UM NOVO MÉTODO PARA ESTUDOS DINÂMICOS, IN SITU, DA INFILTRAÇÃO DA ÁGUA NA REGIÃO NÃO- SATURADA DO SOLO

A agricultura e a atividade humana que mais afeta o meio ambiente. Imensas quantidades de insumos agricolas sao aplicados sobre o solo e grande parte destes degrada os recursos hidricos. Para uma investigacao adequada do efeito destes insumos, estudam-se as propriedades hidraulicas do solo, que influem no transporte de solutos neste meio. Medir tais propriedades e modelar os parâmetros correlatos sao tarefas extremamente complexas, devido ao tempo requerido, dinheiro, instrumentacao e escala. As metodologias convencionais inferem as propriedades hidraulicas em amostras que estao em equilibrio, atraves de tecnicas invasivas e sob restricoes especiais. esta tes contribui com a Ciencia do Ambiente, via Ciencia do Solo, propondo um novo metodo de estudo da infiltracao da agua na regiao nao-saturada do solo, utilizando a tomografia computadorizada (TC). O tomografo foi aqui desenvolvido e construido. A TC, neste trabalho, mediu a umidade durante o fluxo nao-saturado e, atraves da solucao numerica da equacao de Richards e do modelo Rossi-Nimmo, obtiveram-se a curva de retencao, a sortividade, e a difusividade. Resultados qualitativos, como imagens 2D e 3D, e resultados quantitativos demonstraram a boa correlacao do metodo proposto com o metodo tradicional de medida da curva de retencao. Amostras de solo estruturado foram analisadas em laboratorio e em camp.

[1]  J. H. Hubbell,et al.  Photon cross sections, attenuation coefficients, and energy absorption coefficients from 10 keV to 100 GeV , 1969 .

[2]  W. Parton,et al.  Agricultural intensification and ecosystem properties. , 1997, Science.

[3]  R. N. Onody,et al.  Experimental studies of the fingering phenomena in two dimensions and simulation using a modified invasion percolation model , 1995 .

[4]  C. Vaz,et al.  Contribution of water content and bulk density to field soil penetration resistance as measured by a combined cone penetrometer–TDR probe , 2001 .

[5]  R. Cesareo,et al.  USING A COMPUTED TOMOGRAPHY MINISCANNER IN SOIL SCIENCE , 1986 .

[6]  J. Bouma,et al.  The contribution and importance of soil scientists in interdisciplinairy studies dealing with land. , 1996 .

[7]  Karim C. Abbaspour,et al.  Estimating unsaturated soil hydraulic parameters using ant colony optimization , 2001 .

[8]  S. Prasher,et al.  Preferential Solute Flow in Intact Soil Columns Measured by SPECT Scanning , 2000 .

[9]  P. E. Cruvinel,et al.  Calibração e uso de um tomógrafo computadorizado em ciência do solo , 1992 .

[10]  W. Green.  Studies in soil physics : I. The flow of air and water through soils , 1911 .

[11]  Nancy M. Trautmann,et al.  Pesticides and Groundwater: A Guide for the Pesticide User , 1989 .

[12]  C. Vaz,et al.  Automated soil particle size analyzer based on gamma-ray attenuation , 2001 .

[13]  J. Wallace.  Increasing agricultural water use efficiency to meet future food production , 2000 .

[14]  Glenn V. Wilson,et al.  Physical and chemical controls of preferred path flow through a forested hillslope , 1990 .

[15]  H. Panepucci,et al.  MAGNETIC RESONANCE IMAGING AS A NON-INVASIVE TECHNIQUE FOR INVESTIGATING 3-D PREFERENTIAL FLOW OCCURRING WITHIN STRATIFIED SOIL SAMPLES , 1996 .

[16]  W. Bouten,et al.  Soil water content measurements at different scales: accuracy of time domain reflectometry and ground-penetrating radar , 2001 .

[17]  J. Radon.  On the determination of functions from their integral values along certain manifolds , 1986, IEEE Transactions on Medical Imaging.

[18]  L. Aylmore,et al.  The use of computer-assisted tomography to determine spatial distribution of soil water content , 1983 .

[19]  Van Genuchten,et al.  A closed-form equation for predicting the hydraulic conductivity of unsaturated soils , 1980 .

[20]  A. Stikker.  WATER TODAY AND TOMORROW , 1998 .

[21]  Birl Lowery,et al.  Soil water content determination using a network analyzer and coaxial probe. , 2000 .

[22]  Avinash C. Kak,et al.  Principles of computerized tomographic imaging , 2001, Classics in applied mathematics.

[23]  S. O. Prasher,et al.  Three‐Dimensional Quantification of Macropore Networks in Undisturbed Soil Cores , 1999 .

[24]  C. Vaz,et al.  X-ray microtomography to investigate thin layers of soil clod , 1998 .

[25]  C. Vaz,et al.  Soil particle size fractions determined by gamma-ray attenuation , 1999 .

[26]  Paulo Estevão Cruvinel,et al.  X- and gamma -rays computerized minitomograph scanner for soil science , 1990 .

[27]  J. Richter.  The Soil as a Reactor , 1987 .

[28]  Keith A. Smith,et al.  Soil and environmental analysis : physical methods , 2000 .

[29]  G. Hounsfield.  Computerized transverse axial scanning (tomography): Part I. Description of system. 1973. , 1973, The British journal of radiology.

[30]  Jan W. Hopmans,et al.  Optimization of Hydraulic Functions from Transient Outflow and Soil Water Pressure Data , 1993 .

[31]  Silvio Crestana.  A tomografia computadorizada como um novo método para estudos da física da agua no solo. , 1985 .

[32]  H. Flühler,et al.  Evaluation of temperature and bypass flow sensitivity of tensiometers in a field soil , 1999 .

[33]  G. Knoll.  Radiation detection and measurement , 1979 .

[34]  Daniel Hillel,et al.  Introduction to soil physics , 1982 .

[35]  R T Lopes,et al.  Evaluation of a microtomography system with an X-ray microfocus tube. , 1997, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[36]  P. Raats,et al.  Developments in soil-water physics since the mid 1960s , 2001 .

[37]  Kurt Roth,et al.  Transfer Functions and Solute Movement Through Soil: Theory and Applications , 1991 .

[38]  S. Postel.  Entering an era of water scarcity: the challenges ahead. , 2000 .

[39]  A. Cormack.  Representation of a Function by Its Line Integrals, with Some Radiological Applications , 1963 .

[40]  D. R. Nielsen,et al.  FINITE‐DIFFERENCE SOLUTIONS OF THE INFILTRATION EQUATION , 1982 .

[41]  Terence Taylor,et al.  Resolution, artifacts and the design of computed tomography systems , 1986 .

[42]  Kosuke Noborio,et al.  Measurement of soil water content and electrical conductivity by time domain reflectometry: a review , 2001 .

[43]  R. Pozzi-mucelli,et al.  STATIC AND DYNAMIC THREE‐DIMENSIONAL STUDIES OF WATER IN SOIL USING COMPUTED TOMOGRAPHIC SCANNING1 , 1985 .

[44]  Van Genuchten,et al.  Non-equilibrium transport parameters from miscible displacement experiments , 1981 .

[45]  Alfred E. Hartemink,et al.  Developments and trends in soil science: 100 volumes of Geoderma (1967–2001) , 2001 .

[46]  J. Philip,et al.  THE THEORY OF INFILTRATION: 4. SORPTIVITY AND ALGEBRAIC INFILTRATION EQUATIONS , 1957 .

[47]  J. Perret,et al.  3-D Visualization of soil macroporosity using x-ray CAT scanning , 1997 .

[48]  A. Göttlein,et al.  A system for microscale tensiometry and lysimetry , 1996 .

[49]  W. Edwards,et al.  Conservation tillage and macropore factors that affect water movement and the fate of chemicals , 2000 .

[50]  A. Gieske,et al.  Note on the analysis of moisture-depth curves obtained by the hot-air method for the determination of soil moisture diffusivity , 1990 .