The study area is the area to be simulated. There is one study area per application and it must be contiguous. Study areas may be drawn, imported from an existing EFMSim project, or imported from an external data layer. The study area can be drawn and redrawn (via draw or import) in any layout map window, whether a layout is open or not. To draw a study area, click on the Study Area button (red-filled polygon icon; the cursor changes to a “+”), press and hold the control key, use left mouse clicks to enter study area boundary vertices, release the control key and use a final left mouse click to add the final vertex, which is connected to the first vertex to close the study area polygon (Figure).
Figure. Study areas can be drawn by clicking the Study Area button and entering boundary vertices.
Selecting the View – Import Study Area menu option opens a three-step wizard that allows users to pick whether importing from an existing project or an external data layer, selecting the project or data layer, and then selecting features that will comprise the new study area (Figure). If selected features are not contiguous, users are given an option to buffer the selected features. Buffering expands the selected features slightly before merging into a single contiguous polygon. Buffering is only meant to handle small separations between features that are most likely unintended gaps created as neighboring areas are manually created in GIS. If features are separated by more than the buffer distance, a message is provided about the buffer fail, and users are asked whether they would like to select different features.
Figure. Study areas can be imported from existing EFMSim projects or external data layers.