The WITS software toolbox – Water Isotope modelling for Transit time and Storage

In recent years, there has been a significant shift in the modelling approaches used for estimating transit times in hydrological systems. While classical lumped parameter models (LPM) have long been the standard, StorAge Selection functions (SAS-functions) have gained considerable popularity. However, a tool facilitating the use and comparison of both approaches is still lacking.

The WITS toolbox, developed as part of the COST Action WATSON, offers a unique opportunity to explore and compare both methodologies. WITS is an R-based software tool catering to both experienced researchers and newcomers to the field of transit-time modelling. It allows estimating storage volumes and dynamics, and transit times in various systems, including lysimeters, groundwater and catchments through the application of input-output modelling with environmental tracers (i.e., tritium, deuterium, and oxygen-18).

WITS includes a comprehensive manual guiding through the software's functionalities and modelling processes and comes with multiple case studies that demonstrate practical applications of the software in different hydrological settings.

WITS allows users to explore and compare transit-time methodologies, advancing research in hydrology and fostering a deeper understanding of water system behaviors.