Reference Manual SWAP; version 3.0.3

SWAP simulates vertical transport of water, solutes and heat in variably saturated, cultivated soils. The program has been developed by Alterra and Wageningen University, and is designed to simulate transport processes at field scale level and during whole growing seasons. This manual describes the theoretical background and modeling concepts that were used for soil water flow, solute transport, heat flow, evapotranspiration, crop growth, multi-level drainage and interaction between field water balance and surface water management. An overview is given of model use, input requirements and output tables

[1]  L. F. Ernst,et al.  Invloed van grondwateronttrekking voor beregening en drinkwater op de grondwaterstand , 1979 .

[2]  David E. Elrick,et al.  Infiltration from Constant‐Head Well Permeameters and Infiltrometers , 1992 .

[3]  Paul R. Lowe,et al.  The Computation of Saturation Vapor Pressure , 1974 .

[4]  Michel Vauclin,et al.  A note on estimating finite difference interblock hydraulic conductivity values for transient unsaturated flow problems , 1979 .

[5]  Coen J. Ritsema,et al.  How water moves in a water repellent sandy soil: 1. Potential and actual water repellency , 1994 .

[6]  W. R. V. Wijk,et al.  Physics of Plant Environment , 1964 .

[7]  C. R. Lloyd,et al.  Estimating sparse forest rainfall interception with an analytical model , 1995 .

[8]  W.H.J. Beltman,et al.  Analytical modelling of pesticide transport from the soil surface to a drinking water well , 1995 .

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

[10]  M. Th. van Genuchten,et al.  Parameter estimation for unsaturated flow and transport models — A review , 1987 .

[11]  Klaas Oostindie,et al.  Simulation of bromide tracer and nitrogen transport in a cracked clay soil with the FLOCR/ANIMO model combination , 1999 .

[12]  Joe T. Ritchie,et al.  Model for predicting evaporation from a row crop with incomplete cover , 1972 .

[13]  D. R. Causton,et al.  The Biometry of Plant Growth , 1982 .

[14]  W. E. Peat,et al.  Relationships between Photosynthesis and Light Intensity in the Tomato , 1970 .

[15]  O. Tetens,et al.  Uber einige meteorologische begriffe , 1930 .

[16]  W. R. Gardner,et al.  The Prediction of Evaporation, Drainage, and Soil Water Storage for a Bare Soil , 1969 .

[17]  Hannes Flühler,et al.  Tracer Characteristics of Brilliant Blue FCF , 1995 .

[18]  Wesley W. Wallender,et al.  IRRIGATION WATER MANAGEMENT AND SOIL-WATER HYSTERESIS-A COMPUTER MODELING STUDY WITH STOCHASTIC SOIL HYDRAULIC PROPERTIES , 1991 .

[19]  J. Quirk,et al.  Permeability of porous solids , 1961 .

[20]  David Russo,et al.  Estimation of finite difference interblock conductivities for simulation of infiltration into initially dry soils , 1992 .

[21]  Steven G. Thoma,et al.  Impact of fracture coatings on fracture/matrix flow interactions in unsaturated, porous media , 1992 .

[22]  Pavel Kabat,et al.  SWAPS version 1.0; technical reference manual , 1996 .

[23]  Jack C. Parker,et al.  Effects of hysteresis with air entrapment on water flow in the unsaturated zone , 1987 .

[24]  Brent Clothier,et al.  In Situ Measurement of the Effective Transport Volume for Solute Moving Through Soil , 1992 .

[25]  John Angus,et al.  Phasic development in field crops I. Thermal response in the seedling phase , 1980 .

[26]  H. H. Laar,et al.  Products, requirements and efficiency of biosynthesis: a quantitative approach. , 1974, Journal of theoretical biology.

[27]  R. Rabbinge,et al.  Simulation and systems management in crop protection , 1989, Plant Growth Regulation.

[28]  P. Koorevaar,et al.  Elements of soil physics , 1985 .

[29]  Jack C. Parker,et al.  Determining Soil Hydraulic Properties from One‐step Outflow Experiments by Parameter Estimation: II. Experimental Studies , 1985 .

[30]  P. Milly,et al.  A mass-conservative procedure for time-stepping in models of unsaturated flow , 1985 .

[31]  I. Jorritsma,et al.  Adaptation of the AFRC wheat phenology model for dutch conditions , 1986 .

[32]  P. Raats,et al.  Unstable Wetting Fronts in Uniform and Nonuniform Soils1 , 1973 .

[33]  William H. Press,et al.  Numerical recipes , 1990 .

[34]  R. Feddes,et al.  Simulation of field water use and crop yield , 1978 .

[35]  M. Th. van Genuchten,et al.  Two‐Site/Two‐Region Models for Pesticide Transport and Degradation: Theoretical Development and Analytical Solutions , 1989 .

[36]  Coen J. Ritsema,et al.  Preferential flow paths in a water repellent clay soil with grass cover , 1996 .

[37]  Jan M. H. Hendrickx,et al.  Experimental assessment of preferential flow paths in a field soil , 1989 .

[38]  J. W. Biggar,et al.  Spatial variability of the leaching characteristics of a field soil , 1976 .

[39]  G. Fogg.  The state and movement of water in living organisms. , 1966, Journal of the Marine Biological Association of the United Kingdom.

[40]  B. Mohanty,et al.  A new convergence criterion for the modified Picard iteration method to solve the variably saturated flow equation , 1996 .

[41]  J. Parlange,et al.  On Solving the Flow Equation in Unsaturated Soils by Optimization: Horizontal Infiltration , 1975 .

[42]  Joseph Shalhevet,et al.  Using water of marginal quality for crop production: major issues , 1994 .

[43]  Christiaan Dirksen,et al.  Unsaturated hydraulic conductivity , 1990 .

[44]  Stephen Abenney-Mickson,et al.  WATER BALANCE OF FIELD PLOTS PLANTED WITH SOYBEAN AND PUMPKIN , 1997 .

[45]  C. Dirksen,et al.  Hydraulic Conductivity and Diffusivity: Laboratory Methods , 2018, SSSA Book Series.

[46]  Johan Bouma,et al.  A CASE STUDY ON INFILTRATION INTO DRY CLAY SOIL I. MORPHOLOGICAL OBSERVATIONS , 1978 .

[47]  F. van den Berg,et al.  PEsticide Leaching and Accumulation model (PESTLA) version 3.4 : description and user's guide , 1998 .

[48]  Marvin E. Jensen,et al.  Thermodynamic Factors in Evapotranspiration , 1987 .

[49]  J. Bronswijk,et al.  Shrinkage of Dutch clay soil aggregates. , 1990 .

[50]  D. M. Gates,et al.  Effects of Nitrate Application on Amaranthus powellii Wats. : I. Changes in Photosynthesis, Growth Rates, and Leaf Area. , 1985, Plant Physiology.

[51]  Christopher G. Uchrin,et al.  Indirect Methods for Estimating the Hydraulic Properties of Unsaturated Soils , 1994 .

[52]  Wim G.M. Bastiaanssen,et al.  Is large-scale inverse modelling of unsaturated flow with areal average evaporation and surface soil moisture as estimated from remote sensing feasible? , 1993 .

[53]  J. Bouma,et al.  Using morphometric expressions for macropores to improve soil physical analyses of field soils. , 1990 .

[54]  Jack C. Parker,et al.  Development and evaluation of closed-form expressions for hysteretic soil hydraulic properties , 1987 .

[55]  Ole Wendroth,et al.  Reevaluation of the Evaporation Method for Determining Hydraulic Functions in Unsaturated Soils , 1993 .

[56]  G. D. Rooij,et al.  Preferential flow in water repellent sandy soils; model development and lysimeter experiments. , 1996 .

[57]  Y. Mualem.  A New Model for Predicting the Hydraulic Conductivity , 1976 .

[58]  E. G. Youngs,et al.  Scaling of infiltration behavior in dissimilar porous materials , 1981 .

[59]  J. Goudriaan,et al.  Some techniques in dynamic simulation , 1982 .

[60]  Louis W. Dekker,et al.  Moisture variability resulting from water repellency in Dutch soils , 1998 .

[61]  E. Maas,et al.  CROP SALT TOLERANCE–CURRENT ASSESSMENT , 1977 .

[62]  E. Youngs,et al.  Fundamentals of Soil Physics. , 1982 .

[63]  John R. Nimmo,et al.  Unsaturated flow in a centrifugal field: Measurement of hydraulic conductivity and testing of Darcy's Law , 1987 .

[64]  J. Philip,et al.  Theory of Infiltration , 1969 .

[65]  S. Matula,et al.  Automatic atomized water spray system for soil hydraulic conductivity measurements. , 1994 .

[66]  Pratap Singh,et al.  Hydrological response of snowpack under rain-on-snow events: a field study , 1997 .

[67]  D. R. Nielsen,et al.  Simultaneous scaling of soil water retention and hydraulic conductivity curves , 1992 .

[68]  Molly M. Gribb,et al.  Estimating hysteresis in the soil water retention function from cone permeameter experiments , 1999 .

[69]  J.J.B. Bronswijk,et al.  Modelling soil water dynamics in the unsaturated zone — State of the art , 1988 .

[70]  H.W.G. Booltink,et al.  Sensitivity analysis on processes affecting bypass flow. , 1993 .

[71]  Louis W. Dekker,et al.  Water repellency in the dunes with special reference to the Netherlands , 1990 .

[72]  B. K. Khosla,et al.  Agricultural Salinity Assessment and Management , 1996 .

[73]  J.J.B. Bronswijk,et al.  Field-scale solute transport in a heavy clay soil , 1995 .

[74]  G. Bolt.  Soil chemistry. B. Physico-chemical models. , 1979 .

[75]  Lars Bergström,et al.  Interpreting non-steady state tracer breakthrough experiments in sand and clay soils using a dual-porosity model , 1994 .

[76]  J. C. van Dam,et al.  Comparison of six methods to determine unsaturated soil hydraulic conductivity. , 1994 .

[77]  Adel M. El-Prince,et al.  Heat and Mass Transfer in the Biosphere 1. Transfer Processes in Plant Environment , 1976 .

[78]  Jack C. Parker,et al.  Determining Soil Hydraulic Properties from One-step Outflow Experiments by Parameter Estimation: I. Theory and Numerical Studies1 , 1985 .

[79]  Leonard F. DeBano,et al.  Soil wettability: A neglected factor in watershed management , 1965 .

[80]  U. Hornung,et al.  Truncation errors in the numerical solution of horizontal diffusion in saturated/unsaturated media , 1983 .

[81]  H.F.M. ten Berge.  Heat and water transfer at the bare soil surface: aspects affecting thermal imagery. , 1986 .

[82]  William A. Jury,et al.  Simulation of solute transport using a transfer function model , 1982 .

[83]  Alberto Fernández,et al.  An energy balance model of seasonal snow evolution , 1998 .

[84]  W. H. van der Molen,et al.  A solution in closed form and a series solution to replace the tables for the thickness of the equivalent layer in Hooghoudt's drain spacing formula , 1991 .

[85]  C. Rappoldt,et al.  Reference manual of the FORTRAN utility library TTUTIL v. 4 , 2000 .

[86]  J.J.T.I. Boesten,et al.  Behaviour of herbicides in soil: simulation and experimental assessment. , 1986 .

[87]  M. Celia,et al.  A General Mass-Conservative Numerical Solution for the Unsaturated Flow Equation , 1990 .

[88]  John R. Porter,et al.  A winter wheat crop simulation model without water or nutrient limitations , 1984, The Journal of Agricultural Science.

[89]  H. Keulen,et al.  A simple and universal crop growth simulator: SUCROS87. , 1989 .

[90]  M. V. Genuchten,et al.  A dual-porosity model for simulating the preferential movement of water and solutes in structured porous media , 1993 .

[91]  Janice L. Stolzy,et al.  Effects of spatial variability of soil hydraulic properties in water budget modeling , 1977 .

[92]  R. A. Feddes,et al.  CRIWAR 2.0 A simulation model on crop irrigation water requirements. , 1996 .

[93]  S.E.A.T.M. van der Zee,et al.  Transport of reactive solute in spatially variable soil systems , 1987 .

[94]  Smith Martin,et al.  Cropwat : a computer program for irrigation planning and management , 1992 .

[95]  A. Klute.  Methods of soil analysis. Part 1. Physical and mineralogical methods. , 1988 .

[96]  David Russo,et al.  The spatial variability of water and solute transport properties in unsaturated soil: II. Scaling models of water transport , 1987 .

[97]  Aaldrik Tiktak,et al.  PEARL model for pesticide behaviour and emissions in soil-plant systems , 2001 .

[98]  L. Ernst.  Drainage of undulating sandy soils with high groundwater tables: I. A drainage formula based on a constant hydraulic head ratio , 1978 .

[99]  F. D. Vries,et al.  Rates of Respiration and of Increase in Structural Dry Matter in Young Wheat, Ryegrass and Maize Plants in Relation to Temperature, to Water Stress and to Their Sugar Content , 1979 .

[100]  Gedeon Dagan,et al.  Unsaturated flow in spatially variable fields: 2. Application of water flow models to various fields , 1983 .

[101]  J. G. Wesseling.  De invloed van bodemsoort en vochtgehalte op de bodemtemperatuur , 1985 .

[102]  J. C. van Dam,et al.  Numerical simulation of infiltration, evaporation and shallow groundwater levels with the Richards equation , 2000 .

[103]  Jan M. H. Hendrickx,et al.  Preferential flow mechanism in a water repellent sandy soil , 1993 .

[104]  J. Goudriaan,et al.  Simulation of crop growth for potential and water - limited production situations : as applied to spring wheat , 1992 .

[105]  Klaas P. Groen.  Pesticide leaching in polders : field and model studies on cracked clays and loamy sand , 1997 .

[106]  Randel Haverkamp,et al.  A Comparison of Numerical Simulation Models For One-Dimensional Infiltration1 , 1977 .

[107]  A. J. Desbarats.  An Interblock Conductivity Scheme for Finite Difference Models of Steady Unsaturated Flow in Heterogeneous Media , 1995 .

[108]  P. J. Wierenga,et al.  A generalized solution for solute flow in soils with mobile and immobile water , 1979 .

[109]  J. C. van Dam,et al.  Parameter estimation of soil hydraulic functions using inverse modeling of transient outflow experiments. , 1996 .

[110]  Joop G Kroes,et al.  User's guide of SWAP version 2.0 : Simulation of water flow, solute transport and plant growth in the Soil-Water-Atmosphere-Plant environment , 1997 .

[111]  J. Doorenbos,et al.  Guidelines for predicting crop water requirements , 1977 .

[112]  Peter Droogers,et al.  Estimation of Regional Effective Soil Hydraulic Parameters by Inverse Modeling , 1993 .

[113]  J. Bear.  Dynamics of Fluids in Porous Media , 1975 .

[114]  K. Beven,et al.  Macropores and water flow in soils , 1982 .

[115]  C. Dirksen,et al.  Water and salt transport in daily irrigated root zone. , 1987 .

[116]  G. C. Topp,et al.  Advances in Measurement of Soil Physical Properties: Bringing Theory into Practice , 1993 .

[117]  Peter Droogers,et al.  Inverse method to determine soil hydraulic functions from multistep outflow experiments. , 1994 .

[118]  H. van Keulen,et al.  Simulation of water use and herbage growth in arid regions. , 1981 .

[119]  Reinder A. Feddes,et al.  Simulation model of the water balance of a cropped soil: SWATRE , 1983 .

[120]  D. R. Nielsen,et al.  Solute Movement in a Field Soil1 , 1977 .

[121]  L. S. Pereira,et al.  Crop evapotranspiration : guidelines for computing crop water requirements , 1998 .

[122]  Nicholas Kouwen,et al.  Hysteretic effects on net infiltration , 1983 .

[123]  C. S. Durst,et al.  Physical and Dynamical Meteorology , 1935 .

[124]  S. P. Neuman,et al.  Estimation of aquifer parameters under transient and steady-state conditions: 2 , 1986 .

[125]  Henk Ritzema,et al.  Drainage principles and applications. , 1994 .

[126]  Jan M. H. Hendrickx,et al.  Water and solute movement in a coarse-textured water-repellent field soil , 1990 .

[127]  H. H. Cheng,et al.  Pesticides in the soil environment : processes, impacts, and modeling , 1990 .

[128]  J. C. van Dam,et al.  Field-scale water flow and solute transport: SWAP model concepts, parameter estimation and case studies. , 2000 .

[129]  J. E. Glynn,et al.  Numerical Recipes: The Art of Scientific Computing , 1989 .

[130]  R. Allen,et al.  Evapotranspiration and Irrigation Water Requirements , 1990 .

[131]  J.J.T.I. Boesten,et al.  Simple model for daily evaporation from fallow tilled soil under spring conditions in a temperate climate. , 1986 .

[132]  Jan W. Hopmans,et al.  Stochastic analysis of soil water regime in a watershed , 1989 .

[133]  G. Dagan,et al.  Water Flow and Solute Transport in Soils , 1993, Advanced Series in Agricultural Sciences.

[134]  Johan Bouma,et al.  Assessing the suitability of soils with macropores for subsurface liquid waste disposal , 1983 .

[135]  D Rc.  Water, Heat, and Crop Growth , 1972 .

[136]  Feike J. Leij,et al.  Analysis of Measured, Predicted, and Estimated Hydraulic Conductivity Using the RETC Computer Program , 1992 .

[137]  R. Feddes,et al.  SWAP 1993: Input instructions manual. , 1994 .

[138]  Allan Walker,et al.  A Simulation Model for Prediction of Herbicide Persistence , 1974 .

[139]  C. Dirksen,et al.  Flux controlled sorptivity measurements to determine soil hydraulic property functions , 1979 .

[140]  J. Doorenbos,et al.  Yield response to water , 1979 .

[141]  Tissa H. Illangasekare,et al.  Analytical Solutions for Water Flow and Solute Transport in the Unsaturated Zone , 1995 .

[142]  H.D.J. van Heemst,et al.  Crop phenology and dry matter distribution , 1986 .

[143]  R. W. Cleary,et al.  Chapter 10: Movement of Solutes in Soil: Computer-Simulated and Laboratory Results , 1979 .

[144]  C. J. Ritsema,et al.  Flow and transport in water repellent sandy soils , 1998 .

[145]  E. E. Miller,et al.  Physical Theory for Capillary Flow Phenomena , 1956 .

[146]  J. G. Kroes,et al.  Global sensitivity analysis of the Soil-Water-Atmosphere-Plant (Swap) model , 1998 .

[147]  L. F. Ernst,et al.  Drainage of undulating sandy soils with high groundwater tables: II. The variable hydraulic head ratio , 1978 .

[148]  J. Gash.  An analytical model of rainfall interception by forests , 1979 .

[149]  G. C. Miller,et al.  Abiotic Transformations in Water, Sediments, and Soil , 2018, Pesticides in the Soil Environment: Processes, Impacts and Modeling.

[150]  D.W.G. van Kraalingen,et al.  Reference manual of the FORTRAN utility library TTUTIL with applications , 1990 .

[151]  George H. Hargreaves,et al.  Reference Crop Evapotranspiration from Temperature , 1985 .

[152]  Johan Bouma,et al.  The effect of bypass flow and internal catchment of rain on the water regime in a clay loam grassland soil , 1987 .

[153]  R. A Feddes.  Crop factors in relation to makkink reference-crop evapotranspiration , 1987 .

[154]  Reinder A. Feddes,et al.  SWACROP: A water management and crop production simulation model. , 1992 .

[155]  F.W.T. Penning de Vries,et al.  Simulation of plant growth and crop production. , 1983 .

[156]  H.W.G. Booltink,et al.  Morphometric methods for simulation of water flow. , 1993 .

[157]  J. Bronswijk,et al.  Modeling of water balance, cracking and subsidence of clay soils , 1988 .

[158]  M. Th. van Genuchten,et al.  HYSWASOR — Simulation Model of Hysteretic Water and Solute Transport in the Root Zone , 1993 .

[159]  Joe T. Ritchie,et al.  Soil shrinkage relationships of Texas vertisols: I. Small cores. , 1980 .

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

[161]  F.W.T. Penning de Vries,et al.  Simulation of growth processes and the model BACROS , 1982 .

[162]  P. J. Ross,et al.  Efficient numerical methods for infiltration using Richards' equation , 1990 .

[163]  W. R. Stern.  Simulation of water use, nitrogen nutrition and growth of a spring wheat crop , 1989 .

[164]  C. A. Diepen,et al.  Crop-specific simulation parameters for yield forecasting across the European Community , 1993 .

[165]  C. A. van Diepen,et al.  WOFOST 6.0 : user's guide for the WOFOST 6.0 crop growth simulation model , 1994 .

[166]  Coen J. Ritsema,et al.  How water moves in a water repellent sandy soil: 2. Dynamics of fingered flow , 1994 .

[167]  D. B. Jaynes,et al.  Comparison of soil-water hysteresis models , 1984 .

[168]  C. Priestley,et al.  On the Assessment of Surface Heat Flux and Evaporation Using Large-Scale Parameters , 1972 .

[169]  A. W. Warrick,et al.  Numerical approximations of darcian flow through unsaturated soil , 1991 .

[170]  Mehdi Homaee,et al.  Root water uptake under non-uniform transient salinity and water stress , 1999 .

[171]  I. Supit,et al.  System description of the WOFOST 6.0 crop simulation model implemented in CGMS , 1994 .

[172]  H. Berge,et al.  Simulation of Ecophysiological Processes of Growth in Several Annual Crops , 1989 .

[173]  Philippe C. Baveye,et al.  Determining the hydraulic properties of a swelling soil from a transient evaporation experiment , 1997 .

[174]  J. C. Ramírez,et al.  Estimation of aquifer parameters under transient and steady-state conditions , 1984 .

[175]  H. Keulen,et al.  Simulation of Water Use, Nitrogen Nutrition and Growth of a Spring Wheat Crop , 1987, The Journal of Agricultural Science.

[176]  J.J.T.I. Boesten,et al.  Modeling the Influence of Sorption and Transformation on Pesticide Leaching and Persistence , 1991 .

[177]  H.T.L. Massop,et al.  Hydrologisch onderzoek naar de drainageweerstanden van het tertiair ontwateringsstelsel in Oost - Gelderland , 1994 .

[178]  H. L. Penman.  Natural evaporation from open water, bare soil and grass , 1948, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[179]  Uri Shani,et al.  Analyses of infiltration events in relation to determining soil hydraulic properties by inverse problem methodology , 1991 .

[180]  J. C. van Dam,et al.  Unsaturated soil water movement in hysteretic and water repellent field soils , 1996 .