Hilton Silveira Pinto

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.

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

Estimativa de horas de frio abaixo de 7 e de 13°C para regionalização da fruticultura de clima temperado no estado de São Paulo

Estimativa e mapeamento do numero de horas com temperaturas abaixo de 7 e 13°C no Estado de Sao Paulo e analise comparativa do comportamento de fruteiras de clima temperado constituem os objetivos do presente trabalho. Foi cotado o numero de horas com temperaturas inferiores a 7 e 13°C, indices considerados limites necessarios a dormencia dessas plantas. Foram selecionados termogramas de doze postos agrometeorologicos do Instituto Agronomico, situados em altitudes variaveis entre 25 e 1.000m, correspondentes ao periodo 1964-1973. Estabeleceram-se equacoes para estimativa do numero de horas com temperaturas inferiores a 7°C (HF-7) e 13°C (HF-13) em funcao da temperatura media do mes de julho, cujos coeficientes de correlacao foram de -0,88 e -0,93, respectivamente. Com base nessas equacoes foram mapeadas as isolinhas de HF-7 e HF-13 para o Estado de Sao Paulo, encontrando-se desde valores medios anuais de HF-7 inferiores a 20 horas, caracteristicos das regioes de transicao de clima mesotermico a megatermico do Planalto Ocidental e das regioes mais baixas do norte e oeste do Estado, ate valores anuais de HF-7 superiores a 200 horas, caracteristicos das areas acima de 1.500 metros de altitude no Sul do Estado, na serra da Mantiqueira, limitrofe com Minas Gerais, e na serra do Mar, limitrofe com o Rio de Janeiro. Com base na introducao de diferentes frutiferas de clima temperado no Estado de Sao Paulo, verificou-se uma relacao muito grande entre os indices HF-7 e HF-13 mapeados com o comportamento e potencialidade de exploracao comercial.

Rainfalls during great Forbush decreases

SummaryThe changes of rainfall values during great Forbush decreases recorded by the low-latitudinal neutron monitor of Huancayo (47 events from 1956 through 1992) were examined. The data on precipitations were taken from the State of São Paulo and from the Amazonian region, Brazil. As a rule, the data from more than 50 meteorological stations were used for each events. The main result is the following: during strong decreases of cosmic-ray flux in the atmosphere (great Forbush decreases) the precipitation value is decreased. The effect of rainfall changes is seen more distinctly if wet seasons are considered.

An Alternative Model for Dry-Spell Probability Analysis

Abstract The occurrence of sequences of dry days in the wet season was studied for six localities scattered over the State of SāPaulo, Brazil. In order to determine the most suitable probability model for this tropical region, two frequency distribution functions were analyzed: 1) the Markov chain and 2) the truncated negative binomial. In spite of its widespread use, the Markovian model was shown to be less efficient for fitting estimated data with observed data than the truncated negative binomial model.

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.

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.

Surface ozone study in Campinas, Sao Paulo, Brazil

Abstract The first results of the surface ozone study in Campinas, Sao Paulo state, Brazil, are presented. During the local winter (dry season) the photochemical ozone production is found to be a regular process with the afternoon ozone mixing ratio maximum ranging from 10 to 15 ppbv during totally cloudy days to 40–60 ppbv during clear sky weather. Several high-value ozone episodes with ozone mixing ratios from 80 to 140 ppbv have been registered. At the beginning of the wet season the ozone concentration in Campinas did not decrease significantly as in the Amazonia forest region, but diurnal variations became more complicated with sharp dropouts during the days with rainfall and other fast changes of meteorological conditions. The fast irregular pulsations of ozone concentration with periods from the first tens of seconds to tens of minutes have been registered. Possible explanations of the nature of pulsations are briefly discussed. Photochemical ozone production by urban plumes of Campinas or Sao Paulo is named as a first possible source of the elevated ozone concentration and a local biomass burning is suggested as an alternative or an additional source.

A simplifies Gamma probability model for analysis of the frequency distribution of rainfall in the region of Campinas, SP, Brazil

Abstract The frequency distribution of 5-day precipitation totals in Campinas, SP, Brazil was studied. A simplified exponential model of the form f ( x ) = 1n A · A − x was shown to be as accurate as the Gamma and the “Transformed Normal” distributions for fitting expected to observed frequencies for the whole year. The exponential model was found to be a Gamma distribution with the γ parameter constant and equal to one, suitable for rapid interpretation of data with an inverted J-curve frequency distribution.