Overview

WaSiM with TOPMODEL-based soil model was developed between 1994 and 1996 by Jörg Schulla at the Geographical Institute (today: Institute for Atmospheric and Climate Science) at the ETH Zurich, Switzerland. The aim was to quantify the effects of climate change on the regional water balance. Target area for the first WaSiM application was the alpine basin of the river Thur (1700 km²) in north-east Switzerland.

In the following years important technical enhancements were made to WaSiM. In particular, the general desire for a physically better justified soil model had been met with the development of the Richards-version of WaSiM. Along with the new soil model, a groundwater flow and transport module in as well as a tracer module had been integrated into the model.

Not least thanks to its numerous enhancements WaSiM is now used for the solution of various hydrological challanges, such as for the coupling with meteorological models or for the development of optimization strategies for sustainable agriculture.