35 documents found, page 1 of 4
NUGGET EFFECT INFLUENCE ON SPATIAL VARIABILITY OF AGRICULTURAL DATA
Guedes,Luciana P. C.; Bach,Raquel T.; Uribe-Opazo,Miguel A.ABSTRACT Spatial variability description of soil chemical properties by thematic maps depends substantially on suitable geostatistical models. One of the parameters composing a geostatistical model is nugget effect. This study aimed to evaluate the simultaneous influence of nugget effect and sampling design on geostatistical model estimation and estimation of soil chemical properties at unsampled sites, conside...
GRAIN STORAGE SYSTEM IN THE STATE OF PARANÁ, BRAZIL, FROM THE PERSPECTIVE OF MU...
Cima,Elizabeth G.; Uribe-Opazo,Miguel A.; Guedes,Luciana P. C.; Rocha Junior,Weimar F. da; Johann,Jerry A.ABSTRACT This study aimed to identify whether there is an association between types of storage and categories of commercialization and use of grains, group the types of storage with the categories of commercialization, and group static and dynamic capacities of the units in the state of Paraná, Brazil. The data were obtained from the Brazilian Registry System of Storage Units for the 2014/2015 season. The assoc...
GEOSTATISTICAL MODELING OF SOYBEAN YIELD AND SOIL CHEMICAL ATTRIBUTES USING SPA...
Dalposso,Gustavo H.; Uribe-Opazo,Miguel A.; Johann,Jerry A.; Bastiani,Fernanda De; Galea,ManuelABSTRACT The goal of this study was to use the spatial bootstrap method to model the spatial dependence structure of soybean yield and soil chemical attributes in an agricultural area. The study involved developing confidence intervals in probability plots to determine the probability distributions assumed by the data; determine the empirical distributions of the semivariances and model parameters, allowing to ...
REDUCTION OF SAMPLE SIZE IN THE ANALYSIS OF SPATIAL VARIABILITY OF NONSTATIONAR...
Maltauro,Tamara C.; Guedes,Luciana P. C.; Uribe-Opazo,Miguel A.ABSTRACT In the study of spatial variability of soil attributes, it is essential to define a sampling plan with adequate sample size. This study aimed to evaluate, through simulated data, the influence of parameters of the geostatistical model and sampling configuration on the optimization process, and resize and reduce the sample size of a sampling configuration of a commercial area composed of 102 points. For...
GAUSSIAN SPATIAL LINEAR MODEL OF SOYBEAN YIELD USING BOOTSTRAP METHODS
Dalposso,Gustavo H.; Uribe-Opazo,Miguel A.; Johann,Jerry A.; Galea,Manuel; Bastiani,Fernanda DeABSTRACT This study aims to quantify the uncertainties associated to the parameters of a Gaussian spatial linear model (GSLM) and the assumption of normality residuals in the modeling of the spatial dependence of the soybean yield as a function of soil chemical attributes. The spatial bootstrap methods were used to determine the point and interval estimators associated with the model parameters. Hypothesis test...
SPATIAL VARIABILITY OF THE WATER DEPTH APPLIED BY FIXED SPRINKLER IRRIGATION SY...
Tamagi,Jorge T.; Uribe-Opazo,Miguel A.; Vilas Boas,Marcio A.; Johann,Jerry A.; Guedes,Luciana P. C.Abstract The uniformity of water application is an important factor in the evaluation of sprinkler irrigation systems. This uniformity depends on the type of sprinkler and its operating conditions, such as the arrangement and spacing between the sprinklers in the area; velocity and wind direction during the period of water application and the pressure variation of the irrigation system. The objective of this st...
RELATIONSHIP BETWEEN SAMPLE DESIGN AND GEOMETRIC ANISOTROPY IN THE PREPARATION ...
Guedes,Luciana P. C.; Uribe-Opazo,Miguel A.; Ribeiro Junior,Paulo J.; Dalposso,Gustavo H.ABSTRACT Spatial variability depends on the sampling configuration and characteristics associated with the georeferenced phenomenon, such as geometric anisotropy. This study aimed to determine the influence of the sampling design on parameter estimation in an anisotropic geostatistical model and the spatial estimation of a georeferenced variable at unsampled locations. Datasets were simulated with geometric ani...
ANALYSIS OF SPATIAL AUTOCORRELATION OF GRAIN PRODUCTION AND AGRICULTURAL STORAG...
Cima,Elizabeth G.; Uribe-Opazo,Miguel A.; Johann,Jerry A.; Rocha Jr.,Weimar F. da; Dalposso,Gustavo H.ABSTRACT This work aimed to study the spatial autocorrelation of the total static capacity storage, the total number of warehouses in 2013/2014 (CONAB) and the average of the total grain production (soybean, corn 1st and 2nd crops and wheat) in the harvest years 2008/2009 to 2013/2014 (SEAB) in Paraná State, Brazil. The study was based on Moran's global autocorrelation index, Moran's local and Moran's bivariate...
SPATIAL CORRELATION OF SOYBEAN PRODUCTIVITY, ENHANCED VEGETATION INDEX (EVI) AN...
Grzegozewski,Denise M.; Uribe-Opazo,Miguel A.; Johann,Jerry A.; Guedes,Luciana P. C.ABSTRACT The survey information from growing regions, the interaction with the vegetation index and climatic variables is of great importance in the search for soybean productivity increase. Paraná is the second largest soybean producer in Brazil and presents great spatial variability, both in periods of the crop cycle as in soil and climate. The objective of this study was to analyze the spatial correlation of...
SPATIAL VARIABILITY OF SOYBEAN YIELD THROUGH A REPARAMETERIZED T-STUDENT MODEL
Schemmer,Rosangela C.; Uribe-Opazo,Miguel A.; Galea,Manuel; Assumpção,Rosangela A. B.ABSTRACT: The t-Student distribution has been used to the spatial dependence modelling of soybean yield as an alternative to the normal distribution, being used for data with heavier tails or discrepant values. However, a usual Student t-distribution does not allow direct comparisons of geostatistical methods with a normal distribution. The aim of this study was to assess the soybean yield spatial variability t...