The genotype main effects plus the genotype × environment interaction effects model has been widely used to analyze multi-environmental trials data, especially using a graphical biplot considering ...the first two principal components of the singular value decomposition of the interaction matrix. Many authors have noted the advantages of applying Bayesian inference in these classes of models to replace the frequentist approach. This results in parsimonious models, and eliminates parameters that would be present in a traditional analysis of bilinear components (frequentist form). This work aims to extend shrinkage methods to estimators of those parameters that composes the multiplicative part of the model, using the maximum entropy principle for prior justification. A Bayesian version (non-shrinkage prior, using conjugacy and large variance) was also used for comparison. The simulated data set had 20 genotypes evaluated across seven environments, in a complete randomized block design with three replications. Cross-validation procedures were conducted to assess the predictive ability of the model and information criteria were used for model selection. A better predictive capacity was found for the model with a shrinkage effect, especially for unorthogonal scenarios in which more genotypes were removed at random. In these cases, however, the best fitted models, as measured by information criteria, were the conjugate flat prior. In addition, the flexibility of the Bayesian method was found, in general, to attribute inference to the parameters of the models which related to the biplot representation. Maximum entropy prior was the more parsimonious, and estimates singular values with a greater contribution to the sum of squares of the genotype + genotype × environmental interaction. Hence, this method enabled the best discrimination of parameters responsible for the existing patterns and the best discarding of the noise than the model assuming non-informative priors for multiplicative parameters.
Land use capability at recharge zones Calegario, Arthur Telles; Pereira, Luis Flávio; Oliveira da Silva, Laksme Narayana ...
Soil use and management,
July 2021, 2021-07-00, 20210701, Letnik:
37, Številka:
3
Journal Article
Recenzirano
Summary
Land use capability systems do not present any considerations regarding recharge zones (RZs). To improve conservation planning, the objective of this study was to present a parametrization ...method for the land use capability of recharge zones (LUC‐RZ). RZs were characterized as the upper thirds of the elevations of all slopes with rectilinear, concave and/or convex features in the terrains. The LUC‐RZ were parameterized based on the slope of the middle third of the elevations. The proposed methodology was applied to the Doce River basin (DRB) in Brazil, and 27.9% of the total area was characterized as RZs. It was found that 61.9% of the RZs area could be exploited through agricultural and livestock use; however, the usability of most of these areas was conditional on the adoption of rigorous soil and water conservation techniques. The remaining 38.1%, which was equivalent to 10.6% of the DRB, was restricted to native forest cover. Of the 61.9% of RZs area that could be used for agriculture and livestock, 18.2% was occupied by native vegetation. These areas are protected by law and are responsible for several ecosystem services and thus must be preserved. The parameterization of the LUC‐RZ was sensitive to pedogeomorphological characteristics. The methodology used for the determination of the recharge zones has a strong theoretical basis and was simple to implement and therefore has great potential for use in multicriteria analyses for determining recharge zones.
Resumo Este estudo teve como objetivo mapear chuvas intensas com durações de 10, 30, 720 e 1440 minutos, associadas aos tempos de retorno de 10, 50 e 100 anos, para o Estado do Tocantins. Foram ...aplicadas séries históricas de 95 postos pluviométricos localizados no Estado do Tocantins e proximidades, com período padronizado de 1983 a 2013. Foi conduzido um estudo geoestatístico, avaliando-se os modelos de semivariograma esférico, exponencial e gaussiano, ajustados pelo método dos mínimos quadrados ponderados. A partir deste estudo, o modelo que apresentou o menor erro médio com base na validação cruzada foi aplicado ao processo de mapeamento por krigagem ordinária. Houve bom desempenho das técnicas geoestatísticas, podendo-se destacar o modelo esférico para o mapeamento da precipitação máxima diária anual, e o modelo gaussiano para as chuvas calculadas pela metodologia de desagregação. Verificou-se ainda que as áreas de ocorrência das chuvas intensas de maior severidade no estado estão no Bico do Papagaio (norte), Ilha do Bananal (sudoeste) e noroeste do estado.
Abstract This study aimed to map heavy rainfall with durations of 10, 30, 720 and 1440 minutes, associated with return times of 10, 50 and 100 years for the Tocantins State. Historical series of 95 pluviometric stations located in the Tocantins State and nearby were applied, with standard period from 1983 to 2013. A geostatistical study was conducted, evaluating the spherical, exponential and gaussian semivariogram models, adjusted by the weighted least squares method. From this study, the model that presented the smallest average error based on cross-validation was applied to the mapping process by ordinary kriging. There was good performance of the geostatistical techniques, being possible to highlight the spherical model for the mapping of the annual maximum daily precipitation and the Gaussian model for the rains calculated by the methodology of disaggregation. It was also verified that the areas of intense rainfall of greater severity in the state are in the Bico do Papagaio (north), Bananal Island (southwest) and northwest of the state.
Hydroelectricity is responsible for the greatest fraction of the electric energy generated in Brazil. The water footprint of hydropower plants (WFP) is an important indicator of the sustainable and ...efficient use of water resources. In this context, WFP of the Sobradinho Hydropower Plant was determined for the period from 2003 to 2012, taking into account the reservoir’s historical variation for the flooded area. To accomplish this, monthly series of electric energy production, flooded area, evaporation and evapotranspiration rates were used. Average gross and net evaporation were 2,031 and 1,577 mm year-1, respectively. The average power generation of this facility in the analyzed period was 462 MW, and the flooded area of its reservoir presented an average value of 3,054 km². Based on the monthly data, the gross and net water footprints were, respectively, 417 and 325 m³ GJ-1. Based on these results, it can be concluded that the changes in the reservoir’s area exert direct and important influence on the WFP estimates of the Sobradinho hydropower plant. The WFP estimates in this study were different from other studies that adopted a constant value of 4,214 km² for this reservoir’s area, which is taken based on the normal water level of the plant operation.
Irrigation has a great importance in the production of food, and it is responsible for consuming a large part of the water used by human activities. This makes the rational management of water use ...fundamental for sustainable food production. For this purpose, the determination of bulk density is important and needs to be obtained with the simplest, least onerous methods possible, while maintaining precision and accuracy. Therefore, the objective of this work was to evaluate the use of PVC pipes of different dimensions to determine bulk density. For comparison purposes, the volumetric ring, paraffin clod, beaker and excavation methods were also used. Deformed and undisturbed soil samples of different granulometries were collected at the depths of 0.025-0.075, 0.050-0.100, 0.075-0.125 and 0.100-0.150 m. The PVC pipes had diameters of 0.040, 0.050, 0.060 and 0.075 m and heights of 0.10, 0.15, 0.20 and 0.25 m. The bulk density results for each PVC pipe dimension were compared with those of the traditional methods by the unpaired t-test at 5% significance. For soils with a clayey or very clayey texture, the 0.040 m diameter and 0.15 m high PVC pipe presented the best results, with values closer to those of the standard method. For soils with a medium and sandy texture, the best results were found when a PVC pipe with a diameter of 0.060 m and a height of 0.15 m was used.
The present work was performed by applying the principal component analysis, in order to compare the water needs of banana, mango, grape, sugarcane, maize and beans crops in different regions of the ...São Francisco river basin, aiming to identify the climate elements that most influence the reference evapotranspiration (ET0) in the locations of Pirapora-MG, Jaíba-MG, Barreiras-BA and Petrolina-PE. In addition, the locations with more similarities, according to the evaluated parameters, were verified by applying cluster analysis, and the equivalence relations between the studied crops were determined by integrating the parameters related to the climatic elements and the characteristics of crops and soils. Based on the principal components analysis, it was observed that the most significant climate elements for ET0 estimation were different for each place. The model with two components explained 90%, 88%, 95% and 97% of the total variance, respectively for the locations of Pirapora, Jaíba, Barreiras and Petrolina. Because it is in a semi-arid climate region, Petrolina showed high crop water needs, a behavior proven with the cluster analysis. The equivalence relations allowed comparing the water needs for the studied crops, providing, in general terms, a parameter comparison between the crops, and specifying which one will be more adequate depending on the water availability in the São Francisco basin.
In order to design effective Brazilian hydraulic structures, it is necessary to obtain data relating to short-duration intense rainfall from historical series of daily rainfall. This recurring need ...can be fulfilled by rainfall disaggregation methodology. The objective of this study was to determine the intense rainfall disaggregation constants for the State of Tocantins and to compare these constants with those obtained for other regions of Brazil. For the modeling of the frequency of intense rainfall of different durations of less than 24 hours, the Gumbel probability distribution (GPD) was employed using rainfall series from 10 locations in Tocantins state. The results showed that the GPD was adequate by the Kolmogorov-Smirnov and Chi-square tests. The disaggregation constants presented low variability values for different return periods (from 10 to 100 years); the values for Tocantins state are: h12h/h24h=0.93, h6h/h24h=0.86, h4h/h24h=0.82, h3h/h24h=0.78, h2h/h24h=0.72, h1h/h24h=0.61, h50min/h1h=0.92, h40min/h1h=0.83, h30min/h1h=0.68, h20min/h30min=0.76 e h10min/h30min=0.46. The comparison of the results with those from studies developed for other Brazilian regions showed variations of up to -62.30%, allowing us to conclude that the use of local constants is important in the process of rainfall disaggregation.
The dissection of genotype × environment interaction (GEI) is a crucial aspect of the final stages of plant breeding pipelines and recommendation of cultivars. Linear‐bilinear models used to analyze ...this interaction, such as the additive main effects and multiplicative interaction (AMMI) and genotype plus GEI (GGE), often assume homogeneity of the residual variances across environments which affects the estimates and therefore, interpretations and conclusions. Our main objective was to propose a GGE model that considers heteroscedasticity across environments using Bayesian inference and to evaluate its implications in the interpretation of real and simulated data. The GGE model assuming common variance was also fitted for comparison purposes. The great flexibility of the Bayesian inference is transferred to the biplots, allowing the construction of credible regions for genotypic and environmental scores. The inference on the stability and adaptability of genotypes might change when heteroscedasticity is ignored. When real data are used, different patterns of correlations between environments also affect the representativeness and discrimination of the target environment. The modeling of heteroscedasticity allowed the clustering of environments into subgroups, with similar effects for GEI. The proposed GGE model was more adequate and realistic to deal with scenarios of heterogeneous variance in multienvironment trials, which can be useful for exploiting the GEI.
Core Ideas
The GGE model is useful for studying genotype responses across environments.
Heterogeneity of residual variances across environments occurs routinely in MET trials.
To assume homogeneity of the residual variances across environments affects the interpretations.
Bayesian modeling offers wide flexibility to model complex variance‐covariance structures.
The Bayesian GGE model brings promising perspectives for MET data analysis.
PDF
