Eduardo Delgado Assad

Impacto das mudanças climáticas no zoneamento agroclimático do café no Brasil

According to the last report of the Intergovernmental Panel on Climate Change (IPCC), the global temperature is supposed to increase 1°C to 5.8°C and the rainfall 15% in the Tropical area. This paper analyses the effect that these possible scenarios would have in the agroclimatic zoning of the arabic coffee (Coffea arabica L.) main plantation areas in Brazil. The results indicated a reduction of suitable areas greater than 95% in Goias, Minas Gerais and Sao Paulo and about 75% for Parana in the case of a temperature increase of 5.8 o C. These results presume that all the physiological characteristics of the crop will be the same for the varieties analyzed and that the ideal climatic condition for economic development is mean annual temperatures between 18 o C and 23 o C.

POESIA: An ontological workflow approach for composing Web services in agriculture

Abstract.This paper describes the POESIA approach to systematic composition of Web services. This pragmatic approach is strongly centered in the use of domain-specific multidimensional ontologies. Inspired by applications needs and founded on ontologies, workflows, and activity models, POESIA provides well-defined operations (aggregation, specialization, and instantiation) to support the composition of Web services. POESIA complements current proposals for Web services definition and composition by providing a higher degree of abstraction with verifiable consistency properties. We illustrate the POESIA approach using a concrete application scenario in agroenvironmental planning.

Regiões pluviometricamente homogêneas no Brasil

The objective of this work was to identify homogeneous areas in Brazil according to the similarity of their rainfall probability distribution, in order to contribute to the studies of climatic risks in agriculture. These areas were delimited using the hierarchical cluster analysis, with discriminating variables defined by the proportion of dry pentads and by measures of location, scale and shape of the pluviometric frequency distributions. Cluster analysis was able to identify 25 rainfall homogeneous areas in the whole Brazilian territory.

Impact assessment study of climate change on agricultural zoning

If mean temperature increases, in accordance with Intergovernmental Panel on Climate Change (IPCC) projections and adaptations and/or genetic modifications are not considered, suitable areas for farming corn (Zea mays) and coffee (Coffea arabica) will decrease in the state of Sao Paulo (Brazil). Further, increases in precipitation will not be enough to ameliorate the impacts associated with increases in mean temperatures. Suitability for grain production will decrease more rapidly in regions with sandy soils than in regions with clay or medium soils, as the temperature increases. The projected increase in mean temperature of up to 5.8°C would decrease the suitability for grain production drastically in spite of soil texture. Besides the reduction of suitable areas for coffee production, the projections suggest that changes will be more enhanced in the southeast of the state, especially in higher elevation regions, where farming practice, soils, and infrastructure are unsuitable for the economic production of coffee. In both cases, no compensatory increase in suitable areas for production is likely under current IPCC scenarios. Copyright

Eficiência da produção de cana‑de‑açúcar em duas safras no Estado de São Paulo

A conceptual framework for crop production efficiency was derived using thermodynamic efficiency concept, in order to generate a tool for performance evaluation of agricultural systems and to quantify the interference of determining factors on this performance. In Thermodynamics, efficiency is the ratio between the output and input of energy. To establish this relationship in agricultural systems, it was assumed that the input energy is represented by the attainable crop yield, as predicted through simulation models based on environmental variables. The method of FAOs agroecological zones was applied to the assessment of the attainable sugarcane yield, while Instituto Brasileiro de Geografia e Estatistica (IBGE) data were used as observed yield. Sugarcane efficiency production in Sao Paulo state was evaluated in two growing seasons, and its correlation with some physical factors that regulate production was calculated. A strong relationship was identified between crop production efficiency and soil aptitude. This allowed inferring the effect of agribusiness factors on crop production efficiency. The relationships between production efficiency and climatic variables were also quantified and indicated that solar radiation, annual rainfall, water deficiency, and maximum air temperature are the main factors affecting the sugarcane production efficiency.

Impacts of climate change on the agricultural zoning of climate risk for cotton cultivation in Brazil

The objective of this work was to evaluate the effect of the temperature increase forecasted by the Intergovernmental Panel on Climate Change (IPCC) on agricultural zoning of cotton production in Brazil. The Northeastern region showed the highest decrease in the low-risk area for cotton cultivation due to the projected temperature increase. This area in the Brazilian Northeast may decrease from 83 million ha in 2010 to approximately 71 million ha in 2040, which means 15% reduction in 30 years. Southeastern and Center-Western regions had small decrease in areas suitable for cotton production until 2040, while the Northern region showed no reduction in these areas. Temperature increase will not benefit cotton cultivation in Brazil because dimension of low-risk areas for economic cotton production may decrease.

Identificação de impurezas e misturas em pó de café por meio de comportamento espectral e análise de imagens digitais

Para eliminar divergencias na interpretacao dos resultados e agilizar os atuais metodos de deteccao de fraudes em cafe torrado e moido, foi estabelecido um metodo baseado na analise por imagem e fundamentado no principio de que diferentes materiais de origem orgânica, como o po de cafe, podem apresentar reflectâncias distintas em diferentes comprimentos de onda do espectro eletromagnetico. Partiu-se da hipotese de que o po de cafe adulterado, quando submetido a uma fonte artificial de iluminacao, apresenta uma reflectância, nos canais vermelho (R), verde (G) e azul (B), diferente em relacao a do po de cafe nao-adulterado. Apos as etapas de limpeza, secagem e homogeneizacao, foram geradas imagens multiespectrais das amostras de cafe, por meio de uma lupa acoplada a uma câmara CCD (Charge Coupled Device). A quantificacao das impurezas na amostra foi obtida utilizando-se curvas de calibracao entre a area relativa obtida pela classificacao supervisionada de imagens e a porcentagem de impurezas presentes nas amostras. Esse novo metodo permite agilidade da resposta, ausencia de subjetividade nos resultados e nao-destruicao das amostras analisadas, e assegura um patamar minimo de deteccao de 95% das impurezas do produto.

Interpoladores geoestatísticos na análise da distribuição espacial da precipitação anual e de sua relação com altitude

O objetivo deste trabalho foi quantificar a contribuicao da variavel auxiliar altitude, na estimativa da distribuicao espacial da precipitacao anual media no Estado de Sao Paulo. A estatistica quadrado medio do erro (QME) foi usada em dois conjuntos de observacoes de precipitacao anual media (1957 a 1997): o completo, com 1.027 observacoes, e o reduzido, com 445. Bolsoes de precipitacao foram perfeitamente definidos nos mapas de variabilidade espacial que utilizaram o conjunto completo de dados, e indicaram a existencia de possiveis microclimas. O interpolador geoestatistico de krigagem ordinaria apresentou desempenho 82 vezes mais preciso que o interpolador do inverso do quadrado da distância, quando o QME foi usado como criterio de comparacao para o conjunto de dados completo. Para o conjunto reduzido, essa magnitude foi de duas vezes. Os erros de estimacao obtidos por krigagem ordinaria foram menores no conjunto completo, enquanto os obtidos por cokrigagem ordinaria foram menores no reduzido. Isso indica que esses interpoladores devem ser usados para determinacao da distribuicao espacial da precipitacao anual media. O uso da altitude como variavel auxiliar beneficia o interpolador de cokrigagem ordinaria e define microrregioes mais uniformes quanto a distribuicao espacial da precipitacao anual media.

Comparação de dados dos satélites Ikonos-II e Landsat/ETM+ no estudo de áreas cafeeiras

The objective of this work was to assess the impact of the better spatial and radiometric resolutions of the Ikonos-II panchromatic image, for the identification of coffee (Coffea arabica) planting areas, in comparison with a Landsat/ETM+ image. The area of study is situated in the city of Pedregulho, State of Sao Paulo, Brazil, where 50 coffee fields were selected. Information about plants features, like height, age, spacing and variety were collected. Images allowed the identification of coffee areas with different field features, and the calibrated Ikonos-II image showed the best results. Considering the areas with similar field features, images from both satellites were not efficient in the coffee identification. The atmospheric and radiometric corrections applied on the Ikonos-II image did not improve the analyses results. More than half of the identified areas in the Ikonos-II image could be found in the Landsat/ETM+ image (68%). The significant correlation between Landsat/ETM+ band 4 and Ikonos-II panchromatic channel shows a link between both satellite images.

Técnicas de mineração de dados para análise da precipitação pluvial decenal no Rio Grande do Sul

The objective of this study was to analyze the spatio-temporal rainfall in Rio Grande do Sul, between 1987-1996 and 1997-2006 decades by using techniques of data mining. The historical series were acquired from the hydrological information Hidroweb system. The methodology used was based on the CRISP-DM (Cross Industry Standard Process for Data Mining) model. First, homogeneous precipitation areas for the 1987-1996 and 1997-2006 decades were defined. Subsequently, by the overlapping of the clusters obtained from both periods, six common areas were defined ranging from A to F. The changes in the volume of precipitation were evaluated annual seasonal and monthly. The results indicated significant increases (20 to 240 mm) in annual precipitation in all areas, except in area A. In the seasonal analysis, the variations were random, and in the spring all areas showed significant increase (44 to 142 mm). In the monthly analysis, the results revealed a reduction occurred in January in all areas, except in area E. In the other months, the changes were random. The results showed that among the decades there has been a change in the volume of rainfall in all timescales analyzed.