Proposal for an unsaturated zone oxygen transport and consumption model

An oxygen transport and consumption model has been developed as a submodel to a general numerical model for solute transport in the unsaturated zone. The model comprises diffusive and convective transport of oxygen in soil air, convective transport and oxygen consumption in free water and diffusive transport and a constant rate oxygen consumption in the water saturated soil crumbs. The model also estimates the anaerobic fraction of the water saturated crumbs where no oxygen consumption takes place. The oxygen model has been developed as a tool for making predictions of the behaviour of surface and waste water infiltration plants in order to optimize the operation of such plants. However, the model may also be a useful tool in denitrification modelling where an estimate of the anaerobic fraction of the soil is important.