Remoção de MP2,5 por árvores urbanas em áreas com diferentes condições de arborização em São Paulo, utilizando um modelo big-leaf

Air pollution is one of the main environmental problems in megacities, such as the metropolitan area of São Paulo (MASP), in Brazil. Urban forests can alleviate air pollution by providing a surface for the dry deposition of particles and trace gases. To benefit from this environmental service and design future green structures, it is crucial to estimate the removal rate of air pollutants by trees. The removal rates of fine particulate matter (PM2.5) by urban trees were quantitatively assessed for the first time in Brazil. A big-leaf modeling approach was adopted, using the i-Tree Eco software. In situ dendrometric data, hourly PM2.5 concentrations, and meteorological variables were used as inputs to the model. PM2.5 removal fluxes ranged between 0.06 and 0.21 g/m2/year in three study areas with contrasting urban forestry conditions. The neighborhood with the greatest canopy cover and tree diversity had the highest removal rates. The evergreen character of the urban forest in the MASP possibly contributed to the relatively high PM2.5 removal fluxes, as compared to other cities around the world. Removal rates were higher in the austral summer, when high precipitation rates restricted the resuspension of deposited particles back to the atmosphere. When extrapolated to the whole metropolitan area, assuming homogeneous forestry conditions, the estimated PM2.5 removal rates were comparable to the magnitude of vehicular emissions, showing that air pollution removal by trees can be substantial in the MASP. The results demonstrate the contribution of urban trees to the improvement of air quality and can boost the development of public policies on urban afforestation in the MASP.A poluição do ar é um dos problemas ambientais mais proeminentes em megacidades como a área metropolitana de São Paulo (AMSP). Árvores podem contribuir para a mitigação da poluição do ar proporcionando superfície para a deposição de partículas e gases traço. Para melhor aproveitar esse serviço ambiental e planejar futuras infraestruturas verdes, é fundamental estimar as taxas de remoção de poluentes por árvores. Pela primeira vez em uma cidade brasileira, foi quantificada a taxa de remoção anual de material particulado fino (MP2,5) por árvores urbanas. Para isso, foi utilizado o modelo i-Tree Eco, do tipo “folha grande”. Como entrada, foram utilizados dados dendrométricos locais, de concentração de MP2,5 e de variáveis meteorológicas. As taxas de remoção de MP2,5 variaram entre 0,06 e 0,21 g/m2/ano em três áreas de estudo com condições de arborização contrastantes. A vizinhança com maior cobertura de dossel e diversidade de espécies arbóreas apresentou a maior taxa de remoção. O caráter perene da floresta urbana na AMSP pode ter contribuído para as taxas de remoção relativamente altas em comparação com outras cidades do mundo. A remoção foi maior no verão; a precipitação restringiu a ressuspensão de partículas para a atmosfera. Extrapolando-se os resultados para toda a área metropolitana, supondo condições de arborização homogêneas, verificou-se que a remoção de MP2,5 pela vegetação poderia compensar as emissões veiculares desse poluente, demonstrando o potencial de remoção de poluentes pela floresta urbana na AMSP. Os resultados ilustram a contribuição das árvores urbanas para a melhoria da qualidade do ar e podem impulsionar políticas públicas de arborização na AMSP

Earth observation : An integral part of a smart and sustainable city

Over the course of the 21st century, a century in which the urbanization process of the previous one is ever on the rise, the novel smart city concept has rapidly evolved and now encompasses the broader aspect of sustainability. Concurrently, there has been a sea change in the domain of Earth observation (EO) where scientific and technological breakthroughs are accompanied by a paradigm shift in the provision of open and free data. While the urban and EO communities share the end goal of achieving sustainability, cities still lack an understanding of the value EO can bring in this direction, an next a consolidated framework for tapping the full potential of EO and integrating it in their operational modus operandi. The “SMart URBan Solutions for air quality, disasters and city growth” H2020 project (SMURBS/ERA-PLANET) sits at this scientific and policy crossroad, and, by creating bottom-up EO-driven solutions against an array of environmental urban pressures, and by expanding the network of engaged and exemplary smart cities that push the state-of-the-art in EO uptake, brings the international ongoing discussion of EO for sustainable cities closer to home and contributes in this discussion. This paper advocates for EO as an integral part of a smart and sustainable city and aspires to lead by example. To this end, it documents the project's impacts, ranging from the grander policy fields to an evolving portfolio of smart urban solutions and everyday city operations, as well as the cornerstones for successful EO integration. Drawing a parallel with the utilization of EO in supporting several aspects of the 2030 Agenda for Sustainable Development, it aspires to be a point of reference for upcoming endeavors of city stakeholders and the EO community alike, to tread together, beyond traditional monitoring or urban planning, and to lay the foundations for urban sustainability.Peer reviewe

Assessing vulnerability for inhabitants of Dhaka City considering flood-hazard exposure

Globalna opasnost od poplave postupno se povećava. Iako ih je nemoguće izbjeći, gubici i šteta od opasnosti (npr. poplave, cikloni i potresi) mogu se učinkovito smanjiti smanjenjem ranjivosti kućanstava odgovarajućim mjerama. Cilj ove studije je kvantitativno mjerenje ranjivosti kućanstava obzirom na opasnosti od poplave kao alata za njihovo ublažavanje. Također je predložen jedinstveni pristup za kvantificiranje ugroženosti kućanstava obzirom na opasnosti od poplave, a kao primjer predstavljena je primjena u gradu Dhaki sklonom poplavama. Podaci su prikupljeni i sa siromašnih i bogatih područja kako bi bilo pokriveno cijelo urbano područje te kako bi se usporedila razina ugroženosti od poplava. Ukupno 300 kućanstava anketirano je strukturiranim upitnikom na temelju pet čimbenika (ekonomskih, socijalnih, okolišnih, strukturnih i institucionalnih) ugroženosti od poplava. Analitički hijerarhijski postupak (AHP) primijenjen je za mjerenje pojedinačnih rezultata ranjivosti kućanstva korištenjem relativne težine varijabli i pokazatelja uz pravilnu standardizaciju. Analitički rezultati pokazali su da je 63,06% siromašnih kućanstava i 20,02% bogatih kućanstava vrlo osjetljivo na poplave. Uz to, ovaj je rad utvrdio i procijenio čimbenike odgovorne za ranjivost kućanstava u Dhaki. Što se tiče strukturne ranjivosti, rezultati su pokazali da je 82% kućanstava u siromašnim krajevima bilo visoko ranjivo, a 95,3% kućanstava koja nisu iz siromašnih četvrti bilo je umjereno ranjivo. Društveno, 67,3% siromašnih i 78,7% kućanstava koja nisu iz siromašnih naselja bila su umjereno i slabo ranjiva. Većina kućanstava u siromašnoj i nesiromašnoj četvrti (84%, odnosno 59,3%) pokazala je visoku i umjerenu ekonomsku ranjivost. Štoviše, za 69,3% siromašnih i 65,3% nesiromašnih kućanstava institucionalna ranjivost je bila visoka. Od stanovnika siromašnih naselja, 63,3% je bilo izloženo ekološkom riziku, a 78% staništa koja nisu u siromašnim područjima bilo je u kategoriji niske ranjivosti. Uz odgovarajuću prilagodbu ovdje predložen učinkoviti alat za mjerenje ranjivosti koji je ovdje prilagođen specifičnoj lokaciji, primjenjiv je i za mjerenje ranjivosti drugih gradova u svijetu. Na temelju ove studije moglo bi se provesti buduće istraživanje s više čimbenika, varijabli i pokazatelja ljudske ranjivosti na prirodne ili umjetne opasnosti / katastrofe. Budući rad mogao bi pružiti bolju sliku stanja ranjivosti od pojedinačne / višestruke opasnosti / katastrofe.Global flood hazard is gradually increasing. Though it is impossible to avoid them, losses and damage of hazards (e.g., floods, cyclones, and earthquakes) could be efficiently reduced by reducing household vulnerability with appropriate measures. This study aims to quantitatively measure the household vulnerability of flood hazards as a mitigation tool. It also proposed a unique approach to quantify flood-hazard household vulnerability, and shows its application in the flood prone city of Dhaka as an example case. Data were collected from both slum and non-slum areas to cover the entire urban habitat, and to compare their level of flood vulnerability. A total of 300 households were surveyed by structured questionnaire on the basis of five factors (economic, social, environmental, structural, and institutional) of flood vulnerability. The analytical hierarchy process (AHP) was applied to measure individual household vulnerability scores by using the relative weightage of variables and indicators with proper standardisation. Analytical results demonstrated that 63.06% slum and 20.02% non-slum households were highly vulnerable to floods. In addition, this paper determined and assessed responsible factors for household flood vulnerability in Dhaka. For structural vulnerability, results exhibited that 82% of slum households were highly vulnerable, and 95.3% of non-slum households were moderately vulnerable. Socially, 67.3% of slum and 78.7% of non-slum households were moderately and low-vulnerable. The majority of slum and non-slum households (84% and 59.3%, respectively) showed high and moderate vulnerability with respect to economic vulnerability. Moreover, 69.3% of slum and 65.3% of nonslum household institutional vulnerability levels were high. Of slum inhabitants, 63.3% were environmentally at high risk, and 78% of non-slum habitats were in the low-vulnerability category. However, as an effective tool to measure location-specific vulnerability, it is applicable for the measuring vulnerability of other cities in the world with proper customisation. On the basis of this study, future research could be conducted with more factors, variables, and indicators of human vulnerability to natural or artificial hazards/disasters. Future work may provide a better reflection of the vulnerability status of single/multiple hazard(s)/disaster(s)

Proprietà di miscele cementizie sostenibili sottoposte ad alte temperature

L'elaborato verte sullo studio della resistenza di alcune malte cementizie sostenibili alle alte temperature, simulando un ipotetico incendio eseguendo un trattamento termico a 750°C. Viene fatto un confronto tra il cemento Portland e alcune malte LC3 ricavate sostituendo una percentuale di cemento Portland con una polvere di argilla ("Kunkure fine") calcinata. In una delle malte è stata aggiunta una percentuale di carbonato di calcio, che viene sostituito in un'altra delle malte da della Dolomite. La sostituzione rientra nello scopo di ridurre il contenuto di Portland all'interno della malta, la cui produzione è responsabile di grandi quantità di emissioni di CO2. Dopo il trattamento, vengono misurate alcune performance come resistenza a compressione e percolazione di acqua. Infine, tutte le malte vengono sottoposte a indagini al SEM.The paper focuses on the study of the resistance of certain sustainable cement mortars to high temperatures, simulating a hypothetical fire by performing a heat treatment at 750°C. A comparison is made between Portland cement and some LC3 mortars made by replacing a percentage of Portland cement with a calcined clay powder ("Kunkure fine"). In one of the mortars, a percentage of calcium carbonate was added, which is replaced in another of the mortars by Dolomite. The substitution is part of the aim to reduce the Portland content in the mortar, the production of which is responsible for large amounts of CO2 emissions. After treatment, certain performances such as compressive strength and porosity are measured. Finally, all mortars are subjected to SEM investigations

Managing urban sprawl:The politics and governance of implementing urban expansion policies in Egyptian cities

Different policy instruments have been designed and formulated with the aim of achieving sustainable urban expansion and compact cities in the developed and the developing world. This thesis aims at examining the implementation of these instruments and examining the factors that leads to the convergence or divergence of their implementation. A theoretical framework was developed using the new institutionalist perspective of policy implementation and draws on the key components of the actor-centred institutionalism. Two cities were selected from Egypt and five policy instruments were examined, they are: strategic plans and delineation of urban growth boundaries; detailed plans; subdivision plans; land readjustment; and the application of a betterment levy. Implementation of all policy instruments examined were viewed as diverging to some degree as a result in shortage in the resources availed to implementing actors and the conflicting preferences and perceptions of the key actors involved in the implementation. The role of public leaders in supporting implementation and unlocking institutional complexity was seen as critical. Boundary-spanning activities undertaken by local government officials and community leaders to connect various actors and facilitate a constructive dialogue was essential. Several practical insights and recommendations were distilled from the case studies aiming at recognizing the complexity of implementing urban expansion policies

Managing urban sprawl:The politics and governance of implementing urban expansion policies in Egyptian cities

Different policy instruments have been designed and formulated with the aim of achieving sustainable urban expansion and compact cities in the developed and the developing world. This thesis aims at examining the implementation of these instruments and examining the factors that leads to the convergence or divergence of their implementation. A theoretical framework was developed using the new institutionalist perspective of policy implementation and draws on the key components of the actor-centred institutionalism. Two cities were selected from Egypt and five policy instruments were examined, they are: strategic plans and delineation of urban growth boundaries; detailed plans; subdivision plans; land readjustment; and the application of a betterment levy. Implementation of all policy instruments examined were viewed as diverging to some degree as a result in shortage in the resources availed to implementing actors and the conflicting preferences and perceptions of the key actors involved in the implementation. The role of public leaders in supporting implementation and unlocking institutional complexity was seen as critical. Boundary-spanning activities undertaken by local government officials and community leaders to connect various actors and facilitate a constructive dialogue was essential. Several practical insights and recommendations were distilled from the case studies aiming at recognizing the complexity of implementing urban expansion policies

Challenges and opportunities for the development of MEGACITIES

Urbanization is one of the most important social and economic phenomena in the world today. This paper reviews the formation of megacities and summarizes the main problems, challenges and opportunities faced by the sustainable development of such large megacities. Issues discussed include the problems of land subsidence in megacities, environmental issues, traffic problems and energy supply aspects. The sustainable development of megacities in other parts of the world provided the references and experiences for the countermeasures of megacity planning and development in China. The vision of Digital Earth and Digital Cities can play a major role in the efficient management and sustainable growth of such megacities all around the world