GOVERNMENT TECHNOLOGY/Online shared GIS saves resources
Multi-agency and joint GIS systems have been adopted in many areas to take advantage of resource sharing. However, for many rural communities – where populations and budgets often are small – it is difficult to afford the hardware, high-speed networks, software license fees and trained staff required to implement a shared GIS. Instead of purchasing agency-specific GIS hardware, software and data, and hiring specialists to build a GIS, some local governments are using existing resources to access a GIS that is published over the Internet.
Usually, the online GIS consists of a generalized atlas with a variety of data that can be used for specific local applications. Users can access the online GIS via the personal computers and Internet connections they already possess, saving significant time and money.
Once the pertinent data for the county has been collected, GIS developers can organize it into a general-use atlas that is posted on a central server. Client/server software can then be used to request, display and manipulate data at the local level, typically through a client program that acts as a web browser plug-in, Java applet or other platform.
Since a shared GIS can be administered from a central location, changes made to databases and associated data are current as soon as the administrator posts them on the server. A user can then print a map of a specific area with the most current data, eliminating the need to mass produce maps in hard-copy form that become outdated quickly.
The Scotts Bluff County (Neb.) Atlas www.microimages.com/atlasserver) was created with free data provided by the Nebraska Natural Resources Commission (www.nrc.state.ne.us). It includes elevation data, compressed orthophoto quads for the county, state soil geographic data, census data, township and range data, semi-transparent digital raster data and point data for city locations.
The system demonstrates several applications of a shared central GIS. For example: * City administrators and agencies can quickly navigate to a point of interest and obtain database information about a particular feature. * Landowners in the county can use a zoom tool to view their property and gather accurate area and length calculations about their property from their home PCs. * Users can easily activate or deactivate data layers so they may concentrate on a particular data set. For example, if a maintenance worker for a local water utility is looking for a particular valve in a generalized county atlas, he can hide all the data not pertinent to the task. * Users can zoom to a region of interest and print a map with the specific data layers requested from the published atlas. The user-simplified form of the atlas might consist of the orthophotographs of the areas, along with the accompanying vector data for the desired object.
A properly implemented electronic atlas can serve as the basis for a highly efficient, shared GIS that can be used throughout a widespread area and managed from a centralized location by just one or a few people.
While a local GIS implementation is often costly, published geospatial information through specialized software brings complex GIS utility to the desktop of anyone with an Internet connection and a personal computer. That has allowed smaller and less populated counties to take part in complex geospatial analysis without footing the bill for a specific local application.
