The CoupModel is a new updated version of the previous WinSoil model (Jansson, 1998). The name “Coup” stems from the word coupled, and the model actually consists of different sub-models, which have been integrated into a system of models. The previous SOILN model (Eckersten et al, 1998, Johnsson et al., 1987) has been incorporated as an integrated part of the new CoupModel. A new approach with multiple plant canopies and also a substantially modified model for the water uptake have been introduced. The major new updates in this report correspond to the changes made to the description of water and heat flows of the system. The present report is also part of the help to the CoupModel program version 2.0.
Depending on whether the reader is a previous user of the SOIL or SOILN models or not, there are different possible strategies for reading this document. A background chapter, “Overview”, presents the basic ideas behind the model and the main purposes with using the model. This is a good start for a new potential user of the CoupModel.
The chapter “Model Structure” presents the basic structure of the model and how the different sub-models are coupled. This is useful reading before going into the chapters that describes the different processes (e.g. plant water processes or soil heat processes) considered in the model. These latter chapters i.e. the chapters on heat-, soil water-, plant water-, atmospheric and snow- and nitrogen and carbon processes are all divided into several sections that correspond to a certain tab in the model (see Edit menu). These sections all have the same layout. First a presentation of the theory behind the model assumptions is given. The optional approaches, switches, can be compared and details concerning definitions of different functions and parameter values, i.e. parameters and parameter tables, are found. At the end of each section the graphical illustrations found in the model, viewing functions, are included as well as a list of the output variables from the simulations, outputs. These chapters of the help/manual are the reference part of the guide.
Technical aspects on the use of input data and how different input outputs are specified are found in a separate chapter, “Common Characteristics”.
Experiences from use of the model and discussions on the validity of different approaches and parameter values for different examples are only briefly discussed in this report. Details on model use will instead be in the scientific literature. A bibliography on different papers where the models have been used is found in the end of this document (see “Bibliography”).