Modeling 3D spatially distributed water fluxes in an andisol under banana plants

Water fluxes in the subsurface of forested and agricultural ecosystems are spatially widely variable because of several interconnected phenomena. On the one hand, subsurface environments are often highly heterogeneous. On the other hand, infiltration water is often distributed unevenly due to above-ground interception and redistribution of rainfall by the plant canopy. These phenomena have important hydro-ecological consequences because they significantly affect groundwater recharge and nutrient leaching. Field experiments involving subsurface lysimeters and tensiometers were carried out to quantify the spatial distribution of fluxes in an andisol under a banana plant. Wick lysimeters were installed at a depth of 70 cm at several locations with respect to the banana stem to measure spatial distribution of subsurface water fluxes. Collected experimental data were simulated using the HYDRUS software package that numerically solves the Richards equation describing three-dimensional variably-saturated water flow in the subsurface. Spatially distributed drainage fluxes were well reproduced with the numerical model. Due to the impact of stemflow, drainage volumes under the banana stem were up to six times higher than in the row downstream from the stem, as well as between rows, as these areas were sheltered from direct rainfall by the banana leaves and received only throughfall. (Resume d'auteur)

[1]  J. Sansoulet,et al.  Adsorption and transport of nitrate and potassium in an Andosol under banana (Guadeloupe, French West Indies) , 2007 .

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

[3]  K. Vielhauer,et al.  Deep soil water dynamics and-depletion by secondary vegetation in the Eastern Amazon , 2003 .

[4]  G. P. Wind,et al.  Capillary conductivity data estimated by a simple method , 1966 .

[5]  C. A. Young,et al.  Spatially distributed irrigation hydrology: Water balance , 2002 .

[6]  Gerrit H. de Rooij,et al.  Methods of Soil Analysis. Part 4. Physical Methods , 2004 .

[7]  A. Price,et al.  An evaluation of the Gash interception model in a northern hardwood stand , 1999 .

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

[9]  Tammo S. Steenhuis,et al.  Fiberglass wicks for sampling of water and solutes in the vadose zone , 1992 .

[10]  S. Pellerin.  Etude d'une série chronologique de rendements en canne à sucre obtenus en Guadeloupe à partir d'un modèle de simulation du bilan hydrique , 1986 .

[11]  J. Monteith.  Evaporation and environment. , 1965, Symposia of the Society for Experimental Biology.

[12]  M. Taniguchi,et al.  Significance of stemflow in groundwater recharge. 1: Evaluation of the stemflow contribution to recharge using a mass balance approach , 1996 .

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

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

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

[16]  F. Bussière,et al.  3-D modelling of the banana architecture for simulation of rainfall interception parameters , 2005 .

[17]  S. R. Green,et al.  Evaluation of Drainage from Passive Suction and Nonsuction Flux Meters in a Volcanic Clay Soil under Tropical Conditions , 2005 .

[18]  J. Nash,et al.  River flow forecasting through conceptual models part I — A discussion of principles☆ , 1970 .

[19]  Anònim Anònim.  Keys to Soil Taxonomy , 2010 .

[20]  T. Steenhuis,et al.  One‐Dimensional Model to Evaluate the Performance of Wick Samplers in Soils , 1995 .