We investigated the properties of man-made soils of urban green infrastructure

News, 20/08/2020

The main goal of the project solved by the University Center for Energy Efficient Buildings in cooperation with the Faculty of Civil Engineering of CTU was to clarify the complex dynamics of water, heat and particle flows in man-made soils of the urban blue-green infrastructure.


The project team sought to assess soil water and heat fluxes during infiltration, redistribution, drainage and soil evapotranspiration of green roofs and infiltration basins. Furthermore, he tried to apply approaches successfully used for modeling transport processes in natural soils to numerical modeling of these phenomena in engineered soils.

Scientists from Laboratoře hydrometeorologie & hydropedologie CTU UCEEB created two experimental, well-instrumented, bioretention cells (rain gardens) and established four test plots with a green roof, representing different planting strategies and substrates. During two seasons, they investigated precipitation-runoff relations and the development of the water regime at experimental facilities.

On the soil samples taken from the experimental plots, we described the development of the structure using X-ray computed tomography. Our team also used the method of 3D neutron imaging for detailed detection of soil flow paths and moisture distribution and developed a new method for quantitative image processing. We managed to experimentally clarify the impact of soil wetting rate on capillary and structural air trapping in soil pores during water infiltration and subsequently on the hydraulic conductivity and infiltration capacity of man-made soil.

The runoff from the test green roofs was evaluated by a simple hydrological model. The hydrological and thermal regime of a thin green roof system was evaluated by a physically based model.

Research within the project Transport vody, nerozpuštěných látek a tepla v člověkem vytvořených půdách městské zelené infrastruktury was supported by the Grant Agency of the Czech Republic between 2017 and 2019.