Exploring the Information
In this, the final section of the tutorial, you will learn how to explore the map information by working with layers and examining the attributes of various map features.
Hopefully you've had a chance to take a look at the introduction to GIS Concepts section where we discussed layers.
Because there are often many layers available for a map, map layers are organized into related folders on the Layers Tab (if you don't see the Layer list, you can click on the Layers tab at any time). When you initially open the map, some folders may be open and some may be closed. Likewise, some layers may be turned on while others may be turned off by default.
There may be a number of Jump to configurations available at the top of the layers list that
will allow you to jump to a particular Theme. The Jump to feature opens and closes various folders and/or
layers to produce a map comprised of a predefined combination of layers. Since it can also jump to a different
location on the map, this feature is often used to recreate an existing paper map series or provide quick,
efficient access to popular configurations of map information (e.g. a utilities map, a community recreation
map, or a street map for navigation).
To manually set the display of layers, you can open a closed folder by clicking on it. A list of all layers
contained within the folder will be shown. Similarly, you can click on an open folder to close it. Notice that
opening and closing folders doesn't turn layers on or off; it simply helps you stay organized. Next to the
folder icon you will see a small colored rectangle and a small grey and white rectangle. To display all available
layers in a folder, click the small colored rectangle. Clicking on the grey and white rectangle turns off all
layers in the folder. It doesn't matter if a folder is open or closed when you do this.
You can toggle an individual layer on or off by clicking on the adjacent checkbox. A layer is 'on' (displayed on the map)
when there is a check in its checkbox. Some layers are only available at certain scales. Layers that are available
at the current scale will be shown with a light blue identify icon(
) next to the layer name, while layers that are
unavailable at a given scale are shown with a grey identify icon
(
) next to the layer name. Clicking the red asterisk (
)
next to the name of an unavailable layer zooms you to the closest scale at which the layer is available.
A layer is made 'Active' by clicking on the icon adjacent to a layer name. A black identify icon (
) denotes the active
layer, and its name is displayed in the area below the map window. You can only have one active layer selected at a time.
What the heck does this mean? It means that the spotlight is on this layer. In other words, this is our way of telling the computer that this is the layer in which we are interested. How is this relevant, you ask?
Wow, you ask a lot of questions. Read on.
The introduction to GIS Concepts section discussed layers and how features have attributes in a GIS.
Suppose
you are interested in the attributes associated with a property at a particular location into which
you have zoomed. First, you ensure that the layer with property attributes is the active layer (see the above lesson to do this). In this case, the
'Parcels' layer is made active.
The Identify tool allows you to get attribute information about
a feature by clicking on it. You select the Identify tool to
click on the feature whose attributes you want to examine.
The attributes for that feature are displayed in a new window. If the window does not appear, make sure that the feature you are clicking on is part of the layer that is active.
For more information on this topic, go to the Identify tool help page.
If you have been following the tutorial, congratulations. You've finished the basic tutorial. Pretty painless, wasn't it?
GIS technology helps people and organizations around the world use geographic information to make better decisions about how to manage the world around us. While we've only scratched the surface of what can be done during the basic tutorial, it is our hope that we've perhaps opened your eyes to the power of this technology.
We encourage you to start working with a Geocortex-based web map to put to use the information we've shared. While we've shown you the very basics, we encourage you to spend some more time (now or later) to learn some of the amazing things you can do with a Geocortex-based web map. We haven't shown you how you can draw on and add your own things to the map, create your own custom maps as PDF documents (which you can save and/or print), change the color of layers and set colors based on attribute values, save your Geocortex sessions to share with other people, measure distances, select features based on various criteria, search for things, and a whole lot more. We don't claim all these tasks are dead simple, but we work hard to make everything as simple as possible.