GIS WEB SITE

                       WHAT IS GIS?                                

SMART MAPS - LINKING A DATABASE TO THE MAP

A METHOD TO VISUALIZE, MANIPULATE, ANALYZE, AND DISPLAY SPATIAL DATA

GIS (Geographical Information Systems) is computer software that links geographic information (where things are) with descriptive information (what things are).  GIS can present many layers of different information on a common map.

To use a paper map, all you do is unfold it.  Spread out before you is a representation of cities and roads, mountains and rivers, railroads, and political boundaries.  The cities are represented by little dots or circles, the roads by black lines, the mountain peaks by tiny triangles, and the lakes by small blue areas similar to the real lakes.

 A digital map is not much different than a paper map.  A digital map includes more information such as park features and rental, flood plain data, property tax records, voting districts and aerial views.

Think of this geographic data as layers of information underneath the map.  Each layer represents a particular theme or feature of the map.  One theme could be made up of all the roads in an area.  Another theme could represent all the street addresses in the same area.  Yet another could represent all the parks, council districts, school zones, etc.

These themes can be laid on top of one another, creating a stack of information about the same geographic area.  Each layer can be turned off and on, as if you were peeling a layer off the stack or placing it back on.  You control the amount of information about an area that you want to see, at any time, on any specific map by turning individual layers of the map on and/or off.