Building cluster and shading in urban canyon for hot dry climate - Part 1: Air and surface temperature measurements

Under low latitude conditions, minimization of solar radiation within the urban environment may often be a desirable criterion in urban design. The dominance of the direct component of the global solar irradiance under clear high sun conditions requires that the street solar access must be small. It is well known that the size and proportion of open spaces has a great influence on the urban microclimate This paper is directed towards finding the interaction between urban canyon geometry and incident solar radiation. The effect of building height and street width on the shading of the street surfaces and ground for different orientations have been examined and evaluated. It is aimed to explore the extent to which these parameters affect the temperature in the street. This work is based on air and surface temperature measurements taken in different urban street canyons in EL-Oued City (hot and and climate), Algeria. In general, the results show that there are less air temperature variations compared to the surface temperature which really depends on the street geometry and sky view factor. In other words, there is a big correlation between the street geometry, sky view factor and surface temperatures.

Building cluster and shading in urban canyon for hot dry climate Part 2: Shading simulations

Under low latitude conditions, minimisation of solar irradiance within the urban environment may often be an important criterion in urban design. This can be achieved when the obstruction angle is large (high H/W ratio, H = height, W = width). Solar access to streets can always be decreased by increasing H/W to larger values. It is shown in this paper that the street canyon orientation (and not only the H/W ratio) has a considerable effect on solar shading and urban microclimate. The paper demonstrates through a series of shading simulation and temperature measurements that a number of useful relationships can be developed between the geometry and the microclimate of urban street canyons. These relationships are potentially helpful to assist in the formulation of urban design guidelines governing street dimensions and orientations for use by urban designers.

Implications of climate change for diseases, crop yields and food security

Accelerated climate change affects components of complex biological interactions differentially, often causing changes that are difficult to predict. Crop yield and quality are affected by climate change directly, and indirectly, through diseases that themselves will change but remain important. These effects are difficult to dissect and model as their mechanistic bases are generally poorly understood. Nevertheless, a combination of integrated modelling from different disciplines and multi-factorial experimentation will advance our understanding and prioritisation of the challenges. Food security brings in additional socio-economic, geographical and political factors. Enhancing resilience to the effects of climate change is important for all these systems and functional diversity is one of the most effective targets for improved sustainability.

An urban parameterization for a global climate model. Part I: Formulation and evaluation for two cities

Urbanization, the expansion of built-up areas, is an important yet less-studied aspect of land use/land cover change in climate science. To date, most global climate models used to evaluate effects of land use/land cover change on climate do not include an urban parameterization. Here, the authors describe the formulation and evaluation of a parameterization of urban areas that is incorporated into the Community Land Model, the land surface component of the Community Climate System Model. The model is designed to be simple enough to be compatible with structural and computational constraints of a land surface model coupled to a global climate model yet complex enough to explore physically based processes known to be important in determining urban climatology. The city representation is based upon the “urban canyon” concept, which consists of roofs, sunlit and shaded walls, and canyon floor. The canyon floor is divided into pervious (e.g., residential lawns, parks) and impervious (e.g., roads, parking lots, sidewalks) fractions. Trapping of longwave radiation by canyon surfaces and solar radiation absorption and reflection is determined by accounting for multiple reflections. Separate energy balances and surface temperatures are determined for each canyon facet. A one-dimensional heat conduction equation is solved numerically for a 10-layer column to determine conduction fluxes into and out of canyon surfaces. Model performance is evaluated against measured fluxes and temperatures from two urban sites. Results indicate the model does a reasonable job of simulating the energy balance of cities.

Development of the Surface Urban Energy and Water balance Scheme (SUEWS) for cold climate cities

The Surface Urban Energy and Water Balance Scheme (SUEWS) is developed to include snow. The processes addressed include accumulation of snow on the different urban surface types: snow albedo and density aging, snow melting and re-freezing of meltwater. Individual model parameters are assessed and independently evaluated using long-term observations in the two cold climate cities of Helsinki and Montreal. Eddy covariance sensible and latent heat fluxes and snow depth observations are available for two sites in Montreal and one in Helsinki. Surface runoff from two catchments (24 and 45 ha) in Helsinki and snow properties (albedo and density) from two sites in Montreal are also analysed. As multiple observation sites with different land-cover characteristics are available in both cities, model development is conducted independent of evaluation. The developed model simulates snowmelt related runoff well (within 19% and 3% for the two catchments in Helsinki when there is snow on the ground), with the springtime peak estimated correctly. However, the observed runoff peaks tend to be smoother than the simulated ones, likely due to the water holding capacity of the catchments and the missing time lag between the catchment and the observation point in the model. For all three sites the model simulates the timing of the snow accumulation and melt events well, but underestimates the total snow depth by 18–20% in Helsinki and 29–33% in Montreal. The model is able to reproduce the diurnal pattern of net radiation and turbulent fluxes of sensible and latent heat during cold snow, melting snow and snow-free periods. The largest model uncertainties are related to the timing of the melting period and the parameterization of the snowmelt. The results show that the enhanced model can simulate correctly the exchange of energy and water in cold climate cities at sites with varying surface cover.

Subsurface urban heat island and its effects on horizontal ground-source heat pump potential under climate change

Recent urban air temperature increase is attributable to the climate change and heat island effects due to urbanization. This combined effects of urbanization and global warming can penetrate into the underground and elevate the subsurface temperature. In the present study, over-100 years measurements of subsurface temperature at a remote rural site were analysed, and an increasing rate of 0.17⁰C per decade at soil depth of 30cm due to climate change was identified in the UK, but the subsurface warming in an urban site showed a much higher rate of 0.85⁰C per decade at a 30cm depth and 1.18⁰C per decade at 100cm. The subsurface urban heat island (SUHI) intensity obtained at the paired urban-rural stations in London showed an unique 'U-shape', i.e. lowest in summer and highest during winter. The maximum SUHII is 3.5⁰C at 6:00 AM in December, and the minimum UHII is 0.2⁰C at 18:00PM in July. Finally, the effects of SUHI on the energy efficiency of the horizontal ground source heat pump (GSHP) were determined. Provided the same heat pump used, the installation at an urban site will maintain an overall higher COP compared with that at a rural site in all seasons, but the highest COP improvement can be achieved in winter.

Participatory urban planning for climate change adaptation in coastal cities: lessons from a pilot experience in Maputo, Mozambique

This paper proposes a rights-based approach for participatory urban planning for climate change adaptation in urban areas. Participatory urban planning ties climate change adaptation to local development opportunities. Previous discussions suggest that participatory urban planning may help to understand structural inequalities, to gain, even if temporally, institutional support and to deliver a planning process in constant negotiation with local actors. Building upon an action research project which implemented a process of participatory urban planning for climate change in Maputo, Mozambique, this paper reflects upon the practical lessons that emerged from these experiences, in relation to the incorporation of climate change information, the difficulties to secure continued support from local governments and the opportunities for local impacts through the implementation of the proposals emerging from this process.

Reactive nitrogen intermediate susceptibility of Mycobacterium tuberculosis genotypes in an urban setting

BACKGROUND: Mycobacterium tuberculosis genotypes resistant to reactive nitrogen intermediates (RNI) predominate in certain urban communities, suggesting that this phenotype influences disease transmission. OBJECTIVE: To compare different M. tuberculosis genotypes for resistance to RNI generated in vitro. DESIGN: We genotyped 420 M. tuberculosis isolates from a neighborhood in Sao Paulo, Brazil, and analyzed them for susceptibility to RNI generated in acidified sodium nitrite (ASN) solution. RESULTS: Seventy-one (43%) of 167 recent-infection strains and 68 (43%) of 158 endogenous infection strains showed moderate- to high-level ASN resistance. CONCLUSION: ASN resistance of M. tuberculosis is not necessarily a determining factor for enhanced transmission.

Periodontal diseases in a representative urban population in south Brazil

Background and Aims: There is little information about the epidemiology and risk factors of periodontal diseases in Latin America in general, and Brazil in particular. The principal aims of this study were to: 1) describe the prevalence and severity of periodontal attachment loss and gingival recession, and to assess the contribution of demographic, behavioral, and environmental exposures to the occurrence of periodontal disease outcomes in a sample representative of the urban population in the state of Rio Grande do Sul in south Brazil; and 2) report the epidemiology and risk indicators of aggressive periodontitis in this population. Methods: A representative sample consisting of 1,586 subjects 14-103 years of age (mean 38 y) and comprising 45.3% males and 54.7% females was selected using a multi-stage, probability, cluster sampling strategy. The subjects were interviewed using a structured questionnaire and underwent a full-mouth, six sites per tooth clinical examination in a mobile examination center. Results: Moderate and severe clinical attachment loss and gingival recession were widespread among adults in this population. The prevalence and extent of attachment loss ³5 and ³7 mm were 79% and 52% subjects, and 36% and 16% teeth; and for gingival recession ³3 mm and ³5 mm were 52% and 22% subjects, and 17% and 6% teeth, respectively. Aggressive periodontitis was diagnosed in 5.5% of subjects, which is significantly higher than the reported prevalence in most other populations. Among the main risk indicators for chronic as well as aggressive destructive periodontal diseases were: older age, low socioeconomic status, dental calculus, and smoking. Cigarette smoking accounted for an important part of periodontal disease burden, particularly in adults, and should be considered an important target in any prevention strategy aimed at reducing the burden of periodontal diseases. Partial recording methods consistently underestimated the prevalence of attachment loss in the population, and the extent of underestimation was dependent on the type of system used and the threshold of attachment loss. Conclusions: Destructive periodontal diseases are prevalent in this Brazilian population. Suitable disease prevention and health promotion programs should be established to improve the periodontal health in this population.

Relationship among Apis mellifera L. stings, swarming and climate conditions in the city of Rio Claro, SP, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ecosystem services and urban vegetation coverage in Belém: the influence on noise pollution, air pollution and climate regulation

A ligação entre as zonas urbanas e as questões ambientais ficam mais próximas na medida em que cresce a conscientização global de conservar, melhorar e valorizar os serviços ambientais prestados pela natureza para a sustentabilidade da vida, dentro e fora da cidade. Cobertura vegetal (ou cobertura verde) está dentre as principais fontes de tais serviços. Uma vez que o processo de urbanização se mostra irreversível e os problemas ambientais urbanos se alastram em tamanho e extensão, a presença do verde está diretamente relacionada aos indicadores de qualidade de vida urbana. Como reflexo do processo de urbanização, a cidade de Belém perdeu uma grande porcentagem de seus ecossistemas naturais, de modo que este trabalho se concentrou em analisar alguns serviços ecossistêmicos—qualidade do ar, poluição do ar e regulação do clima - fornecidos pela qualidade e pela quantidade de cobertura vegetal local, considerando as alterações na distribuição espaço-temporal, em três distritos administrativos. Um marco teórico foi construído e analisado; a cobertura vegetal foi calculada, utilizando-se NDVI e Cobertura Vegetal Fracional em imagens do LANDSAT 5, ao longo de um período de 23 anos. A partir de uma proposta de escala mais detalhada de NDVI, análises quantitativas e qualitativas da cobertura verde evidenciaram perda significativa de cobertura muito densa, densa, moderada e aumento de áreas de pouca ou nenhuma vegetação. Ademais, lesão das áreas verdes sinalizou tendências de aumento da poluição do ar, da poluição sonora e da temperatura. A carência de dados relacionados ao meio ambiente não deixa dúvida sobre a urgência de investimento nos serviços ambientais provenientes da cobertura vegetal, para a sustentabilidade urbana em Belém, cujos cenários previstos são de drásticas perdas de área verde. Mais pesquisas e iniciativas de instituições públicas e privadas são necessárias para a contribuição aos serviços ambientais em Belém e, consequentemente, ao bem-estar público.

Emerging Marine Diseases: Climate Links and Anthropogenic Factors

Mass mortalities due to disease outbreaks have recently affected major taxa in the oceans. For closely monitored groups like corals and marine mammals, reports of the frequency of epidemics and the number of new diseases have increased recently. A dramatic global increase in the severity of coral bleaching in 1997-98 is coincident with high El Niño temperatures. Such climate-mediated, physiological stresses may compromise host resistance and increase frequency of opportunistic diseases. Where documented, new diseases typically have emerged through host or range shifts of known pathogens. Both climate and human activities may have also accelerated global transport of species, bringing together pathogens and previously unexposed host populations.

Economic Cost of Air Pollution in Cubatao - SP Based on Health Expenses Related to Diseases of the Respiratory and Circulatory Systems

The aim of this research was to evaluate economic costs of respiratory and circulatory diseases in the municipality of Cubatao, in the state of Sao Paulo, Brazil. Data on hospital admissions and on missed working days due to hospitalization (for age group 14 to 70 years old) from the database of Sistema Unico de Sa de (SUS - Brazilian National Health System) were used. Results: Based on these data, it was calculated that R$ 22.1 million were spent in the period 2000 to 2009 due to diseases of the respiratory and circulatory systems. Part of these expenses can be directly related to the emission of atmospheric pollutants in the city. In order to estimate the costs related to air pollution, data on Cubatao were compared to data from two other municipalities that are also located at the coast side (Guaruja and Peru be), but which have little industrial activity in comparison to Cubatao. It was verified that, in both, average per capita costs were lower when compared to Cubatao, but that this difference has been decreasing in recent years.

Climate change and infectious diseases of wildlife: Altered interactions between pathogens, vectors and hosts

Infectious diseases result from the interactions of host, pathogens, and, in the case of vector-borne diseases, also vectors. The interactions involve physiological and ecological mechanisms and they have evolved under a given set of environmental conditions. Environmental change, therefore, will alter host-pathogen-vector interactions and, consequently, the distribution, intensity, and dynamics of infectious diseases. Here, we review how climate change may impact infectious diseases of aquatic and terrestrial wildlife. Climate change can have direct impacts on distribution, life cycle, and physiological status of hosts, pathogens and vectors. While a change in either host, pathogen or vector does not necessarily translate into an alteration of the disease, it is the impact of climate change on the interactions between the disease components which is particularly critical for altered disease risks. Finally, climate factors can modulate disease through modifying the ecological networks host-pathogen-vector systems are belonging to, and climate change can combine with other environmental stressors to induce cumulative effects on infectious diseases. Overall, the influence of climate change on infectious diseases involves different mechanisms, it can be modulated by phenotypic acclimation and/or genotypic adaptation, it depends on the ecological context of the host-pathogen-vector interactions, and it can be modulated by impacts of other stressors. As a consequence of this complexity, non-linear responses of disease systems under climate change are to be expected. To improve predictions on climate change impacts on infectious disease, we suggest that more emphasis should be given to the integration of biomedical and ecological research for studying both the physiological and ecological mechanisms which mediate climate change impacts on disease, and to the development of harmonized methods and approaches to obtain more comparable results, as this would support the discrimination of case-specific versus general mechanisms