Small-scale digital soil maps for interpreting natural resources

Excerpt

THE Chesapeake Bay and its watershed contain natural resources of nationwide significance. Numerous federal, state, local, and private organizations are involved in monitoring and cleaning up pollution problems in the bay area.

Nonpoint-source pollution from agricultural land is a particularly important consideration in the bay area, and information on soils is necessary to target adequately critical areas for pollution control. While resource managers require detailed soil maps for planning at the county level, smaller scale maps are appropriate for planning on regional, state, or multistate levels.

To meet such needs, the Soil Conservation Service (SCS) is developing the State Soil Geographic (STATSGO) data base (4). Nationwide coverage is scheduled for completion in mid-1989. This represents a new series of general soil maps, compiled at a scale of 1:250,000.

Using such a geographic information system, it will be possible to make interpretive maps for a variety of specific soil properties and interpretations. Data can be combined with other maps and used as input for hydrologic, erosion, or other models.

A new approach

There are several problems with using soil maps over large areas. Detailed soil surveys, often published on a county basis at scales from 1:15 …