The Auradé Experimental Watershed encompasses and the agricultural watershed Montoussé (320 ha).
- tributary of the Boulouze (tributary of the Save) to Auradé (village of Gers)
- located 40 km west of Toulouse
- in the Coteaux de Gascogne
Crops (rotating wheat / sunflower) occupy 90% of its surface.
The clay soils (called Terreforts) belong to the sequence of calcareous brown-brown calcic-brown soils leached and developed on
- a muddy clay substratum
- a Miocene carbonate substratum *
- The climate is temperate oceanic (T = 12-13 ° C and P = 700-800 mm.a-1) with high evapotranspiration (500 to 600 mm.a-1).
- The impermeable substratum favors surface runoff and the underground water reserves are very limited to a few perched sheets (sandy lenses) in the molasse and to alluvial and colluvial layers.