Abordagem quantitativa na avaliacao do deposito de carvao de cerquilho - SP

This paper deals with an integrated study concerning the evaluation of the coal deposit at Cerquilho (Sao Paulo State) in the upper part of the Tubarao Group. Palaeogeographical studies from other authors describe the genesis of these deposits as a deltaic system overlapped by a marine transgressive sequence. The study applied four methods for ore reserve estimation (isolines, blocks, polygones and triangles), besides statistical and geostatistical methodology. The technological characterization assays suggest the application for the coal in cement and ceramics industries. The applied methodology showed reserves estimated around 1 400 000 ton. The isolines method tend to underestimate the amount of coal, on the other hand, the kriging method shows a tendency to overestimate the results. The data from the polygonal method are closest to mean values. For the thickness estimation the results close to the mean values are those from the isolines. -after English summary

Modeling and identification of fertility maps using artificial neural networks

The application of agricultural fertilizers using variable rates along the field can be made through fertility maps previously elaborated or through real-time sensors. In most of the cases applies maps previously elaborated. These maps are identified from analyzes done in soil samples collected regularly (a sample for each field cell) or irregularly along the field. At the moment, mathematical interpolation methods such as nearest neighbor, local average, weighted inverse distance, contouring and kriging are used for predicting the variables involved with elaboration of fertility maps. However, some of these methods present deficiencies that can generate different fertility maps for a same data set. Moreover, such methods can generate inprecise maps to be used in precision farming. In this paper, artificial neural networks have been applied for elaboration and identification of precise fertility maps which can reduce the production costs and environmental impacts.

Variabilidade espacial da estabilidade de agregados e matéria orgânica em solos de relevos diferentes

Soils submitted to the same management system in places with small relief variation manifest different spatial variability on their attributes. The objective of this work was to evaluate the spatial variability of the geometric medium diameter, aggregates in the >2 mm class, aggregates in the 2-1 mm class and organic matter of an Oxisol under culture of the sugarcane. Samplings of the soil in regular intervals of 10 m, in grid form, totaling 100 points, collected in the depths of 0.0-0.2 m and 0.2-0.4 m were made. Data were submitted to descriptive statistics, geostatistics and in sequence to kriging analyzes. Values of the variation coefficient were low for organic matter in the depth of 0.0-0.2 m, mean in the depth of 0.2-0.4 m, high for geometric medium diameter and mean for aggregates in the >2 mm class, aggregates in the 2-1 mm class in all studied depths. The occurrence of space dependence was observed for all the variables, and the largest ones were observed in the depth of 0.0-0.2 m. Small variations in the forms of the relief condition spatial variability differentiated for organic matter and stability of aggregates in the studied depths.

Diagnóstico de uma área compactada por atividade minerária, na floresta amazônica, empregando métodos geoestatísticos à variável resistência mecânica à penetração do solo

A quite common problem in the recovery of degraded areas in the mineral exploration understands the compaction of the soil due to the intense traffic of machines and earth movement. The most common problem of the compaction of a degraded surface is: increase of the mechanical resistance to the penetration of the rooats, reduction of the aeration, alteration of the water flow and heat. Thus the present work had the basic objective of diagnosing the compaction of a degraded area by mining in a space way, through the mechanical resistance the way penetration to guide a future subsoiling in the place seeking recovery. Through the studies it was concluded that the kriging method in agreement with the space variation allows the division of the area studies in sub areas facilitating a future work to reduce cost and unnecessary interference to the atmosphere. The method was shown quite appropriate and it can be used in diagnosis of the compaction in a degraded area by mining, foreseeing subsoiling need.

Aplicação da Geoestatística Não-paramétrica para a compartimentação geomecânica de uma extensão típica do túnel do metrô - Linha 4, da cidade de São Paulo

In view of the limited number of drill holes, interpolation of the data becomes a relatively complex task. In this study, we sought to make estimates associated with lithological types, since a quantification based on lithology can be extracted from the empty spaces in the sampling. For example, QBarton is always below the median of the biotitic litotype, information which can be used in the elaboration of geostatistical models in situations where samples are lacking. To overcome bias in the data, required by geostatistical conceptualization, we worked with the residuals obtained from the adjustment of a surface and the observed values, for the variographic analysis. The final results made possible a more optimized evaluation of the final costs required for the construction project.

Variabilidade espacial de perdas de solo, do potencial natural e risco de erosão em áreas intensamente cultivadas

The objective of this work was to identify the spatial variability of the natural erosion potential, soil loss and erosion risk in two intensely cultivated areas, in order to assess the erosion occurrence patterns. The soil of the area located at Monte Alto, São Paulo state, was classified as Paleudalf (PVA) with moderately slope, with different managements. The soil of the area located at Jaboticabal, São Paulo state, was classified as Haplortox(LV) with gentle slope and cultivated with sugarcane. A irregular grid was imposed on the experimental areas. Soil samples were obtained from 0-0.2 m depth at each grid point: 88 samples in Monte Alto area (1465 ha) and 128 samples at Jaboticabal area (2597 ha). In order to obtain the values of the studied variables USLE was applied at each grid point. Descriptive statistics were calculated, and geoestatistical analyses were performed for defining semivariograms. Kriging techniques to develop map showing spatial patterns in variability of selected soil attributes were used. All variables showed spatial dependence. The PVA soil showed higher erosion risk due to the slope and atual management compared to the soil LV.

Mapeamento da produtividade e perímetro do tronco de clones de seringueira em argissolo vermelho amarelo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Planejamento agrícola e implantação de sistema de cultivo de cana-de-açúcar com auxílio de técnicas geoestatísticas

Sugarcane is one of the most important crops of the Brazilian agribusiness and this importance justifies the use of techniques that allow the implementation of cultivation systems capable of reducing the variability of soil characteristics and the establishment of efficient agricultural planning. The aim of the present work was the planning and implementation of cultivation systems for sugarcane using geostatistical techniques, in the Pereira Barreto region, SP. An area of 505 ha was mapped using the global positioning system (GPS) and a Digital Elevation Model was elaborated (MDE). Soil samples were collected for 0-0.25 m depth, in each 7 ha, for their chemical attributes and texture characterization. Data were analyzed by descriptive statistics and geostatistics. The determination of the spatial distribution of soil granulometric and chemical attributes allowed the allocation of the studied sugarcane varieties according to soil fertility and clay content. The kriging maps of soil granulometric and chemical attributes brought useful information to the establishment of production environments with different soil and crop managements. The identification of different environments by means of geostatistical techniques allowed the precise planning of the sugarcane cultivation, as well as the adequacy of fertilization practices and the allocation of suitable sugarcane varieties adapted to the conditions imposed by differences in the soil attributes.

Risk prediction for weed infestation using classification rules

This paper proposes a fuzzy classification system for the risk of infestation by weeds in agricultural zones considering the variability of weeds. The inputs of the system are features of the infestation extracted from estimated maps by kriging for the weed seed production and weed coverage, and from the competitiveness, inferred from narrow and broad-leaved weeds. Furthermore, a Bayesian network classifier is used to extract rules from data which are compared to the fuzzy rule set obtained on the base of specialist knowledge. Results for the risk inference in a maize crop field are presented and evaluated by the estimated yield loss. © 2009 IEEE.

Variabilidade temporal e mapeamento dos dados climáticos de Botucatu-SP

O trabalho teve objetivo estudar a variabilidade temporal da temperatura do ar, precipitação pluviométrica e umidade relativa do ar na cidade de Botucatu-SP, Brasil, utilizando técnicas geoestatísticas. Os dados de precipitação pluviométrica, temperatura do ar e umidade relativa do ar utilizados no presente estudo são provenientes da Estação Meteorológica da Fazenda Lageado, da Faculdade de Ciências Agronômicas-UNESP. As observações foram realizadas no período de 1988 a 2007, referem-se ao total mensal de precipitação pluvial expressa em altura de lâmina d'água (mm), médias mensais de temperatura em ºC e umidade relativa em %. Os dados foram avaliados por meio da estatística clássica e geoestatística. As variáveis climáticas tiveram sua dependência verificada por variogramas, apresentando dependência temporal maior que 76%. A série temporal de umidade relativa do ar foi a que apresentou maior alcance (8,67 meses) e, conseqüentemente, maior estabilidade climática. O conhecimento da distribuição temporal das variáveis climáticas é importante para o estudo e realização do zoneamento agroclimático, bem como para o dimensionamento do sistema de irrigação das culturas.

Métodos de interpolação para estimar o ph em solo sob dois manejos de café Arábica

There are many methods used to estimate values in places no sampled for construction of contours maps. The aim of this study was to use the methods of interpolation kriging, inverse of the square of the distance and polynomial in the representation of the spatial variability of the pH of the soil in the organic and conventional management in the culture of the coffee plantation. For that, irregular meshes were built for soil sampling in the depth of 0-0,10 meters, totaling 40 points sampling in each area. For gauging of the interpolation methods they were solitary 10% of the total of points, for each area. Initially, the data were appraised through the classic statistics (descriptive and exploratory) and spatial analysis. The method inverse square of the distance and kriging has low error in estimating dados. The method of kriging presented low variation around the average in different managements.

Delimitação do Embasamento da Bacia de Taubat

The aim of this study is to define the basement map of the Taubaté Basin applying geostatistics to seismic, gravimetric and deep wells data. The study consisted of the interpretation of eleven seismic sections obtained in the central and northeastern portions of the basin. The altitude of the basement and the distribution of faults was determined based on these sections. New information was obtained from 79 wells located mainly in the regions of São José dos Campos and Jacareí. The method of kriging with an external drift was applied, using seismic and well data as the main variables and the gravimetric map as the secondary variable. The basement contour map obtained has a strong correlation with the main faults. It was possible to obtain a better resolution in the region of São José dos Campos and in the northeast area, where the vast majority of wells are located.

Variabilidade dos atributos de um latossolo vermelho sob plantio direto no cerrado brasileiro e produtividade da soja

The spatial variability of several soil attributes (bulk density, penetration resistance, water content, organic matter content and pH) as well as soybean yield have been assessed during the 2007/08 growing season, in Selviria (MS) in a Hapludox (Typic Acrustox), under no tillage. The objectives were to assess the spatial variability of soil and plant parameters at the small plot scale and to select the best soil attribute explaining most the variability of agricultural productivity. Soil and plant were sampled on a grid with 121 points within a plot of 25,600 m 2 in area and slope of 0.025 mm -1 slope. Medium and low coefficients of variation were obtained for most of the studied soil attributes as expected, due to the homogenizing effect of the no-till system on the soil physical environment. From the standpoint of linear regression and spatial pattern of variability, productivity of soybeans could be explained according to the hydrogen potential (pH). Results are discussed taken into account that the soybean crop in no-tillage is widely used in crop-livestock integration on the national scene.

Espacialização das estimativas de contaminação de águas subterrâneas por Tebuthiuron

Improper use of pesticides can lead to significant environmental impacts such as, contamination of environmental compartments, being the aquatic compartments the most vulnerable. In this context, the spatialization of pesticides concentrations estimative in groundwater provides important insights for decision making in managing and monitoring pesticides use. This study aimed to spatialize estimatives of groundwater contamination by Tebuthiuron, from different irrigation depths in the Rio Pardo basin, Pardinho-SP, Brazil. The simulations were performed using the ARAquá computer system, considering 0mm, 200 mm and 400 mm annual irrigation depths. Geostatistical techniques were used to obtain the spatial distribution of the simulated estimative. Tebuthiuron maps estimating concentration in groundwater were obtained by Kriging interpolation method, and indicated the areas with high potential for groundwater contamination. Considering all the simulations, it was concluded that there was no risk of groundwater contamination by Tebuthiuron in the study area.

Submerged macrophytes height estimation by echosounder data sample

Traditional methods of submerged aquatic vegetation (SAV) survey last long and then, they are high cost. Optical remote sensing is an alternative, but it has some limitations in the aquatic environment. The use of echosounder techniques is efficient to detect submerged targets. Therefore, the aim of this study is to evaluate different kinds of interpolation approach applied on SAV sample data collected by echosounder. This study case was performed in a region of Uberaba River - Brazil. The interpolation methods evaluated in this work follow: Nearest Neighbor, Weighted Average, Triangular Irregular Network (TIN) and ordinary kriging. Better results were carried out with kriging interpolation. Thus, it is recommend the use of geostatistics for spatial inference of SAV from sample data surveyed with echosounder techniques. © 2012 IEEE.