Development-perched watertables and subsurface lateral flows in texture-contrast soils (duplex) are commonly believed to occur as a consequence of the hydraulic discontinuity between the A and B soil horizons. However, in catchments containing shallow bedrock, subsurface lateral flows result from a combination of preferential flow from the soil surface to the soil—bedrock interface, undulations in the bedrock topography, lateral flow through macropore networks at the soil—bedrock interface, and the influence of antecedent soil moisture on macropore connectivity. Review of literature indicates that some of these processes may also be involved in the development of subsurface lateral flow in texture contrast soils. However, the extent to which these mechanisms can be applied to texture contrast soils requires further field studies. Improved process understanding is required for modelling subsurface lateral flows in order to improve the management of waterlogging, drainage, salinity, and offsite agrochemicals movement. 1. Introduction Texture-contrast soils (duplex) cover approximately 20% of the Australian land mass [1] or 2.33？million？km2 [2]. According to Chittleborough et al. [3] texture-contrast soils occur on around 80% of agricultural regions in southern Australia and around 60% of the agricultural regions of south-western Western Australia [4]. The term “texture-contrast soil” has not been explicitly defined in a formal soil classification system. The term “texture-contrast” was first used in the Great Soil Group [5] and Handbook of Australian Soils [6] in reference to the solonetz, solodized solenetz, and the soloths, which all have a marked texture-contrast between the upper and lower horizons. Northcote [7] described the texture-contrast soils as “duplex” in which the subsoil (B horizon) texture is at least one and a half texture groups finer than the surface soil (A Horizon), and horizon boundaries are clear to sharp. The Australian Soil Classification [8] identified three soil orders: Sodosols, Kurosols, and Chromosols, which have a clear or abrupt textural B horizons. Although the term “duplex” has only been used in Australia, soils with contrasting texture between soil horizons are found in other parts of the world [9]. In “Soil Taxonomy” [10], soils showing characteristics most like those of the duplex soils are classified with the formative element “pale” meaning to show excessive development. This includes 15 Great Groups in 3 orders: the Mollisols, Ultisols, and Alfisols. In the FAO-UNESCO World Soil Map (FAO-UNESCO 1987), duplex soils
References
[1]
R. W. Fitzpatrick, S. C. Boucher, R. Naidu, and E. Fritsch, “Environmental consequences of soil sodicity,” Australian Journal of Soil Research, vol. 32, no. 5, pp. 1069–1093, 1994.
[2]
R. F. Isbell, W. S. McDonald, and L. J. Ashton, Concepts and Rationale of the Australian Soil Classification, ACLEP, CSIRO Land and Water, Canberra, Australia, 1997.
[3]
D. J. Chittleborough, K. R. J. Smettem, C. Kirkby, et al., Clay, Phosphate and Water Movement Through a Texture Contrast Soil. Land and Water Resource Research and Development Corporation, for Project UAD1, LWRRC, Canberra, Australia, 1994.
[4]
D. Tennant, G. Scholz, J. Dixon, and B. Purdie, “Physical and chemical characteristics of duplex soils and their distribution in the south-west of Western Australia,” Australian Journal of Experimental Agriculture, vol. 32, no. 7, pp. 827–843, 1992.
[5]
C. G. Stephens, A Manual of Australian Soils, CSIRO, Melbourne, VIC, Australia, 1953.
[6]
H. C. T. Stace, G. D. Hubble, R. Brewer, et al., A Handbook of Australian Soils, Glenside, Australia, 1968.
[7]
K. H. Northcote, A Factual Key for the Recognition of Australian Soils, Rellim Technical, Glenside, South Australia, 1979.
[8]
R. F. Isbell, The Australian Soil Classification, CSIRO, Melbourne, VIC, Australia, 2002.
[9]
D. J. Chittleborough, “Formation and pedology of duplex soils,” Australian Journal of Experimental Agriculture, vol. 32, no. 7, pp. 815–825, 1992.
[10]
Soil Survey Staff, Keys to Soil Taxonomy, USDA—Natural Resource Conservation Service, Washington, DC, USA, 2006.
[11]
W. E. Cotching, J. Cooper, L. A. Sparrow, B. E. McCorkell, and W. Rowley, “Effects of agricultural management on sodosols in northern Tasmania,” Australian Journal of Soil Research, vol. 39, no. 4, pp. 711–735, 2001.
[12]
I. Edwards, “Farming duplex soils: a farmer's perspective,” Australian Journal of Experimental Agriculture, vol. 32, no. 7, pp. 811–814, 1992.
[13]
W. K. Gardner, R. G. Fawcett, G. R. Steed, J. E. Pratley, D. M. Whitfield, and H. Van Rees, “Crop production on duplex soils in south-eastern Australia,” Australian Journal of Experimental Agriculture, vol. 32, no. 7, pp. 915–927, 1992.
[14]
M. Hardie, W. E. Cotching, and P. R. Zund, “Rehabilitation of field tunnel erosion using techniques developed for construction with dispersive soils,” Australian Journal of Soil Research, vol. 45, no. 4, pp. 280–287, 2007.
[15]
H. Morrell, “Catchment issues in farming duplex soils,” Australian Journal of Experimental Agriculture, vol. 32, no. 7, pp. 981–985, 1992.
[16]
M. A. Simeoni, P. D. Galloway, A. J. O'Neil, and R. J. Gilkes, “A procedure for mapping the depth to the texture contrast horizon of duplex soils in south-western Australia using ground penetrating radar, GPS and kriging,” Australian Journal of Soil Research, vol. 47, no. 6, pp. 613–621, 2009.
[17]
G. D. Hubble, R. F. Isbell, and K. H. Northcote, “Features of Australian soils,” in Soils: An Australian Viewpoint, pp. 17–47, CSIRO, Melbourne, VIC, Australia, 1983.
[18]
E. L. Greacen, “Physical properties and water relations,” in Red-Brown Earths of Australia, J. M. Oades, D. G. Lewis, and K. Norrish, Eds., pp. 83–96, Waite Agricultural Research Institute, University of Adelaide and CSIRO, Adelaide, Australia, 1981.
[19]
D. M. Bakker, G. J. Hamilton, D. J. Houlbrooke, and C. Spann, “The effect of raised beds on soil structure, waterlogging, and productivity on duplex soils in Western Australia,” Australian Journal of Soil Research, vol. 43, no. 5, pp. 575–585, 2005.
[20]
J. Brouwer and R. W. Fitzpatrick, “Interpretation of morphological features in a salt-affected duplex soil toposequence with an altered soil water regime in western Victoria,” Australian Journal of Soil Research, vol. 40, no. 6, pp. 903–926, 2002.
[21]
J. W. Cox, E. Fritsch, and R. W. Fitzpatrick, “Interpretation of soil features produced by ancient and modern processes in degraded landscapes. VII. Water duration,” Australian Journal of Soil Research, vol. 34, no. 6, pp. 803–824, 1996.
[22]
J. W. Cox and D. J. McFarlane, “The causes of waterlogging in shallow soils and their drainage in southwestern Australia,” Journal of Hydrology, vol. 167, no. 1–4, pp. 175–194, 1995.
[23]
H. P. Cresswell and J. A. Kirkegaard, “Subsoil amelioration by plant roots—the process and the evidence,” Australian Journal of Soil Research, vol. 33, no. 2, pp. 221–239, 1995.
[24]
J. Eastham, P. J. Gregory, and D. R. Williamson, “A spatial analysis of lateral and vertical fluxes of water associated with a perched watertable in a duplex soil,” Australian Journal of Soil Research, vol. 38, no. 4, pp. 879–890, 2000.
[25]
C. E. Pankhurst, A. Pierret, B. G. Hawke, and J. M. Kirby, “Microbiological and chemical properties of soil associated with macropores at different depths in a red-duplex soil in NSW Australia,” Plant and Soil, vol. 238, no. 1, pp. 11–20, 2002.
[26]
D. J. McFarlane and D. R. Williamson, “An overview of water logging and salinity in southwestern Australia as related to the “Ucarro” experimental catchment,” Agricultural Water Management, vol. 53, no. 1–3, pp. 5–29, 2002.
[27]
P. J. Gregory, D. Tennant, A. P. Hamblin, and J. Eastham, “Components of the water balance on duplex soils in western Australia,” Australian Journal of Experimental Agriculture, vol. 32, no. 7, pp. 845–855, 1992.
[28]
O. R. Lehman and L. R. Ahuja, “Interflow of water and tracer chemical on sloping field plots with exposed seepage faces,” Journal of Hydrology, vol. 76, no. 3-4, pp. 307–317, 1985.
[29]
J. L. Ticehurst, Hydrological analysis for the integration of tree belt plantations into Australia's agricultural systems, Ph.D. thesis, Australian National University, 2004.
[30]
M. G. Anderson and T. P. Burt, “Automatic monitoring of soil moisture conditions in a hillslope spur and hollow,” Journal of Hydrology, vol. 33, no. 1-2, pp. 27–36, 1977.
[31]
C. J. Ritsema, K. Oostindie, and J. Stolte, “Evaluation of vertical and lateral flow through agricultural loessial hillslopes using a two-dimensional computer simulation model,” Hydrological Processes, vol. 10, no. 8, pp. 1091–1105, 1996.
[32]
D. R. Weyman, “Measurements of the downslope flow of water in a soil,” Journal of Hydrology, vol. 20, no. 3, pp. 267–288, 1973.
[33]
J. T. McCord and D. B. Stephens, “Lateral moisture flow beneath a sandy hillslope without an apparent impeding layer,” Hydrological Processes, vol. 1, no. 3, pp. 225–238, 1987.
[34]
C. R. Jackson and T. W. Cundy, “A model of transient, topographically driven, saturated subsurface flow,” Water Resources Research, vol. 28, no. 5, pp. 1417–1427, 1992.
[35]
T. C. Atkinson, “Techniques for measuring subsurface flow on hillslopes,” in Hillslope Hydrology, M. J. Kirkby, Ed., pp. 73–120, John Wiley & Sons, New York, NY, USA, 1978.
[36]
J. W. Cox and R. Ashley, “Water quality of gully drainage from texture-contrast soils in the Adelaide Hills in low rainfall years,” Australian Journal of Soil Research, vol. 38, no. 5, pp. 959–972, 2000.
[37]
J. W. Cox, D. J. Chittleborough, H. J. Brown, A. Pitman, and J. C. R. Varcoe, “Seasonal changes in hydrochemistry along a toposequence of texture-contrast soils,” Australian Journal of Soil Research, vol. 40, no. 4, pp. 581–604, 2002.
[38]
J. W. Cox and A. Pitman, “Chemical concentrations of overland flow and throughflow from pastures on sloping texture-contrast soils,” Australian Journal of Agricultural Research, vol. 52, no. 2, pp. 211–220, 2001.
[39]
D. P. Stevens, J. W. Cox, and D. J. Chittleborough, “Pathways of phosphorus, nitrogen, and carbon movement over and through texturally differentiated soils, South Australia,” Australian Journal of Soil Research, vol. 37, no. 4, pp. 679–693, 1999.
[40]
K. R. J. Smettem, D. J. Chittleborough, B. G. Richards, and F. W. Leaney, “The influence of macropores on runoff generation from a hillslope soil with a contrasting textural class,” Journal of Hydrology, vol. 122, no. 1–4, pp. 235–251, 1991.
[41]
J. Brouwer and R. W. Fitzpatrick, “Restricting layers, flow paths, and correlation between duration of soil saturation and soil morphological features along a hillslope with an altered soil water regime in western Victoria,” Australian Journal of Soil Research, vol. 40, no. 6, pp. 927–946, 2002.
[42]
M. Paul Mosely, “Streamflow generation in a forested watershed, New Zealand,” Water Resources Research, vol. 15, no. 4, pp. 795–806, 1979.
[43]
M. G. Sklash, M. K. Stewart, and A. J. Pearce, “Storm runoff generation in humid headwater catchments: 2. A case study of hillslope and low-order stream response,” Water Resources Research, vol. 22, no. 8, pp. 1273–1282, 1986.
[44]
J. J. McDonnell, “A rationale for old water discharge through macropores in a steep, humid catchment,” Water Resources Research, vol. 26, no. 11, pp. 2821–2832, 1990.
[45]
J. McDonnell, D. Brammer, C. Kendall, et al., “Flow pathways on steep forested hillslopes: the tracer, tensiometer and trough approach,” in Environmental Forest Science, K. Sassa, Ed., pp. 463–474, Kluwer, Boston, Mass, USA, 1998.
[46]
B. L. McGlynn, J. J. McDonnel, and D. D. Brammer, “A review of the evolving perceptual model of hillslope flowpaths at the Maimai catchments, New Zealand,” Journal of Hydrology, vol. 257, no. 1–4, pp. 1–26, 2002.
[47]
H. J. Tromp-van Meerveld and J. J. McDonnell, “Threshold relations in subsurface stormflow: 2. The fill and spill hypothesis,” Water Resources Research, vol. 42, no. 2, 2006.
[48]
J. J. McDonnell, I. F. Owens, and M. K. Stewart, “Case study of shallow flow paths in a steep zero-order basin,” Water Resources Bulletin, vol. 27, no. 4, pp. 679–685, 1991.
[49]
J. J. McDonnell, M. K. Stewart, and I. F. Owens, “Effect of catchment-scale subsurface mixing on stream isotopic response,” Water Resources Research, vol. 27, no. 12, pp. 3065–3073, 1991.
[50]
W. J. van Verseveld, J. J. McDonnell, and K. Lajtha, “A mechanistic assessment of nutrient flushing at the catchment scale,” Journal of Hydrology, vol. 358, no. 3-4, pp. 268–287, 2008.
[51]
D. D. Brammer, Hillslope hydrology in a small forested catchment, M.S. thesis, State University of New York, Environmental Science and Forestry, Maimai, New Zealand, 1996.
[52]
C. B. Graham, R. A. Woods, and J. J. McDonnell, “Hillslope threshold response to rainfall: (1) a field based forensic approach,” Journal of Hydrology, vol. 393, no. 1-2, pp. 65–76, 2010.
[53]
R. C. Sidle, S. Noguchi, Y. Tsuboyama, and K. Laursen, “A conceptual model of preferential flow systems in forested hillslopes: evidence of self-organization,” Hydrological Processes, vol. 15, no. 10, pp. 1675–1692, 2001.
[54]
R. C. Sidle, Y. Tsuboyama, S. Noguchi, I. Hosoda, M. Fujieda, and T. Shimizu, “Seasonal hydrologic response at various spatial scales in a small forested catchment, Hitachi Ohta, Japan,” Journal of Hydrology, vol. 168, no. 1–4, pp. 227–250, 1995.
[55]
Y. Tsuboyama, R. C. Sidle, S. Noguchi, and I. Hosoda, “Flow and solute transport through the soil matrix and macropores of a hillslope segment,” Water Resources Research, vol. 30, no. 4, pp. 879–890, 1994.
[56]
H. J. Tromp-Van Meerveld and J. J. McDonnell, “Threshold relations in subsurface stormflow: 1. A 147-storm analysis of the Panola hillslope,” Water Resources Research, vol. 42, no. 2, 2006.
[57]
H. J. Tromp-van Meerveld and M. Weiler, “Hillslope dynamics modeled with increasing complexity,” Journal of Hydrology, vol. 361, no. 1-2, pp. 24–40, 2008.
[58]
D. Wang, “On the base flow recession at the Panola mountain research watershed, Georgia, United States,” Water Resources Research, vol. 47, no. 3, 2011.
[59]
R. E. Yoder, R. S. Freeland, J. T. Ammons, and L. L. Leonard, “Mapping agricultural fields with GPR and EMI to identify offsite movement of agrochemicals,” Journal of Applied Geophysics, vol. 47, no. 3-4, pp. 251–259, 2001.
[60]
T. J. Gish, W. P. Dulaney, K. J. S. Kung, C. S. T. Daughtry, J. A. Doolittle, and P. T. Miller, “Evaluating use of ground-penetrating radar for identifying subsurface flow pathways,” Soil Science Society of America Journal, vol. 66, no. 5, pp. 1620–1629, 2002.
[61]
S. Noguchi, Y. Tsuboyama, R. C. Sidle, and I. Hosoda, “Subsurface runoff characteristics from a forest hillslope soil profile including macropores, Hitachi Ohta, Japan,” Hydrological Processes, vol. 15, no. 11, pp. 2131–2149, 2001.
[62]
J. Freer, J. J. McDonnell, K. J. Beven et al., “The role of bedrock topography on subsurface storm flow,” Water Resources Research, vol. 38, no. 12, pp. 51–516, 2002.
[63]
N. J. McKenzie, D. Jacquier, R. F. Isbell, and K. Brown, Australian Soil Landscapes: An Illistrated Compendium, CSIRO, 2004.
[64]
W. E. Cotching, S. Lynch, and D. B. Kidd, “Dominant soil orders in Tasmania: distribution and selected properties,” Australian Journal of Soil Research, vol. 47, no. 5, pp. 537–548, 2009.
[65]
M. Hardie, R. Doyle, W. E. Cotching, K. Mattern, and S. Lisson, “Influence of antecedent soil moisture on hydraulic conductivity of a series of texture-contrast soils,” Hydrological Processes. In press.
[66]
R. P. Silberstein, T. J. Hatton, P. Ward, et al., “Modelling drainage and transient water logging in an agricultural catchment,” in Proceedings of the 25th Hydrology and Water Resources Symposium and 2nd International Conference on Water Resources and Environment Research, pp. 999–1004, Institute of Engineers, Brisbane, Australia, July 1999.
[67]
M. Hardie, W. E. Cotching, R. Doyle, G. Holz, S. Lisson, and K. Mattern, “Effect of antecedent soil moisture on preferential flow in a texture contrast soil,” Journal of Hydrology, vol. 398, pp. 191–201, 2011.
[68]
H. J. Tromp-van Meerveld, N. E. Peters, and J. J. McDonnell, “Effect of bedrock permeability on subsurface stormflow and the water balance of a trenched hillslope at the Panola mountain research watershed, Georgia, USA,” Hydrological Processes, vol. 21, no. 6, pp. 750–769, 2007.
[69]
R. Z. Whipkey and M. J. Kirkby, “Flow within soils,” in Hillslope Hydrology, M. J. Kirkby, Ed., pp. 121–144, John Wiley & Sons, New York, NY, USA, 1978.
[70]
F. J. Cook and D. W. Rassam, “An analytical model for predicting water table dynamics during drainage and evaporation,” Journal of Hydrology, vol. 263, no. 1–4, pp. 105–113, 2002.
[71]
W. J. Stolte, R. J. George, and D. J. McFarlane, “Modelling subsurface flow conditions in a salinized catchment in south-western Australia, with a view to improving management practices,” Hydrological Processes, vol. 13, no. 17, pp. 2689–2703, 1999.
[72]
J. L. Ticehurst, B. F. W. Croke, J. M. Spate, and A. J. Jakeman, “Development of a simple cascading bucket model for hillslope hydrology,” in Modsim 2003: Integrative Modeling of Biophysical, Social, and Economic Systems for Resource Management Solutions, pp. 392–397, Modelling and Simulation Society of Australia and New Zealand, Townsville, Australia, July 2003.
[73]
R. E. Smith and R. H. B. Hebbert, “Mathematical simulation of interdependent surface and subsurface hydrologic processes,” Water Resources Research, vol. 19, no. 4, pp. 987–1001, 1983.
[74]
P. G. Sloan and I. D. Moore, “Modeling subsurface stormflow on steeply sloping forested watersheds,” Water Resources Research, vol. 20, no. 12, pp. 1815–1822, 1984.
[75]
R. J. Hunt, J. Doherty, and M. J. Tonkin, “Are models too simple? Arguments for increased parameterization,” Ground Water, vol. 45, no. 3, pp. 254–262, 2007.
[76]
H. S. Lin, W. Kogelmann, C. Walker, and M. A. Bruns, “Soil moisture patterns in a forested catchment: a hydropedological perspective,” Geoderma, vol. 131, no. 3-4, pp. 345–368, 2006.
[77]
M. Weiler and J. J. McDonnell, “Conceptualizing lateral preferential flow and flow networks and simulating the effects on gauged and ungauged hillslopes,” Water Resources Research, vol. 43, no. 3, Article ID W03403, 2007.
[78]
D. Tsutsumi, R. C. Sidle, and K. Kosugi, “Development of a simple lateral preferential flow model with steady state application in hillslope soils,” Water Resources Research, vol. 41, no. 12, pp. 1–15, 2005.
[79]
M. Weiler and J. McDonnell, “Virtual experiments: a new approach for improving process conceptualization in hillslope hydrology,” Journal of Hydrology, vol. 285, no. 1–4, pp. 3–18, 2004.
[80]
K. Beven and P. Germann, “Macropores and water flow in soils,” Water Resources Research, vol. 18, no. 5, pp. 1311–1325, 1982.
[81]
J. C. van Dam, J. Huygen, J. G. Wesseling, et al., Theory of SWAP Version 2.0; Simulation of Water Flow, Solute Transport and Plant Growth in the Soil-Water-Atmosphere-Plant Environment, Wageningen Institute for Environment and Climate Research DLO Winand Staring Centre, Wageningen, The Netherlands, 1997.
[82]
J. Simunek and M. T. van Genuchten, “Modeling nonequilibrium flow and transport processes using HYDRUS,” Vadose Zone Journal, vol. 7, no. 2, pp. 782–797, 2008.
[83]
J. Simunek, N. J. Jarvis, M. T. van Genuchten, and A. Gardenas, “Review and comparison of models for describing non-equilibrium and preferential flow and transport in the vadose zone,” Journal of Hydrology, vol. 272, no. 1–4, pp. 14–35, 2003.
[84]
J. M. K？hne, S. K？hne, and J. Simunek, “A review of model applications for structured soils: a) water flow and tracer transport,” Journal of Contaminant Hydrology, vol. 104, no. 1–4, pp. 4–35, 2009.
[85]
J. Simunek and M. T. van Genuchten, “Contaminant transport in the unsaturated zone: theory and modelling,” in The Handbook of Groundwater Engineering, J. W. Delleur, Ed., chapter 22, pp. 22–38, CRC Press, Boca Raton, Fla, USA, 2007.
[86]
M. T. van Genuchten, “Closed-form equation for predicting the hydraulic conductivity of unsaturated soils,” Soil Science Society of America Journal, vol. 44, no. 5, pp. 892–898, 1980.
[87]
W. Durner, “Hydraulic conductivity estimation for soils with heterogeneous pore structure,” Water Resources Research, vol. 30, no. 2, pp. 211–223, 1994.
[88]
J. S. Christiansen, M. Thorsen, T. Clausen, S. Hansen, and C. J. Refsgaard, “Modelling of macropore flow and transport processes at catchment scale,” Journal of Hydrology, vol. 299, no. 1-2, pp. 136–158, 2004.
[89]
A. I. Gardenas, J. Simunek, N. Jarvis, and M. T. van Genuchten, “Two-dimensional modelling of preferential water flow and pesticide transport from a tile-drained field,” Journal of Hydrology, vol. 329, no. 3-4, pp. 647–660, 2006.
[90]
DHI, 1993, MIKE-SHE, Technical Reference, Manual—Water movement module-release 1.0. Danish Hydraulic Institute, Denmark.
[91]
N. J. Jarvis, The MACRO Model (Version 3.1). Technical Description and Sample Simulations, vol. 19 of Reports and Dissertations, Department of Soil Science, Swedish University of Agricultural Science, Uppsala, Sweden, 1994.
[92]
R. Woods and L. Rowe, “The changing spatial variability of subsurface flow across a hillside,” Journal of Hydrology New Zealand, vol. 35, no. 1, pp. 51–86, 1996.
[93]
C. B. Graham and J. J. McDonnell, “Hillslope threshold response to rainfall: (2) development and use of a macroscale model,” Journal of Hydrology, vol. 393, no. 1-2, pp. 77–93, 2010.
