Formation and Properties of Urban Soils

Urban soils form by the same overall set of processes that are involved in the formation of all soils. In this chapter we combine two general approaches to understanding soil formation, the first based on state factors and the second on soil fluxes. We review the soil properties used for identification and classification. The concepts of anthroposequences and urbanisation gradients are introduced, and the soil groups important for urban environments, Anthrosols and Technosols, are described. Changes in geomorphology caused by urbanisation, such as modification of hydrology and landforms created by additions of removal of material, are discussed. Specific examples of soils in modified urban environments, such as reclaimed coastal land, landfills, and constructed wetlands, are presented. Finally, this chapter explores the archaeological landforms and soil properties present in historical and contemporary cities, and the range of chemical, physical, and biological archaeological information stored in urban soils.