1. European Regional Centre for Ecohydrology PAS; Tylna 3 90-364 Łódź Poland
2. Department of Applied Ecology; Faculty of Biology and Environmental Protection; University of Lodz; Banacha 12/16 90-237 Łódź Poland
3. Ministry of Water, Irrigation and Energy; Haile G/Silassie Avenue P.O. Box 5744 and 5673 Addis Ababa Ethiopia