Christiaan (Chrit) Lemmen is Professor in the Department of Urban and Regional Planning and Geo-information Management (ITC-PGM) at the faculty of ITC. Chrit is co-editors of the ISO standard on the Land Administration Domain (ISO 19152). In the existing, conventional, land administration systems customary and informal tenure cannot be easily handled. Alternative approaches are needed. The concept of the 'Land Administration Domain Model' and its specialisation the 'Social Tenure Domain Model' brings this option by providing a universal standard for representing ‘people – land’ relationships independent of the level of formality, legality and technical accuracy. This model has been developed together with the Global Land Tool Network of UN – Habitat and with the International Federation of Surveyors.

Christiaan holds an MSc in Geodesy from Delft University of Technology, the Netherlands and received a PhD from the same University.