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Year of publication:

Isabelle Braud. IRSTEA-Lyon, Unité de recherche Hydrologie-Hydraulique HHLY, 5 Rue de la Doua, CS70077, F-69626 Villeurbanne Cedex, France, Tel +33 472 20 8778

Youri Rothfuss. Forschungszentrum Jülich GmbH, Institute of Bio- and Geosciences, Agrosphere Institute (IBG-3), Leo-Brandt-Straße, D-52425 Jülich, Germany, Tel +49 2461 61 9429,




SiSPAT (Simple Soil-Plant-Atmosphere Transfer) (Braud et al., 1995; Braud, 2000, 2002) is a 1D mechanistic model able to simulate heat and water in the soil-plant-atmosphere continuum at various time and spatial scales. Coupled heat and water transfer equations within the soil are solved. The latter incorporates liquid and vapor transfer and includes a sink term for root water uptake.

  • Soil temperature and water matric potential are the independent prognostic variables;
  • The model is forced by climatic data (air temperature and humidity, wind speed, incoming solar and longwave radiation and rainfall) measured at a reference height of typically 2 m above the vegetation with a time step of 15–30 min to 1 h and linearly interpolated at the time step of the model;
  • The upper boundary conditions of the soil module is provided by the solution of a set of five equations linking the atmosphere and the surface (energy budget over bare soil and vegetation, respectively, continuity of heat and water vapor transfer fluxes within the canopy, continuity of mass transfer at the soil surface).
  • Root water uptake is simulated using a model based on a resistance network to water transfer approach.

SiSPAT was extensively tested and validated against various data sets covering contrasted climatic and moisture conditions (e.g. Boulet et al., 1997; Braud et al., 1995, 1997; Calvet et al., 1999; Gonzalez-Sosa et al., 1999, 2001; Olioso et al., 2002, Demarty et al., 2005, Moret et al., 2007, Velluet et al., 2014).


SiSPAT-Isotope incorporates stable isotope (18O and 2H) transfer by convection and diffusion in both liquid and vapor phases.

SiSPAT-Isotope was tested and validated against data obtained in the laboratory for bare soil (Braud et al., 2005a and b, 2009) and with vegetation (Rothfuss et al., 2012).


Scientific articles

Boulet, G., Braud, I. and Vauclin, M., 1997. Study of the mechanisms of evaporation under arid conditions using a detailed model of the soil-atmosphere continuum, J. Hydrol., 193 : 114-141.

Braud, I., 2000. SiSPAT User’s manual, Version 3.0, 106 pp.

Braud, I., 2002. SiSPAT User’s Manual Update, version 4.0, 13 pp.

Braud, I., T. Bariac, J. P. Gaudet, and M. Vauclin (2005a), SiSPAT-Isotope, a coupled heat, water and stable isotope (HDO and (H2O)-O-18) transport model for bare soil. Part I. Model description and first verifications, J Hydrol, 309(1-4), 277-300.

Braud, I., T. Bariac, M. Vauclin, Z. Boujamlaoui, J. P. Gaudet, P. Biron, and P. Richard (2005b), SiSPAT-Isotope, a coupled heat, water and stable isotope (HDO and (H2O)-O-18) transport model for bare soil. Part II. Evaluation and sensitivity tests using two laboratory data sets, J Hydrol, 309(1-4), 301-320.

Braud, I., T. Bariac, P. Biron, and M. Vauclin (2009), Isotopic composition of bare soil evaporated water vapor. Part II: Modeling of RUBIC IV experimental results, J Hydrol, 369(1-2), 17-29.

Braud, I., Bessemoulin, P., Monteny, B., Sicot, M., Vandervaere, J.P. and Vauclin, M;, 1997. Unidimensional modelling of a fallow savannah during the Hapex-Sahel experiment using the SiSPAT model, J. Hydrol., 188-189: 912-945 (Hapex-Sahel special issue)

Braud I., A.C. Dantas-Antonino, M. Vauclin, J.L. Thony and P. Ruelle, 1995: A Simple Soil Plant Atmosphere Transfer model (SiSPAT), Development and field verification, J. Hydrol., 166: 213-250.

Calvet, J.C., Bessemoulin, P., Berne, C., Braud, I., Courault, D., Fritz, N., Gonzalez-Sosa, E., Goutorbe, J.P., Haverkamp, R., Jaubert, G., Kergoat, L., Lachaud, G., Laurent, J.P., Mordelet, P., Noilhan, J., Olioso, A., Péris, P., Roujean, J.L., Thony, J.L., Tosca, C., Vauclin, M., Vignes, D., 1999. MUREX : a land-surface field experiment to study the annual cycle of the energy and water budgets, Annales Geophysicae, 17(6): 838-854.

Demarty, J., C. Ottle, I. Braud, A. Olioso, J. P. Frangi, H. V. Gupta, and L. A. Bastidas (2005), Constraining a physically based Soil-Vegetation-Atmosphere Transfer model with surface water content and thermal infrared brightness temperature measurements using a multiobjective approach, Water Resour Res, 41(1).

Gonzalez-Sosa, E., Braud, I., Thony, J.L., Vauclin, M., Bessemoulin, P. and Calvet, J.C., 1999. Modelling heat and water exchanges of fallow land covered with plant-residue mulch, Agr. For. Meteorol., 97: 151-169.

Gonzalez-Sosa, E., I. Braud, J. L. Thony, M. Vauclin, and J. C. Calvet (2001), Heat and water exchanges of fallow land covered with a plant-residue mulch layer: a modelling study using the three year MUREX data set, J Hydrol, 244(3-4), 119-136.

Moret, D., Braud, I., Arrué, J.L., 2007. Water balance simulation of a dry-land soil during fallow under conventional and conservation tillage in semi-arid Aragón, Northeast Spain, Soil Tillage Research, 92(1-2), 251:263.

Olioso, A., et al. (2002), SVAT modeling over the Alpilles-ReSeDA experiment: comparing SVAT models over wheat fields, Agronomie, 22(6), 651-668.

Rothfuss, Y., I. Braud, N. Le Moine, P. Biron, J. L. Durand, M. Vauclin, and T. Bariac (2012), Factors controlling the isotopic partitioning between soil evaporation and plant transpiration: Assessment using a multi-objective calibration of SiSPAT-Isotope under controlled conditions, J Hydrol, 442, 75-88.

Velluet, C., Demarty, J., Cappelaere, B., Braud, I., Issoufou, H. B.-A., Boulain, N., Ramier, D., Mainassara, I., Charvet, G., Boucher, M., Chazarin, J.-P., Oï , M., Yahou, H., Maidaji, B., Arpin-Pont, F., Benarrosh, N., Mahamane, A., Nazoumou, Y.,  Favreau, G., Seghieri, J., 2014. Building a field- and model-based climatology of surface energy and water cycles for dominant land cover types in the cultivated Sahel – Annual budgets and seasonality, Hydrology and Earth System Sciences, in press.


Technical information:

Written in Fortran 77

Modular structure. Consists of:

a-SiSPAT-Isotope main code

b-library of modules called in the code

Operating system(s):



Cecill B


1-time series of simulated soil, plant and atmosphere variables (user-defined time step)

2-time series of soil profiles (user-defined time step)

3-time series of integrated soil profiles (user-defined time step / number of layers)

Export format(s):

.dat / .txt

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