Detecção fotogramétrica de movimentos em arribas costeiras e gestão do inventário num sistema de informação geográfica

Tese de mestrado, Engenharia Geográfica, Universidade de Lisboa, Faculdade de Ciências, 2009A principal causa do recuo sofrido pelas arribas rochosas no litoral é a ocorrência de movimentos de massa de diferentes tipos e dimensões, fenómenos que provocam risco natural considerável. Ao longo do litoral Algarvio, fortemente utilizado e densamente ocupado por estruturas antrópicas, a ocorrência frequente de movimentos dita a necessidade de condução de estudos de carácter científico que permitam conhecer de forma conveniente o comportamento destes fenómenos e, então, mitigar os riscos que lhes estão associados. Para se poder compreender convenientemente o comportamento do litoral no que concerne a ocorrência de movimentos em arribas costeiras, é necessário construir inventários sistemáticos de movimentos, executados através de estudos multi-temporais de fotografias aéreas. Este carácter multi-temporal da análise requer o maior intervalo temporal possível, o que implica a utilização de fotografias aéreas muito antigas, por vezes em condições que dificultam o seu processamento. O objectivo principal do projecto “Avaliação Quantitativa da Intensidade da Erosão das Arribas do Litoral do Algarve Central”, proposto pela CCDR Algarve, era comparar e a actualizar um inventário realizado por Marques [1997] para o intervalo 1947 – 1991, baseado em métodos simplificados [Marques, 2006]. Neste contexto, realizou-se um novo estudo multi-temporal de movimentos em arribas rochosas, para o sector Burgau – Ancão, recorrendo à aplicação de procedimentos fotogramétricos digitais rigorosos às fotografias aéreas do intervalo 1947 a 2007.No desenvolvimento deste trabalho, foram testadas duas metodologias de detecção e caracterização dos movimentos: baseadas em comparação directa dos elementos crista e base de arribas, obtidos por estereorrestituição, e baseadas em modelos digitais de elevação (MDE)gerados automaticamente e diferenças entre esses modelos digitais de elevação, de forma a quantificar as alterações sofridas pelas arribas ao longo do tempo. Dada a elevada importância de um estudo deste tipo, bem como a quantidade de informação necessária à sua persecução e a quantidade de informação subsequente produzida, torna-se fundamental que os resultados se apresentem numa estrutura completa e organizada, e que estejam acessíveis de forma eficiente. Para tal, foi criado um Sistema de Informação Geográfica, denominado SIG-ARRIBA, com o intuito de disponibilizar uma ferramenta de grande utilidade para a gestão da orla costeira. O inventário de movimentos compilado foi integrado no SIGARRIBA,e este foi populado com um vasto conjunto de dados adicionais relevantes(produzidos ao longo do trabalho e adquiridos directamente), proporcionando uma gestão mais eficiente do fenómeno de movimentos em arribas costeiras.The main cause of sea cliff retreat is the occurrence of mass movements of variable dimension sand types, which are a considerable source of natural risk. Throughout the Algarve coast, heavily used and strongly occupied by buildings and structures, the frequent occurrence of mass movements dictates the need to execute scientifically based studies which allow a deeper knowledge on the behaviour of such a phenomenon and, then, reduce the associated risks. In order to truly comprehend the coastal behaviour in what concerns the mass movements phenomena in sea cliffs, it is necessary to perform systematic inventories based on multi temporal studies of aerial photographs. This multi-temporal component requires the widest possible time interval which means using old aerial photos, which are very difficult to process. The main goal of the project “Avaliação Quantitativa da Intensidade da Erosão das Arribas doLitoral do Algarve Central”, proposed to Faculdade de Ciências da Universidade de Lisboa by CCDR Algarve, was comparing and updating an inventory compiled by MARQUES [1997] for the time interval of 1947 to 1991, based on simplified methods. A new multi-temporal study on the sea cliff retreat problem was performed for the coastal segment between Burgau and Ancão, based on the application of digital photogrammetric processing to aerial photographs dating from 1947 to 2007. In the course of this work, methodologies of mass movement detection and characterization were tested: based on direct comparison of the stereo plotted elements cliff top and cliff base, and based on the automatic generation of digital elevation models and digital differential elevation models, in order to quantify the changes suffered by the coastal cliffs. Given the high importance of such a study, as well as the amount of data needed to proceed with the work and the amount of produced information, it is fundamental that all the data is presented in a complete and organized structure which enables easy visualization, query, processing and updating. Therefore, a GIS named SIG-ARRIBA was designed with the goal of offering a tool of great utility to the management of coastal areas. The inventory performed was integrated in SIG-ARRIBA and the latter was populated with a large set of additional relevant data (produced throughout the work and directly acquired), where an efficient management of the phenomena may be pursued

Dunes Open Archive

Criação da Base de Dados com acesso aberto do Projeto DUNESinfo:eu-repo/semantics/publishedVersio

Prática do aleitamento materno em comunidades rurais do semi-árido baiano

A Research project in the establishment and duration of total and exclusive breast-feeding in rural communities of Cansação, BA, Brazil, is presented. It included 226 children, from zero to two years old, of families of peasants living on small-holdings in one of the driest and poorest regions of the Brazilian Northeast. The data were collected through questionnaires answered by mothers or any adult responsible for the child during 1988 and 1989. It relates to all children from these families who were two years of age at the time of the study. The survival time was the statistical method used to calculate the median duration of breast-feeding; 91.6% of the 226 children started to be breast-fed. This finding shows that the establishment of the breast-feeding was high. The median duration of total breast-feeding was of 90.28 days and exclusive breastfeeding presented a median duration of 0.1 day. Through the establishment of breast-feeding can be considered high, the median duration of total breast-feeding is extremely short and that of exclusive breast-feeding insignificant.Com o objetivo de conhecer p estabelecimento e duração do aleitamento materno total e exclusivo em comunidades rurais do Semi-Árido Baiano, Brasil, foram estudadas 226 crianças de O a 2 anos de idade, filhas de pequenos produtores rurais que vivem numa das regiões mais secas do nordeste brasileiro, de pobreza absoluta. Os dados referem-se a todas as crianças da família que à data do estudo tinham até 2 anos de idade. Os dados foram coletados por meio de formulários aplicados às mães ou responsáveis pelo menor, no período de 1988 a 1989. A tábua de vida foi o recurso estatístico utilizado para o cálculo da duração mediana do evento. Das 226 crianças que integraram o estudo, 91,6 iniciaram a amamentação ao peito. A duração mediana do aleitamento total foi de 90,28 dias e o aleitamento exclusivo apresentou duração mediana de 0,1 dia. Ainda que o estabelecimento da amamentação ao peito possa ser considerado alto, a duração mediana do aleitamento total foi extrememente curta, e o aleitamento exclusivo foi desprezível

Impact of a Citywide Sanitation Program in Northeast Brazil on Intestinal Parasites Infection in Young Children

BACKGROUND: Sanitation affects health, especially that of young children. Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites. A citywide sanitation intervention started in 1996 aimed to raise the level of sewer coverage from 26% to 80% of households. OBJECTIVES: We evaluated the impact of this intervention on the prevalence of Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis infections in preschool children. METHODS: The evaluation was composed of two cross-sectional studies (1998 and 2003-2004), each of a sample of 681 and 976 children 1-4 years of age, respectively. Children were sampled from 24 sentinel areas chosen to represent the range of environmental conditions in the study site. Data were collected using an individual/household questionnaire, and an environmental survey was conducted in each area before and after the intervention to assess basic household and neighborhood sanitation conditions. Stool samples were examined for the presence of intestinal parasites. The effect of the intervention was estimated by hierarchical modeling, fitting a sequence of multivariate regression models. FINDINGS: The prevalence ofA. lumbricoides infection was reduced from 24.4% to 12.0%, T. trichuria from 18.0% to 5.0%, and G. duodenalis from 14.1% to 5.3%. Most of this reduction appeared to be explained by the increased coverage in each neighborhood by the sewage system constructed during the intervention. The key explanatory variable was thus an ecological measure of exposure and not household-based, suggesting that the parasite transmission prevented by the program was mainly in the public (vs. the domestic) domain. CONCLUSION: This study, using advanced statistical modeling to control for individual and ecological potential confounders, demonstrates the impact on intestinal parasites of sanitation improvements implemented at the scale of a large population

Técnicas de teledeteção de alta resolução aplicadas à monitorização 3D de arribas litorais : adequabilidade, modelação da informação e resultados

Tese de doutoramento, Ciências Geofísicas e da Geoinformação (Engenharia Geográfica), Universidade de Lisboa, Faculdade de Ciências, 201

Geotechnical characterization and seismic response of shallow geological formations in downtown Lisbon

 The geological and geotechnical characterization of shallow formations is one of the main steps in performing a microzonation study. This paper presents an example of the usefulness of the information compiled in a geological and geotechnical database for the estimation of the seismic response of the shallower formations of the Lisbon downtown area of Baixa. The geotechnical characterization of this area was performed based on the analysis of Standard Penetration Test (SPT) data compiled in the geological and geotechnical database. This database, connected to a geoscientific information system (CGIS), allows, also, the definition of 2D geological profiles used for estimating the thickness of the shallower layers. The shear-wave velocities (VS ) for each layer were estimated from empirical correlations using mean SPT values computed from the statistical evaluation of the compiled data. These VS values were further calibrated with ambient vibration recording analysis. The seismic response of Baixa’s superficial deposits was estimated by applying a 1D equivalent linear method to a set of soil profiles, regularly distributed across the area, and using synthetic accelerograms to simulate input motions associated with probable earthquake occurrences in Lisbon. The results are presented in terms of maps of predominant frequencies, with the corresponding amplification level, as well as spectral amplification factors for 1 Hz and 2.5 Hz. The results show that the fundamental frequency of the Baixa area is between 1.2 Hz and 2 Hz, for the whole central valley, reaching 3 Hz near the edges where anthroprogenic and alluvial deposits have less expression. Amplification factors up to 5 were obtained. These results were achieved regardless of the considered input motion. The similarity of the obtained fundamental frequency with the natural frequency of Baixa’s old building stock increases the probability of resonance effects in future earthquakes

Environmental indicators of intra-urban hetererogeneity Indicadores ambientales para detectar la heterogeneidad intra-urbana Indicadores ambientais para detectar heterogeneidade intraurbana

A large number of human diseases are related to poor access to water and sewer systems, inadequate solid waste management and deficient storm water drainage. The goal of this study was to formulate environmental sanitation indicators and classify sanitation conditions in specific sewer basins and their respective neighborhoods. The database used contains information on the following sanitation components in these areas: water supply, sewer systems, urban drainage, road pavement, building typology and public cleaning. Data was analyzed using cluster analysis. The key variable of each component was identified, and eight sewer basins and twenty-three neighborhoods were classified into the following categories: good, regular, and poor. The use of environmental sanitation indicators allows decision makers to identify critical areas and define priorities for improving environmental sanitation conditions.<br>Varias enfermedades que afectan a los seres humanos están vinculadas a la deficiencia en el acceso a servicios de agua y alcantarillado, la gestión inadecuada de los residuos sólidos y el deficiente sistema de drenaje de aguas pluviales. Este estudio trata de desarrollar indicadores de salud ambiental y clasificar las áreas dentro de las ciudades. Se utilizó una base de datos que contiene información sobre: limpieza urbana, abastecimiento de agua, alcantarillado, drenaje y calles, pavimentación de las calles y tipología de construcción en diferentes barrios. Se aplicó la técnica de clúster para el análisis de datos. Se identificó la variable que mejor representa cada componente y veintitrés áreas de la ciudad se clasificaron en tres categorías: buena, regular y mala. El uso de indicadores de salud ambiental permitió la identificación de áreas críticas y el establecimiento de prioridades en la inversión para la salud y mejora del medio ambiente.<br>Várias patologias que acometem os seres humanos estão ligadas à deficiência de acesso a água e serviços de esgotamento sanitário, inadequado manejo de resíduos sólidos e deficiência do sistema de drenagem das águas pluviais. Este estudo buscou desenvolver indicadores sanitário ambientais e classificar áreas intraurbanas. Utilizou-se uma base de dados contendo informações sobre: abastecimento de água, sistema de esgoto, drenagem e limpeza urbana, pavimentação e tipologia construtiva referentes a bacias de esgotamento sanitário e áreas sentinela. Foi aplicada a técnica de analise de cluster. Identificou-se a variável que melhor representava cada componente, e oito bacias de esgotamento e vinte e três áreas sentinelas foram classificadas em três categorias: boa, regular e insatisfatória. O uso de indicador sanitário ambiental permitiu a identificação de áreas críticas e o estabelecimento de prioridades de investimentos para as melhorias sanitário ambientais

Environmental indicators of intra-urban hetererogeneity

A large number of human diseases are related to poor access to water and sewer systems, inadequate solid waste management and deficient storm water drainage. The goal of this study was to formulate environmental sanitation indicators and classify sanitation conditions in specific sewer basins and their respective neighborhoods. The database used contains information on the following sanitation components in these areas: water supply, sewer systems, urban drainage, road pavement, building typology and public cleaning. Data was analyzed using cluster analysis. The key variable of each component was identified, and eight sewer basins and twenty-three neighborhoods were classified into the following categories: good, regular, and poor. The use of environmental sanitation indicators allows decision makers to identify critical areas and define priorities for improving environmental sanitation conditions