Next: Parameter handling Up: Basic Concepts Previous: Expert Mode vs. Easy-To-Use

### Model system

The current version of GREAT-ER comes with a model system covering three submodels: sewer, treatment plant and river. There are up to three complexity modes for each of this submodels: in the simplest model's modes only first-order elimination rates are considered, higher model modes regard elimination processes related to solved or sorbed fractions in various degrees of detail.

All of the submodels are deterministic in principle. Using the Monte-Carlo method set on top of these models, GREAT-ER drives a stochastic approach and model results are returned as distributions of concentrations. GREAT-ER delivers results for all considered geographic objects: sewers (i.e. the influent of a treatment plant), all treatment plants (effluent) and all river stretches within the catchment under investigation. See the model description for more details.

Model results are displayed by colouring river stretches on a map, or as concentration profiles through a river. GREAT-ER provides users with several options to analyse the results and to derive further values from them. iFor further details see below in the tutorial and menu description.