Correlação entre dados geofísicos e geológicos em ocorrência de cobre localizada na bacia sedimentar do Camaquã - RS

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Surveys on time use and unpaid work in Latin America and the Caribbean: Experience to date and challenges for the future

Incluye bibliografía.

Mexico: Combining monthly inflation predictions from surveys

We examine the problem of combining Mexican inflation predictions or projections provided by a biweekly survey of professional forecasters. Consumer price inflation in Mexico is measured twice a month. We consider several combining methods and advocate the use of dimension reduction techniques whose performance is compared with different benchmark methods, including the simplest average prediction. Missing values in the database are imputed by two different databased methods. The results obtained are basically robust to the choice of the imputation method. A preliminary analysis of the data was based on its panel data structure and showed the potential usefulness of using dimension reduction techniques to combine the experts' predictions. The main findings are: the first monthly predictions are best combined by way of the first principal component of the predictions available; the best second monthly prediction is obtained by calculating the median prediction and is more accurate than the first one.

Digital soil mapping: evaluation of sampling systems for soil surveys and refinement of soil maps at lower cost using legacy data

In soil surveys, several sampling systems can be used to define the most representative sites for sample collection and description of soil profiles. In recent years, the conditioned Latin hypercube sampling system has gained prominence for soil surveys. In Brazil, most of the soil maps are at small scales and in paper format, which hinders their refinement. The objectives of this work include: (i) to compare two sampling systems by conditioned Latin hypercube to map soil classes and soil properties; (II) to retrieve information from a detailed scale soil map of a pilot watershed for its refinement, comparing two data mining tools, and validation of the new soil map; and (III) to create and validate a soil map of a much larger and similar area from the extrapolation of information extracted from the existing soil map. Two sampling systems were created by conditioned Latin hypercube and by the cost-constrained conditioned Latin hypercube. At each prospection place, soil classification and measurement of the A horizon thickness were performed. Maps were generated and validated for each sampling system, comparing the efficiency of these methods. The conditioned Latin hypercube captured greater variability of soils and properties than the cost-constrained conditioned Latin hypercube, despite the former provided greater difficulty in field work. The conditioned Latin hypercube can capture greater soil variability and the cost-constrained conditioned Latin hypercube presents great potential for use in soil surveys, especially in areas of difficult access. From an existing detailed scale soil map of a pilot watershed, topographical information for each soil class was extracted from a Digital Elevation Model and its derivatives, by two data mining tools. Maps were generated using each tool. The more accurate of these tools was used for extrapolation of soil information for a much larger and similar area and the generated map was validated. It was possible to retrieve the existing soil map information and apply it on a larger area containing similar soil forming factors, at much low financial cost. The KnowledgeMiner tool for data mining, and ArcSIE, used to create the soil map, presented better results and enabled the use of existing soil map to extract soil information and its application in similar larger areas at reduced costs, which is especially important in development countries with limited financial resources for such activities, such as Brazil.

Evaluation report: regional workshop on informal sector surveys in the Caribbean's subregion

The Economic Commission for Latin America and the Caribbean (ECLAC) with support from the International Labour Organisation (ILO) and the Central Statistical Office in Saint Lucia convened a two-day Regional Workshop on Informal Sector Surveys for the Caribbean Subregion from 12 – 13 October 2009 in Castries, Saint Lucia. This workshop was one of the culminating activities of the United Nations Statistical Division-commissioned project Measurement of the Informal Sector and Informal Employment being conducted in the subregion since 2007. It was aimed primarily at disseminating the results of a 1-2 survey of the informal sector which was carried out in Saint Lucia over the period April 2008 to January 2009.

Regional workshop on informal sector surveys in the Caribbean subregion

The Economic Commission for Latin America and the Caribbean (ECLAC), Subregional Headquarters for the Caribbean, with support from the International Labour Organisation (ILO) and the Central Statistics Office in Saint Lucia, convened a two-day Data Dissemination Workshop on the Informal Sector and Informal Employment on 12 -13 October 2009 in Castries, Saint Lucia. This workshop was one of the culminating activities of the Interregional Project on the Measurement of the Informal Sector and Informal Employment being conducted in the Caribbean subregion. The workshop served as a forum for presenting the findings of the survey of the informal sector which was carried out in Saint Lucia over the period April 2008 to January 2009.

Análise da utilização de cartas geotécnicas em diferentes escalas para a gestão ambiental de rodovia em operação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A implicação antrópica na qualidade dos recursos hídricos subterrâneos da bacia hidrográfica do rio Urussanga - SC

Pós-graduação em Geociências e Meio Ambiente - IGCE

Inversão vinculada de dados de EMAP e MT-1D anisotrópico

Uma técnica para a inversão de dados magnetotelúricos é apresentada neste trabalho. Dois tipos de dados são tratados aqui, dados gerados por modelos unidimensionais com anisotropia na condutividade das camadas e dados bi-dimensionais de levantamentos do método EMAP (ElectroMagnetic Array Profiling). Em ambos os casos fazemos a inversão usando vínculos aproximados de igualdade para estabilizar as soluções. Mostramos as vantagens e as limitações do uso destes vínculos nos processos de inversão. Mesmo vinculada a inversão ainda pode se tornar instável. Para inverter os dados 2-D do EMAP, apresentamos um processo que consiste de três partes: 1 – A construção de um modelo interpretativo e da aproximação inicial para a inversão a partir dos dados de seções de resistividade aparente filtradas pelo processo de filtragem do EMAP; 2 – a inclusão de uma camada de corpos pequenos aflorantes, chamada de camada destatic shift, aos modelos interpretativos para resolver as fontes de distorções estáticas que contaminam os dados; 3 – o uso dos vínculos aproximados de igualdade absoluta para estabilizar as soluções. Os dois primeiros passos nos permitem extrair o máximo de informação possível dos dados, enquanto que o uso dos vínculos de igualdade nos permite incluir informação a priori que possua significado físico e geológico. Com estes passos, obtemos uma solução estável e significativa. Estudaremos o método em dados sintéticos de modelos bi-dimensionais e em dados reais de uma linha de EMAP feita na Bacia do Paraná.

Aplicação do gravímetro de poço em problemas de avaliação de formação no Brasil

No período de outubro a novembro de 1990, foi realizado na Bacia Sergipe-Alagoas o primeiro levantamento gravimétrico de poço no Brasil, através de um programa com a participação da Universidade Federal do Pará, a PETROBRÁS e o U.S.G.S. (United States Geological Survey). Este levantamento teve como objetivos o teste do equipamento, a resposta dos perfis gravimétricos em relação aos problemas encontrados nas bacias sedimentares brasileiras e a comparação com os dados de densidade obtidos com o perfil de densidade compensada (CDL). Os levantamentos foram realizados em três poços e os dados obtidos passaram por um processo de redução, onde os valores foram transformados para miligals e corrigidos dos efeitos de maré, deriva e terreno, para obter as densidades preliminares. Porém, a região onde foram realizados os levantamentos apresenta além do embasamento muito raso, uma seqüência evaporítica com contraste de densidade grande em relação ao resto do pacote sedimentar, gerando gradientes verticais anômalos. Estes efeitos foram então corrigidos e obtidos os valores finais de densidade. Com base em uma caracterização litológica prévia, os valores de densidade foram então comparados com o perfil CDL. Verificou-se a boa qualidade dos dados, o que permitiu o cálculo de valores de porosidade, mostrando assim possíveis intervalos de interesse à exploração de hidrocarbonetos, tanto no embasamento, reservatório mais importante, quanto no intervalo sedimentar.