Júlio César Ferreira de Melo Júnior

Climatologia do comportamento do período chuvoso da região sudeste do Brasil

ABSTRACT: CLIMATOLOGY OF THE RAINY PERIOD BEHAVIOR IN THE SOUTHEAST REGION OF BRAZILDaily data from 203 pluviometric stations, located in the Southeast region of Brazil, were studied with the objective to characterize climatically and analyze the tendency of the behavior of the rainy period. The results indicate that the rainy period begins early (between 13 and September 22 th ) and has larger duration (210 to 229 days) at the coastal area of Sao Paulo. Behavior opposed to the observed in the areas North and Vale do Jequitinhonha, in Minas Gerais, where the rainy period begins on average, among October 23 th on November 2 nd , only lasting 136 to 155 days. The duration and the dates at the beginning of the rainy period are strongly correlated, as well as, among the precipitation total and the duration of the rainy period in practically the whole Southeast region of Brazil. In general, from middles of the 1970’s, the rainy period has started earlier and lasted more in the Southeast region of Brazil. In regard to the amount of rain, it has been occurred in larger amounts only in the MG3 (Southeast of Minas Gerais) area and in the State of Sao Paulo.

Estimativa e espacialização das temperaturas do ar mínimas, médias e máximas na Região Nordeste do Brasil

Neste trabalho teve-se como objetivo principal, gerar equacoes de regressao multiplas com ajuste de superficie quadratica para estimativa das normais das temperaturas do ar minimas, medias e maximas mensais e anual, para o Nordeste brasileiro, a fim de fornecer subsidios para o planejamento agroclimatico em regioes onde nao ha disponibilidade desses dados. Obtiveram-se os dados de temperatura do ar utilizados para a determinacao dos coeficientes das equacoes, de 74 estacoes meteorologicas listadas nas normais climatologicas dos Estados da regiao Nordeste, fornecidas pelo INMET. A partir das equacoes ajustadas, foram gerados mapas tematicos das normais das temperaturas do ar minimas, medias e maximas mensais e anual. As equacoes obtidas apresentaram bons valores de R2; entretanto, quando utilizadas para altitudes muito elevadas, essas equacoes tenderam a apresentar baixos valores de temperatura do ar, enquanto as equacoes ajustadas e sua espacializacao mostraram tratar-se de uma alternativa viavel para a ampliacao da base de dados climaticos da regiao Nordeste.

Distribuição espacial da freqüência de chuvas na região hidrográfica do Atlântico, Leste de Minas Gerais

A study of spacial analysis was carried out with the rainfalls frequencies for the areas of the Atlântico hydrographic region in the eastern part in the State of Minas Gerais. The physiographic variables, such as natural vegetation, topography and wind direction, as well as the total annual rainfall using the geoestatistic Kriging technique to interpret the geospatial distribution of the rainfall frequency groups that represented the areas with homogeneous characteristics. In general, the geostatistic interpolator provided a good estimate of the total annual average rainfall for the studied area, except for the areas where the rainfall station density was relatively low. The physiographic variables and the continuous surface areas of total annual average rainfall was nearly correlated to the space distribution of the rainfall frequencies groups that represented the hydroclimatically homogeneous areas. The topography and the predominant winds at low levels showed to be the cause of the micro scale mechanisms of rainfall spatial distribution.

Determinação de regiões homogêneas quanto à distribuição de freqüência de chuvas no leste do Estado de Minas Gerais

Hydroclimatically homogeneous areas in relation to the frequency distribution of daily rainfalls were characterized in the hydrographic area of the Atlântico eastern part, in the State of Minas Gerais, Brazil. The hydroclimatically homogeneous areas were delimited through the methodologies of multivariate statistical analyses (rotated principal components analyses and clustering analysis). The method of clustering analysis proposed by Ward was used, because it provided the best space distribution of the groups. The results indicated five and three groups for, respectively, the meso and macro scale hydro climatic classification criteria, in the studied area.

Regionalização do cafeeiro e mudança da composição agrícola do Triângulo Mineiro/Alto Paranaíba, MG

Using tools of spatial analysis, the present work was carried out to investigate the geographical evolution of the coffee (Coffea arabic L.) plantation in an important region of the State of Minas Gerais, to verify the sustainability of the coffee production in different climatic and soil zones. In this context, a soil zoning for coffee plantation for the region of the Triângulo Mineiro and Alto Paranaiba, MG was elaborated. The geographical spatial analysis results were compared to an economic model of decomposition of the variation of the area and its scale substitution effects, for the period of 1985 through 1995/96. The expansion of coffee plantations was observed from the Northwest to the Northeast and accompanied the zoning criteria adopted in the present work. In other words, it was observed that a small expansion verified at Ituiutaba and Frutal have a strong climatic component, while at Araxa the soil factor prevailed. Only Uberaba appears to be an area that meets the climatic conditions for coffee plantation, but, in reality, presented little coffee plantation activity.