GIS & Geospatial Analysis

Geographic Information Systems (GIS) and geospatial analysis offer a way to obtain a visual understanding of subject matter (such as median household income) for geographic areas (such as counties or neighborhoods). A GIS is a set of integrated software and data where the software has the ability to flexibly display maps with different views and configurations of the data. A GIS has the ability to mix, integrate, and modify data and provide geospatial analysis operations that go beyond only displaying map views. One example of this is in site analysis where the GIS is used to tell the user the number of households, for example, that are within a circle of a given radius from a specific location.

Despite the great detail of data available in tabular form for geographic areas such as counties, census tracts, and other political/statistical geography, it remains difficult to understand patterns and relationships among different geographic areas. Maps help us see these relationships more easily than tables.

What is a GIS? See this overview of GIS: http://proximityone.com/aboutgis23.pdf.

One of the most commonly used GIS operations is to display a map depicting different types of geographic objects. The geographic objects can normally be classified as 1) points or markers, 2) lines connecting two points, or 3) polygons connecting three or more points and forming and area. A point represented on the map corresponds to a specific latitude and longitude coordinate set. A line is drawn between two points and thus goes from one latitude-longitude coordinate set (point A) to another latitude-longitude coordinate set (point B).

Rather than having a set of fixed map views, such as might be provided in an atlas, the GIS offers a way to identify patterns. You can flexibly turn map layers, such as streets, on and off with a mouse click. Change intervals ranges in a thematic map to modify the number of areas shown as part of a particular interval. Change the pattern associated with an interval to emphasize or de-emphasize areas in that interval.

Why use a desktop GIS? VDA Desktop GIS is a desktop GIS which means that it is designed to operate on one computer. Unlike Web-based mapping applications, the desktop GIS enables the user to control security, directly manage adding and updating data, perform operations not possible with Web-based counterparts, operate much faster, among other benefits. Multiple users on a shared network can still access the same GIS project(s) using desktop GIS software.