Attribute data for some data elements may be incomplete or missing. Where data are unavailable, a mask should be used to exclude the area from analysis. Selected attributes that cannot be visually verified on plots or on screen are interactively queried and verified on screen. In addition, the attributes are tested against a master set of valid attributes. All attribute data conform to the attribute codes in the classification and correlation document.
Amendments are current as of the date of digitizing.
Each map unit differs from the other units in a survey area and is uniquely identified. Each map unit consists of one to 21 components. In those few areas where detailed maps do not exist, reconnaissance soil surveys are combined with data on geology, topography, vegetation, climate, and remote sensing images to delineate map units and to estimate the percentages of components. The composition for a map unit is generalized to represent the State extent of that map unit and not the extent of any single map unit delineation. The actual composition and interpretive purity of the map unit delineations were based on statistical analysis of transect data.