Elpídio Inácio Fernandes Filho

Avaliação de modelos digitais de elevação para aplicação em um mapeamento digital de solos

In Brazil, the digital elevation models (DEMs) are usually produced by users themselves and little attention has been given to their limitations as source of spatial information. The objective of this study was to evaluate different DEMs to help in choosing an appropriate model to derive topographical attributes used in a digital soil mapping based on a neural networks approach. The evaluation consisted of the following analysis: determination of root mean square error (RMSE) of elevation; analysis of the spurious depressions; comparison between mapped drainage and numeric drainage and between derived contour lines and original contour lines; and analysis of the derived contribution basins. The results demonstrated that RMSE was not enough to evaluate the quality of these models. DEMs derived from contour lines (CARTA, obtained using the TOPOGRID module) presented better quality than those derived from remote sensors (ASTER and SRTM). These presented great amount of errors that can negatively affect the establishment of relationships between topographical attributes and local conditions of soils.

O perfil dos visitantes do parque estadual do Ibitipoca (PEIb), Lima Duarte, MG

The present work was developed at the State Park of Ibitipoca (PEIb) to assess the characteristics of its visitors to gather information on their profile. A total of 324 visitors were interviewed during the months of January, February, April, and June of 2004, while data related to the frequency of monthly and annual visits (1988-2004) were provided by the administration of the Protected Area. The variables used in the interviews were tabulated, analyzed and compared with other protected areas. The variables education level, age, gender, group size and place of origin of the visitors were obtained. The results mainly showed that visitors staying time in the park was than two days and that they had been informed about through informal advertising. Visitor profile showed a high education level, with most visitors having completed the secondary school level. The main objective of the visit was to search for a quiet place, with great landscape beauty and contact with nature. Nowadays, rather than being just a fad, ecotourism is also a form of interaction and recovery of a traditional life style, provided by the Conceicao de Ibitipoca Village, only 3 km distant from the park entrance.

Terra e água na reforma agrária do semi-árido norteriograndense

Este trabalho teve como meta principal avaliar os recursos hidricos em dez projetos de assentamento na regiao Oeste do estado do Rio Grande do Norte. Para isto, analisaram-se parâmetros fisico-quimicos das aguas e se determinou a relacao dos assentados com os recursos hidricos de suas respectivas areas. Os resultados analiticos demonstraram que a qualidade das aguas de todos os assentamentos estudados, apresentou restricao para o seu uso na irrigacao, enquanto em Cordao de Sombra e Esperanca, a agua apresentou teores de cloreto acima do maximo recomendado para o consumo humano. Deve-se considerar a limitacao das reservas hidricas ao se diagnosticar a sustentabilidade dos agrossistemas na regiao, pois a agua e o fator determinante para o sucesso ou fracasso do empreendimento de reforma agraria nas condicoes de semi-aridez.

Uso de imagens orbitais como base de dados para projetos de reforma agrária

Analises tecnica e economica foram realizadas em imagens dos sensores IKONOS, TM/Landsat 5, ETM+/Landsat 7 e CCD/CBERS, objetivando a verificacao da viabilidade destas como base de dados em projetos de reforma agraria. Essas analises efetuadas e a situacao de mercado indicaram que a imagem IKONOS apresenta excelente desempenho tecnico, mas o custo de aquisicao inviabiliza sua utilizacao como base de dados para a reforma agraria. A imagem do Landsat 7, com baixo custo de aquisicao, apresentou grande viabilidade tecnica para fins de reforma agraria. No entanto, a perda do contato com a plataforma Landsat 7 inviabilizou a compra de novas imagens do sensor ETM+. A imagem CCD/CBERS apresentou a segunda maior similaridade com a verdade de campo e o menor indice Kappa para a classificacao. Apesar do baixo indice de exatidao para a classificacao, as analises de custo, o lancamento do CBERS-2 e a possibilidade de correcao dos problemas de radiometria podem tornar as imagens da plataforma CBERS-2 concorrentes de peso no mercado e, ainda, preencher a lacuna deixada pela perda do Landsat 7. A imagem do Landsat 5 apresentou o mais baixo desempenho tecnico nas analises efetuadas. Entretanto, seu potencial como base de dados e amplamente reconhecido pelo INCRA, que ainda utiliza tais imagens. O declinio da vida util do Landsat-5 atribui mais importância ao lancamento do CBERS-2.

POTENCIAL DO WEBSIG PARA DIVULGAÇÃO DE DADOS ESPACIAIS DA PENÍNSULA POTTER, ANTÁRTICA MARÍTIMA

POLLINATOR FORAGING STRATEGY IN Galactia peduncularis (BENTH.) TAUB. (LEGUMINOSAE: PAPILIONOIDEA) IN THE PARQUE ESTADUAL DA SERRA DE CALDAS NOVAS BRAZIL The way the animals look for food is an important characteristic of their behavior. The optimal foraging theory is based on the existence of a balance between costs and benefits of these behavioral decisions. The present study aimed to evaluate the behavior of the pollinator in response to increased availability of floral resources. The experiment was conducted in a recently burned Cerrado area (Campo rupestre) in the State Park of Serra de Caldas Novas , located in the municipalities of Caldas Novas and Rio Quente Brazil. The species chosen to test our hypothesis was Galactia peduncularis (Benth.) Taub. (Leguminosae: Papilionoidea). 17 pairs of specimens were selected with a number of flowers, and the individuals of each pair were spaced by about 2m. In these pairs, one of them was considered the focal, and the other, the isolated. To test possible differences in pollination between isolated plants and focus, we performed two randomization tests: a test binary (TB), where all pairs were analyzed and verified the number of times where the focus on the individual floral visits were higher than the number of visits in isolated. According to the data analyzed, floral visitors preferred to use plants that could provide a greater amount of floral resources so that the number of visitors varied positively with the increment of flowers. Plants with many flowers can provide a greater amount of food in one location so that visitors do not need to flower around for long distances in search of meeting their energy needs.