Climate Change Adaptation: Assessment and Simulation for Hot-Arid Urban Settlements – The Case Study of the Asmarat Housing Project in Cairo, Egypt

Abstract

Urban areas in hot-arid climatic zones, especially in Egypt, are facing real challenges in responding to heat island effect, providing thermal comfort and adapt to climate change (CC) impacts. Such challenges are mounting due to CC risks that are manifested worldwide, e.g., severe storms that recently slashed the Gulf of Mexico, Texas, and Florida, USA. Metrological data indicate that the increase in hot summer days would result in rapid multiplication in heat stress, death cases, and economic impacts. A severe event was observed in Cairo, Egypt, in August 2015, where air temperature was recorded high 49 °C above the normal temperature for 10 days, hence resulting in 200 cases that were hospitalized from heat stress and 98 deaths. The CC direct risks are not only limited to urban areas and public health. Due to the fact that Egypt is highly dependent on fossil fuels to produce electricity, GHG emissions, mainly CO2 will be significantly increasing. Therefore, sustainable and green measures and actions are vital to be considered and implemented in all sectors. Under such adverse CC impacts, it is necessary for all stakeholders to examine current urban projects in order to assess their ability to respond to CC adaptation measures. This paper presents the assessment of a low-income housing settlement that was recently built in Cairo. The Asmarat project is selected as the case study to simulate the long-term impact of CC scenarios by 2080 on one of the capital’s urban settlements and to test the role of passive cooling configurations in mitigating CC effect in cities to identify possible countermeasures. Simulation programs ENVI-met and DesignBuilder were used to assess and measure the resilience and sustainability of the selected urban project. The study simulates the urban microclimate in terms of the urban form by 2016 and 2080 to evaluate CC impact. Six measures were tested including passive cooling design configurations, building elevation, buildings’ envelops, vegetation, and water features, and orientation and high albedo were tested, and results were presented. These findings address adaptation policies, actions and measures, and simulations of the role of buildings’ retrofitting and cities’ upgrading in coping with CC mitigation/adaptation to narrow the information gap and yet understand the challenges facing the adaptation measures in hot-arid zones. The changes in climatic parameters resulted in an increased magnitude of thermal discomfort by 1 point on the PMV thermal sensation scale in the built environment within hot-arid climate zones. In addition, results indicate that adaptation measures through buildings’ retrofitting and upgrading cities’ strategies played a vital role in adapting with CC risks through the enhancement of outdoor and indoor thermal comfort and mitigating CO2 emissions.