First, the web allows visual interaction with your data. You can set up a web server that produces maps and generates charts from your data. These maps and charts can be updated in real time as new data are received. At the same time, you can interact with maps or charts to highlight key areas or relationships. Since the maps and charts are published on the Internet, your colleagues and clients can view these updates with you, helping to speed your evaluation.

This last point alludes to the second key capability. Because of the near ubiquitous nature of the Internet (at least in North America and Europe), your data can be widely accessible. You can work on it from almost any location. Perhaps, more interestingly, you can update your data from almost anywhere. This means that you can collect data in the field and instantly update your data sets with the new data.

Both of these features will probably alter the way geoscientist do their work in the very near future. The combination of easy access to your data and visual presentation of these data addresses some of the primary difficulties in performing geoscience evaluations.

Geosciences, and geology in particular, are visual in nature. Most geologist need to see a visual representation of data (cross sections, maps, hydrographs, etc) to fully understand it. The requirements of the science (understanding 3-D and 2-D spacial relationship) probably attracts people who are primarily visual based. The geologist needs to see the outcrop and its spatial relationships to understand its history.

This is probably why geoscientists, in general, were not early adopters of computer technology. Text based input and table based output provides little obvious insight into spacial relationships. The development of graphical interfaces and good applications for generating graphics have allowed geoscientists to begin using computers to display and understand the spatial relationships that are key to their work.

Another fact of geoscience studies is that they usually require field work. Data are not collected in the office or an adjacent lab, but from remote sites away from the office. This separation often leads to delays in getting data from the field and into a usable form. At the same time, transcribing data from field notes into an office database may lead to errors. Finally, if errors occur in the field, it may be several days to weeks before those errors are caught, at which point it may be too late too correct them.

As you can see, the Internet and the web are well suited to serve geoscientists. Not only does the web provide a visual base for analyzing data, its distributed nature provides ready access to your data, as well as, links between your office and field sites.

To date, however, the web and Internet have not been used as primary tools for geoscience evaluations. This is not to say geoscientists are not using new tools. Increasingly, to improve the efficiency and quality of their work, geoscientists are employing GIS.

Geographic Information Systems (GIS) are a very useful way for presenting data in a spatial context. Data that seem incoherent when viewed in tabular form become clear when viewed in a map form.

The most important step in developing a GIS is setting up links between maps and databases. With these links in place, it is possible to query the database by clicking on the map, or send a query to the database and have the query results displayed on the map. Most of the GIS tools have been developed as workstation applications and recently, many of these tools have migrated to personal computers. Unfortunately, these tools require a significant investment in equipment, time, and training to be useful. As a result, application of GIS in geosciences is typically limited to large consulting firms and large projects that can support these costs.

With the advent of the world wide web, it is possible to develop GIS applications without relying on the existing GIS tools. Links between maps and data are a common feature of most web sites. By clicking on a map or graphic, the user is linked to another page or site on the web. This simple linking can be enhanced to perform more extensive database queries through the addition of CGI (common gateway interface, a standard for communication between web servers and other application) scripts. Alternatively, database queries can be set up so that their output is displayed in map form.

A strength of web-based GIS is that it can use common programs and links between them to perform the various pieces of a GIS application. For instance, queries from a web site can be handled by any database program as long as it can be linked to receive commands from a web server. Similarly, the database can send data and direct a charting program to produce a graph based on the query results and send the graph back to the user. Powerful GIS systems can be set up without the cost of purchasing and learning a dedicated GIS package.

Web-Based GIS is not without its faults. The primary problem is speed, GIS relies on extensive use of graphics. Connection speeds over the Internet can make heavy use of graphics intolerably slow for users. For most web-based GIS will probably occur on intranets (internal web sites on local area networks) for the foreseeable future.

In addition, the primary graphics formats (GIF & JPEG) used on web are raster based. Raster images are pixel based, where every point on the image has a pixel value that depends on is color. These images tend to be larger and more difficult to edit than vector-based images. Some of these shortcomings are being addressed by plug-ins for Netscape Navigator. These plug-ins allow users to view vector-based images as well as animations with Netscape Navigator and other browsers that support plug-ins.

Web-based GIS will probably never match the complexity of dedicated GIS programs such as "ArcView & ArcInfo", or "MapInfo". On the other hand, web-based GIS does not require the same resources as these programs. Powerful computers, extensive training, and expensive site licenses are not required for a site wide GIS solution. Running on relatively low-cost "Macintosh web servers", web-based GIS solutions can run as clients on most existing computer systems. Using a Macintosh server ensures comparatively simple setup and maintainance. Costs for a site wide system are limited to the server costs and web browser site licenses.

ES Designs is at the forefront of developing web-based systems for GIS and other geoscience applications. We currently have systems for remote data collection, database queries, and simple GIS. If you are interested in learning more about web-based GIS and its capabilities, please contact us at tclifton@es-designs.com\.