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- Estudos sobre cidades e alterações climáticasPublication . Alcoforado, Maria Joao; Andrade, Henrique; Lopes, António; Oliveira, Sandra; Fragoso, Marcelo; Lombardo, Magda; Matzarakis, AndreasNum momento, em que todas as atenções se viram para as alterações climáticas do planeta, discute-se, neste texto, as relações entre as modificações do clima ditas “globais” e aquelas que ocorrem no espaço urbano. Em Portugal, em 2005, as áreas urbanas concentravam 57.6% da população prevendo-se que, em 2020, essa percentagem atinja 66.4%. São primeiro sucintamente apresentadas as principais conclusões do IPCC (Intergovernmental Panel on Climate Change, 2007), referentes às previsões de variação climática para 2100, em função de diversos cenários, realçando as variações de temperatura. Prevêem-se acréscimos de temperatura entre 1,8 e 4ºC até 2100, modificações substanciais nos regimes de precipitação e na sua distribuição espacial, na frequência de ocorrência de episódios meteorológicos extremos (vagas de calor e de frio, precipitações intensas, secas prolongadas), assim como a subida do nível do mar. Detalhando a escala de análise, apresentam-se os resultados do projecto SIAM (Scenarios, Impacts and Adaptation Measures, Santos et al., 2006), em que é feito, por um lado, o downscaling das previsões para Portugal, também sob diferentes cenários e, por outro, são tratados os impactes das alterações climáticas previstos na agricultura, na saúde, no consumo de energia, nas áreas costeiras, nos recursos hídricos, etc. Numa escala de análise de maior detalhe, as mudanças climáticas impostas pelo meio urbano são igualmente reais: modificação dos balanços radiativo e energético, aumento da temperatura das superfícies e do ar (Ilha de calor – IC), diminuição da velocidade média do vento (embora com a ocorrência de acelerações e turbilhões indesejáveis), aumento da poluição atmosférica, diminuição da visibilidade e, mesmo em certos casos, aumento da precipitação convectiva. Neste texto, trata-se sobretudo do problema de excesso de carga térmica e de poluição atmosférica, que ocorre em meio urbano e que tem impactes evidentes sobre a saúde, o conforto e as actividades dos citadinos. É discutida a relação complexa entre o aquecimento urbano e o aquecimento dito global (AG), fenómenos de escala e natureza muito diferentes. Contudo, a acumulação dos efeitos térmicos a diferentes escalas, nas áreas urbanas, faz temer que estas venham a sofrer impactes particularmente graves; por exemplo, em Londres, nas noites de Verão, a IC pode acrescentar 5º a 6º C ao aquecimento esperado. Os problemas ambientais associados às cidades estão a ser incrementados pela expansão da área urbanizada e pelo crescimento dos rendimentos dos citadinos. E, em certas cidades, já se verificam incrementos térmicos semelhantes aos esperados a nível “global” para daqui a várias dezenas de anos (Grimmond, 2006). Por isso, apesar das incertezas inerentes à variação espacial das alterações climáticas, é toda a urgência o estudo das alterações do clima em curso nas cidades, dos impactes que poderão ter e das medidas de adaptação a adoptar para minimizar os seus efeitos negativos e tirar partido das suas potencialidades, contribuindo para a sustentabilidade urbana, uma vez que estas são particularmente vulneráveis devido à elevada densidade populacional, à grande percentagem de população idosa e de baixo nível sócio-económico. O ordenamento urbano é o factor chave para reduzir os impactos e potenciar os aspectos positivos das alterações climáticas. São enumeradas, na parte final, diversas “boas práticas” de adaptações às alterações climáticas, levadas a cabo em diversos locais do globo, desde o Japão, ao Reino Unido e à Austrália e Portugal.
- Geografia Física em regiões de montanha: a Ilha da Madeira e as Serras da Arrábida e da Estrela. Homenagem a Orlando RibeiroPublication . Mora, Carla; Alcoforado, Maria João; Jansen, Jan; Fragoso, Marcelo; Lopes, António; Lopes, Sérgio; Vieira, GonçaloO presente livro é composto por dois textos, partindo de alguns trabalhos de Orlando Ribeiro e mostram como o Zephyrus tem estudado os temas seleccionados. O primeiro trata do clima e da vegetação da Arrábida e da Madeira, embora estes não sejam temas centrais na obra de Orlando Ribeiro. O. Ribeiro dedicou-se primeiro à investigação sobre a Arrábida, tema da sua tese de doutoramento em 1935 e estudou a Madeira em 1947 e 1948, quando preparava o livro-guia de uma das excursões do XVIº Congresso Internacional de Geografia, que o CEG de Lisboa organizou em 1949, sob a sua orientação. O segundo texto refere parte de uma investigação, feita na sequência do Projecto ESTRELA, liderado pelo Professor António de Brum Ferreira, falecido em 2013, que lembramos com saudade e admiração, e que muito contribuiu para o conhecimento da Geografia Física de Portugal, em particular no campo da Geomorfologia. Apresenta-se um estudo de unidades de paisagem, em que se investigam as interacções entre o clima, a dinâmica geomorfológica e as comunidades vegetais no circo glaciário do Covão Cimeiro, na Serra da Estrela, cuja glaciação quaternária foi inicialmente estudada por E. Fleury e H. Lautensach e, posteriormente, por Suzanne Daveau. O trabalho é feito a uma escala muito detalhada, com o objectivo de delimitar unidades de paisagem, adaptadas ao sistema de classificação de habitats Natura2000. A metodologia pode ser extrapolada e permite aplicação no ordenamento e na gestão do território. A ligação com o trabalho de Orlando Ribeiro tem aqui a ver com a selecção da metodologia (seguindo-se uma perspectiva de Geografia naturalista, focada nas inter-relações entre os elementos físicos e biofísicos da paisagem) e com os trabalhos que desenvolveu na Cordilheira Central, onde guiou excursões de numerosas gerações de geógrafos. Os dois textos mostram que, apesar da evolução dos conceitos em torno da paisagem, os trabalhos de Orlando Ribeiro são muito inovadores para a época, apresentando já a paisagem como um conceito dinâmico, resultado das relações entre geomorfologia, clima e vegetação e incluindo a marca do Homem.
- An urban energy balance-guided machine learning approach for synthetic nocturnal surface Urban Heat Island prediction: a heatwave event in NaplesPublication . Oliveira, Ana; Lopes, António; Niza, Samuel; Soares, AmílcarSouthern European functional urban areas (FUAs) are increasingly subject to heatwave (HW) events, calling for anticipated climate adaptation measures. In the urban context, such adaptation strategies require a thorough understanding of the built-up response to the incoming solar radiation, i.e., the urban energy balance cycle and its implications for the Urban Heat Island (UHI) effect. Despite readily available, diurnal Land Surface Temperature (LST) data does not provide a meaningful picture of the UHI, in these midlatitudes FUAs. On the contrary, the mid-morning satellite overpass is characterized by the absence of a significant surface UHI (SUHI) signal, corresponding to the period of the day when the urban-rural air temperature difference is typically negative. Conversely, nocturnal high-resolution LST data is rarely available. In this study, an energy balance-based machine learning approach is explored, considering the Local Climate Zones (LCZ), to describe the daily cycle of the heat flux components and predict the nocturnal SUHI, during an HW event. While the urban and rural spatial outlines are not visible in the diurnal thermal image, they become apparent in the latent and storage heat flux maps – built-up infrastructures uptake heat during the day which is released back into the atmosphere, during the night, whereas vegetation land surfaces loose diurnal heat through evapotranspiration. For the LST prediction model, a random forest (RF) approach is implemented. RF results show that the model accurately predicts the LST, ensuring mean square errors inferior to 0.1 K. Both the latent and storage heat flux components, together with LCZ classification, are the most important explanatory variables for the nocturnal LST prediction, supporting the adoption of the energy balance approach. In future research, other locations and time-series data shall be trained and tested, providing an efficient local urban climate monitoring tool, where in-situ air temperature observations are not available.
- Surface radiation balance of urban materials and their impact on air temperature of an urban canyon in Lisbon, PortugalPublication . Matias, Márcia; Lopes, AntónioUrban climate results from the modifications caused by the characteristics of cities, which modifies the regional climatic conditions of a city. When urban areas are warmer than the surrounding areas, the urban heat island (UHI) phenomenon occurs. Being a major phenomenon and a global topic of interest for all affected cities, there are already numerous studies that address this subject. However, most studies are only focused on the macro and mesoscales. This study looks at the micrometeorological scale in a neighborhood of Lisbon (Telheiras). Having as a main objective to evaluate how the radiation balance of urban materials influences air temperature in an urban canyon, thermal images of different urban materials were obtained using infrared thermography, a technique that allowed understanding how the temperatures registered in the facades and other urban surfaces can affect the air temperature of the urban canyon. The components of the radiation budget were obtained by using a pyranometer and a pyrgeometer. Moreover, a microclimatic network to monitor air temperature and relative humidity was installed in the study area. The results show that, when the streets are less exposed to the prevailing wind direction in Lisbon (north and northwest), air temperatures are slightly higher than those found in opposite conditions. Both the temperature and the radiative balance of the facades and other surfaces (asphalt, light Portuguese sidewalk, and tile floor) respond directly to incident solar radiation. As expected, it was found that south facades have the highest temperatures of the four exposures under study (>4 ◦C when compared to the opposite facade), and the highest radiative balance was always registered on asphalt when compared to the sidewalk (at 9:00 a.m. + 30 W·m−2 , at 1:00 p.m. + 149 W·m−2 , and at 7:00 p.m. + 66 W·m−2 ).
- LCZ4r package R for local climate zones and urban heat islandsPublication . Anjos, Max; Medeiros, Dayvid; Castelhano, Francisco; Meier, Fred; Silva, Tiago; Correia, Ezequiel; Lopes, AntónioThe LCZ4r is a novel toolkit designed to streamline Local Climate Zones (LCZ) classification and Urban Heat Island (UHI) analysis. Built on the open-source R statistical programming platform, the LCZ4r package aims to improve the usability of the LCZ framework for climate and environment researchers. The suite of LCZ4r functions is categorized into general and local functions (https://bymaxanjos.githu b.io/LCZ4r/index.html). General functions enable users to quickly extract LCZ maps for any landmass of the world at different scales, without requiring extensive GIS expertise. They also generate a series of urban canopy parameter maps, such as impervious fractions, albedo, and sky view factor, and calculate LCZ-related area fractions. Local functions require measurement data to perform advanced geostatistical analysis, including time series, thermal anomalies, air temperature interpolation, and UHI intensity. By integrating LCZ data with interpolation techniques, LCZ4r enhances air temperature modeling, capturing well-defined thermal patterns, such as vegetation-dominated areas, that traditional methods often overlook. The openly available and reproducible R-based scripts ensure consistent results and broad applicability, making LCZ4r a valuable tool for researchers studying the relationship between land use-cover and urban climates.
- Multitemporalidade das anomalias da temperatura de superfície: o caso da cidade de Iporá, BrasilPublication . Alves, Elis; Anjos, Max; Lopes, AntónioO objetivo desta pesquisa foi analisar, a partir de dados do satélite Landsat - 5, o padrão multitemporal e espacial das anomalias térmicas na cidade de Iporá - Goiás. Para tanto, foram utilizadas imagens multiespectrais (banda termal do satélite Landsat 5), dos anos de 1984 a 2011. Para o processamento das imagens foram desenvolvidos modelos matemáticos por meio da ferramenta Model Maker do software Erdas Imagine 11. Os resultados evidenciaram que: 1 - com a utilização das anomalias térmicas, os mapas ficaram homogêneos, o que possibilitou comparação temporal; 2 - Anomalias térmicas máximas de superfície ocorreram em áreas de pouca urbanização, com solo exposto; 3 - O maior número de anomalias positivas ocorreu nas áreas de baixa urbanização, com solos expostos. Enquanto que nas áreas mais urbanizadas com presença de vegetação e próximas a superfície de água, ocorreu a maior quantidade de anomalias negativas; 4 - Nos pontos B, E, F e H foram observadas tendências estatisticamente significativas.
- The influence of the summer sea breeze on thermal comfort in Funchal (Madeira): a contribution to tourism and urban planningPublication . Lopes, António; Lopes, Sérgio; Matzarakis, Andreas; Alcoforado, Maria JoaoTourism plays a crucial role for the development of coastal areas. Despite the mildness of Madeira’s climate, very hot days can occur during summer, a situation to which most tourists from northern Europe (the majority of foreign tourists) are poorly adapted. As sea breezes strongly contribute to moderate heat stress in urban environments, their influence on the thermal comfort on the island has been studied. Sea breezes occurred on 84 % of the days during the period under study (May to October 2006). They usually start around 09:30 h and end after 22:00 h, with an average duration of about 12:50 hours and a mean velocity of 2.9 m/s. Physiologically Equivalent Temperature (PET) was used to evaluate the thermal comfort of a sample of days during the summer of 2006. It was concluded that most of the sites in the city are “slightly comfortable” during normal days with sea breeze, but only shore sites and the highest green areas offer some comfort during hot days. Inside the city, the thermal perception is generally “hot” and strong heat stress can occur. As sea breezes are important to mitigate heat stress, some basic guidelines were presented: urban planners should take advantage of this wind system avoiding dense construction near the shoreline that would act as a barrier to the renewal of the air inside the city. In terms of tourism, planners and local authorities should provide solutions to mitigate the negative effects during hot periods, creating a system to warn and relocate more vulnerable tourists to places near the shore line, to the mountains, to gardens and air-conditioned buildings. In combination with other components (beauty of the island, gastronomy, cultural values and safety), climate information can be a factor of attractiveness to tourists.
- Beyond usual geographical scales of analysis: implications for healthcare management and urban planningPublication . Morais, Liliane; Lopes, António; Rocha, Jorge; Nogueira, Paulo JorgeIntroduction: In the context of climate emergency, advances in geographic information systems, geocoding, and geomedicine allow us to go beyond the conventional usual scales and be aligned with people’s needs, improving knowledge and accuracy of the spatial pattern of health outcomes. This study shows that the geographical scale of analysis affects the interpretation of health outcomes. Methods: All mortality that occurred in Portugal in 2014–2017 was geocoded. From 435,291 addresses, 412,608 were geocoded with success. As an example, we use the spatial patterns of the elderly’s heat-related cardiorespiratory mortality. Results: It is shown: (i) it is possible to have high quality and accuracy of spatial data used in health outcomes analysis; (ii) how geographic scales reveal different degrees of detail in health outcomes analysis; (iii) the neighbourhood scale revealed different patterns of cardiorespiratory mortality from the usually available scale (parish). Discussion: Our findings suggest the relevance of geocoding health outcomes with a finer scale in tackling the challenges of the healthcare sector, and in support of planning decision-making, closely matching citizens’ needs. Without running the risk of losing potentially major prospects, better healthcare management is achievable, with optimal resource allocation, and improved detailed and informed policymaking, allowing enhanced climate health equity in cities promotion.
- An urban energy balance-guided machine learning approach for synthetic nocturnal surface Urban Heat Island prediction: a heatwave event in NaplesPublication . Oliveira, Ana; Lopes, António; Niza, Samuel; Soares, AmílcarSouthern European functional urban areas (FUAs) are increasingly subject to heatwave (HW) events, calling for anticipated climate adaptation measures. In the urban context, such adaptation strategies require a thorough understanding of the built-up response to the incoming solar radiation, i.e., the urban energy balance cycle and its implications for the Urban Heat Island (UHI) effect. Despite readily available, diurnal Land Surface Temperature (LST) data does not provide a meaningful picture of the UHI, in these midlatitudes FUAs. On the contrary, the mid-morning satellite overpass is characterized by the absence of a significant surface UHI (SUHI) signal, corresponding to the period of the day when the urban-rural air temperature difference is typically negative. Conversely, nocturnal high-resolution LST data is rarely available. In this study, an energy balance-based machine learning approach is explored, considering the Local Climate Zones (LCZ), to describe the daily cycle of the heat flux components and predict the nocturnal SUHI, during an HW event. While the urban and rural spatial outlines are not visible in the diurnal thermal image, they become apparent in the latent and storage heat flux maps – built-up infrastructures uptake heat during the day which is released back into the atmosphere, during the night, whereas vegetation land surfaces loose diurnal heat through evapotranspiration. For the LST prediction model, a random forest (RF) approach is implemented. RF results show that the model accurately predicts the LST, ensuring mean square errors inferior to 0.1 K. Both the latent and storage heat flux components, together with LCZ classification, are the most important explanatory variables for the nocturnal LST prediction, supporting the adoption of the energy balance approach. In future research, other locations and time-series data shall be trained and tested, providing an efficient local urban climate monitoring tool, where in-situ air temperature observations are not available.
- Application of climatic guidelines to urban planning: the example of Lisbon (Portugal)Publication . Alcoforado, Maria Joao; Andrade, Henrique; Lopes, António; Vasconcelos, JoãoIn order to contribute to the sustainability of the urban environment, knowledge about the urban climate should be translated into climatic guidelines for planning. However, there are hardly any studies on applied urban climatology in areas with a Mediterranean type of climate. The study presented in this paper has several aims: to identify the climatic needs in a coastal city with Mediterranean climate; to describe the methodology, which can be adapted in order to be used in other cities; to discuss some of the problems that arise when applying climatic knowledge to urban planning, including the selection of the adequate scale of analysis, the required data and tools, the selection of the planning priorities, and the need to develop a shared language among planners and climatologists; and last to contribute to furthering the debate on the advantages of including climatic guidelines in Master Plans of urban municipalities in a systematic way. Lisbon’s case study is presented. As planners need spatialized guidelines, the mapping of Lisbon’s physical features was carried out using a Geographical Information System. Based on a Digital Terrain Model and on data of urban roughness a “ventilation map” was produced. A “building-density” map was also prepared based on the analysis of a Landsat image and field work. By crosstabulating these two layers, a final map depicting Lisbon’s “homogeneous climatic-response units” was prepared. Finally, a series of climatic guidelines for planning were put forth for the different units.