Experimental and numerical analysis to assess the substrate hydraulic properties and the retention capacity of a green wall module

Green Wall systems (GW) can be considered suitable solutions to mitigate the adverse effects of urbanisation and climate change. However, although they present similar hydrological processes to other green infrastructure solutions, only a few studies have evaluated their hydrological efficiency. In this regard, the proper evaluation of the growing media’s unsaturated hydraulic properties, which are directly linked to the retention capacity, is crucial. Based on this background, the analysis of the green wall systems’ hydrological processes is a key aspect of urban hydrology, and it represents a gap to be solved. Thus, we present several experimental investigations on different substrates used as construction materials for a GW coupled with a physically based approach applying the HYDRUS-1D model to identify good growing media to be used in the GW construction under the Mediterranean climate.