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Search Results: 1 - 10 of 28620 matches for " Jaime Ricardo Tavares;Matzenauer "
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Estimativa do consumo relativo de água para a cultura da soja no Estado do Rio Grande do Sul
Matzenauer, Ronaldo;Barni, Nídio Antonio;Maluf, Jaime Ricardo Tavares;
Ciência Rural , 2003, DOI: 10.1590/S0103-84782003000600004
Abstract: the objective of this work was to estimate the relative water consumption (etr/etm) for the critical period of soybean in several sowing dates for ten places of rio grande do sul state, brazil. the maximum evapotranspiration (etm) was estimated using the crop coefficient (kc) while the real evapotranspiration (etr) was estimated through the water balance, calculated for the period from 1975/76 to 2000/2001. considering the average values of the periods, the relative water consumption varied from 0.46 in the sowing of october, in rio grande, to 0.74 in the sowing of december in veranópolis. s?o gabriel and rio grande are the places that present the smallest values of relative water consumption, therefore with larger risk for the production of grains. in years of strong drought, the relative water consumption, in some situations, was smaller than 0.20, evidencing the problem of water deficiency. in 46.3% of the cases the relative water consumption was classified as of high or medium risk (index etr/etm < 0.60 during the critical period). rio grande presented 63.3% of the cases with index equal to or smaller than 0.60, followed by s?o gabriel with 61.1%, encruzilhada do sul with 52.6% and júlio de castilhos with 50.8%. the places of smaller risk were passo fundo, veranópolis and santa rosa, with indexes equal to or smaller than 0.60 happening in 30.3%, 37.5% and 38% of the cases, respectively. the sowing date with higher risk was october and with lower risk was december. for the group of the places, it can be expected that every twenty years, in about nine reduction of soybean yield should happen due to water deficiency, with variable intensity, depending on the place, year and sowing date.
Variabilidade temporal e espacial do tamanho de amostra da temperatura mínima do ar no Rio Grande do Sul, Brasil
Cargnelutti Filho, Alberto;Matzenauer, Ronaldo;Maluf, Jaime Ricardo Tavares;
Ciência Rural , 2006, DOI: 10.1590/S0103-84782006000400018
Abstract: the aim of this work was to verify temporal and spatial variability of the size sample of the monthly average of air minimum temperature, in 37 localities of the rio grande do sul state, brazil. the minimum temperature data were collected from 1931 to 2000. it was calculated the sample size, in each month and locality. localities and months were clustered by the complete linkage method. there are variability temporal and spatial of the size sample (number of years) of the monthly average of air minimum temperature in the rio grande do sul state. greater sample size occur in the months of may, june and july, with gradual reduction up to january and december. there are variability in the size sample among locaties in the rio grande do sul state.
Coordenadas geográficas na estimativa das temperaturas máxima e média decendiais do ar no Estado do Rio Grande do Sul
Cargnelutti Filho, Alberto;Maluf, Jaime Ricardo Tavares;Matzenauer, Ronaldo;
Ciência Rural , 2008, DOI: 10.1590/S0103-84782008005000005
Abstract: the objective of this research was to estimate ten-day maximum (tx) and mean (tm) air temperature using altitude and the geographic coordinates latitude and longitude for the rio grande do sul state, brazil. normal ten-day maximum and mean air temperature of 41 counties in the state of rio grande do sul, from 1945 to 1974 were used. correlation analysis and parameters estimate of multiple linear regression equations were performed using tx and tm as dependent variable and altitude, latitude and longitude as independent variables, for the 36 ten-day periods of the year. pearson's linear correlation coefficient between estimated and observed tx and tm, calculated for tem counties using data of were used as independent data sets. the ten-day maximum and mean air temperature may be estimated from the altitude and the geographic coordinates latitude and longitude in the state of rio grande do sul.
Variabilidade temporal e espacial do tamanho de amostra da temperatura mínima do ar no Rio Grande do Sul, Brasil
Cargnelutti Filho Alberto,Matzenauer Ronaldo,Maluf Jaime Ricardo Tavares
Ciência Rural , 2006,
Abstract: Com o objetivo de verificar a existência de variabilidade temporal e espacial do tamanho de amostra da temperatura mínima do ar média mensal de trinta e sete municípios do Rio Grande do Sul, utilizaram-se os dados de temperatura mínima do ar do período de 1931 a 2000. Determinou-se o tamanho de amostra da temperatura mínima do ar média mensal em cada mês e município. Realizou-se análise de agrupamento dos meses e dos municípios pelo método hierárquico "vizinho mais distante". Há variabilidade do tamanho de amostra (número de anos) para a estimativa da temperatura mínima do ar média mensal no Estado do Rio Grande do Sul no tempo e no espa o. Maior tamanho de amostra, no Estado do Rio Grande do Sul, é necessário nos meses de maio, junho e julho, com diminui o gradativa em dire o a janeiro e dezembro. Há variabilidade do tamanho de amostra entre os municípios do Estado do Rio Grande do Sul.
Estimativa do consumo relativo de água para a cultura da soja no Estado do Rio Grande do Sul
Matzenauer Ronaldo,Barni Nídio Antonio,Maluf Jaime Ricardo Tavares
Ciência Rural , 2003,
Abstract: Estimou-se o consumo relativo de água (raz o ETr/ETm) para o período crítico da cultura da soja em três épocas de semeadura, para dez localidades do Estado do Rio Grande do Sul. A evapotranspira o máxima (ETm) foi estimada utilizando-se o coeficiente de cultura (Kc) e a evapotranspira o real (ETr), calculada pelo balan o hídrico decendial, para o período de 1975/76 a 2000/2001. Considerando-se os valores médios dos períodos, o consumo relativo de água variou de 0,46 na época de semeadura de outubro, em Rio Grande, a 0,74 na semeadura de dezembro em Veranópolis. S o Gabriel e Rio Grande foram os locais que apresentaram os menores valores de consumo relativo de água, portanto, com maior risco para a produ o de gr os. Em anos de forte estiagem, o consumo relativo de água, em algumas situa es, foi menor do que 0,20, evidenciando o problema da deficiência hídrica no Estado. Em 46,3% dos casos analisados, o consumo relativo de água classifica-se como de médio ou alto risco para a cultura da soja (índice ETr/ETm < 0,60 durante o período crítico). A localidade de Rio Grande apresentou 63,3% dos casos com índice igual ou menor a 0,60, seguido-se S o Gabriel com 61,1 %, Encruzilhada do Sul com 52,6% e Júlio de Castilhos com 50,8% dos casos. Os locais de menor risco foram Passo Fundo, Veranópolis e Santa Rosa com índices iguais ou menores do que 0,60 ocorrendo em 30,3%, 37,5% e 38% dos casos, respectivamente. A época de semeadura de maior risco por deficiência hídrica para a soja foi a de outubro, enquanto a semeadura de dezembro foi a de menor risco. Para o conjunto dos locais analisados, pode-se esperar redu o de rendimento de gr os de soja por deficiência hídrica, em cerca de nove safras a cada vinte, com intensidade variável, dependendo do local, do ano e da época de semeadura.
Variabilidade temporal e espacial da precis?o das estimativas de elementos meteorológicos no Rio Grande do Sul
Cargnelutti Filho, Alberto;Matzenauer, Ronaldo;Maluf, Jaime Ricardo Tavares;Radin, Bernadete;
Ciência Rural , 2009, DOI: 10.1590/S0103-84782009005000051
Abstract: planning agricultural activities requires that climatic risks in each location and time of year are estimated with maximum precision. in this estudy data from15 locations of rio grande do sul, brazil, were used with the objective of studing spatial and temporal variability of the precision estimates average of monthly rainfall, sunshine, solar radiation global and temperatures minimum, mean and maximum. it was estimated the estimation error (half-amplitude of the confidence interval) (ee) in percentage of estimate average monthly rainfall, sunshine, solar radiation global and temperatures minimum, mean and maximum for each month and location, which was used as a measure of precision. from the ee, for each meteorological elements, months and locations were clustered by hierarchical method of ward. the pearson's linear correlation coefficient between the arrays of the standardized average euclidian distance and graphics was calculated in order to check the clusters consistency. it was concluded that the precision estimates, average of months and locations, between the meteorological elements, increases in the following order: rainfall (ee=21.66%), sunshine (ee=6.74%), global solar radiation (ee=5.52%) and temperatures minimum (ee=4.40%), mean (ee=2.63%) and maximum (ee=2.27%). results showed that there is variability in precision estimate of monthly average rainfall, sunshine, global solar radiation and minimum, mean and maximum temperatures in rio grande do sul, both in temporal and spatial scale. estimates based on 30 years data are less precision in april, may, june, july, august and september in relation to the others.
Dimensionamento da amostra para a estima??o da média de precipita??o pluvial mensal em diferentes locais do Estado do Rio Grande do Sul
Cargnelutti Filho, Alberto;Matzenauer, Ronaldo;Radin, Bernadete;Maluf, Jaime Ricardo Tavares;Hauser, Lisiane;
Ciência Rural , 2010, DOI: 10.1590/S0103-84782009005000226
Abstract: it was used data from 19 locations of the rio grande do sul state, brazil, collected from 1953 to 2007, with the objective to determine the sample size to estimate the average monthly rainfall. the central tendency, variability and asymmetry was calculated for each of the 228 time series (12 months x 19 locations) and the aleatory and normality data were tested. then it was verified the homogeneity of variance among months in each locality and among places in each month and it was determined the sample size to estimate the average monthly rainfall in each month and locality. the sample size (number of years) to estimate the average monthly rainfall is dependent on the month and locality. one concluded that 51 years of data are enough to predict the average monthly rainfall, with an estimation error equal to 25% of estimated average, with a degree confidence of 95%.
Número de anos para a estima??o da média decendial de dura??o diária do brilho solar no Rio Grande do Sul
Cargnelutti Filho, Alberto;Matzenauer, Ronaldo;Radin, Bernadete;Maluf, Jaime Ricardo Tavares;
Ciência Rural , 2012, DOI: 10.1590/S0103-84782012000300004
Abstract: the objective of this research was to determine the sample size (number of years) to estimate the ten-day average of daily sunshine duration in 30 locations of the rio grande do sul state, brazil. with sunshine data duration of the period from 1960 to 2007, 1,080 time series (30 locations x 36 ten-days) of ten-day of daily sunshine duration average were formed. the aleatory and normality, in each time series, was verified through the run test and lilliefors test, respectively. for each ten-day and locality, it was determined the sample size using bootstrap resampling with replacement of 3,000 samples. twenty-five years of data are enough to predict the ten-day average of daily sunshine duration, with amplitude of bootstrap confidence interval of 95%, equal to 2.00 hour day-1.
Tamanho de amostra para a estima??o da média mensal de insola??o diária em diferentes locais do estado do Rio Grande do Sul
Cargnelutti Filho, Alberto;Matzenauer, Ronaldo;Radin, Bernadete;Maluf, Jaime Ricardo Tavares;
Ciência Rural , 2010, DOI: 10.1590/S0103-84782010005000112
Abstract: it was used data from 30 locations of the rio grande do sul state, brazil, collected from 1960 to 2007, with the objective to determine the sample size (number of years) to estimate the average daily month insolation . the average and variance was calculated for each of the 360 time series (12 months x 30 locations) and the aleatory and normality data were tested. then it was verified the homogeneity of variance among months in each locality and among places in each month and it was determined the sample size to estimate the average monthly insolation daily in each month and locality. the sample size (number of years) to estimate the average monthly insolation daily is dependent on the month and locality. one concluded that 44 years of data are enough to predict the average monthly insolation daily, with an estimation error equal to ±0.5 hours days-1, with a degree confidence of 95%.
Modelo harm?nico para a estimativa da temperatura do ar média mensal em diferentes locais do Estado do Rio Grande do Sul
Cargnelutti Filho, Alberto;Matzenauer, Ronaldo;Maluf, Jaime Ricardo Tavares;Radin, Bernadete;
Ciência Rural , 2010, DOI: 10.1590/S0103-84782010005000143
Abstract: the objective of this research was to adjust the harmonic model for the estimation of average monthly air temperature, in 37 locations of rio grande do sul state, brazil, with data from the period 1931 to 2000. in each locality, data from 1931 to 1990 (60 years) was used to estimate the coefficients of the harmonic model and from 1991 to 2000 (10 years) to validate the model. it was tested the normality and homogeneity of variance among months, estimated trends and incorporated into the models harmonic based in waves annual and semiannual. the coefficients linear, angular, correlation and determination, the root mean square error and the index of willmott (1981) and camargo & sentelhas (1997) were used to validate the models. the coefficient of determination (r2) of the harmonic model, was high in all sites (r2≥0.9867), giving reliability for future forecasts. the harmonic model generated for each of the 37 location in the the rio grande do sul state, brazil, is adequate to estimate the average monthly air temperature.
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