11. Conclusion

Great physicist Nobel Prize Winner Feynman (1965) wrote. “Science is uncertain; the moment you make a proposition about a region of experience that you have not directly seen then you must be uncertain. But we always must make statements about the regions that we have not seen, or whole business is no use”. Hydrogeological modeling, as hydrogeology as a whole, is a science. Even more, they are an applied science. Their results are used for practical and often very responsible decision making. Hydrogeologists, including modelers, usually, if not always, “must make statements about the region we have not seen” and make decisions based on incomplete and erroneous data (US EPA 1987). Therefore, the issue of finding effective decisions under condition of uncertainty is one of the most important for them and for the users of the information provided by them.