Marine Unsaturated Model
The Marine Unsaturated Model is a two-dimensional finite element model capable of simulating the migration of water and solutes in saturated-unsaturated porous media while accounting for the impact of solute concentration on water density and viscosity, as saltwater is heaving and more viscous than freshwater. The detailed formulation of the MARUN model is found in and. The model was used to investigate seepage flow in trenches and dams, the migration of brine following evaporation and, submarine groundwater discharge, and beach hydrodynamics to explain the persistence of some of the Exxon Valdez oil in Alaska beaches.
Model formulation
In the absence of source/sink terms, the equation for the conservation of the fluid mass is:where is the porosity of the medium and S is the water saturation ratio of soil moisture with a value of 1 implying fully saturated soil,
In the absence of source/sink terms, the equation for the conservation of the solute equation is expressed as:
BIOMARUN
The model BIO-MARUN resulted from combining the model BIOB with the MARUN model. The BIOB model and requires the concentration of hydrocarbons, the microbial density, and oxygen and nutrient concentrations. It uses Monod kinetics to predict microbial growth, oxygen consumption, and production. An implementation of the model was also conducted by. The BIOB model can also revert to using default values.The BIOMARUN model allows tracking of two substrates, two microbial communities, and up to 8 solutes, and it was used to predict oil biodegradation under natural conditions and with amendments . The BIOMARUN model was also used to investigate the biodegradation of benzene in tidally influenced beaches