Soil water solute process characterization an integrated approach

SOIL-WATERSOLUTE PROCESS CHARACTERIZATION An Integrated Approach SOIL-WATERSOLUTE PROCESS CHARACTERIZATION An Integrated Approach Edited by Javier álvarez-benedí ~ rafael munoz-carpena CRC PR E S S Boca Raton London New York Washington, D.C Library of Congress Cataloging-in-Publication Data Soil-water-solute process characterization: an integrated approach / [edited by] Javier A´lvarez Benedı´ and Rafael Mun˜oz-Carpena p cm Includes bibliographical references and index ISBN 1-56670-657-2 (alk paper) Soil moisture–Mathematical models Soils–Solute movement–Mathematical models Soil permeability–Mathematical models Groundwater flow– Mathematical models I A´lvarez-Benedı´ , Javier II Mun˜oz-Carpena, Rafael III Title S594.S6935 2005 631.4' 32' 011–dc22 2004015853 This book contains information obtained from authentic and highly regarded sources Reprinted material is quoted with permission, and sources are indicated A wide variety of references are listed Reasonable efforts have been made to 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arranged The consent of CRC Press does not extend to copying for general distribution, for promotion, for creating new works, or for resale Specific permission must be obtained in writing from CRC Press for such copying Direct all inquiries to CRC Press, 2000 N.W Corporate Blvd., Boca Raton, Florida 33431 Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe Visit the CRC Press Web site at www.crcpress.com ß 2005 by CRC Press No claim to original U.S Government works International Standard Book Number 1-5667-0657-2 Library of Congress Card Number 2004051920 Printed in the United States of America Printed on acid-free paper Preface The development and application of methods for monitoring and characterizing soil-water-solute processes are among the most limiting factors in understanding the soil environment Experimental methods are a critical part of scientific papers, and their design and implementation are usually the most time-consuming tasks in research When selecting a method to characterize a property governing a soil process, the practitioner or researcher often faces complex alternatives In many cases these alternatives are bypassed in favor of recommendations from colleagues on well-established methods that might not be the most suitable for the specific conditions of a study Several factors add to the complexity of selecting the best characterization method for a particular case:  The governing properties or parameters are referred to by similar names although in fact their actual values depend greatly on the conceptual model selected to explain the process (e.g., several empirical models of soil infiltration have different parameters associated with saturated hydraulic conductivity)  The ultimate goal of the characterization effort, whether it be general classification of the soil, qualitative estimation of an output, exploratory modeling to gain insight on a process, quantitative modeling prediction, etc., may determine the method of choice  Since many of the soil characteristics are intrinsically variable (spatially and temporally), the most accurate method might not necessarily be the best choice when compared with a simpler one that can provide a larger number of samples with the same or lower investment An integrated approach for soil characterization is needed that combines available methods with the analysis of the conceptual model used to identify the governing property of a soil process, its intrinsic nature (variability), and the ultimate use of the values obtained This holistic approach should be applied to the selection of methods to characterize energy and mass transfer processes in the soil (i.e., water and solute flow), sorption, transformation, and phase changes, including microbiological processes This book applies this integrated approach to present a comparative discussion of alternative methods, their practical application for characterization efforts, and an evaluation of strengths, weaknesses, and trade-offs This book is not a laboratory or field handbook The authors present the v vi Preface information with a critical spirit, showing benefits, limitations, and alternatives to the methods when available Numerous references to some of the excellent handbooks and publications available are given for details on each of the methods Some nontraditional state-of-the-art characterization methods (NMRI, x-ray tomography, fractals) and modeling techniques are also presented as alternatives or as integral components The book is divided into six sections (Fig P.1) The first section defines the basis for the integrated strategy that will be developed in the following sections (i.e., need and use, issues of spatial and temporal variability, and modeling as an integral part of the process) Sections II–IV present the critical evaluation of methods available for energy and water transfer, chemical transport, and soil microbiological processes Different methods of characterization are presented and compared using numerous tables and diagrams to help the users identify the most suitable option for their application Section V discusses tools and applications to account for the intrinsic temporal and spatial variability and scale of soil processes The last section is devoted to modeling aspects including uncertainty, inverse modeling, and practical recommendations Section I contains three chapters In Chapter 1, Corwin and Loague discuss the problem of subsurface non-point-source pollution and present the application of an integrated array of multidisciplinary, advanced information technologies useful in characterizing the process This chapter introduces FIGURE P.1 Book structure and contents roadmap Preface vii the methods Sections II–IV In Chapter 2, Campbell and Garrido explore the role of deterministic and stochastic approaches to describe soil processes, and how their intrinsic temporal and spatial variability affect method selection in field studies These issues remain the greatest challenges for field research and limit the quantitative comparison of existing field studies This chapter provides the background for the chapters in Section V Chapter 3, written by Alvarez-Benedı´ et al., proposes that modeling (conceptual and mathematical) is at the core of the characterization effort, affecting not only the method selection but also the final application of the study A review of the conceptual building blocks needed to construct a soil-water-solute mathematical model is presented here to illustrate current assumptions and limitations when modeling soil-water-solute phenomena This chapter leads into the final section (VI) of the book Section II, devoted to soil physical processes, opens with Chapter 4, in which Polo et al offer a review of water and energy exchange processes between soil-plant and the atmosphere A comparison of methods to account for energy and water balance, with emphasis on evapotranspiration, is presented This chapter serves as background for the rest of the section, in which water or energy are discussed The authors reflect on how the selection and success of the physically based methods presented require knowledge of the relevant spatial and temporal scales and a determination of the uncertainty associated with the variables of interest In Chapter Mun˜ozCarpena et al present current field methods to monitor soil water status Soil water potential and soil water content devices are presented and compared in terms of desired moisture range to measure, soil type, accuracy, soil volume explored by the device, soil salinity levels, device maintenance and installation issues, and cost A criterion to select the most suitable method for a given application is presented Chapter 6, by Reynolds and Elrick, introduces current methods to characterize soil hydraulic parameters that control soil water redistribution and flow They point out that in situ measurements are essential for dealing with the extreme complexity of the field, and that rather than using a single method, the correct approach seems to use a ‘‘suite’’ of complementary methods They propose the infiltrometer, permeameter, and instantaneous profile methods as the core of such a suite of methods In Chapter 7, Deurer and Clothier give an indepth look at the complex soil topology using two state-of-the-art methods — NMRI and x-ray tomography These complementary techniques provide a new look at the microscopic scale and topology of pore geometry and of water and solute transport Although for most practical applications these methods are not yet cost-effective, they may be so in the near future Chapter 8, by Shirmohammadi et al., offers a critical assessment of one of the most daunting problems encountered when describing flow and transport processes in the soil: preferential flow Preferential flow, probably more often than not, presents a limit to our classical description of such processes Different experimental methods to quantify the presence of preferential paths are compared A detailed presentation of the theoretical representation viii Preface of the process and alternative models follows, with emphasis on their limitations It is concluded that our handling of the preferential flow either fails to be properly represented mathematically, or fails in the parametrization for proper representation of the system Within Section III, dedicated to solute processes, Tuller and Islam present in Chapter an exhaustive review of field methods for characterizing solute transport They conclude that our ability to measure and characterize spatial distribution of chemicals and preferential migration pathways is restricted due to the application of in situ point measurements with limited volume and geophysical techniques that only work indirectly or qualitatively The authors present electrical methods such as time domain reflectometry (TDR), electrical resistivity tomography (ERT), and magnetic induction as the most promising for large-scale and real-time monitoring In Chapter 10, Vogeler et al show the modern application of the TDR technique to measure not only water content but also saline solute concentration through soil electrical conductivity (ECa) changes The method can be applied reliably and successfully to study nonreactive and reactive solutes Although the estimation of ECa with TDR is well established, the relation of that with solute concentration is soil specific, influenced by soil texture/structure and bulk density, and not yet fully understood Two weaknesses of the method are the relatively small zone of influence and inability to discriminate between different ionic species The method should not replace existing monitoring techniques, but rather complement them In Chapter 11, Alvarez-Benedı´ et al build on Chapters 3, 5, 9, and 10 to discuss the laboratory characterization of solute transport through miscible displacement experiments This method is presented as the most important for characterizing solute transport at small to large lysimeter (column) scale, especially if several experiments can be performed varying hydrodynamic conditions and tracers in the same column However, extending this methodology to the field scale is usually not feasible, and field experiments like the ones presented in Chapter are preferred for validation purposes of the parameters obtained in the column studies Chapter 12, by Cornejo et al., compares methods to determine sorption of pesticides in the soil This process controls pesticide transport in different soils and conditions and has important environmental implications The selection of the method is governed by the accuracy required for the intended use and regulatory environment In Chapter 13, Rochette and McGinn take a critical look at state-of-the-art methods to quantify another controlling factor in the distribution and degradation of contaminants from the soil, volatilization Three types of techniques are compared: soil mass balance, chambers, and micrometeorology Because of the usually significant error associated with any one technique, the authors recommend the use of two techniques when possible to increase confidence in the gas flux estimates Further research is recommended in all these techniques to reduce current uncertainty in measurements Chapter 14 completes Section III Li et al present a critical and exhaustive look at one important aspect often overlooked by field researchers and practitioners in soil solute characterization Preface ix studies, i.e., the chemical analysis of the samples There is a multitude of available techniques to analyze any given element or compound The selection of the appropriate method is often complex, since new methods and techniques are continuously entering the market In addition, the intrinsic uncertainty, interferences, and method detection limit (MDL) are not always taken into account when interpreting the results, although these can vary greatly across methods Comparison of results obtained with a standard method is the important criterion in the selection of an appropriate method Laboratory accreditation is discussed as a growing trend that will benefit the scientist and clientele of analyses Section V (and Chapter 15) is devoted to the emerging area of soil microbiological processes Pell and Stenstroăm discuss the fact that, although soil quality is closely related to soil microbiology, the latter has received little attention This common oversight is at the root of many of the difficulties found in measuring or predicting reactive solute transport of important contaminants such us pesticides and fertilizers The authors describe how microbial respiration and nitrification/denitrification processes affect soil sample handling, soil reactive behavior, and how microbial parameters can be used in soil function description and assessment of special variability at different scales The authors conclude that cooperation between soil physicists, chemists, and microbiologists is needed to advance our understanding of soil processes Section VI reviews available techniques that could be incorporated in methods to address the intrinsic soil variability In Chapter 16, Van Meirvenne et al give a comprehensive review of available geostatistical techniques and how to incorporate them in field and laboratory methods Despite its promise, there is no single solution for all situations, and the user must understand the underlying hypotheses and limitations before embarking on a geostatistical analysis In Chapter 17, Kravchenko and Pachepsky present the use of fractals as an innovative technique to address scaling issues in soil processes Fractal and multifractal techniques show promise in identifying scaling laws in soil science Although soils are not ideal fractals and because fractal scaling is only applicable within a range of scales, these models present limitations One important advantage of fractal models of variability is their ability to better simulate ‘‘rare’’ occurrences in soils (i.e., large pores, preferential pathways, very high conductivities, localized bacteria habitats, etc.) These rare occurrences often define soil behavior at scales coarser than observational ones Corwin provides in Chapter 18 an overview of the characterization of soil spatial variability using ECa-directed soil sampling for three different landscape-scale applications: (1) solute transport modeling in the vadose zone, (2) site-specific crop management, and (3) soil quality assessment Guidelines, methodology, and strengths and limitations are presented for characterizing spatial and temporal variation in soil physicochemical properties using ECa-directed soil sampling Fast geospatial ECa measurements can be made with available mobile electrical resistivity (ER) or electromagnetic induction (EMI) equipment coupled with GPS The author 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Amplitude domain reflectometry Advanced very high-resolution radiometry (AVHRR), 32 Advection-dispersion equation (ADE), 101, 102, 115, 374, 398, 400 Aerial photography, 28, 151, 640 Aerodynamic roughness, 481 AF, see Attenuation factor Agricultural activities, movements of NPS pollutants caused by, Agricultural fields, evaporation rates from, 466 Agricultural lands, salinity, 27 Agricultural productivity, pesticide use and, 436 Agriculture, precision, 660 Agrochemicals, leaching estimates, 45 Air -cored electromagnets, 267 entrapment, 706 -entry permeameter, modified, 211 value, 201 permeability, 423 pollution fallout, sampling, 471 Akaike criterion, 706 Alkaline and Acid Persulfate Digestion Method, 535 Alternating current (AC), 329, 366 Alundum tension plate sampler, 413 American Public Health Association (APHA), 506 American Society for Testing and Materials (ASTM), 207, 507 Ammonia determination field monitoring probes, 521 field testing kits, 521 laboratory methods for, 517 diffusion of, 519 loss, 467 open-path lasers for, 494 -oxidizing bacteria (AOB), 567, 571 samplers accumulating, 488 Amplitude domain reflectometry (ADR), 176, 177 Analysis of variance (ANOVA), 683 ANNs, see Artificial neural networks ANOVA, see Analysis of variance AOAC, see Association of Official Analytical Chemists–International AOB, see Ammonia-oxidizing bacteria APECOP project, 728 APHA, see American Public Health Association APHA Standard Methods, 508–515, 519, 524, 526 Apparent dispersivity, 106 Apparent hysteresis effect, 108 Apparent soil bulk electrical conductivity, 322 Apparent soil electrical conductivity, 640, 650 Apparent tortuosity factor, 106 Aquifers, prevention of pollution of, 310 Arbitrary scales, 71 Artificial neural networks (ANNs), 304 ASCII grid, 679 Association of Official Analytical Chemists–International (AOAC), 507 ASTM, see American Society for Testing and Materials Atmospheric turbulence theory, 111 Atomic absorption (AA) spectrometry, 539 ATP, see Adenosine triphosphate Atrazine, 108, 442, 443, 449 757 758 Attenuation coefficients, 275 factor (AF), 44 Autocovariance, definition, 589 Automated soil solution samplers, automated, 311 AVHRR, see Advanced very high-resolution radiometry Index BREB, see Bowen ratio energy balance Bremsstrahlung, 273 Bresler-Dagan model, 62, 67 Brownian motion, 620, 622, 625 BTC, see Breakthrough curve Bulk electrical conductivity, 328 Bulk liquid phase conductivity, 324 Bulk magnetization, 257 Bulk soil electrical conductivity, 360, 380 Bulk surface conductivity, 324 B Backward Lagrangian stochastic technique, 491 Bare soil evaporation effectiveness, 135 Batch equilibration technology, 455 Batch slurry experiments, 449 Bayesian maximum entropy (BME), 601, 602, 603 Bayes theorem, 700 Bench marking, 16 Best management practices (BMPs), 168, 290 Bi-modal porosity models, 101 Biochemical oxygen demand (BOD), 540 Biocide, sampler pretreatment with, 313 Biomarkers, 572 BME, see Bayesian maximum entropy BMPs, see Best management practices BOD, see Biochemical oxygen demand Boltzmann probability distribution, 255 Boolean algebra, 42 Borehole permeameters, 217, 218–218 Boundary condition, free drainage, 402 Bound water, 365 Bourdon-type vacuum gauge, 211 Bowen ratio definition of, 145 energy balance (BREB), 145 field unit, 483 technique, 111, 482 Breakthrough curve (BTC), 326, 358, 396 asymmetry, 411, 414, 415 data analysis, 79 description of, 397 effluent, 377 inverse simulation of, 426 miscible displacement experiments, 395 normalized, 698, 699 optimized parameters, 409 perturbations, 427 shape analysis of, 404 parameters, 407 skewed, 406 symmetry, 406, 407 tracer, 416 C Cable impedance, 323 Calibration constant, 373 definition of, 18 model site-specific limits and, 19 Canopy conductance, 138 precipitation measurements above and below, 141 water interception flux, 140 Capacitor, electrical capacitance of, 175 Capacity models, 733 parameters, 15 Capillary absorbers, 319, 320 electrophoresis (CE), 526 rise equation, 311 zone electrophoresis (CZE), 526 Carbohydrates, oxidized, 568 Carbon analyzers, automated, 530 natural cycles of, 466 turnover, 29 Catabolite response profiles (CRPs), 574 Cation exchange capacity (CEC), 32, 643 CBM, see Chloride balance method CDE, see Convection-dispersion equation CE, see Capillary electrophoresis CEC, see Cation exchange capacity Cell death rate coefficient, 113 CFE, see Chloroform fumigation–extraction CFITIM, 702 Chamber(s) deployment strategies, optimum, 469 design, 470 evaporation rates inside, 469 flow-through, 473, 474, 479 headspace gas concentration, 469 nonflow-through, 474, 475, 476, 478 nonsteady-state, 472, 476 opaque, 475 759 Index steady-state, 472, 473 techniques characteristics, 480 soil-surface gas emissions estimated using, 468 strengths and weaknesses of, 479 Chemical application rates, 21 nonequilibrium, 448 oxygen demand (COD), 540 tracer, requirements for, 403 Chemical methods for soil and water characterization, 503–557 assessment of uncertainty, 516 criteria for method selection, 506–516 fitting to analytical purposes, 507 method detection limit, 507–516 using standard methods, 506–507 critical discussion of analytical methods of soil and water, 517–549 metals, 538–539 nitrogen, 517–529 organic matter/carbon, 540–542 pesticides, 543–549 phosphorus, 529–538 recommendations and future trends, 549–550 Chlordane, Chloride balance method (CBM), 149 Chlorinated organic solvents, Chloroform fumigation–extraction (CFE), 571 CI, see Confidence interval Clay content, 453 minerals, exchangeable cations associated with, 642 soil, drainage water in, 290 surfaces, organic molecules sorbed on, 442 CLSM, see Confocal laser scanning microscopy CLT, see Convective lognormal transfer function Coarse-graining, 627, 628 COD, see Chemical oxygen demand Cokriging, 41, 594 Colloidal tracers, 417 Colloids, soil mineral–derived, 441 Compound extractability, 445 Compton scattering, 273, 274, 275 Computational scales, 71 Computed tomography (CT), 254, 292 dual-energy, 281 image reconstruction, 278 Conceptual model(s) numerical model vs., 88 soil water hysteresis, 100 Conditional stochastic simulation, 603 Condition sampling, 486 Confidence interval (CI), 707 Confocal laser scanning microscopy (CLSM), 572 Conservation of energy, 144 Conservation-tillage systems, 436 Constant head well permeameter, schematic, 220 Construction, Contact sand hydraulic contact and, 240 –induced variations, 241 layer, hydraulic head loss across, 238, 239 saturated hydraulic conductivity, 238 Convection-dispersion equation (CDE), 298, 374 mobile-immobile version of, 379 solution for, 375 transient water flow conditions, 376 model, 107 transport, 293 Convective lognormal transfer function (CLT), 374, 375 Convective mass flux, 95 Copper-cadmium, 523 Corn belt, U.S., 743 CPMAS, 453 Cramer-Rao theorem, 707 Critical moisture state, 136 Crop cycle, 718 management site-specific, 640 productivity, reduced, 11 status, monitoring of, 695 water requirements, assessment of, 142 water stress index (CWSI), 153 -yield variation, within-field, 661 Cross-borehole ERT, 329 CRPs, see Catabolite response profiles CT, see Computed tomography Cumulative infiltration, 211 CWSI, see Crop water stress index CXTFIT, 409, 702 CZE, see Capillary zone electrophoresis D Darcy’s equation, 96, 297 Darcy’s law, 63, 96, 210, 239 Darcy’s scale, 254 Data analysis, methods of, 607 760 Database(s) geographical, 586 GIS NPS pollutant modeling using, 35 pesticide, 743 soil survey, 30 Decision Support System (DSS), 744, 748 Deep infiltration unit flow, 133 Deforestation, Degradation phenomena, 436 DEM, see Digital elevation models Denaturing gradient gel electrophoresis (DGGE), 570 Denitrification, 566 field measurements of, 574 pathway, 566 products, 568 Desertification, 11 Desorption, 438, 444 Deterministic models, 23, 36, 37 Deterministic process, 62 DGGE, see Denaturing gradient gel electrophoresis Dielectric lysimeter, 363 Dielectric techniques, 172 Diffusion ammonia, 519 law kinetics, 94 molecular, 104, 105, 470 processes, isolating, 415 theory, 478 Diffusive mass transfer, 449 Digital elevation models (DEM), 13 Digital terrain, 3, 13 Dioxins, 4, 5, Dirac’s delta function, 278 Direct calibration, 368, 371, 372 Directed-sampling tool, 651 DISC, 236 Disk permeameter, 361 Dispersion mass flux, 95 models, 494 phenomena, levels in study of, 104 Dispersivity, use of tracers for characterizing, 393 Dissolved organic matter (DOM), 441, 442 Distillation-titration, 519 DNA direct extraction of from soil, 569 extractions, results of, 577 hybridization, 561 reassociation kinetics, 561 DOM, see Dissolved organic matter Downscaling, 128 DRASTIC model, 38 Index Drinking water, maximum contamination levels for, 516 DSS, see Decision Support System Dual-energy CT, 282 Dual-energy imaging, 276, 277 Dual porosity models, 100 Dye staining, 412 E EC, see Electrical conductivity ECD, see Electron-capture detector Echo time, 264 Eddy covariance technique, 487 EDWC, see Estimated drinking water concentrations EECs, see Expected environmental concentrations Effective diffusion coefficient, 104 Effective range of measurement criterion, 188 Einstein’s theory of relativity, 20 Electrical conductivity (EC), 656 determination of, 362 meter, handheld, 325 pore water, 369 soil solution, 370 Electrical resistivity (ER), 326, 644 method, surface-based, 329 tomography (ERT), 329 Electromagnetic induction (EMI), 28, 32, 329, 644, 654 geometric mean, 656 measurements, basic principle of, 331 methods, 180 Electromagnetic measurements (EM), 331 Electromagnets air-cored, 267 iron-core, 267 Electromotive force, 257 Electron-capture detector (ECD), 545, 547 Elution-front tailing, 414 EM, see Electromagnetic measurements EMI, see Electromagnetic induction Endocrine disruptors, Energy balance equation, 132, 134, 484 Environmental management, pesticide leaching models and, 742 Environmental sink, 436 EPDM, see Ethylene propylene diene monomer EPS, see Extracellular polysaccharides Equation advection-dispersion, 101, 374, 398 capillary rise, 311 convective-dispersive, 298, 374 761 Index Darcy’s, 96, 297 energy balance, 132, 134, 484 Freundlich, 444 Giese and Tiemann, 324 hydraulic conductivity, 99 Kelvin’s, 186 mass-transfer, 110 Monod, 112 Navier–Stokes, 296, 297 Penman, 147, 487 Richards, 63, 221, 695 limitation, 98 mixed form of, 97 numerical inversion of, 235 solute transport, 397 -solving algorithm, 18 tracer mass balance, 149 Equilibrium, sorption, 114 ER, see Electrical resistivity ERT, see Electrical resistivity tomography Estimated drinking water concentrations (EDWC), 747 ET, see Evapotranspiration Ethylene propylene diene monomer (EPDM), 471 Ethylvinylbenzene (EVB), 524 Euclidian dimension, 631 European hydrologic model, 127 European Project PEGASE, 686 European Union APECOP, 749–750 Council Directive 91/414/EEC, 749 groundwater scenarios, 749 EuroPEARL, metamodel, 751 Evaporation rates, real-time measurements of, 466 Evapotranspiration (ET), 142, 316 flux(es) measurement of, 146 modeling of, 147 methods for calculating crop, 147 methods for estimating, 143 modeling, 147 parts, 135 total annual, 136 EVB, see Ethylvinylbenzene Expected environmental concentrations (EECs), 745 Experimental semivariogram, 40 Extended kinetics models, 93 Extracellular polysaccharides (EPS), 561 Extractants, 506, 532 Extraction accelerated solvent, 446 microwave-assisted, 446 subcritical water, 446 supercritical fluid, 446, 450 ultrasonic, 446 F FA, see Fluorescent polyclonal antibodies Farm management, pesticide-fate models and, 743 Fate models, 674 Faunal burrowing, 203 FD, see Frequency domain FDR, see Frequency domain reflectometry Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 746–747 Fertile Crescent, Fertilizer(s), phosphorus, 531 recommendations, 505 FIA, see Flow injection analysis Fick’s first law of diffusion, 104 FID, see Free induction decay Field analysis, sophisticated instruments for, 527 -portable x-ray fluorescence (FPXRF), 539, 550 -saturated hydraulic conductivity, 200 scale, 618 -scale heterogeneity, 103 solute transport studies, examples, 76–78 study(ies) design, issues in, 69 need for, 60 work, frustrating activity of, 61 FIFRA, see Federal Insecticide, Fungicide, and Rodenticide Act Film diffusion, 92 Filtering techniques, 139 First-order kinetics, 92, 112 First-order second-moment (FOSM) analysis, 22 First-order variance propagation methods, 22 FISH, see Fluorescent in situ hybridization Flame AA, 539 Flame ionization detector, 547 Flooding, 74 Flow, see also Preferential flow Darcian-based, 291 deep infiltration unit, 133 injection analysis (FIA), 537, 521, 569 interruption, 416, 417, 419, 423, 427 near-saturated, 424 piston, 290, 293 preferential, 706 762 Flow (Continued ) sap, 146 stochastic-convective, 380 three-dimensional, 74 three-domain, 301 -through (FT) chambers, 473, 474, 479 water characteristics, homogeneous, 28 forces, 95 study of, 64 -weighted mean pore size, 231 well permeameter, 220 Fluid displacement efficiency, 405 -dynamics models, 269 Fluorescence detector, 548 Fluorescent in situ hybridization (FISH), 573 Fluorescent polyclonal antibodies (FA), 572 Flux(es) calculation chamber techniques used for, 470 procedures, 469 law, 96, 297 matching, 128 power law function for, 297 vapor, 124 Food demand, global, 10 Food Quality Protection Act (FQPA), 747 Forage crop, salt-tolerant, 659 Force restore, 131 Fortran computer program, 235 Forward model, 695, 706 FOSM analysis, see First-order second-moment analysis Fourier imaging, 259, 263 Fourier slice theorem, 278 Fourier transformed signal, 262 FPXRF, see Field-portable x-ray fluorescence FQPA, see Food Quality Protection Act Fractal geometry, 281 Fractal scaling methods, 67 Fractal techniques, soil variability assessment with, 617–638 critical assessment and future research, 634–635 fractal models and parameters of spatial variability, 619–631 monofractal models, 620–625 multifractal models, 626–627 multifractal spectra, 627–631 simulating spatial variability with fractal models, 632–634 Fractional Brownian motion model, 623 Free induction decay (FID), 258, 259 Index Freeze-thaw action, 203 Frequency domain (FD), 175, 176 Frequency domain reflectometry (FDR), 175 calibration, 193 sensor, 188 Freundlich equation, 444 Freunlich isotherm, 414 FT chambers, see Flow-through chambers Fulvic acids, dissolved, 441 Furans, Fuzzy logic, 3, 12 Fuzzy set theory, 39, 42 G Gas chromatography (GC), 472, 545 Gas concentration analysis, 471 Gas diffusion fluorescence method (GDF), 521 Gas exchange soil surface, 111 techniques for estimating, 467 Gas fluxes, soil-surface, 465–502 chamber techniques, 468–479 air sampling and gas concentration analysis, 471–472 chamber design, 470–471 chamber impacts on gas fluxes, 468–469 chamber types, 472–479 strengths and weaknesses of chamber techniques, 479 mass exchange using micrometeorological techniques, 479–492 aerodynamic technique, 480–482 backward Lagrangian stochastic technique, 491–492 Bowen ratio–energy balance technique, 482–485 combined techniques, 487 eddy covariance technique, 485–486 integrated horizontal flux technique, 487–489 mass difference technique, 489 relaxed eddy accumulation technique, 486 strengths and weaknesses, 492 theoretical profile shape technique, 489–491 notation, 494–496 recommendations and future research, 492–494 soil mass balance approach, 467–468 Gash model, 141 Gaussian models, 624 763 Index GC, see Gas chromatography GCM, see General circulation models GDF, see Gas diffusion fluorescence method General circulation models (GCM), 129 Geographical database, soil maps and, 586 Geographic information systems (GIS), 3, 25, 128, 619, 676, 744 advantages of, 34 applications, hydrologic modeling, 36 -based deterministic models, 37 -based NPS pollutant models, 12, 22 -based stochastic models, 38 data pool, 39 definition of, 34 -linked solute transport model, 29 Geometric scaling, 39 GeoPEARL, 685 Geostatistical procedures for characterizing soil processes, 585–615 case study, 608–614 materials and methods, 608–609 results, 609–614 geostatistical sampling, 605–607 method of data analysis, 607 number of samples, 605–606 sampling configuration and sampling goal, 606–607 sampling support, 605 secondary information, 607 geostatistics, 587–605 kriging interpolation, 591–605 models for variograms, 590–591 theoretical concepts, 587–589 variogram estimation, 589–590 Giese and Tiemann equation, 324 GIS, see Geographic information systems Global food demand, 10 Global multilevel search coordinates (GMCS), 409 Global positioning systems (GPS), 12, 327, 641, 644, 662 Glover relationship, 221 GMCS, see Global multilevel search coordinates GMS, see Granular matrix sensors GPR, see Ground-penetrating radar GPS, see Global positioning systems Granular matrix sensors (GMS), 184 Graphical user interface (GUI), 737 Gravity –capillarity–geometry interaction, 230, 238 dominated infiltration, 237 drainage lysimeters, 317 Newton’s theory of, 20 Green–Ampt assumption, 246 Green–Ampt model, 206 Green–Ampt soil, 224 Green–Ampt wetting front, 216, 217, 227 Griess assay, 522, 523 Ground conductivity meter, 332 Ground-penetrating radar (GPR), 28, 179, 291, 640 Groundwater degradation of, 11 quality, 38 ubiquity score (GUS), 439, 440 vulnerability assessment, 34, 46 GUI, see Graphical user interface GUS, see Groundwater ubiquity score Gypsum block, 183 H Half-life, 93 Half-saturation constant, 113 Hard photons, 276 Headspace autosampler, 471 Heat dissipation sensors, 185, 186 Henry’s law, 109, 110 Herbicide(s) biological losses, 467 groundwater contamination of, 743 postemergence, 747 sorbed, 443 sorption coefficients, 452–453 leaching estimation, 108 substituted-urea, 544 High-performance liquid chromatography (HPLC), 545, 547 High-temperature combustion (HTC) method, 528, 529 Highway deicing, Hillslope hydrology, 72 Hoălder exponent, 628 Horotiu soil, 379 Hounsfield units (HU), 277 HPLC, see High-performance liquid chromatography HTC method, see High-temperature combustion method HU, see Hounsfield units Hurst exponent, 622, 623 Hydraulic capacity function, 97 Hydraulic conductivity, 133, 231 contact sand, 238 equations, 99 field-saturated, 200 macropores, 300, 634 764 Hydraulic conductivity (Continued ) –matric potential relations, 26 –pressure head relationships, 98 saturated, 241, 302 –water content relationship, 243 Hydraulic diffusivity function, 97 Hydraulic properties, heterogeneity of, 280 Hydrazine sulfate, 523 Hydrologic data assimilation, 138 Hydrologic-response model, trial-and-error calibration of, 17 HYDRUS model, 148, 702 Hyperspectral imagery, 640 Hypothesis testing, uses for, 61 Hysteresis, 445, 706 I IC, see Ion chromatography ICP, see Inductively coupled plasma emission spectrometry ICP-MS, see Inductively coupled plasma mass spectrometry Impedance -matching pulse transformer, 362 mismatches, 363 sensors, 177 TDR-measured, 368 Incubation experiments, 449 Indicator kriging, 598, 600 Indirect calibration, 367, 372 Indophenol blue colorimetry, 519 Inductively coupled plasma emission spectrometry (ICP), 539 Inductively coupled plasma mass spectrometry (ICP-MS), 539 Infectious agents, increased human exposure to, 10 Infiltration cumulative, 211 gravity dominated, 237 modeled, 299 rate, steady, 209 spatial variability and, 294 steady-state, 204 transient, 206 vertical, 206 Infiltrometer methods double-ring, 207 multiple-ring, 213, 214 single-ring, 207 schematic, 205 Infrared gas analyzers, 484 Input parameter error, 676 Index Instantaneous equilibrium, 90, 91 Instantaneous profile method, 218–219, 242, 245 In-stream sludge accumulation, Integrated horizontal flux technique, 487 Interactions soil-biosphere-atmosphere (ISBA) model, 131 International Organization for Standardization (ISO), 507 International Union of Pure and Applied Chemistry (IUPAC), 437 Interpolation methods, 138 Intrinsic hypothesis, 589 Inverse characterization, soil processes, 115 Inverse modeling, 33, 89 advantages, 242 application of, 245 characterizing transport mechanisms through, 408 disadvantages, 242 technique, 235, 236 Inverse modeling techniques, transport processes in soil-crop continuum characterized by, 693–713 assessing well-posedness of inverse problem, 703–709 response surface analysis, 703–706 stability analysis, 707–709 uncertainty analysis, 706–707 validity, 706 forward model, 695–697 existence, 696 identifiability, uniqueness, and sensitivity, 696–697 model adequacy, 697 objective function, 697–701 definition, 697–699 multi-informative objective functions, 699–701 optimization algorithms, 701–702 Ion chromatography (IC), 521, 524 Ion-selective electrode, 519 Iron-core electromagnets, 267 Irreversible kinetics, 115 Irreversible soil process description, 90 Irrigated crop production, Irrigation, 73 management, 169, 283 methods, 74, 76–78, 270 rate, 65 requirements, calculation of, 170 ISBA model, see Interactions soil-biosphere-atmosphere model ISO, see International Organization for Standardization 765 Index Isotopic exchange experiment, 447 IUPAC, see International Union of Pure and Applied Chemistry K Kalman filtering, 139 Kelvin’s equation, 186 Kinetic adsorption model, 103 Kinetics diffusion law, 94 first-order, 92, 112 irreversible, 114 reversible, 94 sorption, 114, 446 zero-order, 93, 112 Kinetic sorption model, 114 Kriging indicator, 598, 600 interpolation, 591 lognormal, 597, 598 maps, 578 moisture residuals and, 614 ordinary, 611, 612 requirements, 592 schematic flowchart of, 593 techniques, 40 Kyoto Protocol, L Laboratory calibration systems, 494 LAI, see Leaf area index Land resource region (LRR), 33 Larmor frequency, 256, 260, 268 Latin hypercube sampling (LHS), 688 Leachability index, 439 Leaching, 436 estimates agrochemicals, 45 herbicide sorption, 108 experiment, 379 models, 734, 750 pesticide, 66 water flow during, 423 Leaf area index (LAI), 141 LHS, see Latin hypercube sampling Lindane, Linear equilibrium model, 92 Liquid phase, mass flow in, 95 Local equilibrium assumption, 101 Lognormal kriging, 597, 598 Longwave radiation flux, 130 LRR, see Land resource region Lumped dispersivity, 106 Lysimeter(s) comparison between disturbed and undisturbed, 395 dielectric, 363 gravity drainage, 317 sidewall flow, 394 soil column, 393 spring-loaded wick, 413 studies, history, 316 suction, 317 M MACRO, 283, 299, 686 Macropore(s) networks, three-dimensional, 280 quantitative definition of, 293 tracing, 423 Macroscopic capillary length, 202 Magnetic fields, 256, 267 Magnetic moments, 257 Magnetic resonance imaging (MRI), 32 Major land resource area (MLRA), 33 Malachite green–phosphomolybdenum complex, 537 MAROV index, see Maximum absolute ratio of variation index Mass difference technique, 489 Mass flow, liquid phase, 95 Mass spectrometry (MS), 517, 545 Mass transfer diffusive, 449 equation, 110 kinetics barrier, 423 Mathematics, use of to imitate reality, 719 Matric flux potential, 216, 231 Matrix decomposition, 41 Matrix pore flow parameters, 240 Maximum absolute ratio of variation (MAROV) index, 681, 682 Maximum concentration levels (MCLs), 5, 516 MCLs, see Maximum concentration levels MCS, see Monte Carlo simulations MDL, see Method detection limit MDS, see Minimum data sets ME, see Mercaptoethanol Mean pore water velocity, 399 Mean-square estimation error, 602 Measurement error, soil water content and, 708, 709 scales, 71 Mechanical dispersion, 104, 105 Mediterranean environment, occurrence of rains in, 126 766 Mercaptoethanol (ME), 520 Mesopotamian marshlands, Metal(s), determination in situ method for, 539 laboratory methods for, 539 nutritional, 538 Meta-model, 679 Method detection limit (MDL), 507, 521 Method of moments (MOM), 410, 412, 427 Method of multipliers, 630 Methoxychlor, Metolachlor, 450 Michaelis-Menten rate constants, 112 Microbial communities, methods for characterization of, 565 Microbial diversity, 561 Microbial habitat, soil as, 562 Micrometeorological techniques characteristics of, 493 mass exchange using, 479 aerodynamic technique, 480 backward Lagrangian stochastic technique, 491 Bowen ratio–energy balance technique, 482 eddy covariance technique, 485 mass difference technique, 489 relaxed eddy accumulation technique, 486 strengths and weaknesses, 492 theoretical profile shape technique, 489 Microscale flow, see NMRI and x-ray tomography Microwave -assisted extraction, 446 emission, 154 Minimum data sets (MDS), 576 Minimum measurement variance volume (MMVV), 72 Miscible displacement experiments, characterization of solute transport through, 391–433 breakthrough curve, 395–413 analysis, 404–412 beyond BTC, 412–413 miscible displacement experiment and mathematical description, 395–404 characterization of solute transport, 392–395 recommendations and future research, 426–427 techniques for characterizing nonequilibrium during solute transport in soils, 414–426 Index estimation of nonequilibrium parameters, 423–426 techniques based on breakthrough curves, 414–423 Mixing models, 322, 365 MLRA, see Major land resource area MMVV, see Minimum measurement variance volume Model(s) adequacy, 697 ADE solute transport, 115 bi-modal porosity, 101 Bresler-Dagan, 62, 67 calibration, 729 capacity, 733 cause-and-effect relationships within, 14 classification schemes, 717 components, errors between, 21 conceptual numerical vs., 88 soil water hysteresis, 100 convection-dispersion, 107 design, philosophical axioms guiding, 14 deterministic, 23, 36, 37 digital elevation, 13 dispersion, 494 documentation, 726 DRASTIC, 38 dual porosity, 100 error, 21, 676, 681 European hydrologic, 127 extended kinetics, 93 fate, 674 fluid-dynamics, 269 FOCUS, 750 forward, 695, 706 fractional Brownian motion, 623 Gash, 141 Gaussian, 624 general circulation, 129 GeoPEARL, 685 GIS-based NPS pollutant, 31 GIS-linked solute transport, 29 GLEAMS, 720–725, 738, 740, 741, 742 Green–Ampt, 206 hydrologic response, 17 HYDRUS, 148 interactions soil-biosphere-atmosphere, 131 kinetic adsorption, 103 kinetic sorption, 114 landscape-scale, 32 leaching, 734, 750 LEACHM, 720–725, 738 linear equilibrium, 92 Index MACRO, 283, 299 meta-, 679, 751 mixing, 322, 365 monofractal, 620 multifractal, 626, 629 nonequilibrium, 102 nonlinear, 18 NPS pollutants, 30 numerical transport, 695 parameters, 15 PEARL, 720–725, 738, 750 PELMO, 720–725, 732, 738, 741, 742, 747, 750 pesticide fate, 674, 716 leaching, 686, see also One-dimensional pesticide leaching models sensitivity analysis, 680 practice-oriented operational, 62 predictions, methods for estimating uncertainty of, 22 preferential flow, 687 process-based index, 38 PRZM-3, 720–725, 734, 738 Rao’s attenuation factor, 38 regression, 37 regulatory, 718 reliability, 727 robustness analysis, 728 sensitivity, 697 sequential-equilibria, 450 SHE, 127 snow runoff, 152 soil-crop system, 694 soil hydrology, 736 solute nonequilibrium sorption, 103 transport, 40, 291, 392 sorption, 444 spatially distributed catchments, 684 static, 140 stochastic, 23, 36, 38 stream-tube, 29, 39 SWAP, 703 three-phase mixing, 173 TOPLATS, 139 TOPMODEL, 127 trajectory, 489, 491 transfer function, 303 transport, 359 Laplace transformed version of, 407 optimization algorithm and, 409 uncertainty analysis, 728 causes of, 675 767 use, uncertainty analysis and, 689 user-friendliness of, 727 vadose zone, 20, 23, 24 validation, 15, 729 van Genuchten, 703 variograms, 590 VARLEACH, 718, 719, 720, 738, 743 water balance, 133, 137 WAVE, 113 Modeling, characterization of soil water and chemical fate and transport, 87–121 general conceptualization of soil processes, 90–96 instantaneous equilibrium, 91–92 irreversible kinetics, 92–94 reversible kinetics, 94–95 transport, 95–96 modeling of soil processes, 113–115 building soil process models, 113–114 inverse characterization of soil processes, 115 notation, 116–117 soil-solute transport processes, 101–113 classical description of solute movement, 101–102 nonequilibrium models, 102–104 solute dispersion, 104–107 sorption, 107–109 transformation, 111–113 volatilization and gas solubility, 109–111 soil-water transport processes, 96–101 classical description of water movement, 96–98 dual porosity models, 100–101 water content–pressure head and hydraulic conductivity–pressure head relationships, 98–100 Moisture residuals kriging and, 614 variogram of, 613 tension, 292 Molecular diffusion, 104, 470 MOM, see Method of moments Moment analysis, 79, 406 Momentum roughness, 481 Monin-Obukhov stability parameter, 481 Monod equation, 112 Monte Carlo method, 67 Monte Carlo sensitivity analyses, 681 Monte Carlo simulations (MCS), 22, 682, 683, 684, 741 Most-probable-number (MPN) technique, 572 768 MPN technique, see Most-probable-number technique MRI, see Magnetic resonance imaging MS, see Mass spectrometry Multispectral imagery, 32 MUUF dataset, 619 N Nanotechnology, preferential flow mechanism, 304 National Laboratory Environmental Accreditation Conference (NELAC), 506 National Water-Quality Assessment Program, 543 Natural scale, 70, 618 Natural tracer methods, 148 Natural variability, 676 Navier-Stokes equation, 296, 297 NELAC, see National Laboratory Environmental Accreditation Conference Nesslerization method, 517 Neural networks, Neutron moderation, 170 probe, 171 Newton’s theory of gravity, 20 NFT chambers, see Nonflow-through chambers Nitrate determination field monitoring probes, 527 field testing kits, 527 in situ methods for, 527 electrode, 525 reductions, enzymatic, 526 transport, 62 Nitrite -oxidizing bacteria (NOB), 567 reduction of nitrate to, 523 Nitrogen analyzers, automated, 530 determination, organic, 527 distillation-titrimetric method, 520 forms, analytical methods and, 517 natural cycles of, 466 -phosphorus detector (NPD), 547 turnover, 113 NMR, see Nuclear magnetic resonance NMRI, see Nuclear magnetic resonance imaging NMRI and x-ray tomography, 253–288 nuclear magnetic resonance imaging, 255–271 Index applications of NMRI to soil-plant-water processes, 268–270 Fourier imaging, 259–268 measurement principle, 255–259 strengths and weaknesses of NMR imaging, 271 prospects and future research imperatives, 283 macroscale, 283 microscale, 283 use of NMRI and x-ray tomography for practical engineering purposes, 282–283 x-ray computed tomography, 272–282 analysis of measured attenuation, 274–279 applications of x-ray tomography to soil-plant-water processes, 279–281 measurement components, 273–274 measurement principle, 272–273 strengths and weaknesses of x-ray tomography, 281–282 NOB, see Nitrite-oxidizing bacteria NOEC, see No effect concentrations No effect concentrations (NOEC), 575 NOELs, see No observable effect levels Nonequilibrium chemical, 448 models, 102 transport-related, 448 Nonflow-through (NFT) chambers, 474, 478 first description of, 475 perfectly designed, 476 performance, 478 Nonideal sorption, 103 Nonideal transport, factors responsible for, 102 Nonirrigated crop production, Nonlinear models, 18 Nonpoint-source (NPS) pollution, broad-scale modeling of, 29 challenge to modeling, 653 effects of on human health, model(s), 30 discrimination, 18 GIS-based, 12, 22 Nonpoint-source pollution, subsurface, 1–58 case study, 42–46 definition and characteristics of NPS pollution, 3–4 justification for assessing NPS pollution in soil, 9–11 multidisciplinary approach for assessing subsurface NPS pollutants, 11–42 deterministic modeling process, 13–23