Jérôme Harmand is a researcher at the LBE laboratory of INRA in Narbonne, France.Claude Lobry is a former Professor of both the University of Bordeaux and University of Nice in France.Alain Rapaport is a researcher at the Applied Mathematics and Informatics Department of INRA in Montpellier, France.Tewfik Sari is Research Director at the National Research Institute of Science and Technology for Environment and Agriculture (IRSTEA) in Montpellier, France.