Marianne Hayes August and Kati Long
Surface-water, ground-water, and water-quality data are published annually on a statewide basis as U.S. Geological Survey Water-Data reports. In 1991, a comprehensive geographic information system (GIS) was created to produce the map illustrations for the annual Nevada water-data report. A description of each data-collection sampling site was stored as point data, in a digital GIS data base or coverage. Each point coverage represented a different category of data-collection sites. Because some sites fell into several categories of data-collection sites, these multiple-point coverages were found to be inefficient and confusing. In 1992, a single point coverage was developed that allows for interactive display and query of the complex point data. This data-base structure was designed to accommodate USGS publication needs. The data base was normalized to reduce the redundancy and remove inconsistencies. The data base also was optimized by clustering the data into distinct groups and by using consistent attributes and naming conventions. The data base will be updated annually for the Nevada water-data report, but data from previous years will be retained.