José Edson Florentino de Morais

EVAPOTRANSPIRAÇÃO DO GIRASSOL PELO MÉTODO DO TANQUE CLASSE “A” NA REGIÃO DO SEMIÁRIDO BRASILEIRO

Objetivou-se com esta pesquisa estimar a evapotranspiracao do girassol ( Helianthus annuus L.), com diferentes valores do coeficiente do Tanque Classe “A” (Kp) na regiao do Vale do Pajeu, Pernambuco, Semiarido brasileiro. A pesquisa foi realizada em Serra Talhada, Pernambuco, empregando dados meteorologicos e do Tanque Classe “A” do periodo de outubro de 1999 a fevereiro de 2011. Com os valores medios mensais de Kp de sete metodos, obtidos dos anos impares do periodo de estudo estimou-se os valores de evapotranspiracao de referencia pelo metodo do Tanque Classe “A” (ETo (TCA) ) e evapotranspiracao da cultura do girassol pelo metodo do Tanque Classe “A” (ETc (TCA) ), para os anos pares do mesmo periodo. Em sequencia, os valores de ETc (TCA) foram estimados para diferentes ciclos da cultura ao longo do ano e avaliados por meio do teste de Tukey, ao nivel de 5% de probabilidade, e atraves de indices estatisticos, sempre considerando a evapotranspiracao da cultura pelo metodo de Penman-Monteith FAO 56 (ETc PM ), como referencia. Os resultados mostraram que todos os valores de ETo (TCA) , superestimaram a ETo PM , tendo destaque ETo (TCA) Kp Snyder por apresentar a maior diferenca. Para a simulacoes dos valores de ETc (TCA) nos diferentes ciclos, os piores desempenhos foram para as ETc (TCA) Kp FAOB eETc (TCA) Kp Snyder , e os melhores foram expressos pelas ETc (TCA) Kp ref e ETc (TCA) Kp Pereira . As ETc (TCA) Kp Snyder eETc (TCA) Kp FAOB ,tambem, se comportaram de forma insatisfatoria quando foram submetidas aos indices estatisticos, superestimando as lâminas de irrigacao. Ja os resultados das ETc (TCA) Kp ref e ETc (TCA) Kp Pereira tiveram os melhores desempenhos, assim recomenda-se o uso dos valores dos Kp ref e Kp Pereira .

Impacts of climate change on water demand and duration forage sorghum and cowpea cycle in the state of Pernambuco

The increase in the occurrence of extreme weather events in recent decades is a strong evidence of climate change. In semiarid regions, where the pressure of desertification has intensified, are expected to decrease in the availability of water and higher occurrence of drought periods, and, consequently, effects on physiological response of plants. Thus, the objective of analyzing the impacts of climate change scenarios on the duration of phenological cycle and water demand of forage sorghum and cowpea, grown in the State of Pernambuco. Monthly values were used normal climatological solar brightness, air temperature, relative humidity and wind speed of ten municipalities. It was considered an increase of 1.8° C (B2 Scenario) and 4.0° C (A1F1 Scenario) on air temperature and a decrease of 5.0% of the absolute values of relative humidity, in addition to the 22% increase in stomatal resistance and 4% in leaf area index. Based on this information were generated three scenarios: current situation and future projections for B2, A1F1. Revista Brasileira de Geografia Física vol. 08, número especial (IV SMUD), (2015) 542-559.

Gross water demand of forage cactus on future scenarios of climate change in the State of Pernambuco

Objective to evaluate the water demand for irrigation of forage cactos in future scenarios B2 and A2 of air temperature, rainfall and carbon dioxide levels (CO2) in State of Pernambuco. 292 observation posts of Pernambuco and surrounding States with observed and estimated data were used. Increased projections were considered and reduction of 10 and 20% of the rainfall about local normal climatological, associated with two climate change scenarios (B2 and A2) of the meteorological variables (maximum and minimum air temperature), influencing the duration of the crop cycle and atmospheric demand. In addition, it was assumed the effect of concentration of CO2 in the atmosphere, affecting in stomatal resistance 22% and 4% on leaf area index of the reference surface (grass), and their effects were extrapolated to the forage cactus, through the crop coefficient. The increase of air temperature in the light of the future scenarios of Revista Brasileira de Geografia Física vol. 08, n.06 (2015) 1628-1643.

Evaluation of the method of FAO data 56 Monteith Penman with missing data and of alternative methods in the estimation of reference evapotranspiration in the Submedium Valley of San Francisco

Objective to evaluate the performance of the Penman Monteith method parameterized on the 56 FAO Bulletin (PMFAO56) with the absence of data and of alternative methods for the estimation of reference evapotranspiration in the Submedium Valley of San Francisco. Weather variables for the period March 2003 to April 2008 were used of five automatic stations belonging to the network of Embrapa semi-arid. In the evaluation of this method were considered to be different combinations as the lack of measurement of meteorological variables (radiation balance, global solar radiation, temperature and relative humidity, and wind speed), and alternative methods of Hargreaves and Samani, Jensen and Haise and Makkink. The performance was analyzed by means of indices and statistical errors. The results revealed that the PM-FAO56 has good estimates of ETo values when the absence of data is limited to the variables of relative humidity, for the estimation of the water vapor partial pressure, and, or, the wind speed, as soon as the square root of the square of the average error was less than 0.65 mm day, when there is no data of these two variables at the same time. The estimation of the radiation balance values despite the good precision and accuracy in most weather stations (r > 0.93 and angular coefficient < 1.19) raises the miscalculation of ETo in the region. Alternative methods of Revista Brasileira de Geografia Física vol. 8, n.6 (2015) 1644-1660.