Winner of the UNI LAB Award 2023
Daniel Yoshida
2nd Place
Daniel Felipe Outa Yoshida is an architect and urbanist with an MSc. in Architecture and Urbanism from the University of São Paulo. His research, titled “Green infrastructure: microclimatic effects for climate change adaptation and plant health in an urban warming scenario,” reflects his keen interest in green infrastructure and its potential to mitigate the impacts of climate change, particularly in urban settings. Currently, he serves as a lecturer in undergraduate courses in Architecture and Urbanism.
Both Daniel and Luiza are actively involved in research projects, including “Centre for Water and Food Security in Critical Zones” and “Resilience and adaptation to climate change in cities: time for action with nature-based solutions.
Luiza Sobhie Muñoz
2nd Place
Luiza Sobhie Muñoz, also an architect and urbanist, is pursuing her PhD at the School of Architecture and Urbanism, University of São Paulo. Her research focuses on urban greening, urban design, and climate adaptation, with the project titled “Urban heating, lack of green, and lack of space: proposals for urban redesign to adapt to climate change at the microscale in the city of São Paulo.” She is currently conducting a research internship as part of her PhD, titled “Urban heating, lack of green, and lack of space: proposal of a new green factor for the city of São Paulo,” at Glasgow Caledonian University (GCU) in Glasgow, Scotland. From 2018 to 2022, she also served as a lecturer in two undergraduate Architecture and Urbanism courses.
Both Daniel and Luiza are actively involved in research projects, including “Centre for Water and Food Security in Critical Zones” and “Resilience and adaptation to climate change in cities: time for action with nature-based solutions.
Laudatio for Daniel Yoshida & Luiza Sobhie Muñoz
“In a world grappling with the effects of climate change, the work of Daniel Yoshida and Luiza Muñoz stands out as both timely and essential. Their thesis explores the use of ENVImet to collect insights on the intricate relationship between plant health and microclimates in the context of a warming planet, shedding light on a crucial yet often overlooked greenery related aspect of environmental study.
Their research navigates through the complexities of ecological systems, presenting a nuanced understanding of how plants health is intricately linked to, and affected by, the changing microclimates. Their study moves beyond the conventional, incorporating innovative methodologies and offering insights that are not only academic in nature but also practical for policy-making and urban planning. Yoshida and Munoz’s work exemplifies a careful balance of scientific rigor in their simulation settings and a deep understanding of the environmental challenges we face today.”
Emanuele Naboni
Norman Foster Academic; University of New South Wales Sydney Adjunct Professor; Royal Danish Academy Lecturer; School of Sustainability Mario Cucinella Module Leader; UNIPR Professor; Atkins Global Consultant; World Health Organization Consultant; European Commission TAIEX Expert for Climate Change
Why Sao Paulo?
Cities play an important role in tackling climate change. While greenhouse gases (GHGs) are the main driver on the global scale, anthropogenic actions, such as the suppression of vegetation and changes in ground surface patterns, are responsible for aggravating this environmental problem at the local level. These actions are mainly related to urbanization processes in which the importance of the presence of vegetation throughout the urban fabric is generally not taken into account.
São Paulo, the most developed city in Brazil and one of the largest in Latin America, which houses approximately 12 million people in its 1500 km², has been a scenario for these processes. In terms of greenery, São Paulo presents an unequal distribution of green coverage, where some large and densely populated urban areas have less vegetation than some smaller and less populated ones. The relationship between the lack of greenery and urban heating is clear when land surface temperature and the presence of vegetation are compared. In general, vegetated areas present lower temperatures than densely built ones.
Moreover, the city presents a complex morphology and patterns of built density, resulting in high variation in its landscape. The importance of vegetation, especially trees, as a climate adaptation measure is mainly due to two mechanisms – the shading effect and the evapotranspiration process. However, to perform well, its health and leaf structure conditions are vital parameters. For most tropical or subtropical trees, when the leaf temperature is close to 47ºC and higher than 50ºC, its structure can present initial and permanent damage, respectively.
This leads us to the central question of this work: what are the impacts of different urban morphology patterns and different climate conditions on plant health and leaf structure? And beyond this: will trees be able to continue providing those services and promoting climate adaptation in the city of São Paulo in these different scenarios and under the constant increase in temperature? The results showed that, despite the tendency to lose their potential to reduce air temperature during a period of extreme heat, trees are still able to mitigate surface and mean radiant temperatures.
Results
The work aimed to assess the effects of the built environment on plant’s health under three conditions: a) the current climate, b) the future climate (RCP 8.5, a monthly average of December from 2079 to 2099) and c) the hottest day under RCP 8.5 projection (23/11/2099) in different urban morphology patterns found in Sao Paulo, Brazil. Simulations of leaf temperature, vapor flux and stomatal resistance of the most common urban tree in the city, presenting a LAD of 0,67/m²/m³, were carried out on ENVI-met V5.1.0 and developed for Local Climate Zones 1 (Compact High-rise), 3 (Compact Low-rise), 6 (Open Low-rise) and 8 (Large Low-rise).
The results for current and future climates showed similar tendencies. For the former, maximum leaf temperature was up to 29ºC, while for the latter these values were up to 33 ºC. For both, the lowest mean values were registered in LCZ-1 and were always lower than the air temperature, a consequence of urban morphology and evapotranspiration, expressed by the decrease in stomatal resistance and an increase in vapour flux of the leaves, showing that vegetation is not under heat stress.
Stomatal resistance was kept low during the day for both conditions, meaning higher conductance between the leaves and environment, confirming the evapotranspiration process occurrence. Vapour fluxes were slightly higher under future climate conditions.
On the hottest day, the mean leaf temperature was higher than the air temperature, indicating that the vegetation is no longer able to evapotranspirate, except in LCZ-1. The values in LCZ-3 and LCZ-6 were higher than 45ºC, close to 50ºC in LCZ-8 and up to 41ºC in LCZ 1. In LCZ-3, LCZ-6 and LCZ-8, vegetation is under heat stress, which can cause irreversible damages to its leaf structure and health.
In LCZ-1, the leaves are not under heat stress. The difference among LCZ tipologies highlights the influence of permeable surfaces and urban morphology, in LCZ-6 and LCZ-1, respectively, on plant’s health, since these features are related to lower values of mean radiant and air temperatures registered. Due to shading, there is a difference up to 10ºC between leaves temperature in LCZ-1 and LCZ-8. Trees can lose their potential to reduce air temperature during a period of extreme heat, but are still able to mitigate surface and mean radiant temperatures.