The term "Urban" soils is a shorthand for all soils located in urbanized, industrial, trafficked, mining and military areas; these are the same soils studied by the Soils of Urban, Industrial, Traffic & Mining Areas (SUITMA) working group of the IUSS. They are increasingly important as the world continues to urbanise. Their classification and mapping present particular challenges. For several years I have been involved with SUITMA, mainly in the area of urban soil classification. I coordinated the group that defined the WRB Technosols reference group.
This is my explanation of the changes in WRB 2006 to better accommodate urban soils.
Presented at the International Conference on Soil Classification 2004, Petrozavodsk, Russia, 3-5 August, 2004. A systematic view of human influence on soil genesis. (PDF, 143Kb)
A popular description of soils and their role in urban areas, with many good photos and diagrams. 77 pp.
URL:
http://www.itc.nl/personal/rossiter/research/suitma/suitma.html