Estudo do nivel piezometrico por analise geoestatistica

160 groundwater bores in the Ribeirao Preto region were used to study the behaviour of the piezometric surface of the Botucatu Formation aquifer by geostatistical methodology. The semi-variogram showed the following results: nugget = 50 m2; sill = 450 m2 and range = 4.5 km. The piezometric surface, obtained by punctual kriging in a 100 x 100 knot grid, revealed two lowered zones: one in a southwest to north-northeastern trend, indicating the groundwater flow north toward the Rio Pardo; and the other in the central part due to the high concentration of holes in the urban region of Ribeirao Preto city. -from English summary

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

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.

Correlação espacial entre a altitude e as precipitaç ões pluviométricas no estado de São Paulo

The rain occurrence is one of the most important phenomena to determinate the climate and, as most of the other climatic phenomena, shows a continuous spatial variability that can be detected through special geostatistical methods. Besides the great influence of the topographic relief on the specific climate of each region, it is normal to expect spatial correlations of this variable with the precipitations; the determinism of this correlation may help to elaborate more precise conclusions involving these phenomena. In this paper, the spatial variability of altitude and of the pluviometric precipitations was rigorously analyzed, besides the existing correlation between these variables. It was concluded that these variables show strong spatial dependence and they are directly correlated. The mapping of the occurrence of both the phenomena was done by geostatistical methods pased on the infomiation concerning the spatial variability of each one.

Batimetria fluvial estimada com dados orbitais: Estudo de caso no alto curso do rio Paraguai com o sensor ASTER

The Paraguay River is the main tributary of the Paraná River and has an extension of 1.693 km in Brazilian territory. The navigability conditions are very important for the regional economy because most of the central-west Brazilian agricultural and mineral production is transported by the Paraguay waterway. Increased sedimentation along the channel requires continuous dredging to waterway maintenance. Systematic bathymetric surveys are periodically carried out in order to check depth condition along the channel using echo-sounding devices. In this paper, digital image processing and geostatistical analysis methods were used to analyze the applicability of the ASTER sensor to estimate channel depths in a segment of the upper Paraguay River. The results were compared with field data in order to choose the band with better adjustment and to evaluate the standard deviation. Comparing the VNIR bands, the best fit was presented by the red wavelength (band 2; 0,63 - 0,69 μm), showing a good representation of the channel depths shallow than 1,7 m. Applying geostatistical methods, the model accuracy was enhanced from 43 cm to 36 cm and undesired components were slacked. It was concluded that the digital number of band 2, converted to bathymetry information allows a good estimation of river depths and channel morphology.

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.

Variabilidade espacial do estado nutricional do cafeeiro canephora visando o manejo localizado

Mapping the plant nutritional condition allows viewing different regions in a cropping area, providing the producers with different criteria to use foliar and soil fertilization. The aim of this study was to evaluate the spatial variability of the nutritional condition of canephora coffee (Coffea canephora Pierre ex Froehner) regarding the site specific management of foliar and soil fertilization. In a one hectare area 60 georeferenced points were sampled at irregular intervals. There were five plants in each sampled point; two pairs of leaves were removed from the lateral branches (3 rd and 4 th pairs from extremity to the basis) in the cardinal points of each plant, counting up 40 leaves per point. The foliar samples were chemically analyzed for the following nutrients: N, P, K, Ca, Mg, S, B, Cu and Zn. The same pattern of spatial dependence was presented with adjustment for K and B. Except for N and P, which presented random distribution, the other nutrients presented mild to severe spatial dependence justifying the geostatistical data analysis for making maps for differential and located, foliar and soil fertilizer application in coffee crop.

Correlação linear e espacial entre a produtividade e o teor de proteína bruta do guandu anão e os atributos de um Latossolo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variabilidade espacial na produção da alface em ambiente protegido

Este artigo mostra a dinâmica da água após ser aplicada sobre a superfície de um solo cultivado com alface, num sistema fechado de um ambiente protegido. A aplicação de água se deu por meio de um sistema de irrigação por gotejamento, com o CUD ( Coeficiente de Uniformidade de Distribuição ) igual a 97,06 %, o que garantiu uma ótima uniformidade de distribuição, desconsiderando como possíveis causas das variações de umidade do solo, a aplicação de lâminas variadas. Fazendo uso de técnicas de geoestatística, interpolando sessenta pontos amostrais de evaporação, umidade do solo e produtividade da alface, com as mesmas sessenta coordenadas para os três atributos, verificou-se que a umidade do solo, mesmo momentos após a irrigação, não permanece uniforme ao longo do sistema de irrigação, constatando-se que a evaporação local exerce influência de forma predominante sobre a dinâmica da água na superfície do solo. Concluiu-se que as regiões no interior da estufa de maiores evaporações, foram as de maiores variações de umidade do solo e na produção de massa verde da alface.

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.

Delineation of specific management areas for coffee cultivation based on the soil-relief relationship and numerical classification

Predicting and mapping productivity areas allows crop producers to improve their planning of agricultural activities. The primary aims of this work were the identification and mapping of specific management areas allowing coffee bean quality to be predicted from soil attributes and their relationships to relief. The study area was located in the Southeast of the Minas Gerais state, Brazil. A grid containing a total of 145 uniformly spaced nodes 50 m apart was established over an area of 31. 7 ha from which samples were collected at depths of 0. 00-0. 20 m in order to determine physical and chemical attributes of the soil. These data were analysed in conjunction with plant attributes including production, proportion of beans retained by different sieves and drink quality. The results of principal component analysis (PCA) in combination with geostatistical data showed the attributes clay content and available iron to be the best choices for identifying four crop production environments. Environment A, which exhibited high clay and available iron contents, and low pH and base saturation, was that providing the highest yield (30. 4l ha-1) and best coffee beverage quality (61 sacks ha-1). Based on the results, we believe that multivariate analysis, geostatistics and the soil-relief relationships contained in the digital elevation model (DEM) can be effectively used in combination for the hybrid mapping of areas of varying suitability for coffee production. © 2012 Springer Science+Business Media New York.

Spatial correlation between the composition of the clay fraction and contents of available phosphorus of an Oxisol at hillslope scale

Relief is regarded as the abiotic factor most strongly influencing pedogenic processes at a local scale. The spatial correlations between the composition of the clay fraction (iron - Fe and aluminum - Al oxides, kaolinite and organic matter - OM) and contents of available phosphorus (P) of an Oxisol were evaluated at hillslope scale under sugarcane cultivation. A total of 119 samples were collected at intersection points on a 100. ×. 100. m georeferenced grid of regularly spaced points 10. m apart in the 0.2-0.4. m depth in an area consisting of two landform components namely: component I (an area with a linear hillslope curvature), and component II (one with a concave-convex hillslope curvature). Soil OM and available P contents were subjected to descriptive statistics and geostatistical analyses in order to assess their variability and spatial dependence. All attributes studied were spatially dependent. Available phosphorus had positive spatial correlation with high crystalline goethite, hematite and gibbsite. Identifying small hillslope curvatures is useful with a view to better understanding their relationships with soil organic matter and available phosphorus, as well as kaolinite and Fe and Al oxide attributes. A simple correlation analysis by itself is inadequate to relate attributes, which requires a supplemental, geostatistical technique. © 2012 Elsevier B.V..

Produção de matéria seca da braquiária de acordo com os atributos químicos de um Latossolo em Selvíria, Mato Grosso do Sul

Rustic forages as the signal-grass are predominant in areas of Cerrado in extensive livestock systems that favor soil degradation. However, with time, not even these forages can have a good development in those areas. The objective of this study was to analyze the variability of plant and soil attributes; to define the linear and spatial correlations between signal-grass yield and the chemical attributes of the studied soil, and to evaluate, among the chemical attributes of the soil, which one that best explain the variability in this forage yield. The experiment was conducted in an area that had been under pasture for more than 30 years, belonging to UNESP - Ilha Solteira Campus, located in Selvíria - MS. A geostatistical grid was installed in an oxisol, for soil and plant data collection, with 121 sampling stations, consisted of eleven transections with 160 m width in the direction of the Cartesian axes. The dry mass yield of signal-grass was low, presenting high variation. The attributes MSr, N, PB, MO1, MO2, pHa1, pHa2, pHk1 and pHk2 did not vary at random. They presented data variability from low to high and followed clearly defined spatial patterns, ranging between 17.7-162.9 m. There was significant linear correlation at 1% between MSr and N leaf, and between MSr and PB. The cross semivariograms MSr=f(N) and MSr=f(PB) confirmed that the dry matter can be estimated from data of nitrogen leaf and crude protein content of this forage.

Variabilidade espacial dos atributos físicos e químicos de argissolo sob diferentes usos e ocupação na Microbacia do Córrego Fazenda Glória, Taquaritinga – SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variabilidade espacial de atributos do solo em áreas intensamente cultivadas nas regiões de Jaboticabal e Monte Alto - SP

Pós-graduação em Agronomia (Ciência do Solo) - FCAV