For this purpose, different indicators can be used. Effects are mapped in terms of pressure fields. Severalnumerical simulations allow to specify and complete the model input condi- tions. Therefore, we can build a database of avalanches that can be used in defining the protection for the desired site. Thepowder snow avalanches are characterized by a low density, high velocities and by the structure of its particularflow.
Whirlwinds are one of the remarkable characteristics that differentiate it from the dense avalanche.
The intense turbulence inducesa strong incorporation of air and causes a hugeincrease of the vol- ume. The powdersnow avalancheis similarto the gravity current from the visual point of view and also in term of physical process. The equations governing this flow are fluid mechanics conservation laws. The strong turbulence requires the use of a closure model that allows to calculate both its inten- sity and scale.