GeoTwinn training on uncertainty assessment of groundwater flow and solute transport modelling for members of Work Package (WP) 2.1 was held in June 2021. Due to the COVID-19 pandemic, implementation of this activity was performed online, using the Microsoft Teams platform.

The workshop agenda implied short morning sessions for catching up on the results of the activities performed the previous day, which were followed by an introductory training and knowledge exchange session on the application of stochastic groundwater modelling taking into account the uncertainties in the hydrogeological systems. The rest of the day was dedicated to testing and applying the new groundwater modelling techniques on the local Croatian groundwater model.

The hands-on training and interaction between the HGI-CGS and the GEUS researchers followed the ’Deep work’ concept where the whole group met at the start and the end of a focused work session. At the start, the content of the work session was discussed and planned, and at the end of each session encountered problems were shared and the progress was presented. In such a way one or two loops of ‘deep work’ were completed each day.

The last day of the training was also reserved for a short review and discussion regarding the draft version of  WP2.1’s scientific paper.

The main outcomes of this workshop were reached by the education of  HGI-CGS staff on  the application of the methods of particle tracking and age distribution, and implementation of uncertainties in climate model projections in groundwater modelling analyses and concluding final arrangements regarding WP2.1 publication.