%0 Book part %A Galdean Nicolae %D 1999 %G English %B Tiscia monograph series %B The Upper Tisa valley : preparatory proposal for Ramsar site designation and an ecological background Hungarian, Romanian, Slovakian and Ukrainian co-operation %@ 1418-0448 %T Some considerations about the rheophilic elements of the benthic fauna (ord. Ephemeroptera, Plecoptera and Trichoptera) of the Upper Tisa region %U http://acta.bibl.u-szeged.hu/10215/1/tiscia_mono_004_413-425.pdf %X Many present-day rivers in the temperate zone flow directly within coarsegrained gravel masses that have been inherited from deglaciation out-wash and valley fill deposits (Gregory and Maizels, 1991). The Upper Tisa is one of such rivers. From the confluence of Bila Tisa with Chorna Tisa and up to the mouth of River SomeĀ§, River Tisa can be divided into two main sections: a) the section from Rahiv to Troznik (in Ukrainian territory), characterised by stony bottom (with boulders, gravel, cobbles and pebbles). b) the section from Jand to Vasarosnameny, and a little further (in the Hungarian territory) characterised by sandy bottom (except for the left bank where there are some locations with stony substratum consisting of boulders).