Infiltration and evaporation processes in pyroclastic soils illustrated by selected representative events

Rainfall and potential evaporation represent maximum water fluxes across the ground surface. Actual fluxes instead depend also on crop characteristics and the state of the topsoil (water content and suction). To understand and characterize mechanisms that regulate the soil atmosphere interaction in pyroclastic soils a physical model has been arranged. It consists in a tank containing 1 m(3) of pyroclastic soil exposed at elements and suitably instrumented to measure those variables describing atmosphere and soil states. The monitoring activity carried out over more than two years provides several meteorological events, either representative or singular, occurring during wet and dry periods. This activity also provides the wide experimental dataset needed to understand how the soil state affects seepage mechanisms associated with and regulating actual evaporation and infiltration.