‘‘Spolic,’’ or earthy materials from industrial activities (mine spoil, dredging, highway construction); and ‘‘Urbic,’’ or earthy materials containing greater than 35% (by volume) human artifacts and building rubble (ISSS-ISRIC-FAO, 1994).
The World Reference Base proposes the Regosols major soil grouping for ‘‘recently exposed, earthy materials at the earth surface’’ (ISSS-ISRIC-FAO, 1994). The Regosols major soil grouping uses the genetic soil classification approach to identify soils that are ‘‘very weakly developed’’ and thus do not exhibit soil characteristics from ‘‘normal’’ pedogenic processes. The time factor of soil formation is not significant for this major soil grouping and the soil characteristics reflect the mode of parent material accumulation and the inherent (unweathered) properties of the parent material. The Anthropic Regosols soil unit is proposed for soils that have anthropogenic soil materials or were extensively modified by human activities. Extensive modifications from human activities range from deep ploughing to surface mining, land filling, dredging, and highway construction. Future soil survey and classification activities
should characterize the composition of soils along selected urban-rural land use gradients and modify the current soil classification system to document the impact of human activities on soil formation in urban landscapes.