Models, Digital Twins and Virtual Research Environments

The intrinsic complexity of the Critical Zone (CZ) poses unique challenges to modelling. The high number of components and scales involved in the CZ dynamics allows to describe this zone from different perspectives, thus resulting in a variety of modelling methods. This chapter provides an overview of the issues encountered when modelling the CZ, and the main approaches applied to date, spanning from conceptual and classical models to machine learning techniques and digital twins. Future perspectives to advance our knowledge of the CZ are then discussed. These includes: (i) the creation of open and accessible datasets that assist in data assimilation within models; (ii) global alliance of scientists sharing objectives, vocabulary, knowledge, and possibly coding languages; (iii) platforms fostering collaborations and interactive modelling, such as virtual research environments. Such efforts would lead to the synthesis of knowledge from different disciplines, working groups and networks to finally achieve a “whole-system” approach capable of reproducing most CZ processes at once.