You may display GIS layers as overlays or backgrounds on your WEAP Schematic. These background maps are listed on the left side of the Schematic View, below the legend. The checkbox next to each layer can be used to hide or show it on the schematic.
To add a layer, right click on the list of background layers and choose Add Vector Layer (e.g. ArcView Shape files: *.shp) or Add Raster Layer (e.g. ArcView GRID or GeoTIFF). This menu also allows you to edit, delete, set labels or reorder the background maps. For instance, to view or edit the attribute data associated with a GIS layer, right-click on the layer name, then select Edit to go to the Map Layer window (shortcut: double click on the layer name to edit). On the Map Layer window that appears, click on an element in the map to see its data (displayed in the table to the left of the map). In Split or Table view, click the Edit button (below the map) to be able to edit the attribute values.
Vector layers display geographic features using discrete X-Y locations. Lines are constructed from strings of points, and polygons (regions) are built from lines which close. Vector methods are sometimes contrasted with raster techniques which record geographic features within a matrix of grid cells. A raster display builds an image from pixels, pels, or elements of coarse or fine resolution, from centimeters to kilometers. Many satellites, like Landsat, transmit raster images of the earth's surface.