They are described by parameters like height, width and position in space.
Every polygon can be a target.
In addition, there is the possibility to define more than one target. Hills and mountains, which have a large distance to the tagets, can be taken into consideration by the input of the horizon. The boundary conditions of the simulation can be chosen by the user. First and last day respectively month can be predefined. In addition, the user can look at the values of every simulated time step.