Fig. 3. Summary of GIS process to map soil types. Process steps include: (a) selected Pittsburgh area with census tracts outlined, (b) area added with greenways (green), prime
agricultural land (dark green), agricultural land of statewide importance (light green), and land with slope greater than 15% (gray), (c) area with urban soils added in brown, and (d) area with marginal soils added in red. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)