Modelling man-made ground to link the above- and below- ground urban domains

This report describes the results of STSM TU1206-36204. During a visit to GEUS (DK) between 23 and 27 January 2017, Jeroen Schokker (TNO-GSN, NL) has focussed on the modelling of man-made ground as a linking pin between the above- and below-ground urban domains. Key results include: • Man-made ground is all-inclusive and its definition and modelling should encompass everything that is present between the land surface and the natural subsurface that is of influence to the model properties at the intended use scale of the model. This means not only reworked natural deposits and artificial deposits, but, if present, also tunnels, cables, foundations, basements and archaeological heritage. • The types of input data that are eventually used should be dependent on the modelling purpose and the associated modelling scale, but are in practice also determined by the data that can be made available and the project means to do so, as well as by the modelling method applied. The use of, preferably nation-wide, standardised publically available datasets is advised. • Man-made ground modelling may be used to bridge the scale and information gap between above-surface information and natural subsurface information. Combination of these layers or submodels within one model (cf. GeoCIM approach) results in nesting of different model scales, both laterally and vertically. • The ideas and technical solutions for efficient model maintenance are there. It is of prime importance that all parties involved acknowledge the need to keep models up-to-date to preserve their value. This requires maintenance funding and a feedback loop to report back model issues. Maintenance and update ask for sustainable relationships between cities and companies and/or institutes.