Background Maps

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 hide all maps at once, right click on the list of background layers and choose Hide All Layers from the popup menu.  Choose Show All Layers to turn them all on.

To add a layer, right click on the list of background layers to open the background layers menu and choose Add Vector Layer (e.g. ESRI Shape files: *.shp) or Add Raster Layer (e.g. ArcGIS GRID, GeoTIFF, spatially referenced JPG or GIF, Band Interleaved by Line (BIL), or Band Interleaved by Pixel (BIP)), or choose these options from the Schematic menu at the top.  For vector layers, you have much flexibility in choosing map colors, data, styles and labels for display, which can be very helpful in highlighting various features from the layers.  These options are available when you first add a vector layer, or when you edit an existing vector layer (double click the layer name to edit, or right click and choose Edit).  See Map Layer for more information.  

You can also make some changes directly from the context menu for the layer.  Right click on the background layer's name and choose one of the following options:

A new, blank WEAP area comes preloaded with several global background layers: Major Rivers, Cities, States, Countries and Oceans.  You can remove them if you want, but your Schematic must have at least one background layer (either a preloaded layer or one of your own).

All background layers must use the same geographic projection.  If you add a layer and it does not appear on the Schematic, it may be because it does not use the same projection as the existing background layers.  WEAP's preloaded global layers use the WGS84 projection (WGS84 files are sometimes referred to as "unprojected," because they are based directly on latitude and longitude.)  If you want to add layers that use a projection different from WGS84, here is what you should do.  (Note: you must do this BEFORE you add any WEAP objects, such as rivers or demand sites, because when you add them they will use the projection in effect, and will disappear when you change to using a different projection.)  Add one of your layers.  Remove all layers (such as the preloaded layers) that are in a different projection.  Go to Set Area Boundaries and set the boundary using your new layer.  If your layer is visible in the Schematic then you have done it correctly.

To use an image file (.jpg, .bmp or .tif) in WEAP as a background on the map, you need a "world" file that georeferences the image (.jgw, bpw, tfw). A world file is simply a 6-line text file that describes the size, location and rotation of an image file. For general information on world files, see  If you don't have a world file for your image, you can create one in any GIS package, such as ArcGIS or QGIS. For a jpeg file (.jpg), the world file would be the same name but with ".jgw" as the extension; for a TIFF file (.tif)z, it would have a .tfw extension; for a .bmp file, it would be .bpw.  To see an example, look in the _Maps\Tutorial subdirectory (within the WEAP Areas path) for the files Map.jpg and Map.jgw. These are used in the Tutorial chapter "Data, Results and Formatting."

WEAP can automatically download and display background maps from several internet sources, such as USGS, OpenStreetMap, Google, National Geographic and ESRI.  These include satellite images, street maps and topographic maps, and can be very helpful when building your WEAP model.  To load a map, right click on the Schematic and choose Background Image Layer from the popup menu, then select the internet source to use, e.g., "USGS Satellite."  Not all sources have good coverage for all parts of the globe, and some are higher resolution than others.  You can explore the various sources to see which works best for your area.  (The number after the name indicates the maximum zoom level for which a map exists, with 22 being the highest.)  WEAP will automatically download the maps for the currently displayed area.  The maps are composed of 256 pixel square "tiles."  As you pan or zoom the map, WEAP will download new map tiles to fill in.  Once a tile has been downloaded, it is cached in the _Maps\Tiles\ folder under the WEAP Areas folder.  Occasionally the background will cover up the WEAP schematic objects (demand sites, etc.).  In this case, just pan or zoom the map a bit to refresh the schematic.  Note that it only works if your projection is WGS84.  To turn off the background map, right click on the Schematic, choose Background Image Layer then select "< None >."  Exiting and restarting WEAP will also clear the background image layer.