soils in the urban environment

Most urban soils are artificial ‘made ground’ or ‘techno soils’. There is little fundamental understanding of the science of urban soils. We do not know what goes on under the concrete, thus sealed soils are a particular area of concern to the soil science community. Of specific concern is the flooding risk that is posed by artificial soils, for example that the development of brown field sites leads to a loss of the water-holding and carbon capture / storage functions provided by soils. 

Sealed soil science is in its infancy, but we do know that basic soil function is lost through development that uses artificial soils.   

We need:

  1. Industry guidelines to ensure artificial soils are produced to have healthy functions 

  2. A requirement on engineers to preserve soil function in urban / developed soils

A set of guidelines is needed to ensure that industry produces artificial soils that have the right characteristics to ensure that with time these will have functions. While the biology element is missing, engineers should be able to solve this if the brief is to create soils to an industry-agreed standard of water holding capacity and carbon storage and benign flow systems.  

This is a logical next step to the work already done on SUDS with permeable pavements, etc. Now, the same approach is needed for the material underneath them. By extending standards around SUDS to take consideration of the 1m volume under them, flooding will be hugely reduced. 

10% of the UK is covered in cities. Our country could be a global leader in the movement towards sustainable urban soils.


SSA Science Panel member Karen Johnson is a Professor of Environmental Engineering at Durham University with a passion for soil and raising understanding around the role of mineral-organic interactions in maintaining and enhancing soil health. She is working on the use of sustainable soil improvement technologies to enhance soil functions like flood and drought resilience. Her ROBUST project (Regeneration of Brownfield land Using Sustainable Technologies) is based at the Institute of Hazard, Risk and Resilience, Durham University and has produced this introductory video:


The following panel discussion was co-organised by Durham University and POST (Parliamentary Office of Science & Technology) for World Soils Day in 2016:

K Johnson EAC Inquiry 2016.jpg

Professor Johnson contributed to the Environmental Audit Committee’s Inquiry in to Soil Health in 2016, at which she stated that urban soils are currently unprotected, and that engineers should lead the way in the sustainable management of urban soils as they have an important role to play both in climate change adaptation and mitigation. Watch the session in full here.

Explore Prof Johnson’s full list of publications here.

‘We’re Black Sheep’ - The people who are fascinated by soil in cities: Can better urban soils help solve our environmental problems?

The Guardian, 16 January 2019

Systems approach reveals urban pollinator hotspots & conservation opportunities Some urban land uses can support substantial pollinator populations.

Nature, 14 January 2019