Kansas Geological Survey
1930 Constant Avenue
Campus West, University of Kansas
Lawrence, KS 66047
Telephone: (913) 864-3965
Fax: (913) 864-5317
e-mail: aspiazu@jerez.kgs.ukans.edu
Communication of information about local or regional geology and its relationship to human activity is the fundamental justification for virtually every state or national geological survey. Raw data, a measured value or derived attribute of a particular feature or object at a particular place, is rarely the information of concern to our clients. What people want to know is the relationship of the measurements and attributes of one feature to those other features around it. How close is one object with its particular attributes to another object with different attributes? Just as the three keys to success of a business are location, location, and location -- the three keys to the value of geologic data are spatial, spatial, and spatial. This statement of the obvious translates directly to recognition that, in this age of 'Information Super-Highways,' the use of geographic information system (GIS) technologies is essential to the success of our communication efforts.
The Kansas Geological Survey (KGS) recently completed a project to provide the Kansas Department of Agriculture's Division of Water Resources (DWR) with the tools necessary for its clients to have direct access to databases maintained by the DWR on water wells in Kansas. The databases contain very large volumes of data, and the client base ranges from public policy makers to private businesses and individuals. The data exists in digital form, but is relatively inaccessible even to staff within DWR. Annual reports presented dumps of data tables, which contributed little to communication of information about the data. Water table contour maps were occasionally produced with very low distribution or utility compared to their cost of publication.
This paper will describe the successful application of GIS technology by the Kansas Survey to solve the Division of Water Resource's information communication problem. This project is seen as a prototype for providing public access to the information which can be derived from the Survey's digital geologic data, including the Kansas Digital Geologic Map Database, via the Internet.
Since establishment of an observation well network in 1984, KGS and DWR have been involved in a cooperative annual water level measurement program. About 1380 wells (including stock, irrigation, domestic, and monitoring wells) spread over 47 counties in western and central Kansas are scheduled for annual measurement in January of each year. This year a crew of six people from the KGS successfully measured water levels in 542 of 551 wells visited during a 6 and one-half day field trip.
Each member of the KGS crew was deployed with acquisition software running on a notebook PC interfaced to a GPS unit, along with field notes, maps, a cellular phone and other supplies. The data acquisition software system, WaterWitch, was developed at the KGS. It provides historical data, warning messages for out-of-trend water level measurements or probable errors in well identification, and real-time vehicle tracking and location display (Miller, Davis, and Olea, 1998). The system also helps to enforce completeness in well site documentation. It is clear that this type of data acquisition system is also well suited for collection of field data for mapping surface geology.
Various problems, including plugged, damaged, or destroyed wells, occasionally force wells to be dropped from the observation well network. When this occurs, or when geostatistical analysis identifies areas of spatial under-sampling, it is necessary to identify new wells as candidates for inclusion in the observation network.
Databases relating to various subsets from the total of approximately 51,860 water wells in Kansas have historically been maintained by many separate agencies, including: the U.S. and Kansas Geological Surveys, the Kansas Department of Health and Environment, five Groundwater Management Districts, and the DWR. In addition to agency needs to improve communication of information, development of a comprehensive Kansas water well database was undertaken by the KGS in an attempt to make information accessible about all water wells in Kansas for consideration of potential replacement or enhancement wells in the observation network.
The resulting database, called the Water Information Storage and Retrieval system (WIZARD), has been implemented as an ORACLE database on a Solaris 2.5, UNIX operating system. WIZARD consists of numerous tables which focus on different types of information pertaining to each well, such as water quality, water levels, geology, well construction, use, location, and elevation. Unique well identification numbers are included in each table as a common element to link the tables.
At present, listings of water level measurements and well construction data can be obtained by queries through the WIZARD water well search form provided at the KGS web site: http://magellan.kgs.ukans.edu/WaterLevels/. Using this mechanism, data is provided as a listing without visualization of the spatial context of the data. This mode of data access requires a browser at the user end, which connects, via the Internet, to the data provider's web server. The web server then connects, through middleware, to the relational database management system (RDBMS). The middleware establishes the communications protocols between application programs and the appropriate databases. Middleware may be provided by the vendor of the database management system, the vendor of the application program, or by an independent vendor of communications solutions. The choice of middleware depends upon the operating system of the server and the specific RDBMS. The middleware that implements web access to WIZARD through the water well search form consists of code written in ORACLE's SQL*Plus programming language, and is run by the ORACLE Application Server (OAS). In this case, where no attempt is made to visualize spatial relationships, OAS provides an effective database connection, taking maximum advantage of application libraries bundled with the ORACLE RDBMS.
The web services just described for access to raw data can be extended to include visualization of spatial data by the addition of geographic information systems technology. A GIS is inserted, as an intermediate step between the provider's web server and the RDBMS connection software, enhancing the basic middleware. For the water well project at the KGS this was accomplished using ESRI's ArcView GIS.
Queries on attributes of water wells are handled as before, through RDBMS connection software. However, the choice of connection software depends upon the operating system of the workstation running the GIS project to be served. The KGS has successfully served GIS projects running on a UNIX platform with Solaris 2.5 and on PC platforms with Windows NT.
Running ArcView on a UNIX workstation, the Survey chose ORACLE's SQL*Net as its database connection software. This is a practical solution when both the GIS application and the external database (ORACLE) are both running on UNIX systems. SQL*Net handles the communications protocols between ArcView and the ORACLE database. Within ArcView, the UNIX Database Integrator identifies the location of the databases to which the project may be connected.
When the ArcView project is running on a PC, the Kansas Survey uses database connection software obtained from a third party vendor, the Open Database Connectivity (ODBC) driver from Intersolv. The same company also provides a Java version (JDBC), and similar products can be obtained from a variety of vendors.
For spatial queries, water wells are viewed as map features (points in 2-D map space, or lines (the vertical well bore) in 3-D space. Spatial features (points, lines, polygons, or volumes) are represented by boundary coordinate data maintained in a GIS map feature database. This data is typically maintained in tables separate from the attribute data in the RDBMS. Unique identification codes for the spatial map features are used to relate each feature to its own attribute data. Many coverages displaying characteristics of well attributes (such as water levels in a given year or changes in water level over time) and coverages of other map features which provide spatial context for the well information are developed before the project is served to the web.
The complexity of serving a multitude of spatial features to the web as map images requires the addition of one more component to the system, a GIS map server. The map server functions as a connection between the web server and the GIS in much the same way that the database connection software (middleware) operates between the GIS and the external RDBMS database. The map server establishes the communication protocols between the providers web server and the GIS. It may serve as a network administrator to handle multiple GIS sessions on multiple workstations. Most importantly, the map server provides efficient facilities for browsing, viewing and querying maps. An extension of ArcView, marketed as Internet Map Server (IMS), was used as the map server for the water well project. In IMS, the map browsing, viewing and querying functions are handled by a Java applet. IMS places a minor constraint on potential users since this Java applet requires that the user's browser must be compatible with Java. Microsoft's Internet Explorer would fail this requirement in all but the latest version.
The cooperative effort of the KGS with the DWR to provide spatial data and GIS applications via the Internet was accomplished by the extended system integration outlined in the preceding section. The complete sequence of components from the user to the raw GIS attribute data in an external relational database is shown in Figure 1.
Figure 1. System configuration for providing spatial data and GIS applications via the Internet. |
The GIS map server, GIS application software, and database connection software reside on the provider's system. The only requirement at the user end is access to an appropriate web browser. Once a GIS project has been served to the web, a user may access the project via the Internet from any platform (UNIX, PC, or Macintosh). Users do not need to be running any GIS product at their end in order to browse, view and query the served GIS project. This meets a critical objective of the KGS and DWR for systems designed to provide access to public information. The end result should be robust while placing minimal requirements on the user for hardware or software. As presented here, users need no more than the bare minimum of capabilities currently provided on any personal computer sold with Internet access capability.
Once connected to the served project, the user is able to carry out all of the basic browse, view, and query functions available with the GIS when viewing an existing project. Via the Internet, the user may view tables providing data on all or selected subsets of wells. More importantly, data may be viewed in the spatial context of selected map features. Figure 2 shows a user's view of nine-year changes of water level in western Kansas observation wells. County boundaries, hydrology, and the extent of the High Plains aquifer are selected as base map information. In Figure 3, the user has zoomed in on an area of the Walnut Creek and Pawnee River valleys and has queried for data on one of the wells. In Figure 4, the user has selected a graphic display of depth to water, measured over ten years, for wells near Great Bend, KS. This type of connection permits real time access to changes in the underlying databases. As updates occur in water level or water quality measurements, the user sees the change immediately, rather than waiting for the next published report. The primary limit on functionality to the user is the inability to create or modify coverages in the GIS.
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Figure 2. View of nine-year changes of water level in western Kansas observation wells, accessed via the Internet. |
Figure 3. Walnut Creek and Pawnee River valleys, with data table displayed for a queried well. |
Figure 4. Graphic display of depth to water, measured over ten years, for wells near Great Bend, KS. |
The resulting systems have been thoroughly tested and found to perform quite well. While the concepts are reasonably simple, it should be emphasized that arrival at a fully integrated, working system does not occur without considerable effort and attention to detail. Extreme care should be taken to insure that the map server and database connection software actually meet the communication protocol needs for the specific releases of the web servers, GIS applications software, and relational databases to be used in the system. In addition, all software must be compatible with the intended operating systems running on the provider's hardware. The presentation of these concepts to the Digital Mapping Techniques '98 workshop, based on this article, may be accessed on the Internet at: http://www.kgs.ukans.edu/General/Geology/dmt/spatial.html, where access is also provided to the project described here.
Ground-water resource information is only one specialized aspect of geologic information that could be provided in a useful manner via the Internet using the type of system described here. The merits of such systems are not restricted to political boundaries. Live demonstrations of web access to the KGS water well project have recently been provided to companies and government agencies in Austria responsible for collection and distribution of geochemical data for use in development of mining activities and mitigation of possible adverse environmental impacts of mining.
As additional digital county geologic maps are completed in Kansas, this system will be used by the Kansas Geological Survey in a pilot project to provide enhanced access to geologic data. In addition to viewing the basic digital geologic map database, users will be able to identify on the geologic map image the locations of supplemental data, such as measured sections, images of outcrops, regional cross sections derived from well log data, or subsurface structure maps.
With appropriate application of available technology, effective service of spatial data and geographic information systems applications on the web can be accomplished with only minimum requirements placed upon potential users of the information system. As access to Internet browsers becomes almost universal, providing complex geologic data to the public through systems that make available the visualization capabilities of geographic information systems is good policy.
Miller, R.D., Davis, J.C., and Olea, R.A., 1998, 1998 Annual Water Level Raw Data Report for Kansas: Kansas Geological Survey Open-File Report No. 98-7.
U.S.Department of the Interior, U.S. Geological Survey
<https://pubs.usgs.gov/openfile/of98-487/ross1.html>
Maintained by Dave Soller
Last updated 10.06.98