area traps waste heat and end up significantly warmer than the surrounding area. UHI can be considered to be the earliest form of human induced local climate change produced, being observed as early as the early 19th century and has a direct correlation with the urbanisation process. The effect is created through the shift from the city’s original, often vegetated surfaces to hard surfaces that absorb energy and emit heat. This also means that UHI can be reversed and mitigated through urban design measures focused at green infrastructure and added vegetation. This thesis looks at how mitigation of UHI can take form in the context of Beirut, Lebanon. Both through comprehensive planning encapsulating the whole city, as well as through detailed design of a new mixed-use residential area in the southwestern part of the city. The design site consists of old churches, mosques, large scale paving stone industries, modern condominium towers and Lebanon’s smallest Palestinian refugee camp. One of the main challenges of the project have been how to connect this multitude of typologies through densification, while at the same time managing to lower urban temperatures. Finally, the finished design is compared to an unbuilt scenario through microclimate simulations in ENVI-met V4 in order to quantify and assess the mitigation measures.