MOHID Land is the hydrology module within the three-dimensional MOHID Water Modelling System. MOHID is an integrated system for water flow, consisting of three main modules: Water for three-dimensional fluid dynamics, Land for hydrology and Soil for groundwater flow. The MOHID Land module is a watershed mathematical model or hydrological transport model designed to simulate the flow of water in a drainage basin and aquifer. The processes which are simulated include two-dimensional overland runoff, infiltration into the ground, one-dimensional drainage network flow through rivers and canals, as well as (saturated and unsaturated) porous medium transport. The interactions between the different processes (like water exchange between aquifer and river) are calculated dynamically by the model, using the hydraulic gradients. The different processes occurring in a basin are programmed in different modules. The porous media module was developed in close collaboration with soil scientists from EAN-INIA (Portuguese National Agronomic Station).