Layers in ResSim can be displayed, one on top of the other, in the Map Display area of ResSim. There are three types of layers used in the display: map layers, image layers, and ResSim layers. Map layers typically come from GIS shapefiles, DEMs, or DLGs and may contain features such as roads, political boundaries (cities, counties, etc.), rivers, subbasins, waterbodies, etc. Image layers are geospatially referenced images, which may also contain similar information, or perhaps photographic or satellite imagery. Each of these files, along with its associated data, is a called layer. In addition to these static map and image layers are ResSim schematic layers that are shown by default depending on the current module and the currently open dataset. Each ResSim module includes its own default layers – Watershed Setup: Time Series Icons, Study, and Stream Alignment; Network: ResSim and Stream Alignment; Simulation: Model Schematic (which contains the ResSim layer) and Stream Alignment. These ResSim schematic layers contain elements that represent parts of the model schematic you create for your watershed.
Layers are considered hierarchical, which means that they may contain zero or more sub-layers. The first or top layer of a layer hierarchy is referred to as the primary or root layer. Each sub-layer usually represents a different type of component or element contained in the layer. Layers that do not have sub-layers usually contain only one type of drawing element or type. Most static map or image layers contain only one element type.
This section describes the various functions of the Layer Selector including: