Laurent Kergoat¹, Grippa Manuela², Elodie Robert¹, Laetitia Gal³, Amadou Abdourahmane Toure⁴, Amelie Picot⁵, Bruno Lartiges¹ and Guillaume Morin¹, (1)GET Géosciences Environnement Toulouse, Toulouse, France, (2)GET Géosciences Environnement Toulouse, toulouse, France, (3)CNRS, Paris Cedex 16, France, (4)Niamey University, Niamey, Niger, (5)GET Geosciences Environnement Toulouse, Toulouse, France