1. Institute of Hydrology, Slovak Academy of Sciences, Račianska 75, 83102 Bratislava, Slovakia.
2. Departament de Geografia, Universitat de València, Blasco Ibàñez, 28, 46010-Valencia, Spain
3. Institute of Hydrodynamics of the Academy of Sciences of the Czech Republic, Pod Paťankou 5, Prague 6, Czech Republic
4. Centre for Agricultural Research, Hungarian Academy of Sciences, Institute for Soil Science and Agricultural Chemistry, Herman Ottó u. 15, H-1022 Budapest, Hungary