Want to know the slope of that hill on the north forty? Or the soil conditions there? What about the stream that flows through the middle -- how much water flows and what's its chemical composition? While we're at it, what are the demographics of the people who live along the length of that stream, and how did they vote in the last election?

You can get all that, and a lot more, from a new collection of databases available on the World Wide Web through Cornell University's Albert R. Mann Library. The Cornell University Geospatial Information Repository (CUGIR) is a searchable, browsable, online repository of data about agriculture, ecology, natural resources and social-political information in New York state, all keyed to precise geographic locations.

Through partnerships with the New York State Department of Environmental Conservation and the Soil Information Systems Laboratory at Cornell, CUGIR provides over 3,000 data files that can be downloaded without cost or use restrictions.

The data is in special file formats in which almost any kind of information can be linked to precise latitude and longitude coordinates. A database on roads, for example, includes the coordinates of all the points on a road linked to information about things like the kind of pavement, the address ranges of buildings located on that road and what government entity is responsible for maintaining it.

Computer programs known as "geospatial information systems" can display such data as a map. Many databases can be combined into a single display, for example to show roads and waterways overlaid on elevation data to create a topographic map. This in turn could be combined with geopolitical data, like census records or land-use zoning.

For example, a site for an industrial plant might need to be near a waterway for cooling, adjacent to a railroad for transportation, within a certain land-use zone and not less than a certain distance from schools and parks. The proper software could pull the appropriate data from CUGIR databases and produce a map of all possible sites.

The data in CUGIR has been pulled together from a wide variety of sources, including government databases not previously available to the public, according to Philip Herold, information services coordinator for Mann Library. It has been made available through the National Spatial Data Infrastructure (NSDI) initiative, created by executive order of the Clinton administration. The NSDI both requires and funds the creation of "clearinghouse nodes" like CUGIR, which is one of two such collections of geospatial data about New York state and part of a linked system of over 90 such nodes worldwide.

CUGIR has been online for about three months, and already users have downloaded some 7,000 files, Herold said. The data is being used by city, state and local governments, farmers, researchers and even high school students, he said.

CUGIR can be found on the web at http://cugir.mannlib.cornell.edu. The other New York state node is the New York State GIS Clearinghouse in Albany at http://www.nysl.nysed.gov/gis/. Users can select any set of clearinghouse nodes, or all nodes, to be searched simultaneously at the NSDI Geospatial Data Clearinghouse Gateway Site at http://130.11.52.178/gateways.html. Software used to analyze the data ranges from highly sophisticated and expensive commercial programs to a free program called ARC Explorer, available at http://www.esri.com/software/arcexplorer/index.html. The U.S. Geological Survey provides a brief introduction to the use of geographic information systems at http://www.usgs.gov/research/gis/title.html.

For more information, contact Philip Herold, information services coordinator, Albert R. Mann Library, Cornell University, Ithaca, N.Y. 14853-4301; phone (607) 255-7959.