GISDATA is a place we provide access to geospatial datasets that have been specially prepared for seamless access and delivery. Some data serve many applications and have national extent. Other data were prepared for a particular time or event, and usually for a limited region. In some cases, similar datasets are also available from some other agency or web site. In these cases, our data may have been reprocessed to serve a particular application, or may be kept as a "snapshot in time" to document an historic event. We have tried to document the "authoritative source" so that users may locate the most up-to-date source for each data layer.

We are actively involved in research activities leading to seamless access and delivery for selected geospatial data (both raster and vector) and in full compliance with relevant standards. Our goal is to introduce seamless browse and delivery of the National Elevation Dataset, the National Land Cover Dataset, and the National Hydrography Dataset.

The creation of this web site was originally motivated by a need to better manage and maintain project databases that we have used for GIS applications. As we have participated in development of project databases over the last 25 years, we have prepared geospatial data to serve the needs of scientific investigations, land use inventories, natural hazard mitigation, and disaster assessments. When projects reach completion, final reports are submitted, scientific teams begin to take on new projects, and databases may begin to lose their immediate relevance and visibility. Plans for long-term data management often seem to languish. Without a data "steward", data may be lost to future GIS applications. A typical problem is that valuable historic data may be cast on media that becomes obsolete (e.g. 9 track tape) and then is lost when we lose the means to read it.

As new standards for digital media evolve and we adopt new transfer formats and standards for GIS interoperability, it is increasingly challenging for us to keep these legacy datasets accessible. For example, the FGDC metadata we have dutifully and carefully collected for a project may not stay current with evolving metadata standards. Metadata collected only a few years ago needs to be upgraded and converted to "parsed and fielded" versions that can be spatially searched and featured in modern NSDI clearinghouse nodes. Another recent example involves raster data written in dozens of ad-hoc formats, all predating our draft SDTS Raster Profile. Will we be able to convert these legacy data to this emerging standard?

What is a place-based partnership? This term is a being used to indicate the sort of grass roots partnership efforts that have arisen to develop and distribute geospatial data that are relevant to a particular localized region (e.g. a watershed, an ecosystem, a National Park, a state, a council-of-governments). An excellent place to see data collections coming online is in the form of NSDI clearinghouse nodes. An example of the sort of grass roots partnerships that have inspired the creation of this web site and our GIS data stewardship is the Aurora Partnership.

What is the role of GISDATA in a place-based GIS paradigm? This web site presently serves several place-based projects that have been developed in recent years. In an ideal world, we will see some of these datasets adopted by operators/maintainers of place-based partnerships and/or NSDI clearinghouse consortia. As this happens, our web site will "work its way out of a job" and revert to the role of a back-up or mirror site. As this happens, we will be able to spend more time on the ambitious undertaking of developing consistent national datasets (i.e. a national synthesis) and seamless data delivery tools. Our goal is to contribute to the National Spatial Data Infrastructure (NSDI) and to the global concept of "digital earth", by providing the best-available geospatial data that comply with and promote the use of geospatial data standards.

If you have comments or suggestions, please contact greenlee@usgs.gov.
Dave Greenlee