Estudo do balanço de umidade por meio de modelos regionais para o clima do passado e do futuro sobre a América do Sul

In the context of climate change over South America (SA) has been observed that the combination of high temperatures and rain more temperatures less rainfall, cause different impacts such as extreme precipitation events, favorable conditions for fires and droughts. As a result, these regions face growing threat of water shortage, local or generalized. Thus, the water availability in Brazil depends largely on the weather and its variations in different time scales. In this sense, the main objective of this research is to study the moisture budget through regional climate models (RCM) from Project Regional Climate Change Assessments for La Plata Basin (CLARIS-LPB) and combine these RCM through two statistical techniques in an attempt to improve prediction on three areas of AS: Amazon (AMZ), Northeast Brazil (NEB) and the Plata Basin (LPB) in past climates (1961-1990) and future (2071-2100). The moisture transport on AS was investigated through the moisture fluxes vertically integrated. The main results showed that the average fluxes of water vapor in the tropics (AMZ and NEB) are higher across the eastern and northern edges, thus indicating that the contributions of the trade winds of the North Atlantic and South are equally important for the entry moisture during the months of JJA and DJF. This configuration was observed in all the models and climates. In comparison climates, it was found that the convergence of the flow of moisture in the past weather was smaller in the future in various regions and seasons. Similarly, the majority of the SPC simulates the future climate, reduced precipitation in tropical regions (AMZ and NEB), and an increase in the LPB region. The second phase of this research was to carry out combination of RCM in more accurately predict precipitation, through the multiple regression techniques for components Main (C.RPC) and convex combination (C.EQM), and then analyze and compare combinations of RCM (ensemble). The results indicated that the combination was better in RPC represent precipitation observed in both climates. Since, in addition to showing values be close to those observed, the technique obtained coefficient of correlation of moderate to strong magnitude in almost every month in different climates and regions, also lower dispersion of data (RMSE). A significant advantage of the combination of methods was the ability to capture extreme events (outliers) for the study regions. In general, it was observed that the wet C.EQM captures more extreme, while C.RPC can capture more extreme dry climates and in the three regions studied.

Energia eólica em alto mar: distribuição dos recursos e complementaridade hídrica

The stabilization of energy supply in Brazil has been a challenge for the operation of the National Interconnected System in face of hydrological and climatic variations. Thermoelectric plants have been used as an emergency source for periods of water scarcity. The utilization of fossil fuels, however, has elevated the cost of electricity. On the other hand, offshore wind energy has gained importance in the international context and is competitive enough to become a possibility for future generation in Brazil. In this scenario, the main goal of this thesis was to investigate the magnitude and distribution of offshore wind resources, and also verify the possibilities of complementing hydropower. A data series of precipitation from the Climatic Research Unit (CRU) Blended Sea Winds from the National Climatic Data Center (NCDC/NOAA) were used. According to statistical criteria, three types of complementarity were found in the Brazilian territory: hydro × hydro, wind × wind and hydro × wind. It was noted a significant complementarity between wind and hydro resources (r = -0.65), mainly for the hydrographical basins of the southeast and central regions with Northeastern Brazil winds. To refine the extrapolation of winds over the ocean, a method based on the Monin-Obukhov theory was used to model the stability of the atmospheric boundary layer. Objectively Analyzed Air-Sea Flux (OAFLUX) datasets for heat flux, temperature and humidity, and also sea level pressure data from NCEP/NCAR were used. The ETOPO1 from the National Geophysical Data Center (NGDC/NOAA) provided bathymetric data. It was found that shallow waters, between 0-20 meters, have a resource estimated at 559 GW. The contribution of wind resources to hydroelectric reservoir operation was investigated with a simplified hybrid wind-hydraulic model, and reservoir level, inflow, outflow and turbine production data. It was found that the hybrid system avoids drought periods, continuously saving water from reservoirs through wind production. Therefore, from the results obtained, it is possible to state that the good winds from the Brazilian coast can, besides diversifying the electric matrix, stabilize the hydrological fluctuations avoiding rationing and blackouts, reducing the use of thermal power plants, increasing the production cost and emission of greenhouse gases. Public policies targeted to offshore wind energy will be necessary for its full development.

Impacts of the Madden-Julian oscillation on intraseasonal precipitation over northeast Brazil

Este estudo tem como objetivo investigar os impactos da oscilação de Madden-Julian (OMJ) na precipitação da região Nordeste do Brasil (NEB). Para tanto foram utilizados dados diários de precipitação baseados em 492 pluviômetros distribuídos na região e cobrindo um período de 30 anos (1981 − 2010). As análises através de composições de anomalias de precipitação, radiação de onda longa e fluxo de umidade, foram obtidas com base no índice da OMJ desenvolvido por Jones-Carvalho. Para distinguir o sinal da OMJ de outros padrões de variabilidade climática, todos os dados diários foram filtrados na escala de 20 − 90 dias; portanto somente dias classificados como eventos da OMJ foram considerados nas composições. Uma análise preliminar baseada apenas nos dados de precipitação foi feita para uma pequena área localizada no interior semiárido do NEB, conhecida como Seridó. Essa microrregião é uma das áreas mais secas do NEB e foi reconhecida pela Convenção das Nações Unidas para o Combate à Desertificação e Mitigação dos Efeitos das Secas como particularmente vulnerável à desertificação. Composições de anomalias de precipitação foram feitas para cada uma das oito fases da OMJ durante Fevereiro-Maio (principal período chuvoso da microrregião). Os resultados mostraram a existência de variações significativas nos padrões de precipitação (de precipitação excessiva à deficiente) associados à propagação da OMJ. A combinação dos sinais de precipitação obtidos durantes as fases úmidas e secas da OMJ mostrou que a diferença corresponde cerca de 50 − 150% de modulação das chuvas na microrregião. Em seguida, uma investigação abrangente sobre o papel da OMJ sobre toda a região Nordeste foi feita considerando-se as quatro estações do ano. Os resultados mostraram que os impactos da OMJ na precipitação intrassazonal do NEB apresentam forte sazonalidade. A maior coerência espacial dos sinais de precipitação ocorreram durante o verão austral, quando cerca de 80% das estações pluviométricas apresentaram anomalias positivas de precipitação durante as fases 1 − 2 da OMJ e anomalias negativas de precipitação nas fases 5 − 6 da oscilação. Embora impactos da OMJ na precipitação intrassazonal tenham sido encontrados na maioria das localidades e em todas as estações do ano, eles apresentaram variações na magnitude dos sinais e dependem da fase da oscilação. As anomalias de precipitação do NEB observadas são explicadas através da interação existente entre as ondas de Kelvin-Rossby acopladas convectivamente e as características climáticas predominantes sobre a região em cada estação do ano. O aumento de precipitação observado sobre a maior parte do NEB durante o verão e primavera austrais encontra-se associado com o fluxo de umidade de oeste (regime de oeste), o qual favorece a atividade convectiva em amplas áreas da América do Sul tropical. Por outro lado, as anomalias de precipitação durante o inverno e outono austrais apresentaram uma variabilidade espacial mais complexa. Durante estas estações, as anomalias de precipitação observadas nas estações localizadas na costa leste do NEB dependem da intensidade do anticiclone do Atlântico Sul, o qual é modulado em grande parte por ondas de Rossby. As características topográficas do NEB parecem desempenhar um papel importante na variabilidade observada na precipitação, principalmente nestas áreas costeiras. A intensificação do anticiclone aumenta a convergência dos ventos alísios na costa contribuindo para a ocorrência de precipitação observada à barlavento do planalto da Borborema. Por outro lado, o aumento da subsidência parece ser responsável pelos déficits de precipitação observados à sotavento. Tais condições mostraram-se típicas durante o predomínio do regime de leste sobre a região tropical da América do Sul e o NEB, durante o qual ocorre uma diminuição no fluxo de umidade proveniente da Amazônia.

"Aqui se faz Gostoso”: uma etnografia do turismo em São Miguel do Gostoso (RN)

This study it is an ethnography on the process of the tourist coast area of São Miguel do Gostoso, whose origin is made from a village of traditional fishermen located on the northeast coast of Rio Grande do Norte. From the late 90s, there were the first initiatives that transformed São Miguel do Gostoso in one of the state's major tourist destinations. The municipality is promoted within the national and international tourism scene through the sun and beach tourism - whose object of consumption is the natural landscape - and sports tourism - which exploited element is the "natural" geographic location (in the continent curve) of municipality that provides winds considered ideal for the practice of “Kitesurfing “ and Windsurfing. From this context, this ethnography had as a theme the social changes promoted by the tourism process in place here addressed, taking into account the perceptions produced by the actors involved in this social net. In this qualitative research, I endeavored to me in the methodological use of ethnographic techniques - bibliographic and field research, participant observation, open and structured interviews recorded by recording and field notes and photographic record. I also made use of theoretical tools and methodology inherent in ciberetnografia when analyzing the blogs and websites of intermediaries and institutions linked to local tourism.

Precificação da energia eólica offshore no Brasil

Offshore wind power emits low amounts of gases, is renewable and has better performance than onshore due to its greater stability and higher wind power density, less visual and noise impact, among others. Brazil has a high capacity of generation, but has not yet developed any offshore projects. High costs are a strong impediment. This study is an effort towards pricing offshore resources through Livelized Cost of Energy - LCOE, which represents the minimum return to cover the costs of development, production and maintenance of a wind project. Initially LCOE was calculated for all Brazilian onshore wind farms listed at Bloomberg New Energy Finance R○, accounting for 71 farms. Then hypothetical offshore wind farms were created from the onshore farms, tripling the cost of generation, which is consistent with the literature, and estimating the offshore energy for two locations off the Brazilian coast using satellite data extracted from National Oceanic and Atmospheric Administration. The results demonstrate that offshore resources have the potential to significantly reduce the energy price due to the better performance of the wind at sea

Teoria de carteiras e a alocação de parques eólicos offshore

The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

Ventilação e prescrições urbanísticas: uma aplicação simulada para a Orla da Praia do Meio em Natal/RN

This work analyses a study on natural ventilation and its relation to the urban legislation versus the building types in an urban fraction of coastal area of Praia do Meio in the city of Natal/RN, approaching the type or types of land use most appropriate to this limited urban fraction. The objective of this study is to analyse the effects of the present legislation as well as the types of buildings in this area on the natural ventilation. This urban fraction was selected because it is one of the sites from where the wind flows into the city of Natal. This research is based on the hypothesis stating that the reduction on the porosity of the urban soil (decrease in the set back/boundary clearance), and an increase in the form (height of the buildings) rise the level of the ventilation gradient, consequently causing a reduction on the wind speed at the lowest part of the buildings. Three-dimensional computational models were used to produce the modes of occupation allowed in the urban fraction within the area under study. A Computational Fluid Dynamics (CFD) software was also used to analyse the modes of land occupation. Following simulation, a statistical assessment was carried out for validation of the hypothesis. It was concluded that the reduction in the soil porosity as a consequence of the rates that defined the minimum boundary clearance between the building and the boundary of the plot (and consequently the set back), as well as the increase in the building form (height of the buildings) caused a reduction in the wind speed, thus creating heat islands

Análise bioclimática do bairro do Renascença II São Luis-MA: realidade e perspectiva do conforto térmico em espaços externos

The present research concerns about outdoor s thermal comfort conditions in hot-humid climate cities, understanding that life quality is a result of the urban object s type built for the human being in an environment with specific climate and morphological characteristics. It is presented as object of study the correlation between the neighborhood Renascença II s microclimate in São Luis /MA-Brazil, hot-humid climate city, and its urban morphological changes. As well as the thermal comfort s satisfaction level of its outdoor users. The research has as general goal to diagnosis the way these transformations caused by the urbanization influence the Renascença II s microclimate, identifying critical spots of the studied area, in order to contribute with land use recommendations based on bioclimatic architecture concepts and supply bases to urban design decisions adequate to the São Luis climate. It is presented as theoretical bases the urban climate, its concepts and elements. After that, the thermal comfort conditioners and its prediction models of thermal comfort sensation in outdoor are presented. The predictive models are presented along with bioclimatic assessment methods. Finally the use of bioclimatic assessment as an effective tool to identify places that need changes or preservation in order to seek environment quality. The applied methodology was based on the studies of Katzschner (1997), complemented by Oliveira s (1988) and Bustos Romero s (2001) studies that suggest an analysis and evaluation of maps of topography, buildings floors, land use, green areas and land covering, in order to overlap their characteristics and identify climate variable s measurements points; then a quantitative analysis of the climate variables (air temperature and humidity, wind speed and direction) of the chosen points takes place. It was perceived that Renaissance II has no permanence areas as squares or parks, its outdoor has little vegetation and presets high land impermeability and built density levels. The majority of the people interviewed said that was comfortable in a range of air temperature between 27,28ºC and 30,71ºC. The elaboration of a neighborhood master plan is important, which defines strategies for improvement of the life quality of its inhabitants

Adequação bioclimática para os espaços urbanos abertos do centro de Fortaleza, CE

This research presents a study investigating the correlation between the environmental-physycal charcateristics of cities and the formation of its micro-climates. The study was conducted in the central area of Fortaleza characterized as a stable and consolidated area, where the city originated and currently faces serious problems in its urban dynamics. The points of measurements were determined by the elaboration and analysis of topography maps, height of buildings, land use, type of surface coating and vegetation, following the methodology of Katzschner (1997). A zoning map was then determined, according to common morphological characteristics of the 12 measurement points, which were based on a set of Romero s (2001) bioclimatic criteria. Air measurements, temperature, humidity, intensity and direction of winds were made in transect form in two different circuits in the study area, with six points of data collection in each area, in three different times: 6:00 am, 1:00pm and 7:00pm, during two periods of the year: August 2008 and March 2009. The results verified the influence of different environmental-physical types in the behavior of the climatic variables that were collected. A verticalização tão condenada em algumas situações se bem equilibrada e controlada pode reduzir as temperaturas do ar através do sombreamento dos espaços urbanos e possibilidade de maior permeabilidade a ventilação natural. The highest average air temperature and lower humidity were recorded at the point I at all times. This situation may have been in result of the high density, poor vegetation and extended paving of the ground. According to the results, it s clear the positive influence vegetation has on easing air temperature. Another indicator observed that areas with a greater variation in building heights tend to present decreased average air temperature. High rise structure, planned in accordance to urban air quality parameters, can reduce air temperatures by the shading of urban spaces and the possibility of greater penetration of natural ventilation

Qualidade do ar interior e conforto térmico : um estudo em espaços de estacionamento em Natal/RN

The recent tendency to utilize parking lots for other purposes has demonstrated that more time has been spent by visitors, mainly in great cities. Therefore, this paper investigates the thermal comfort and the air quality indoors in areas specifically used as parking lots by analyzing the direct relation between such environments and vehicular pollution. The thermal comfort and the quality of air indoors in parking lots with different architectonic typology (ground-floor and underground) are also studied, aiming to contribute to the proposition of suitable new areas designated to human usage. Field research was done, in two distinct periods within different weather conditions (January and July) in, two naturally cooled, parking lots located in Natal - RN. The internal environment agents were measured by using tools for air temperature, humidity, speed and direction; interviews with employees and visitors and chemical analysis through appropriate tools to analyze specific material, carbon monoxide and ozone. The results showed that chemical agents densely concentrate mostly in the closed parking space, aggravated by weather conditions, which dissatisfied the visitors. Still, it was shown that architectonic typology, alongside topographical aspects compromise internal environmental conditions, which increases the retention of pollution, leading to dissatisfactory thermal comfort levels and becoming less suitable for usage by visitors considering air and thermal comfort aspects. Consequently, they are not suitable for human stay due to the poor quality of the indoor air

Avaliação do potencial passível de conversão em energia elétrica das correntes na plataforma continental sul brasileira

O contínuo crescimento da população mundial aumenta a demanda e a competição por energia, colocando grande esforço sobre as fontes de energia não renováveis existentes. Devido a isso, políticas globais para geração de energias renováveis e menos poluentes estão sendo fortalecidas, além de promoverem o desenvolvimento de novas tecnologias. Várias formas de conversão de energia foram desenvolvidas no decorrer dos anos, com destaque para os conversores de energia das correntes a base de turbinas, que demonstram alta capacidade de conversão energética e já se encontram em funcionamento. O modelo tridimensional TELEMAC3D foi utilizado para a investigação dos processos hidrodinâmicos. Este modelo foi acoplado ao módulo de conversão de energia para as análises nos locais de maior viabilidade e conversão energética na Plataforma Continental do Sul do Brasil. A região de estudo demonstrou possuir duas regiões com alto potencial para a exploração da energias das correntes marinhas, entretanto a região mais viável para a instalação de conversores de corrente é a região norte delimitada entre o Farol da Conceição e o Farol da Solidão, podendo atingir potência média de 10kW=Dia, e alcançando valores integrados de 3:5MW=Ano. Através de uma análise da sazonalidade foram observados, durante a primavera os períodos mais energéticos em ambas as regiões estudadas. As maiores intensidades de conversão de energia foram estimadas com variabilidade temporal de 16 dias, demonstrando alta correlação com eventos associados à passagem de frentes meteorológicas na região. O sítio da região norte, com a presença de barreiras que representam a forma dos conversores, se destaca mantendo boa conversão durante os eventos de ótimo potencial energético. Esta melhora se deve ao efeito de intensificação do campo de correntes associado à presença da estrutura física que otimiza a eficiência do sítio. Não foram observadas diferenças significativas no padrão de variabilidade temporal das simulações estudadas, indicando que a presença das barreiras não induz grandes alterações no padrão temporal da conversão de energia nas escalas temporais analisadas neste trabalho. Os eventos de alta geração de energia foram relacionados a incidência de fortes ventos de quadrante sul e norte, indicando que pelo formato e disposição dos conversores, ventos de sudoeste e norte podem favorecer ótimos eventos de conversão de energia. As simulações dos sítios de conversão demonstraram alta capacidade de geração energética, com quatro eventos de extrema geração de energia. Entretanto, o sítio da região norte demonstrou eficiência superior a 59,39 GWh ao ano, equivalendo a 0.22% do consumo energético do estado do Rio Grande do Sul no ano de 2010.

Circulações locais no Rio Grande do Sul: brisas marítima/terrestre e sua interação com as brisas lacustres/terrestres

A região sul do Rio Grande do Sul está em localização favorável à formação de tipos de brisa bem caracterizados devido a sua proximidade com os sistemas lacustres e também o Oceano Atlântico. A diferença de vegetação e as temperaturas da superfície do mar, da laguna e do solo, são os principais impulsionadores das circulações locais. Uma das formas de analisar estas circulações locais é através de modelos que simulam a formação da brisa. Desta forma utilizou-se o modelo de mesoescala Weather Research and Forecasting para caracterizar as circulações locais na região sul do Brasil devido às influências do Oceano Atlântico e das lagoas presentes na região: Lagoa dos Patos, Lagoa Mangueira e Lagoa Mirim. Ao todo foram realizadas três simulações: uma para a validação do modelo e duas para simulação das brisas. O modelo apresentou correlações entre 0,7 e 0,9 para a temperatura do ar a dois metros e para a pressão atmosférica. As correlações para a umidade específica e para o vento a dez metros ficaram entre 0,3 e 0,8. Na simulação básica, a brisa lacustre apresentou intensidade máxima às 15 UTC (12 HL) sobre a Lagoa dos Patos e Mangueira e às 18 UTC (15 HL) sobre a Lagoa Mirim. Nos horários entre 0 UTC (21HL) e 9 UTC (6 HL), período em que a brisa terrestre está atuante, observou-se a rotação do vento no sentido anti-horário e também diminuição de intensidade. Para a simulação idealizada onde foi suprimido o efeito sinótico, a brisa marítima no início de sua formação sofreu um bloqueio pela brisa lacustre no horário das 15 UTC (12 HL). Esta oclusão permanece até às 18 UTC (15 HL). Após este período a brisa lacustre diminui a intensidade e dá lugar a brisa marítima que possui direção leste com intensidade menor do que a que foi observada na simulação básica. A brisa terrestre teve início às 0 UTC (21 HL) e seu valor máximo foi de 4 m/s as 9 UTC (6 HL). Para a validação do modelo concluiu-se que o mesmo é adequado para a avaliação das circulações locais. A brisa terrestre caracterizou-se melhor sem a presença do vento sinótico. As brisas Lacustres das Lagoas Mirins e dos Patos possuem influência maior do que a brisa gerada pela Lagoa Mangueira e em determinados períodos opõem-se ao avanço da brisa marítima. A associação do vento sinótico a brisa marítima intensifica a velocidade dos ventos, que por sua vez sobrepõem-se a brisa lacustre no final da tarde. A brisa terrestre formada durante a noite não é forte o suficiente para sobrepor o vento sinótico, mas reduz sua intensidade e altera sua direção.

Análise bioclimática e investigação do conforto térmico em ambientes externos: uma experiência no bairro de Petrópolis em Natal/RN

This study was intended to investigate how the urban form has been influencing the changes in the climate of the city and make a correlation between the climate and the thermal sensation of the users of open spaces. The research was developed in the district of Petrópolis in Natal/ RN whose occupation has been almost consolidated. Among other reasons, this district was selected because it was planned considering the environmental aspects of comfort. The methodologies used are based on KATZSCHNER (1997) and OLIVEIRA (1988) studies, which suggest the drawing and analysis of maps of the area under study, including topography, height of the buildings, land use, green areas, and types of soil pavement, as well as measurement of the environmental variables: air temperature, relative humidity, direction and wind speed for a comparative study. As part of this, study local users of the district were interviewed about their thermal sensations in open spaces. For the statistical analysis, data was collected at 10 distinct points characterized by BUSTOS ROMERO (2002), being 8 within the district and 2 at different places (outside the district), at climatologic stations, in 3 periods (August/2000, January/2002 and June/2002), for 4 consecutive days for each measurement (from Sunday to Wednesday) at the time of lower and higher temperatures in the city, 6:00 am and 1:00 pm, respectively. At the same time interviews were carried out with users of the open spaces in the area, totaling 171 valid formularies. The urban form showed a rather leveled topography, great diversity of land use and height of the buildings, with the existence of an area mostly occupied with high buildings, very little green area and soil practically impermeable. The statistical analysis showed high temperature and humidity levels. The wind direction is predominantly Southeast with extremely variable speeds. When the data from this district is compared with the data from other areas in the city and its outskirt, it was observed that this district is hotter and less ventilated than the others; besides, most users said that they felt uncomfortable in the local environmental conditions. The results of the analysis generated a zoning for the district with recommendations for soil occupation. The profile of the user was defined regarding the thermal comfort, as well as some discussion about the comfort parameters, including the proposal of limiting areas of temperature and humidity for the thermal comfort in the open spaces

Ventilação e prescrições urbanísticas: uma aplicação simulada no bairro de Petrópolis em Natal/RN

The present work studies the natural ventilation and its relationship with the urban standards, which establishes the form of occupation and use of the land in our cities. The method simulates the application of the urban standards of the City Master Plan over the last three years. The simulation takes place in the District of Petrópolis, in the city of Natal , Brazil and analyses the effects of the standards of natural ventilation. The formulated hypothesis states that the reductions in the urban spaces between buildings rises up the vertical profile of ventilation, reducing, therefore, the velocity of the wind at the lower levels of the buildings. To develop the study, occupation models were built, using computerized, three-dimensional models. These occupation models were analyzed using the CFD (Computational Fluid Dynamics) code. The conclusion is that the more we reduce the urban space between buildings, the more we reduce the wind speed in constructed areas, increasing, therefore, the possibility to generate heat islands

Potencialidades de cultivo de macroalgas no litoral do Rio Grande do Norte (NE, Brasil): uma perspectiva de integração de dados ambientais em sistemas de informação geográfica (SIG)

Since centuries ago, the Asians use seaweed as an important source of feeding and are their greatest world-wide consumers. The migration of these peoples for other countries, made the demand for seaweed to increase. This increasing demand prompted an industry with annual values of around US$ 6 billion. The algal biomass used for the industry is collected in natural reservoirs or cultivated. The market necessity for products of the seaweed base promotes an unsustainable exploration of the natural banks, compromising its associated biological balance. In this context, seaweed culture appears as a viable alternative to prevent the depletion of these natural supplies. Geographic Information Systems (GIS) provide space and produce information that can facilitate the evaluation of important physical and socio-economic characteristics for the planning of seaweed culture. This objective of this study is to identify potential coastal areas for seaweed culture in the state of Rio Grande do Norte, from the integration of social-environmental data in the SIG. In order to achieve this objective, a geo-referred database composed of geographical maps, nautical maps and orbital digital images was assembled; and a bank of attributes including physical and oceanographical variables (winds, chains, bathymetry, operational distance from the culture) and social and environmental factors (main income, experience with seaweed harvesting, demographic density, proximity of the sheltered coast and distance of the banks) was produced. In the modeling of the data, the integration of the space database with the bank of attributes for the attainment of the map of potentiality of seaweed culture was carried out. Of a total of 2,011 ha analyzed by the GIS for the culture of seaweed, around 34% or 682 ha were indicated as high potential, 55% or 1,101 ha as medium potential, and 11% or 228 ha as low potential. The good indices of potentiality obtained in the localities studied demonstrate that there are adequate conditions for the installation of seaweed culture in the state of Rio Grande do Norte